WO2022049845A1 - Polishing composition, method for machining wafer, and silicon wafer - Google Patents

Polishing composition, method for machining wafer, and silicon wafer Download PDF

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Publication number
WO2022049845A1
WO2022049845A1 PCT/JP2021/020581 JP2021020581W WO2022049845A1 WO 2022049845 A1 WO2022049845 A1 WO 2022049845A1 JP 2021020581 W JP2021020581 W JP 2021020581W WO 2022049845 A1 WO2022049845 A1 WO 2022049845A1
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polishing
wafer
etching
abrasive grains
amount
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PCT/JP2021/020581
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French (fr)
Japanese (ja)
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正彬 大関
達夫 阿部
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信越半導体株式会社
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Priority to CN202180053731.0A priority Critical patent/CN116210073A/en
Priority to KR1020237007342A priority patent/KR20230061382A/en
Publication of WO2022049845A1 publication Critical patent/WO2022049845A1/en

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    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09GPOLISHING COMPOSITIONS; SKI WAXES
    • C09G1/00Polishing compositions
    • C09G1/02Polishing compositions containing abrasives or grinding agents
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02041Cleaning
    • H01L21/02057Cleaning during device manufacture
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304Mechanical treatment, e.g. grinding, polishing, cutting
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/306Chemical or electrical treatment, e.g. electrolytic etching
    • H01L21/30604Chemical etching
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/306Chemical or electrical treatment, e.g. electrolytic etching
    • H01L21/30625With simultaneous mechanical treatment, e.g. mechanico-chemical polishing

Definitions

  • the present invention relates to a polishing composition, a wafer processing method, and a silicon wafer.
  • the silicon wafers that form the basis of semiconductor devices are also required to have higher cleanliness and surface quality.
  • defects are one of the causes of impairing surface quality. Defects are roughly divided into crystal defects and polishing defects.
  • Crystal defects refer to defects introduced during crystal pulling, and include oxygen precipitation defects, metal precipitation defects, and voids.
  • the purpose of cleaning after polishing is to remove components contained in the polishing composition such as abrasive grains, water-soluble polymers, and surfactants before shipping, but if the etching amount is reduced, these components will be removed. There is a high possibility that it cannot be removed and remains.
  • the present invention has been made to solve the above problems, and the polishing composition capable of providing a wafer in which the manifestation of crystal defects and polishing defects is suppressed, and the manifestation of crystal defects and polishing defects are suppressed. It is an object of the present invention to provide a wafer processing method capable of providing a wafer, and a silicon wafer capable of suppressing the appearance of crystal defects and polishing defects even after being etched.
  • the composition for polishing is used.
  • Abrasive grains and Containing at least one of a water-soluble polymer and a surfactant Provided is a polishing composition characterized in that the ratio of the concentration (ppmw) of the abrasive grains to the concentration (ppmw) of total organic carbon in the polishing composition is 30 or less.
  • polishing the wafer using such a polishing composition of the present invention it is possible to suppress the adsorption of abrasive grains on the wafer.
  • the amount of abrasive grains adsorbed on the wafer during polishing can be reduced, and the amount of abrasive grains remaining on the surface of the wafer after polishing can be reduced.
  • the water-soluble polymer and / or surfactant remaining on the wafer after polishing can be easily removed by decomposing it with an oxidizing agent or the like, so that even a small amount of etching remains on the surface of the wafer after polishing for polishing.
  • the components of the composition can be sufficiently removed.
  • the polishing composition of the present invention it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • it is a method for processing a wafer.
  • the polishing composition of the present invention is used in the wafer processing method of the present invention, the polishing composition remaining on the surface of the wafer after polishing while suppressing the appearance of crystal defects and polishing defects due to etching.
  • the components of can be sufficiently removed. That is, according to the wafer processing method of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • the polishing step can be performed so that the amount of abrasive grains adhered on the surface of the wafer after polishing is 5 pieces / ⁇ m 2 or less.
  • the components of the polishing composition remaining on the surface of the wafer after polishing can be removed. It can be reliably removed.
  • the present invention is a silicon wafer polished using the polishing composition, wherein the amount of abrasive grains adhered on the surface after polishing is 5 pieces / ⁇ m 2 or less. I will provide a.
  • the silicon wafer of the present invention has an abrasive grain adhesion amount of 5 pieces / ⁇ m 2 or less on the surface after polishing, the abrasive grains can be sufficiently removed even with a small etching amount. As a result, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the silicon wafer of the present invention, it is possible to provide a high quality silicon wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • the polishing composition of the present invention can provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • a wafer in which the manifestation of crystal defects and polishing defects is suppressed has high surface quality and can be effectively used as a wafer that can meet the demand for miniaturization of semiconductor devices.
  • the wafer processing method of the present invention it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed. Since the wafer obtained by this method has high surface quality, it can be effectively used as a base for a semiconductor device.
  • the silicon wafer of the present invention can provide a high-quality silicon wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • a wafer having high surface quality can be manufactured, and by extension, a semiconductor device that meets the demand for miniaturization can be manufactured based on the wafer having high surface quality.
  • Example 6 is an SEM image of the surface of the wafer after the polishing step obtained in each of Comparative Example 1 and Example 2. It is a graph which shows the number of LLS defects on the wafer surface after the etching process obtained in each of an Example and a comparative example.
  • the present inventor aims to find cleaning conditions such that crystal defects and polishing defects do not become apparent, and to find conditions for a polishing composition that can be removed under such cleaning conditions. As a result, we conducted diligent research.
  • the inventor examined the cleaning conditions and compared the actualization of crystal defects and polishing defects, and found that the etching amount of cleaning had a large effect.
  • cleaning with solution for example, cleaning with a mixed solution of NH 3 and H 2 O 2 , cleaning with a natural oxide film peeled off by HF, cleaning with a mixed solution of O 3 or H 2 O 2 and HF, HCl and H 2 O
  • cleaning with a mixed solution of 2 and cleaning with a mixed solution of NH 3 and H 2 O 2 cleaning with HF to peel off the natural oxide film, and mixing of O 3 and H 2 O 2 with HF.
  • Cleaning with solution involves etching.
  • the residual abrasive grains of the wafer after polishing can be reduced, it is considered that the residual abrasive grains of the wafer after etching can also be reduced.
  • the present inventor has added at least one of a water-soluble polymer and a surfactant in addition to the abrasive grains to the polishing composition, and the polishing composition.
  • a water-soluble polymer and a surfactant in addition to the abrasive grains to the polishing composition, and the polishing composition.
  • the present invention is a polishing composition.
  • Abrasive grains and Containing at least one of a water-soluble polymer and a surfactant The polishing composition is characterized in that the ratio of the concentration (ppmw) of the abrasive grains to the concentration (ppmw) of total organic carbon in the polishing composition is 30 or less.
  • the present invention is a method for processing a wafer.
  • the processing method is characterized in that the etching step is performed so that the total etching amount is 5 nm or less.
  • the present invention is a silicon wafer polished using a polishing composition, wherein the amount of abrasive grains adhered on the surface after polishing is 5 pieces / ⁇ m 2 or less. Is.
  • claim 1 is an invention of a cerium oxide slurry containing cerium oxide particles, a dispersant and water, wherein the cerium oxide weight / dispersant weight ratio is 20 to 80.
  • cerium oxide is contained as an abrasive.
  • poly (meth) acrylic acid salt, polyacrylic acid-polyacrylic acid alkylammonium salt copolymer, and the like are described as examples of dispersants. ..
  • claim 8 of Patent Document 1 describes a method of polishing a substrate using this slurry. Further, paragraph 0102 of Patent Document 1 describes that such a cerium oxide slurry and a polishing method can reduce polishing scratches and further increase the polishing rate.
  • Patent Document 1 does not pay any attention to the total organic carbon concentration in the cerium oxide slurry, and therefore, the concentration of abrasive grains (ppmw) with respect to the concentration of total organic carbon in the cerium oxide slurry (ppmw). No attention is paid to the ratio of 30 or less.
  • the polishing composition of the present invention contains abrasive grains and at least one of a water-soluble polymer and a surfactant, and is composed of the abrasive grains with respect to the concentration (ppmw) of total organic carbon in the polishing composition. It is characterized in that the ratio of the concentration (ppmw) is 30 or less.
  • polishing composition of the present invention it is possible to suppress the adsorption of abrasive grains on the wafer. As a result, the amount of abrasive grains adhering to the wafer during polishing can be reduced, and the amount of abrasive grains remaining on the surface of the wafer after polishing can be reduced.
  • the silicon wafer being polished has high activity because there is no natural oxide film on the surface, and it is in an environment where abrasive grains, water-soluble polymers and surfactants are easily adsorbed on the surface.
  • the ratio of the water-soluble polymer and the surfactant adsorbed on the wafer surface can be increased. It is considered that the residual abrasive grains were reduced by reducing the physical room for the abrasive grains to be adsorbed on the surface of the wafer.
  • the water-soluble polymer and the surfactant may remain on the surface of the wafer after polishing instead, but these can be decomposed by an oxidizing agent such as O 3 or H 2 O 2 , and as a result. It can be removed more easily than abrasive grains, and therefore can be removed without etching.
  • the polishing composition of the present invention when a wafer is polished using the polishing composition of the present invention, the components of the polishing composition can be sufficiently removed from the surface of the polished wafer even with a small etching amount. As a result, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the polishing composition of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • the extent to which at least one of the water-soluble polymer and the surfactant can be adsorbed and coated on the wafer surface is considered to be most dependent on the length of the carbon-carbon bond in these components.
  • the organic components of water-soluble polymers and surfactants can often be evaluated as TOC (total organic carbon).
  • the TOC (total organic carbon) is a value obtained by subtracting the IC (inorganic carbon) from the TC (total carbon). Therefore, the concentration of total organocarbon (TOC) can be suitably used as an index of the length of the carbon-carbon bond of the water-soluble polymer and the surfactant.
  • the concentration ratio of the abrasive grains to the TOC can be appropriately controlled, the residual abrasive grains of the wafer after polishing can be reduced.
  • the present inventor found that it is important that the ratio of the concentration of abrasive grains (ppmw) to the concentration of TOC (ppmw) in the polishing composition is 30 or less.
  • the ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is set to 30 or less, the amount of the abrasive grains adsorbed on the wafer surface during polishing is sufficiently suppressed. As a result, it was found that the amount of residual abrasive grains on the surface of the wafer after polishing can be reduced.
  • the lower limit of the ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is not particularly limited, but may be, for example, 1 or more.
  • the ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is preferably 1 or more and 30 or less. Within this range, the amount of residual abrasive grains after polishing can be further reduced while achieving sufficient polishing with abrasive grains.
  • the above ratio is more preferably 3 or more and 10 or less.
  • the concentration of total organic carbon (TOC) in the polishing composition can be measured, for example, with the TOC-L series manufactured by Shimadzu Corporation.
  • the concentration of the abrasive grains in the polishing composition can be measured, for example, with a density hydrometer DA-100 manufactured by Kyoto Electronics Manufacturing Co., Ltd.
  • the ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is adjusted by adjusting the amount of the abrasive grains contained in the composition, the amount of the water-soluble polymer, and the amount of the surfactant. By doing so, it can be adjusted.
  • polishing composition of the present invention will be described in more detail.
  • abrasive grains include silicon dioxide, aluminum oxide, cerium oxide, chromium oxide, titanium dioxide, zirconium oxide, magnesium oxide, manganese dioxide, zinc oxide, silicon nitride, boron nitride, silicon carbide, boron carbide, diamond, fullerene, etc.
  • silicon dioxide is preferable in order to suppress surface defects.
  • Silicon dioxide includes colloidal silica, fumed silica, water glass silica, etc. depending on the manufacturing method, but colloidal silica is preferable in order to prevent scratches.
  • the primary particle size of colloidal silica is preferably 1000 nm or less, more preferably 300 nm or less, and further preferably 100 nm or less from the viewpoint of defect reduction. Further, from the viewpoint of increasing the polishing rate, 1 nm or more is preferable, and 10 nm or more is more preferable.
  • the concentration of colloidal silica is preferably 10 wt% or less, more preferably 1 wt% or less from the viewpoint of preventing aggregation. Further, from the viewpoint of increasing the polishing rate, 0.0001 wt% or more is preferable, and 0.001 wt% or more is preferable.
  • Water-soluble polymer for example, a cellulose derivative is preferably used, and hydroxyethyl cellulose, propionyl ethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose and the like are used. These can also be called water-soluble semi-synthetic polymers.
  • a synthetic polymer different from the above semi-synthetic polymer as the water-soluble polymer, and for example, a polymer such as polyvinyl alcohol or polyvinylpyrrolidone is preferably used.
  • a cationic surfactant As the surfactant, a cationic surfactant, an anionic surfactant, or a nonionic surfactant can be used, but a nonionic surfactant is particularly preferable.
  • nonionic surfactants suitable examples include polyoxyethylene-polyoxypropylene block copolymers, random copolymers, polyoxyethylene alkyl ethers, polyoxyethylene phenyl ethers and the like.
  • the polishing composition of the present invention may further contain, for example, a dispersion medium, a pH adjuster, and the like, in addition to the abrasive grains, the water-soluble polymer, and the surfactant.
  • water especially pure water, as the dispersion medium.
  • the pH adjuster is preferably basic in order to enhance the dispersion stability of colloidal silica.
  • the basic compound potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, lithium hydroxide, tetramethylammonium hydroxide, ammonia, amines and the like are preferably used.
  • the wafer processing method of the present invention is A step of polishing both sides or one side of the wafer using the polishing composition of the present invention.
  • the etching step is characterized in that the total etching amount is 5 nm or less.
  • the amount of abrasive grains adsorbed on the wafer surface during polishing can be sufficiently suppressed, and as a result, the wafer surface after the polishing step can be sufficiently suppressed.
  • the amount of residual abrasive grains on the top can be reduced.
  • the water-soluble polymer and / or the surfactant remaining on the wafer surface after the polishing step is decomposed by a chemical solution containing at least one of O 3 and H 2 O 2 in the subsequent step of decomposing the organic substance. ..
  • the wafer processing method of the present invention it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
  • both sides or one side of the wafer are polished using the polishing composition of the present invention.
  • the wafer used for polishing is, for example, a silicon wafer.
  • the silicon wafer may be, for example, sliced from a silicon ingot to obtain a slice piece, and the slice piece may be subjected to surface grinding.
  • the polishing step may be a one-step step or a multi-step step. From the viewpoint of surface quality, it is preferable to perform at least two polishing steps.
  • polishing is performed while holding the wafer and pressing it against the polishing pad, continuously supplying the polishing composition to the surface to be polished of the wafer, and rotating one or both of the wafer and the polishing pad.
  • Polishing may be either double-sided polishing or single-sided polishing.
  • double-sided polishing for example, polishing cloths are placed above and below the wafer, and both sides are polished at the same time.
  • single-sided polishing the polishing cloth is placed only on one side of the wafer.
  • the polishing cloth is preferably made of resin from the viewpoint of surface quality, and urethane resin is preferable because it has good wear resistance.
  • a fiber impregnated with a fiber such as a non-woven fabric may be used as a polishing cloth, a urethane foam may be heated to form a urethane foam resin and used as a polishing cloth, or a PET film or the like may be used.
  • a urethane resin may be applied onto the base material to form a suede by hydrolysis, which may be used as a polishing cloth.
  • the hardness of the polishing cloth is preferably 30 or more in shore A hardness, and more preferably 50 or more.
  • the hardness of the polishing cloth is preferably 95 or less, more preferably 90 or less, from the viewpoint of surface quality.
  • the polishing cloth preferably has a groove-like texture structure in order to efficiently act on the polishing composition.
  • the polishing step can be performed so that the amount of abrasive grains adhered on the surface of the wafer after polishing is 5 pieces / ⁇ m 2 or less.
  • the polishing remaining on the surface of the wafer after polishing is performed.
  • the components of the composition for use can be reliably removed.
  • the amount of abrasive grains adhered on the wafer surface can be measured by, for example, a scanning electron microscope (SEM).
  • SEM scanning electron microscope
  • the amount of abrasive grains adhered on the surface can be, for example, 0.1 piece / ⁇ m 2 or more and 5 pieces / ⁇ m 2 or less, and 1 piece / ⁇ m 2 or more 3
  • the number is preferably 2 or less per ⁇ m.
  • the organic substance on the wafer after polishing is decomposed with a chemical solution containing at least one of O 3 and H 2 O 2 .
  • O 3 and / or H 2 O 2 can act as an oxidant and decompose organic substances on the polished wafer, that is, organic substances caused by water-soluble polymers and / or surfactants.
  • the products produced by the decomposition of organic matter can be removed from the wafer without etching.
  • the chemical solution used in the step of decomposing the organic substance may contain components other than O 3 and H 2 O 2 . Specific examples will be described later.
  • the polished wafer is etched with a chemical solution containing at least one of NH 3 and HF. At this time, etching is performed so that the total etching amount is 5 nm or less.
  • the total etching amount here is the total etching amount of the surface to be etched when one side of the wafer is etched, and is the total etching amount of each surface to be etched when both sides of the wafer are etched. Total etching amount. That is, the total etching amount is the total etching amount per one side of the wafer.
  • the lower limit of the total etching amount is not particularly limited, but can be, for example, 3 nm.
  • the total etching amount is preferably 0.1 nm or more and 5 nm or less, and more preferably 1 nm or more and 5 nm or less.
  • the total etching amount in the etching process can be confirmed by the following procedure.
  • a reference SOI (Silicon On Insulator) wafer is prepared, and the SOI film thickness is measured with a spectroscopic ellipsometer UNECS-3000 manufactured by ULVAC, Inc. to obtain the SOI film thickness before etching.
  • the reference SOI wafer is etched under the same conditions as those of the etching process to be confirmed.
  • the SOI film thickness after etching is measured with the same spectroscopic ellipsometer to obtain the SOI film thickness after etching.
  • the difference in SOI film thickness before and after etching is taken as the total etching amount of the etching process to be confirmed.
  • the total etching amount in the etching step can be adjusted by, for example, the concentration of the etching agent in the chemical solution containing at least one of NH 3 and HF, the etching time, and the temperature of the chemical solution.
  • the chemical solution may be heated if necessary.
  • the amount of etching increases by heating.
  • the chemical solution used in the etching step may contain components other than NH 3 and HF. Specific examples will be described later.
  • the step of decomposing the organic substance and the step of etching may be performed separately or at the same time.
  • the process of decomposing organic matter and the process of etching can also be collectively referred to as a cleaning process.
  • the wafer processing method of the present invention may further include, for example, an evaluation step after the etching step.
  • an evaluation step after the etching step For example, surface defect evaluation may be performed in the evaluation process.
  • the surface defect evaluation device for example, the Surfscan series manufactured by KLA Corporation can be used.
  • ⁇ Chemical solution> In the step of decomposing the organic substance and the step of etching, one chemical solution may be used or a plurality of chemical solutions may be used, respectively.
  • a mixed solution containing at least one of O 3 and H 2 O 2 and at least one of NH 3 and HF may be used.
  • a mixed solution containing NH 3 and H 2 O 2 , a mixed solution containing HF and O 3 , and a mixed solution containing HF, O 3 and H 2 O 2 can be used as a chemical solution. can.
  • a mixed solution containing HCl and H 2 O 2 a solution containing H 2 O 2 , and O 3 are used as the chemical solution for decomposing the organic substance.
  • the solution containing can be mentioned.
  • examples of the chemical solution used in the etching step include a mixed solution containing HF and HNO 3 , a solution containing NH 3 , and a solution containing HF. can.
  • These chemicals can also contain water, especially pure water, as a solvent.
  • the silicon wafer of the present invention is a silicon wafer polished using a polishing composition, and is characterized in that the amount of abrasive grains adhered on the surface after polishing is 5 pieces / ⁇ m 2 or less.
  • the silicon wafer of the present invention can be obtained, for example, by the polishing process of the wafer processing method of the present invention described above.
  • the silicon wafer of the present invention By subjecting such a silicon wafer to the steps of decomposing organic substances and etching described above, it is possible to reliably remove the components of the polishing composition remaining on the surface of the wafer after polishing. In addition, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the silicon wafer of the present invention, it is possible to provide a silicon wafer in which the manifestation of crystal defects and polishing defects is suppressed.
  • Comparative Example 1 In Comparative Example 1, the wafer was processed according to the following procedure.
  • a silicon wafer having a diameter of 300 mm and a thickness of 775 ⁇ m was prepared as a wafer to be processed.
  • Colloidal silica was prepared as abrasive grains. Further, polyvinyl alcohol (PVA) as a water-soluble polymer and polyoxyethylene-polyoxypropylene block copolymer (EOPO) as a surfactant were prepared.
  • PVA polyvinyl alcohol
  • EOPO polyoxyethylene-polyoxypropylene block copolymer
  • colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 10000: 90: 10 to obtain the polishing composition of Comparative Example 1. rice field.
  • the HF aqueous solution used had an HF concentration of 1 wt%, and the temperature at the time of supply was 25 ° C. The time of contact with the HF aqueous solution was 5 minutes. As a result, the total etching amount by HF was set to 1 nm.
  • Example 1 In Example 1, the abrasive grain concentration of the polishing composition in the polishing step was 3000 ppmw, the TOC concentration was 100 ppmw, and the mixture of NH 3 / H 2 O 2 / H 2 O in the etching step was used.
  • the same wafer as that processed in Comparative Example 1 was processed by the same procedure as in Comparative Example 1 except that the total etching amount was 9 nm and the total etching amount by HF was 1 nm.
  • Example 1 colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 3000:90:10, and the polishing composition of Example 1 was added.
  • Example 1 the mixture of NH 3 / H 2 O 2 / H 2 O supplied in the etching step was the same as that used in Comparative Example 1, and the temperature at the time of supply was 50 ° C. And said.
  • the time of contact with the mixture of NH 3 / H 2 O 2 / H 2 O was set to 15 minutes.
  • Example 1 the concentration of the HF aqueous solution supplied in the etching step was 1 wt%, and the temperature at the time of supply was 25 ° C. The time of contact with the HF aqueous solution was 5 minutes.
  • Example 2 In Example 2, the procedure is the same as that of Example 1 except that the total etching amount by the mixed solution of NH 3 / H 2 O 2 / H 2 O in the etching step is 3 nm and the total etching amount by HF is 1 nm. Then, the same wafer as that processed in Comparative Example 1 was processed.
  • Example 2 the etching step was performed under the same conditions as in Comparative Example 1.
  • Example 3 In Example 3, the same wafer as that processed in Comparative Example 1 by the same procedure as in Example 2 except that the abrasive grain concentration of the polishing composition in the polishing step was 1000 ppmw and the TOC concentration was 100 ppmw. Was processed.
  • Example 3 colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were put into pure water at a weight ratio of 1000:90:10, and the polishing composition of Example 3 was added.
  • Example 4 In Example 4, the same wafer as that processed in Comparative Example 1 by the same procedure as in Example 2 except that the abrasive grain concentration of the polishing composition in the polishing step was 370 ppmw and the TOC concentration was 50 ppmw. Was processed.
  • Example 4 colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 370: 45: 5, and the polishing composition of Example 4 was added.
  • Example 5 In Example 5, the same wafer as that processed in Comparative Example 1 by the same procedure as in Example 2 except that the abrasive grain concentration of the polishing composition in the polishing step was 1000 ppmw and the TOC concentration was 167 ppmw. Was processed.
  • Example 5 colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 1000: 150: 17, and the polishing composition of Example 5 was added.
  • Table 1 below shows the abrasive grain concentration, the TOC concentration (total organic carbon concentration), the abrasive grain concentration with respect to the TOC concentration, and the etching amount for each Example and Comparative Example.
  • the ratio of the concentration of abrasive grains (ppmw) to the concentration of total organic carbon (ppmw) in the polishing composition is 30 or less.
  • Examples 1 to 5 using the polishing compositions of Examples 1 to 5 achieved better defect levels than Comparative Example 1 using the polishing composition of Comparative Example 1 in which the ratio exceeded 30. You can see that it was done.
  • the portion that looks white is the abrasive grain.
  • the amount of abrasive grains remaining on the surface of the wafer obtained after the polishing step in Example 2 is 0.42 pcs / ⁇ m 2 .
  • the amount of residual abrasive grains was 8.5 pcs / ⁇ m 2 , which was significantly smaller than that of 8.5 pcs / ⁇ m 2.
  • the amount of residual abrasive grains in Examples 1 and 3 to 5 was also about the same as in Example 2.
  • Example 2 to 5 in which the polishing composition of the present invention was used and the total etching amount in the etching step was 5 nm or less, the total etching amount was determined. It can be seen that a better defect level could be achieved than in Example 1 having a size larger than 5 nm.
  • the present invention is not limited to the above embodiment.
  • the above-described embodiment is an example, and the present invention can be anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. Is included in the technical scope of.

Abstract

The present invention is a polishing composition characterized by including abrasive grains and at least one material from among water-soluble polymers and surfactants, the ratio of the concentration (ppmw) of abrasive grains relative to the concentration (ppmw) of total organic carbon in the polishing composition being 30 or less. This makes it possible to provide: a polishing composition with which it is possible to provide a wafer in which manifestation of crystal defects and polishing defects is inhibited; a method for machining a wafer with which it is possible to provide a wafer in which manifestation of crystal defects and polishing defects is inhibited; and a silicon wafer in which manifestation of crystal defects and polishing defects can be inhibited, even when the silicon wafer is etched.

Description

研磨用組成物、ウェーハの加工方法、及びシリコンウェーハPolishing composition, wafer processing method, and silicon wafer
 本発明は、研磨用組成物、ウェーハの加工方法、及びシリコンウェーハに関する。 The present invention relates to a polishing composition, a wafer processing method, and a silicon wafer.
 半導体デバイスは微細化が進むにつれ、その土台となるシリコンウェーハもますます高い清浄度、表面品質が求められる。 As semiconductor devices become finer, the silicon wafers that form the basis of semiconductor devices are also required to have higher cleanliness and surface quality.
 表面品質を損なう原因の1つに欠陥の存在がある。欠陥は大まかに結晶欠陥と研磨欠陥とに分けられる。 The existence of defects is one of the causes of impairing surface quality. Defects are roughly divided into crystal defects and polishing defects.
 結晶欠陥に関しては、結晶引き上げ時に導入された欠陥のことを指し、酸素析出欠陥や金属析出欠陥、ボイドなどが挙げられる。 Crystal defects refer to defects introduced during crystal pulling, and include oxygen precipitation defects, metal precipitation defects, and voids.
 一方、研磨欠陥に関しては、研磨中に異物が混入するなどして表面にダメージが導入され発生する。 On the other hand, with regard to polishing defects, damage is introduced to the surface due to foreign matter being mixed during polishing.
 結晶欠陥及び研磨欠陥はどちらも変質しているため、例えば研磨などの平坦化機構を有さない湿式エッチングなどの処理を行うと、変質部のエッチングレートが周囲と異なるため、突起やピットを生成し、さらにエッチング量が大きくなるほどにその顕在化量が大きくなってしまう。 Since both crystal defects and polishing defects are altered, if a treatment such as wet etching that does not have a flattening mechanism such as polishing is performed, the etching rate of the altered portion is different from that of the surroundings, and protrusions and pits are generated. However, the larger the etching amount, the larger the actual amount.
 したがって、特に研磨後の洗浄工程でのエッチング量は可能な限り減らすことが望ましい。 Therefore, it is desirable to reduce the etching amount as much as possible, especially in the cleaning process after polishing.
 一方で、洗浄工程でのエッチング量を減少すると、別の問題が発生する。 On the other hand, reducing the amount of etching in the cleaning process causes another problem.
 研磨後の洗浄の目的は、砥粒や水溶性高分子、界面活性剤などの研磨用組成物に含まれる成分を除去し出荷することにあるが、エッチング量を落としてしまうとこれらの成分を除去できずに残留してしまう可能性が高くなる。 The purpose of cleaning after polishing is to remove components contained in the polishing composition such as abrasive grains, water-soluble polymers, and surfactants before shipping, but if the etching amount is reduced, these components will be removed. There is a high possibility that it cannot be removed and remains.
 そこで、エッチング量を落としても研磨用組成物の成分が残留しないような研磨方法の開発が求められる。 Therefore, it is required to develop a polishing method so that the components of the polishing composition do not remain even if the etching amount is reduced.
国際公開第WO2007/046420号パンフレットInternational Publication No. WO2007 / 046420 Pamphlet
 本発明は、上記問題を解決するためになされたものであり、結晶欠陥及び研磨欠陥の顕在化が抑えられたウェーハを提供できる研磨用組成物、結晶欠陥及び研磨欠陥の顕在化が抑えられたウェーハを提供できるウェーハの加工方法、及びエッチングを受けても結晶欠陥及び研磨欠陥の顕在化を抑制できるシリコンウェーハを提供することを目的とする。 The present invention has been made to solve the above problems, and the polishing composition capable of providing a wafer in which the manifestation of crystal defects and polishing defects is suppressed, and the manifestation of crystal defects and polishing defects are suppressed. It is an object of the present invention to provide a wafer processing method capable of providing a wafer, and a silicon wafer capable of suppressing the appearance of crystal defects and polishing defects even after being etched.
 上記目的を達成するために、本発明では、研磨用組成物であって、
 砥粒と、
 水溶性高分子及び界面活性剤の少なくとも1種と
を含み、
 前記研磨用組成物中の全有機体炭素の濃度(ppmw)に対する前記砥粒の濃度(ppmw)の比が30以下のものであることを特徴とする研磨用組成物を提供する。
In order to achieve the above object, in the present invention, the composition for polishing is used.
Abrasive grains and
Containing at least one of a water-soluble polymer and a surfactant,
Provided is a polishing composition characterized in that the ratio of the concentration (ppmw) of the abrasive grains to the concentration (ppmw) of total organic carbon in the polishing composition is 30 or less.
 このような本発明の研磨用組成物を用いてウェーハを研磨することにより、ウェーハへの砥粒の吸着を抑制することができる。それにより、研磨中のウェーハへの砥粒吸着量を減らし、ひいては研磨後のウェーハの表面上に残留する砥粒の量を減らすことができる。研磨後、ウェーハ上に残留した水溶性高分子及び/又は界面活性剤は、酸化剤等で分解することにより容易に除去できるので、少ないエッチング量でも、研磨後のウェーハ表面上に残留した研磨用組成物の成分を十分に除去できる。その結果、エッチングによって結晶欠陥及び研磨欠陥が顕在化するのを防ぐことができる。すなわち、本発明の研磨用組成物によると、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のウェーハを提供できる。 By polishing the wafer using such a polishing composition of the present invention, it is possible to suppress the adsorption of abrasive grains on the wafer. As a result, the amount of abrasive grains adsorbed on the wafer during polishing can be reduced, and the amount of abrasive grains remaining on the surface of the wafer after polishing can be reduced. The water-soluble polymer and / or surfactant remaining on the wafer after polishing can be easily removed by decomposing it with an oxidizing agent or the like, so that even a small amount of etching remains on the surface of the wafer after polishing for polishing. The components of the composition can be sufficiently removed. As a result, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the polishing composition of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
 また、本発明では、ウェーハの加工方法であって、
 前記ウェーハの両面又は片面を、本発明の研磨用組成物を用いて研磨する工程と、
 O及びHの少なくとも1種を含む薬液により研磨後の前記ウェーハ上の有機物を分解する工程と、
 NH及びHFの少なくとも1種を含む薬液により研磨後のウェーハをエッチングする工程と
を含み、
 前記エッチングする工程を、総エッチング量が5nm以下となるように行うことを特徴とするウェーハの加工方法を提供する。
Further, in the present invention, it is a method for processing a wafer.
A step of polishing both sides or one side of the wafer using the polishing composition of the present invention.
A step of decomposing an organic substance on the wafer after polishing with a chemical solution containing at least one of O 3 and H 2 O 2 .
Including a step of etching a wafer after polishing with a chemical solution containing at least one of NH 3 and HF.
Provided is a method for processing a wafer, wherein the etching step is performed so that the total etching amount is 5 nm or less.
 本発明のウェーハの加工方法であれば、本発明の研磨用組成物を用いるので、エッチングによる結晶欠陥及び研磨欠陥の顕在化を抑えながら、研磨後のウェーハの表面上に残留する研磨用組成物の成分を十分に除去することができる。すなわち、本発明のウェーハの加工方法によれば、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のウェーハを提供できる。 Since the polishing composition of the present invention is used in the wafer processing method of the present invention, the polishing composition remaining on the surface of the wafer after polishing while suppressing the appearance of crystal defects and polishing defects due to etching. The components of can be sufficiently removed. That is, according to the wafer processing method of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
 例えば、前記研磨する工程を、研磨後の前記ウェーハの表面上の砥粒付着量が5個/μm以下となるように行うことができる。 For example, the polishing step can be performed so that the amount of abrasive grains adhered on the surface of the wafer after polishing is 5 pieces / μm 2 or less.
 表面上の砥粒付着量が5個/μm以下であるウェーハを、有機物を分解する工程及びエッチングする工程に供することで、研磨後のウェーハの表面上に残留する研磨用組成物の成分を確実に除去することができる。 By subjecting a wafer having an abrasive grain adhesion amount of 5 pieces / μm 2 or less on the surface to a step of decomposing an organic substance and a step of etching, the components of the polishing composition remaining on the surface of the wafer after polishing can be removed. It can be reliably removed.
 また、本発明では、研磨用組成物を用いて研磨されたシリコンウェーハであって、研磨後の表面上の砥粒付着量が5個/μm以下のものであることを特徴とするシリコンウェーハを提供する。 Further, the present invention is a silicon wafer polished using the polishing composition, wherein the amount of abrasive grains adhered on the surface after polishing is 5 pieces / μm 2 or less. I will provide a.
 本発明のシリコンウェーハは、研磨後の表面上の砥粒付着量が5個/μm以下なので、少ないエッチング量でも砥粒を十分に除去できる。その結果、エッチングによって結晶欠陥及び研磨欠陥が顕在化するのを防ぐことができる。すなわち、本発明のシリコンウェーハによると、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のシリコンウェーハを提供できる。 Since the silicon wafer of the present invention has an abrasive grain adhesion amount of 5 pieces / μm 2 or less on the surface after polishing, the abrasive grains can be sufficiently removed even with a small etching amount. As a result, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the silicon wafer of the present invention, it is possible to provide a high quality silicon wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
 以上のように、本発明の研磨用組成物であれば、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のウェーハを提供できる。結晶欠陥及び研磨欠陥の顕在化が抑えられたウェーハは、表面品質が高く、半導体デバイスの微細化の要求に応えられるウェーハとして有効に使用できる。 As described above, the polishing composition of the present invention can provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed. A wafer in which the manifestation of crystal defects and polishing defects is suppressed has high surface quality and can be effectively used as a wafer that can meet the demand for miniaturization of semiconductor devices.
 また、本発明のウェーハの加工方法であれば、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のウェーハを提供できる。この方法で得られるウェーハは、表面品質が高いので、半導体デバイスの土台として有効に使用できる。 Further, according to the wafer processing method of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed. Since the wafer obtained by this method has high surface quality, it can be effectively used as a base for a semiconductor device.
 そして、本発明のシリコンウェーハであれば、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のシリコンウェーハを提供できる。本発明のシリコンウェーハを用いれば、表面品質の高いウェーハを製造でき、ひいては、表面品質の高いウェーハを土台として、微細化の要求に応えた半導体デバイスを製造できる。 The silicon wafer of the present invention can provide a high-quality silicon wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed. By using the silicon wafer of the present invention, a wafer having high surface quality can be manufactured, and by extension, a semiconductor device that meets the demand for miniaturization can be manufactured based on the wafer having high surface quality.
比較例1及び実施例2のそれぞれで得られた、研磨工程後のウェーハの表面のSEM像である。6 is an SEM image of the surface of the wafer after the polishing step obtained in each of Comparative Example 1 and Example 2. 実施例及び比較例の各々で得られた、エッチングする工程の後のウェーハ表面上のLLS欠陥数を示すグラフである。It is a graph which shows the number of LLS defects on the wafer surface after the etching process obtained in each of an Example and a comparative example.
 上述のように、結晶欠陥及び研磨欠陥の顕在化が抑えられたウェーハを提供できる研磨用組成物の開発が求められていた。 As described above, there has been a demand for the development of a polishing composition capable of providing a wafer in which the manifestation of crystal defects and polishing defects is suppressed.
 本発明者は、上記課題を解決するために、結晶欠陥および研磨欠陥が顕在化しないような洗浄条件を見つけるとともに、そのような洗浄条件で除去可能な研磨用組成物の条件を見つけることを目的として、鋭意研究を行なった。 In order to solve the above problems, the present inventor aims to find cleaning conditions such that crystal defects and polishing defects do not become apparent, and to find conditions for a polishing composition that can be removed under such cleaning conditions. As a result, we conducted diligent research.
 まず、発明者は、洗浄条件を検討し、結晶欠陥及び研磨欠陥の顕在化を比較したところ、洗浄のエッチング量が大きく影響することを見出した。 First, the inventor examined the cleaning conditions and compared the actualization of crystal defects and polishing defects, and found that the etching amount of cleaning had a large effect.
 洗浄では、例えばNHとHとの混合溶液による洗浄や、自然酸化膜をHFにより剥離する洗浄、OやHとHFとの混合溶液による洗浄、HClとHの混合溶液による洗浄などがあるが、これらのうちNHとHとの混合溶液による洗浄、自然酸化膜をHFにより剥離する洗浄、OやHとHFとの混合溶液による洗浄ではエッチングを伴う。 In the cleaning, for example, cleaning with a mixed solution of NH 3 and H 2 O 2 , cleaning with a natural oxide film peeled off by HF, cleaning with a mixed solution of O 3 or H 2 O 2 and HF, HCl and H 2 O There are cleaning with a mixed solution of 2 and cleaning with a mixed solution of NH 3 and H 2 O 2 , cleaning with HF to peel off the natural oxide film, and mixing of O 3 and H 2 O 2 with HF. Cleaning with solution involves etching.
 これらのエッチング量の多寡で結晶欠陥および研磨欠陥の顕在化程度が変わることが分かり、結晶欠陥及び研磨欠陥の顕在化抑制には、片面当たりのエッチング量を合計5nm以下に抑えることが重要であることが分かった。 It was found that the degree of manifestation of crystal defects and polishing defects changes depending on the amount of these etchings, and it is important to suppress the total etching amount per side to 5 nm or less in order to suppress the manifestation of crystal defects and polishing defects. It turned out.
 また、エッチング工程における片面当たりの総エッチング量を5nm以下に抑えることで、エッチング装置の生産性も向上し、薬液使用量も抑えることができることが分かった。 It was also found that by suppressing the total etching amount per side in the etching process to 5 nm or less, the productivity of the etching apparatus can be improved and the amount of chemical solution used can be suppressed.
 しかし、エッチング工程での総エッチング量を5nm以下に抑えることで別の問題が浮上した。 However, another problem emerged by keeping the total etching amount in the etching process to 5 nm or less.
 総エッチング量を5nm以下に抑えることで、結晶欠陥および研磨欠陥は減少したものの、残存砥粒が逆に増加し、パーティクルカウンターで検出される欠陥数としては増加してしまった。 By suppressing the total etching amount to 5 nm or less, crystal defects and polishing defects were reduced, but the number of residual abrasive grains increased, and the number of defects detected by the particle counter increased.
 この現象は、エッチング量を従来より減少することで、研磨後ウェーハに付着した砥粒がリフトオフせずに表面に残り続けてしまったためと考えられる。 It is probable that this phenomenon is due to the fact that the amount of etching is reduced compared to the conventional method, so that the abrasive grains adhering to the wafer after polishing continue to remain on the surface without being lifted off.
 したがって、研磨後のウェーハの残留砥粒を減少することができれば、エッチング後のウェーハの残留砥粒も減少することができると考えた。 Therefore, if the residual abrasive grains of the wafer after polishing can be reduced, it is considered that the residual abrasive grains of the wafer after etching can also be reduced.
 本発明者は、以上の知見を踏まえて更に鋭意検討を重ねた結果、研磨用組成物に、砥粒に加えて、水溶性高分子及び界面活性剤の少なくとも1種を含ませ、研磨用組成物中の全有機体炭素(TOC:Total Organic Carbon)の濃度に対する砥粒の濃度の比を30以下とすることにより、研磨中のウェーハへの砥粒吸着量を減らすことができ、ひいては研磨後ウェーハの表面上の残留砥粒も減少させられることを見出し、本発明を完成させた。 As a result of further diligent studies based on the above findings, the present inventor has added at least one of a water-soluble polymer and a surfactant in addition to the abrasive grains to the polishing composition, and the polishing composition. By setting the ratio of the concentration of abrasive grains to the concentration of total organic carbon (TOC) in the material to 30 or less, the amount of abrasive grains adsorbed on the wafer during polishing can be reduced, and by extension, after polishing. The present invention has been completed by finding that the residual abrasive grains on the surface of the wafer can also be reduced.
 即ち、本発明は、研磨用組成物であって、
 砥粒と、
 水溶性高分子及び界面活性剤の少なくとも1種と
を含み、
 前記研磨用組成物中の全有機体炭素の濃度(ppmw)に対する前記砥粒の濃度(ppmw)の比が30以下のものであることを特徴とする研磨用組成物である。
That is, the present invention is a polishing composition.
Abrasive grains and
Containing at least one of a water-soluble polymer and a surfactant,
The polishing composition is characterized in that the ratio of the concentration (ppmw) of the abrasive grains to the concentration (ppmw) of total organic carbon in the polishing composition is 30 or less.
 また、本発明は、ウェーハの加工方法であって、
 前記ウェーハの両面又は片面を、本発明の研磨用組成物を用いて研磨する工程と、
 O及びHの少なくとも1種を含む薬液により研磨後の前記ウェーハ上の有機物を分解する工程と、
 NH及びHFの少なくとも1種を含む薬液により研磨後のウェーハをエッチングする工程と
を含み、
 前記エッチングする工程を、総エッチング量が5nm以下となるように行うことを特徴とする加工方法である。
Further, the present invention is a method for processing a wafer.
A step of polishing both sides or one side of the wafer using the polishing composition of the present invention.
A step of decomposing an organic substance on the wafer after polishing with a chemical solution containing at least one of O 3 and H 2 O 2 .
Including a step of etching a wafer after polishing with a chemical solution containing at least one of NH 3 and HF.
The processing method is characterized in that the etching step is performed so that the total etching amount is 5 nm or less.
 また、本発明は、研磨用組成物を用いて研磨されたシリコンウェーハであって、研磨後の表面上の砥粒付着量が5個/μm以下のものであることを特徴とするシリコンウェーハである。 Further, the present invention is a silicon wafer polished using a polishing composition, wherein the amount of abrasive grains adhered on the surface after polishing is 5 pieces / μm 2 or less. Is.
 なお、特許文献1の請求項1には、酸化セリウム粒子、分散剤及び水を含有する酸化セリウムスラリーであって、酸化セリウム重量/分散剤重量比が20~80である酸化セリウムスラリーという発明が記載されている。特許文献1に記載のスラリーにおいて、酸化セリウムは、研磨剤として含まれている。また、特許文献1の例えば段落0032及び請求項4には、分散剤の例として、ポリ(メタ)アクリル酸塩、及びポリアクリル酸-ポリアクリル酸アルキルアンモニウム塩共重合体などが記載されている。さらに、特許文献1の請求項8には、このスラリーを用いた基板の研磨方法が記載されている。そして、特許文献1の段落0102には、このような酸化セリウムスラリー及び研磨方法によれば、研磨傷を低減させさらには研磨速度を速くすることができることが記載されている。 According to claim 1, claim 1 is an invention of a cerium oxide slurry containing cerium oxide particles, a dispersant and water, wherein the cerium oxide weight / dispersant weight ratio is 20 to 80. Are listed. In the slurry described in Patent Document 1, cerium oxide is contained as an abrasive. Further, for example, in paragraph 0032 and claim 4 of Patent Document 1, poly (meth) acrylic acid salt, polyacrylic acid-polyacrylic acid alkylammonium salt copolymer, and the like are described as examples of dispersants. .. Further, claim 8 of Patent Document 1 describes a method of polishing a substrate using this slurry. Further, paragraph 0102 of Patent Document 1 describes that such a cerium oxide slurry and a polishing method can reduce polishing scratches and further increase the polishing rate.
 しかしながら、特許文献1は、酸化セリウムスラリー中の全有機体炭素濃度については何ら着目しておらず、そのため、酸化セリウムスラリー中の全有機体炭素の濃度(ppmw)に対する砥粒の濃度(ppmw)の比を30以下のものとすることについても何ら着目していない。 However, Patent Document 1 does not pay any attention to the total organic carbon concentration in the cerium oxide slurry, and therefore, the concentration of abrasive grains (ppmw) with respect to the concentration of total organic carbon in the cerium oxide slurry (ppmw). No attention is paid to the ratio of 30 or less.
 以下、本発明について詳細に説明するが、本発明はこれらに限定されるものではない。 Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.
 (研磨用組成物)
 本発明の研磨用組成物は、砥粒と、水溶性高分子及び界面活性剤の少なくとも1種とを含み、前記研磨用組成物中の全有機体炭素の濃度(ppmw)に対する前記砥粒の濃度(ppmw)の比が30以下のものであることを特徴とする。
(Polishing composition)
The polishing composition of the present invention contains abrasive grains and at least one of a water-soluble polymer and a surfactant, and is composed of the abrasive grains with respect to the concentration (ppmw) of total organic carbon in the polishing composition. It is characterized in that the ratio of the concentration (ppmw) is 30 or less.
 このような本発明の研磨用組成物であれば、ウェーハへの砥粒の吸着を抑制することができる。それにより、研磨中のウェーハへの砥粒付着量を減らし、ひいては研磨後のウェーハの表面上に残留する砥粒の量を減らすことができる。 With such a polishing composition of the present invention, it is possible to suppress the adsorption of abrasive grains on the wafer. As a result, the amount of abrasive grains adhering to the wafer during polishing can be reduced, and the amount of abrasive grains remaining on the surface of the wafer after polishing can be reduced.
 本結果が発現した理由は、以下のとおりであると考えられる。 The reason why this result appeared is considered to be as follows.
 研磨中のシリコンウェーハは、表面の自然酸化膜が存在しないため活性が高く、その表面に砥粒や水溶性高分子及び界面活性剤を吸着しやすい環境にある。 The silicon wafer being polished has high activity because there is no natural oxide film on the surface, and it is in an environment where abrasive grains, water-soluble polymers and surfactants are easily adsorbed on the surface.
 そのような環境の中で、砥粒に対して水溶性高分子や界面活性剤の存在割合を高めることで、水溶性高分子や界面活性剤のウェーハ表面への吸着の割合を増やすことができ、ウェーハの表面における砥粒が吸着する物理的余地を減らしたことで残留砥粒が減少したと考えられる。 In such an environment, by increasing the abundance ratio of the water-soluble polymer and the surfactant to the abrasive grains, the ratio of the water-soluble polymer and the surfactant adsorbed on the wafer surface can be increased. It is considered that the residual abrasive grains were reduced by reducing the physical room for the abrasive grains to be adsorbed on the surface of the wafer.
 このとき、水溶性高分子や界面活性剤が代わりに研磨後のウェーハの表面上に残留してしまう懸念はあるが、これらは、OやHといった酸化剤で分解でき、その結果砥粒に比べて容易に除去可能であり、そのためエッチングを伴わずして除去可能である。 At this time, there is a concern that the water-soluble polymer and the surfactant may remain on the surface of the wafer after polishing instead, but these can be decomposed by an oxidizing agent such as O 3 or H 2 O 2 , and as a result. It can be removed more easily than abrasive grains, and therefore can be removed without etching.
 したがって、本発明の研磨用組成物を用いてウェーハを研磨した場合、少ないエッチング量でも、研磨後のウェーハの表面から研磨用組成物の成分を十分に除去できる。その結果、エッチングによって結晶欠陥及び研磨欠陥が顕在化するのを防ぐことができる。すなわち、本発明の研磨用組成物によると、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のウェーハを提供できる。 Therefore, when a wafer is polished using the polishing composition of the present invention, the components of the polishing composition can be sufficiently removed from the surface of the polished wafer even with a small etching amount. As a result, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the polishing composition of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
 また、このとき、水溶性高分子及び界面活性剤の少なくとも1種がウェーハ表面にどの程度吸着して被覆できるかは、これらの成分における炭素-炭素結合の長さに最も依存すると考えられる。 At this time, the extent to which at least one of the water-soluble polymer and the surfactant can be adsorbed and coated on the wafer surface is considered to be most dependent on the length of the carbon-carbon bond in these components.
 水溶性高分子及び界面活性剤の有機物成分はよくTOC(全有機体炭素)として評価されうる。なお、TOC(全有機体炭素)はTC(全炭素)からIC(無機体炭素)を差し引いた値である。そのため、水溶性高分子及び界面活性剤の炭素-炭素結合の長さの指標として、全有機体炭素(TOC)の濃度を好適に使用することができる。 The organic components of water-soluble polymers and surfactants can often be evaluated as TOC (total organic carbon). The TOC (total organic carbon) is a value obtained by subtracting the IC (inorganic carbon) from the TC (total carbon). Therefore, the concentration of total organocarbon (TOC) can be suitably used as an index of the length of the carbon-carbon bond of the water-soluble polymer and the surfactant.
 そして、TOCに対する砥粒の濃度割合を適切にコントロールできれば研磨後のウェーハの残留砥粒を減らすことができる。 Then, if the concentration ratio of the abrasive grains to the TOC can be appropriately controlled, the residual abrasive grains of the wafer after polishing can be reduced.
 本発明者は、検討の結果、研磨用組成物における砥粒の濃度(ppmw)のTOCの濃度(ppmw)に対する比を30以下にすることが重要であることが分かった。 As a result of the study, the present inventor found that it is important that the ratio of the concentration of abrasive grains (ppmw) to the concentration of TOC (ppmw) in the polishing composition is 30 or less.
 より詳細には、研磨用組成物中の全有機体炭素の濃度に対する砥粒の濃度の比を30以下にすることにより、研磨中にウェーハ表面上に吸着する砥粒の量を十分に抑えることができ、その結果、研磨後のウェーハ表面上の残留砥粒量を小さくすることができることが分かった。 More specifically, by setting the ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition to 30 or less, the amount of the abrasive grains adsorbed on the wafer surface during polishing is sufficiently suppressed. As a result, it was found that the amount of residual abrasive grains on the surface of the wafer after polishing can be reduced.
 一方、この比が30を超える場合、研磨中にウェーハ表面上への砥粒吸着量が過剰となり、研磨後の残留砥粒を十分に除去するには、その後に行なうエッチング工程におけるエッチング量を多く確保しなければいけなくなる。エッチング量を増やすと、結晶欠陥及び研磨欠陥の顕在化がより起こり易くなる。 On the other hand, when this ratio exceeds 30, the amount of abrasive grains adsorbed on the wafer surface during polishing becomes excessive, and in order to sufficiently remove the residual abrasive grains after polishing, the etching amount in the subsequent etching step is large. You will have to secure it. When the etching amount is increased, crystal defects and polishing defects are more likely to become apparent.
 研磨用組成物中の全有機体炭素の濃度に対する砥粒の濃度の比の下限は、特に限定されないが、例えば、1以上とすることができる。研磨用組成物中の全有機体炭素の濃度に対する砥粒の濃度の比は、1以上30以下であることが好ましい。この範囲内であれば、砥粒による十分な研磨を達成しながら、研磨後の残留砥粒量を更に小さくすることができる。上記比は、3以上10以下であることがより好ましい。 The lower limit of the ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is not particularly limited, but may be, for example, 1 or more. The ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is preferably 1 or more and 30 or less. Within this range, the amount of residual abrasive grains after polishing can be further reduced while achieving sufficient polishing with abrasive grains. The above ratio is more preferably 3 or more and 10 or less.
 研磨用組成物中の全有機体炭素(TOC)の濃度は、例えば島津製作所株式会社製のTOC-Lシリーズにて測定することができる。研磨用組成物中の砥粒の濃度は、例えば京都電子工業株式会社製密度比重計DA-100にて測定することができる。 The concentration of total organic carbon (TOC) in the polishing composition can be measured, for example, with the TOC-L series manufactured by Shimadzu Corporation. The concentration of the abrasive grains in the polishing composition can be measured, for example, with a density hydrometer DA-100 manufactured by Kyoto Electronics Manufacturing Co., Ltd.
 研磨用組成物中の全有機体炭素の濃度に対する砥粒の濃度の比は、組成物中に含ませる砥粒の量と、水溶性高分子の量と、界面活性剤の量とを互いに調整することで、調整することができる。 The ratio of the concentration of the abrasive grains to the concentration of the total organic carbon in the polishing composition is adjusted by adjusting the amount of the abrasive grains contained in the composition, the amount of the water-soluble polymer, and the amount of the surfactant. By doing so, it can be adjusted.
 以下、本発明の研磨用組成物をより詳細に説明する。 Hereinafter, the polishing composition of the present invention will be described in more detail.
 <砥粒>
 砥粒の例としては、二酸化ケイ素、酸化アルミニウム、酸化セリウム、酸化クロム、二酸化チタン、酸化ジルコニウム、酸化マグネシウム、二酸化マンガン、酸化亜鉛、窒化ケイ素、窒化ホウ素、炭化ケイ素、炭化ホウ素、ダイヤモンド、フラーレンなどが挙げられるが、表面欠陥を抑制するためには二酸化ケイ素が好ましい。
<Abrasion grain>
Examples of abrasive grains include silicon dioxide, aluminum oxide, cerium oxide, chromium oxide, titanium dioxide, zirconium oxide, magnesium oxide, manganese dioxide, zinc oxide, silicon nitride, boron nitride, silicon carbide, boron carbide, diamond, fullerene, etc. However, silicon dioxide is preferable in order to suppress surface defects.
 二酸化ケイ素は製法により、コロイダルシリカ、フュームドシリカ、水ガラスシリカなどがあるが、スクラッチを防止するためにはコロイダルシリカが好ましい。 Silicon dioxide includes colloidal silica, fumed silica, water glass silica, etc. depending on the manufacturing method, but colloidal silica is preferable in order to prevent scratches.
 コロイダルシリカの1次粒径は、欠陥低減の観点から1000nm以下が好ましく、さらに300nm以下が好ましく、さらには100nm以下が好ましい。また、研磨レート増大の観点から1nm以上が好ましく、さらには10nm以上が好ましい。 The primary particle size of colloidal silica is preferably 1000 nm or less, more preferably 300 nm or less, and further preferably 100 nm or less from the viewpoint of defect reduction. Further, from the viewpoint of increasing the polishing rate, 1 nm or more is preferable, and 10 nm or more is more preferable.
 コロイダルシリカの濃度は凝集防止の観点から10wt%以下が好ましく、さらには1wt%以下が好ましい。また、研磨レート増大の観点から0.0001wt%以上が好ましく、0.001wt%以上が好ましい。 The concentration of colloidal silica is preferably 10 wt% or less, more preferably 1 wt% or less from the viewpoint of preventing aggregation. Further, from the viewpoint of increasing the polishing rate, 0.0001 wt% or more is preferable, and 0.001 wt% or more is preferable.
 <水溶性高分子>
 水溶性高分子としては、例えばセルロース誘導体が好適に用いられ、ヒドロキシエチルセルロースや、プロピオニルエチルセルロース、カルボキシメチルセルロース、カルボキシエチルセルロースなどが用いられる。これらは、水溶性半合成高分子と呼ぶこともできる。
<Water-soluble polymer>
As the water-soluble polymer, for example, a cellulose derivative is preferably used, and hydroxyethyl cellulose, propionyl ethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose and the like are used. These can also be called water-soluble semi-synthetic polymers.
 また、欠陥低減の観点から、水溶性高分子として、上記半合成高分子と異なる合成高分子を用いる傾向もあり、例えば、ポリビニルアルコール、ポリビニルピロリドンなどの高分子が好適に用いられる。 Further, from the viewpoint of defect reduction, there is a tendency to use a synthetic polymer different from the above semi-synthetic polymer as the water-soluble polymer, and for example, a polymer such as polyvinyl alcohol or polyvinylpyrrolidone is preferably used.
 <界面活性剤>
 界面活性剤としては、カチオン性界面活性剤、アニオン性界面活性剤、又はノニオン性界面活性剤を用いることができるが、特にノニオン性界面活性剤が好ましい。
<Surfactant>
As the surfactant, a cationic surfactant, an anionic surfactant, or a nonionic surfactant can be used, but a nonionic surfactant is particularly preferable.
 ノニオン性界面活性剤の中でも、好適な例として、ポリオキシエチレン-ポリオキシプロピレンブロック共重合体やランダム共重合体、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンフェニルエーテルなどが挙げられる。 Among the nonionic surfactants, suitable examples include polyoxyethylene-polyoxypropylene block copolymers, random copolymers, polyoxyethylene alkyl ethers, polyoxyethylene phenyl ethers and the like.
 <その他の成分>
 本発明の研磨用組成物は、砥粒、水溶性高分子、及び界面活性剤の他に、例えば分散媒及びpH調整剤等を更に含むことができる。
<Other ingredients>
The polishing composition of the present invention may further contain, for example, a dispersion medium, a pH adjuster, and the like, in addition to the abrasive grains, the water-soluble polymer, and the surfactant.
 分散媒としては、水、特に純水を用いることが好ましい。 It is preferable to use water, especially pure water, as the dispersion medium.
 砥粒としてコロイダルシリカを用いる場合、コロイダルシリカの分散安定性を高めるため、pH調整剤は塩基性が好ましい。塩基性化合物としては、水酸化カリウム、水酸化ナトリウム、炭酸カリウム、炭酸ナトリウム、水酸化リチウム、水酸化テトラメチルアンモニウム、アンモニア、アミン類などが好適に用いられる。 When colloidal silica is used as the abrasive grains, the pH adjuster is preferably basic in order to enhance the dispersion stability of colloidal silica. As the basic compound, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, lithium hydroxide, tetramethylammonium hydroxide, ammonia, amines and the like are preferably used.
 (ウェーハの加工方法)
 本発明のウェーハの加工方法は、
 前記ウェーハの両面又は片面を、本発明の研磨用組成物を用いて研磨する工程と、
 O及びHの少なくとも1種を含む薬液により研磨後の前記ウェーハ上の有機物を分解する工程と、
 NH及びHFの少なくとも1種を含む薬液により研磨後のウェーハをエッチングする工程と
を含み、
 前記エッチングする工程を、総エッチング量が5nm以下となるように行うことを特徴とする。
(Wafer processing method)
The wafer processing method of the present invention is
A step of polishing both sides or one side of the wafer using the polishing composition of the present invention.
A step of decomposing an organic substance on the wafer after polishing with a chemical solution containing at least one of O 3 and H 2 O 2 .
Including a step of etching a wafer after polishing with a chemical solution containing at least one of NH 3 and HF.
The etching step is characterized in that the total etching amount is 5 nm or less.
 本発明の研磨用組成物を用いることにより、先に説明したように、研磨中にウェーハ表面上に吸着する砥粒の量を十分に抑えることができ、その結果、研磨する工程後のウェーハ表面上の残留砥粒量を小さくすることができる。また、研磨する工程後にウェーハ表面上に残留する水溶性高分子及び/又は界面活性剤は、続く有機物を分解する工程で、O及びHの少なくとも1種を含む薬液によって分解される。このように表面上の有機物が分解されたウェーハを、総エッチング量が5nm以下となるように、NH及びHFの少なくとも1種を含む薬液によりエッチングすることにより、エッチングによる結晶欠陥及び研磨欠陥の顕在化を抑えながら、研磨後のウェーハの表面上に残留する研磨用組成物の成分を十分に除去することができる。 By using the polishing composition of the present invention, as described above, the amount of abrasive grains adsorbed on the wafer surface during polishing can be sufficiently suppressed, and as a result, the wafer surface after the polishing step can be sufficiently suppressed. The amount of residual abrasive grains on the top can be reduced. Further, the water-soluble polymer and / or the surfactant remaining on the wafer surface after the polishing step is decomposed by a chemical solution containing at least one of O 3 and H 2 O 2 in the subsequent step of decomposing the organic substance. .. By etching the wafer on which the organic matter on the surface is decomposed with a chemical solution containing at least one of NH 3 and HF so that the total etching amount is 5 nm or less, crystal defects and polishing defects due to etching are removed. It is possible to sufficiently remove the components of the polishing composition remaining on the surface of the wafer after polishing while suppressing the actualization.
 すなわち、本発明のウェーハの加工方法によれば、残留砥粒量が少なく、結晶欠陥及び研磨欠陥の顕在化が抑えられた高品質のウェーハを提供できる。 That is, according to the wafer processing method of the present invention, it is possible to provide a high-quality wafer in which the amount of residual abrasive grains is small and the manifestation of crystal defects and polishing defects is suppressed.
 次に、本発明のウェーハの加工方法の各工程を、順に詳細に説明する。 Next, each step of the wafer processing method of the present invention will be described in detail in order.
 <研磨する工程>
 この研磨工程では、ウェーハの両面又は片面を、本発明の研磨用組成物を用いて研磨する。
<polishing process>
In this polishing step, both sides or one side of the wafer are polished using the polishing composition of the present invention.
 研磨に供するウェーハは、例えばシリコンウェーハである。シリコンウェーハは、例えば、シリコンインゴットからスライスしてスライス片を得、このスライス片を平面研削に供したものであり得る。 The wafer used for polishing is, for example, a silicon wafer. The silicon wafer may be, for example, sliced from a silicon ingot to obtain a slice piece, and the slice piece may be subjected to surface grinding.
 研磨する工程は、1段の工程でもよいし、複数段の工程でもよい。表面品質の観点から、少なくとも2段の研磨工程を行うことが好ましい。 The polishing step may be a one-step step or a multi-step step. From the viewpoint of surface quality, it is preferable to perform at least two polishing steps.
 研磨は、ウェーハを保持しながら研磨布に押し付け、研磨用組成物をウェーハの被研磨面に連続的に供給しながら、ウェーハ及び研磨布の一方又はこれらの両方を回転させながら行うことが望ましい。 It is desirable that polishing is performed while holding the wafer and pressing it against the polishing pad, continuously supplying the polishing composition to the surface to be polished of the wafer, and rotating one or both of the wafer and the polishing pad.
 研磨は、両面研磨でも片面研磨でもどちらもでも良い。両面研磨の場合は、例えば、ウェーハの上下に研磨布を配置し、両面同時に研磨を行う。また、片面研磨の場合は、ウェーハの一方の面にのみ研磨布を配置する。 Polishing may be either double-sided polishing or single-sided polishing. In the case of double-sided polishing, for example, polishing cloths are placed above and below the wafer, and both sides are polished at the same time. In the case of single-sided polishing, the polishing cloth is placed only on one side of the wafer.
 研磨布は、表面品質の観点から樹脂製のものが望ましく、耐摩耗性が良好なことからウレタン樹脂を用いるのが良い。 The polishing cloth is preferably made of resin from the viewpoint of surface quality, and urethane resin is preferable because it has good wear resistance.
 ウレタン樹脂を不織布などの繊維に含浸させたものを研磨布として用いても良いし、ウレタン樹脂を加熱して発泡ウレタン樹脂を形成しそれを研磨布として用いても良いし、又はPETフィルムなどの基材上にウレタン樹脂を塗布し、加水分解によりスウェードを形成しそれを研磨布として用いても良い。 A fiber impregnated with a fiber such as a non-woven fabric may be used as a polishing cloth, a urethane foam may be heated to form a urethane foam resin and used as a polishing cloth, or a PET film or the like may be used. A urethane resin may be applied onto the base material to form a suede by hydrolysis, which may be used as a polishing cloth.
 研磨布の硬度は、研磨レートの観点から、ショアA硬度で30以上が好ましく、さらには50以上が好ましい。また、研磨布の硬度は、表面品質の観点から、95以下が好ましく、さらには90以下が好ましい。 From the viewpoint of polishing rate, the hardness of the polishing cloth is preferably 30 or more in shore A hardness, and more preferably 50 or more. The hardness of the polishing cloth is preferably 95 or less, more preferably 90 or less, from the viewpoint of surface quality.
 研磨布は、研磨用組成物を効率的に作用するため、溝のようなテクスチャ構造を有しているのが好ましい。 The polishing cloth preferably has a groove-like texture structure in order to efficiently act on the polishing composition.
 例えば、研磨する工程を、研磨後のウェーハの表面上の砥粒付着量が5個/μm以下となるように行うことができる。 For example, the polishing step can be performed so that the amount of abrasive grains adhered on the surface of the wafer after polishing is 5 pieces / μm 2 or less.
 表面上の砥粒付着量が5個/μm以下であるウェーハを、以下にそれぞれ説明する、有機物を分解する工程及びエッチングする工程に供することで、研磨後のウェーハの表面上に残留する研磨用組成物の成分を確実に除去することができる。 By subjecting a wafer having an abrasive grain adhesion amount of 5 pieces / μm 2 or less on the surface to the steps of decomposing organic substances and etching, which are described below, the polishing remaining on the surface of the wafer after polishing is performed. The components of the composition for use can be reliably removed.
 ウェーハ表面上の砥粒付着量は、例えば、走査型電子顕微鏡(SEM)によって測定することができる。本発明のウェーハ加工方法の研磨する工程によると、表面上の砥粒付着量を、例えば0.1個/μm以上5個/μm以下とすることができ、1個/μm以上3個/μm以下とすることが好ましい。 The amount of abrasive grains adhered on the wafer surface can be measured by, for example, a scanning electron microscope (SEM). According to the polishing step of the wafer processing method of the present invention, the amount of abrasive grains adhered on the surface can be, for example, 0.1 piece / μm 2 or more and 5 pieces / μm 2 or less, and 1 piece / μm 2 or more 3 The number is preferably 2 or less per μm.
 <有機物を分解する工程>
 有機物を分解する工程では、O及びHの少なくとも1種を含む薬液により研磨後の前記ウェーハ上の有機物を分解する。
<Process of decomposing organic matter>
In the step of decomposing the organic substance, the organic substance on the wafer after polishing is decomposed with a chemical solution containing at least one of O 3 and H 2 O 2 .
 O及び/又はHは、酸化剤として働き、研磨後のウェーハ上の有機物、すなわち水溶性高分子及び/又は界面活性剤に起因する有機物を分解することができる。有機物の分解によって生じた生成物は、エッチングを伴わずに、ウェーハから除去できる。 O 3 and / or H 2 O 2 can act as an oxidant and decompose organic substances on the polished wafer, that is, organic substances caused by water-soluble polymers and / or surfactants. The products produced by the decomposition of organic matter can be removed from the wafer without etching.
 有機物を分解する工程で用いる薬液は、O及びH以外の成分を含んでいても良い。具体例は後述する。 The chemical solution used in the step of decomposing the organic substance may contain components other than O 3 and H 2 O 2 . Specific examples will be described later.
 <エッチングする工程>
 エッチングする工程では、NH及びHFの少なくとも1種を含む薬液により研磨後のウェーハをエッチングする。この際、総エッチング量が5nm以下となるように、エッチングを行う。
<Etching process>
In the etching step, the polished wafer is etched with a chemical solution containing at least one of NH 3 and HF. At this time, etching is performed so that the total etching amount is 5 nm or less.
 ここでの総エッチング量は、ウェーハの片面をエッチングする場合には、エッチングに供される面の総エッチング量であり、ウェーハの両面をエッチングする場合には、エッチングに供される各面当たりの総エッチング量である。すなわち、総エッチング量は、ウェーハの片面当たりの総エッチング量である。 The total etching amount here is the total etching amount of the surface to be etched when one side of the wafer is etched, and is the total etching amount of each surface to be etched when both sides of the wafer are etched. Total etching amount. That is, the total etching amount is the total etching amount per one side of the wafer.
 総エッチング量が5nm以下となるようにエッチングをすることで、エッチングによる結晶欠陥及び研磨欠陥の顕在化を十分に抑えることができる。 By etching so that the total etching amount is 5 nm or less, it is possible to sufficiently suppress the manifestation of crystal defects and polishing defects due to etching.
 総エッチング量の下限は、特に制限されないが、例えば3nmとすることができる。総エッチング量は、0.1nm以上5nm以下とすることが好ましく、1nm以上5nm以下とすることがより好ましい。 The lower limit of the total etching amount is not particularly limited, but can be, for example, 3 nm. The total etching amount is preferably 0.1 nm or more and 5 nm or less, and more preferably 1 nm or more and 5 nm or less.
 エッチング工程における総エッチング量は、以下の手順で確認することができる。まず、参照SOI(Silicon On Insulator)ウェーハを準備し、SOI膜厚をULVAC社製分光エリプソメーターUNECS-3000にて測定して、エッチング前のSOI膜厚を得る。次いで、参照SOIウェーハを、確認対象のエッチング工程の条件と同じ条件でエッチングする。次いで、エッチング後のSOI膜厚を、同じ分光エリプソメーターにて測定して、エッチング後のSOI膜厚を得る。そして、エッチング前後のSOI膜厚の差分を、確認対象のエッチング工程の総エッチング量とする。 The total etching amount in the etching process can be confirmed by the following procedure. First, a reference SOI (Silicon On Insulator) wafer is prepared, and the SOI film thickness is measured with a spectroscopic ellipsometer UNECS-3000 manufactured by ULVAC, Inc. to obtain the SOI film thickness before etching. Next, the reference SOI wafer is etched under the same conditions as those of the etching process to be confirmed. Next, the SOI film thickness after etching is measured with the same spectroscopic ellipsometer to obtain the SOI film thickness after etching. Then, the difference in SOI film thickness before and after etching is taken as the total etching amount of the etching process to be confirmed.
 また、エッチング工程における総エッチング量は、例えばNH及びHFの少なくとも1種を含む薬液におけるエッチング剤の濃度、エッチング時間、及び薬液の温度によって調整することができる。 Further, the total etching amount in the etching step can be adjusted by, for example, the concentration of the etching agent in the chemical solution containing at least one of NH 3 and HF, the etching time, and the temperature of the chemical solution.
 例えば、必要に応じて薬液は加温しても良い。加温することでエッチング量が増加する。 For example, the chemical solution may be heated if necessary. The amount of etching increases by heating.
 エッチングする工程で用いる薬液は、NH及びHF以外の成分を含んでいてもよい。具体例は後述する。 The chemical solution used in the etching step may contain components other than NH 3 and HF. Specific examples will be described later.
 また、上記有機物を分解する工程と、エッチングする工程とは、別々に行っても良いし、同時に行なっても良い。有機物を分解する工程と、エッチングする工程とを合わせて、洗浄工程と呼ぶこともできる。 Further, the step of decomposing the organic substance and the step of etching may be performed separately or at the same time. The process of decomposing organic matter and the process of etching can also be collectively referred to as a cleaning process.
 <その他の工程>
 本発明のウェーハの加工方法は、エッチングする工程の後に、例えば評価工程を更に含むことができる。例えば、評価工程において、表面欠陥評価を行なってもよい。表面欠陥評価装置としては、例えばKLA株式会社製Surfscanシリーズを用いることができる。
<Other processes>
The wafer processing method of the present invention may further include, for example, an evaluation step after the etching step. For example, surface defect evaluation may be performed in the evaluation process. As the surface defect evaluation device, for example, the Surfscan series manufactured by KLA Corporation can be used.
 <薬液>
 有機物を分解する工程と、エッチングする工程では、それぞれ、1つの薬液を用いても良いし、複数の薬液を用いても良い。
<Chemical solution>
In the step of decomposing the organic substance and the step of etching, one chemical solution may be used or a plurality of chemical solutions may be used, respectively.
 また、有機物を分解する工程とエッチングする工程とを同時に行う場合、O及びHの少なくとも1種と、NH及びHFの少なくとも1種とを含む混合溶液を用いても良い。 When the step of decomposing the organic substance and the step of etching are performed at the same time, a mixed solution containing at least one of O 3 and H 2 O 2 and at least one of NH 3 and HF may be used.
 例えば、洗浄工程では、NHとHとを含む混合溶液、HFとOとを含む混合溶液、及びHFとOとHとを含む混合溶液を薬液として用いることができる。 For example, in the washing step, a mixed solution containing NH 3 and H 2 O 2 , a mixed solution containing HF and O 3 , and a mixed solution containing HF, O 3 and H 2 O 2 can be used as a chemical solution. can.
 エッチングする工程とは別に有機物を分解する工程を行う場合、有機物を分解する為の薬液として、例えば、HClとHとを含む混合溶液、Hを含む溶液、及びOを含む溶液を挙げることができる。 When the step of decomposing the organic substance is performed separately from the step of etching, for example, a mixed solution containing HCl and H 2 O 2 , a solution containing H 2 O 2 , and O 3 are used as the chemical solution for decomposing the organic substance. The solution containing can be mentioned.
 有機物を分解する工程とは別にエッチングする工程を行う場合、エッチングする工程で用いる薬液として、例えば、HFとHNOとを含む混合溶液、NHを含む溶液、及びHFを含む溶液を挙げることができる。 When the etching step is performed separately from the step of decomposing the organic substance, examples of the chemical solution used in the etching step include a mixed solution containing HF and HNO 3 , a solution containing NH 3 , and a solution containing HF. can.
 これらの薬液は、溶媒として、水、特に純水を含むこともできる。 These chemicals can also contain water, especially pure water, as a solvent.
 (シリコンウェーハ)
 本発明のシリコンウェーハは、研磨用組成物を用いて研磨されたシリコンウェーハであって、研磨後の表面上の砥粒付着量が5個/μm以下のものであることを特徴とする。
(Silicon wafer)
The silicon wafer of the present invention is a silicon wafer polished using a polishing composition, and is characterized in that the amount of abrasive grains adhered on the surface after polishing is 5 pieces / μm 2 or less.
 本発明のシリコンウェーハは、例えば、先に説明した、本発明のウェーハの加工方法の研磨工程によって得ることができる。 The silicon wafer of the present invention can be obtained, for example, by the polishing process of the wafer processing method of the present invention described above.
 このようなシリコンウェーハを、先に説明した有機物を分解する工程及びエッチングする工程に供することにより、研磨後のウェーハの表面上に残留する研磨用組成物の成分を確実に除去することができるのに加え、エッチングによって結晶欠陥及び研磨欠陥が顕在化するのを防ぐことができる。すなわち、本発明のシリコンウェーハによると、結晶欠陥及び研磨欠陥の顕在化が抑えられたシリコンウェーハを提供できる。 By subjecting such a silicon wafer to the steps of decomposing organic substances and etching described above, it is possible to reliably remove the components of the polishing composition remaining on the surface of the wafer after polishing. In addition, it is possible to prevent crystal defects and polishing defects from becoming apparent due to etching. That is, according to the silicon wafer of the present invention, it is possible to provide a silicon wafer in which the manifestation of crystal defects and polishing defects is suppressed.
 以下、実施例及び比較例を用いて本発明を具体的に説明するが、本発明はこれらに限定されるものではない。 Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
 (比較例1)
 比較例1では、以下の手順で、ウェーハの加工を行なった。
(Comparative Example 1)
In Comparative Example 1, the wafer was processed according to the following procedure.
 [準備]
 まず、加工対象のウェーハとして、直径300mm及び厚さ775μmのシリコンウェーハを準備した。
[Preparation]
First, a silicon wafer having a diameter of 300 mm and a thickness of 775 μm was prepared as a wafer to be processed.
 [研磨する工程]
 比較例1では、以下の手順で、砥粒の濃度が10000ppmwであり、TOC濃度が100ppmwである比較例1の研磨用組成物を調製した。
[Abrasion process]
In Comparative Example 1, the polishing composition of Comparative Example 1 having an abrasive grain concentration of 10000 ppmw and a TOC concentration of 100 ppmw was prepared by the following procedure.
 砥粒として、コロイダルシリカを準備した。また、水溶性高分子としてのポリビニルアルコール(PVA)と、界面活性剤としてポリオキシエチレン-ポリオキシプロピレンブロック共重合体(EOPO)とを準備した。 Colloidal silica was prepared as abrasive grains. Further, polyvinyl alcohol (PVA) as a water-soluble polymer and polyoxyethylene-polyoxypropylene block copolymer (EOPO) as a surfactant were prepared.
 次に、コロイダルシリカと、ポリビニルアルコールと、ポリオキシエチレン-ポリオキシプロピレンブロック共重合体とを、重量比10000:90:10で、純水に投入し、比較例1の研磨用組成物を得た。 Next, colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 10000: 90: 10 to obtain the polishing composition of Comparative Example 1. rice field.
 次に、比較例1の加工対象のウェーハの片面を、比較例1の研磨用組成物を用いて研磨した。比較例1における研磨する工程で得られた研磨後のウェーハの表面のSEM像を、図1の左側に示す。 Next, one side of the wafer to be processed in Comparative Example 1 was polished using the polishing composition of Comparative Example 1. The SEM image of the surface of the wafer after polishing obtained in the polishing step in Comparative Example 1 is shown on the left side of FIG.
 [有機物を分解する工程]
 次に、研磨後のウェーハの表面に、オゾン(O)を含んだ薬液を供給し、次いで純水を用いて薬液を洗い流した。
[Process of decomposing organic matter]
Next, a chemical solution containing ozone ( O3) was supplied to the surface of the polished wafer, and then the chemical solution was washed away with pure water.
 [エッチングする工程]
 次いで、研磨後のウェーハの表面にNH/H/HOの混合液を供給した。用いたNH/H/HOの混合液は、NHの濃度を28wt%とし、Hの濃度を30wt%とし、NH:H:HO=1:1:10の割合で混合することにより調製した。供給時の温度を50℃とした。NH/H/HOの混合液に接触させている時間は、5分間とした。それにより、NH/H/HOの混合液による総エッチング量を3nmとした。
[Etching process]
Next, a mixed solution of NH 3 / H 2 O 2 / H 2 O was supplied to the surface of the polished wafer. In the mixed solution of NH 3 / H 2 O 2 / H 2 O used, the concentration of NH 3 was 28 wt%, the concentration of H 2 O 2 was 30 wt%, and NH 3 : H 2 O 2 : H 2 O =. It was prepared by mixing at a ratio of 1: 1:10. The temperature at the time of supply was set to 50 ° C. The time of contact with the mixture of NH 3 / H 2 O 2 / H 2 O was set to 5 minutes. As a result, the total etching amount by the mixed solution of NH 3 / H 2 O 2 / H 2 O was set to 3 nm.
 次いで、ウェーハの表面に、HF水溶液を供給した。用いたHF水溶液は、HFの濃度が1wt%であり、供給時の温度を25℃とした。HF水溶液に接触させている時間は、5分間とした。それにより、HFによる総エッチング量を1nmとした。 Next, an HF aqueous solution was supplied to the surface of the wafer. The HF aqueous solution used had an HF concentration of 1 wt%, and the temperature at the time of supply was 25 ° C. The time of contact with the HF aqueous solution was 5 minutes. As a result, the total etching amount by HF was set to 1 nm.
 (実施例1)
 実施例1では、研磨する工程での研磨用組成物の砥粒濃度を3000ppmw、TOC濃度を100ppmwとしたこと、及びエッチングする工程でのNH/H/HOの混合液による総エッチング量を9nm、HFによる総エッチング量を1nmとしたこと以外は比較例1と同様の手順で、比較例1で加工したのと同様のウェーハを加工した。
(Example 1)
In Example 1, the abrasive grain concentration of the polishing composition in the polishing step was 3000 ppmw, the TOC concentration was 100 ppmw, and the mixture of NH 3 / H 2 O 2 / H 2 O in the etching step was used. The same wafer as that processed in Comparative Example 1 was processed by the same procedure as in Comparative Example 1 except that the total etching amount was 9 nm and the total etching amount by HF was 1 nm.
 実施例1では、コロイダルシリカと、ポリビニルアルコールと、ポリオキシエチレン-ポリオキシプロピレンブロック共重合体とを、重量比3000:90:10で、純水に投入し、実施例1の研磨用組成物を得た。 In Example 1, colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 3000:90:10, and the polishing composition of Example 1 was added. Got
 また、実施例1では、エッチングする工程において供給したNH/H/HOの混合液は、比較例1で用いたのと同様のものを用い、供給時の温度を50℃とした。NH/H/HOの混合液に接触させている時間は、15分とした。 Further, in Example 1, the mixture of NH 3 / H 2 O 2 / H 2 O supplied in the etching step was the same as that used in Comparative Example 1, and the temperature at the time of supply was 50 ° C. And said. The time of contact with the mixture of NH 3 / H 2 O 2 / H 2 O was set to 15 minutes.
 そして、実施例1では、エッチングする工程において供給したHF水溶液の濃度を1wt%とし、供給時の温度を25℃とした。HF水溶液に接触させている時間は、5分間とした。 Then, in Example 1, the concentration of the HF aqueous solution supplied in the etching step was 1 wt%, and the temperature at the time of supply was 25 ° C. The time of contact with the HF aqueous solution was 5 minutes.
 (実施例2)
 実施例2では、エッチングする工程でのNH/H/HOの混合液による総エッチング量を3nm、HFによる総エッチング量を1nmとしたこと以外は実施例1と同様の手順で、比較例1で加工したのと同様のウェーハを加工した。
(Example 2)
In Example 2, the procedure is the same as that of Example 1 except that the total etching amount by the mixed solution of NH 3 / H 2 O 2 / H 2 O in the etching step is 3 nm and the total etching amount by HF is 1 nm. Then, the same wafer as that processed in Comparative Example 1 was processed.
 実施例2では、比較例1と同様の条件で、エッチングする工程を行った。 In Example 2, the etching step was performed under the same conditions as in Comparative Example 1.
 実施例2の研磨用組成物を用いて研磨した後のウェーハの表面のSEM像を、図1の右側に示す。 The SEM image of the surface of the wafer after polishing with the polishing composition of Example 2 is shown on the right side of FIG.
 (実施例3)
 実施例3では、研磨する工程での研磨用組成物の砥粒濃度を1000ppmw、TOC濃度を100ppmwとしたこと以外は実施例2と同様の手順で、比較例1で加工したのと同様のウェーハを加工した。
(Example 3)
In Example 3, the same wafer as that processed in Comparative Example 1 by the same procedure as in Example 2 except that the abrasive grain concentration of the polishing composition in the polishing step was 1000 ppmw and the TOC concentration was 100 ppmw. Was processed.
 実施例3では、コロイダルシリカと、ポリビニルアルコールと、ポリオキシエチレン-ポリオキシプロピレンブロック共重合体とを、重量比1000:90:10で、純水に投入し、実施例3の研磨用組成物を得た。 In Example 3, colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were put into pure water at a weight ratio of 1000:90:10, and the polishing composition of Example 3 was added. Got
 (実施例4)
 実施例4では、研磨する工程での研磨用組成物の砥粒濃度を370ppmw、TOC濃度を50ppmwとしたこと以外は実施例2と同様の手順で、比較例1で加工したのと同様のウェーハを加工した。
(Example 4)
In Example 4, the same wafer as that processed in Comparative Example 1 by the same procedure as in Example 2 except that the abrasive grain concentration of the polishing composition in the polishing step was 370 ppmw and the TOC concentration was 50 ppmw. Was processed.
 実施例4では、コロイダルシリカと、ポリビニルアルコールと、ポリオキシエチレン-ポリオキシプロピレンブロック共重合体とを、重量比370:45:5で、純水に投入し、実施例4の研磨用組成物を得た。 In Example 4, colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 370: 45: 5, and the polishing composition of Example 4 was added. Got
 (実施例5)
 実施例5では、研磨する工程での研磨用組成物の砥粒濃度を1000ppmw、TOC濃度を167ppmwとしたこと以外は実施例2と同様の手順で、比較例1で加工したのと同様のウェーハを加工した。
(Example 5)
In Example 5, the same wafer as that processed in Comparative Example 1 by the same procedure as in Example 2 except that the abrasive grain concentration of the polishing composition in the polishing step was 1000 ppmw and the TOC concentration was 167 ppmw. Was processed.
 実施例5では、コロイダルシリカと、ポリビニルアルコールと、ポリオキシエチレン-ポリオキシプロピレンブロック共重合体とを、重量比1000:150:17で、純水に投入し、実施例5の研磨用組成物を得た。 In Example 5, colloidal silica, polyvinyl alcohol, and a polyoxyethylene-polyoxypropylene block copolymer were added to pure water at a weight ratio of 1000: 150: 17, and the polishing composition of Example 5 was added. Got
 以下の表1に、各実施例及び比較例についての、研磨用組成物の砥粒濃度、TOC濃度(全有機体炭素濃度)、及びTOC濃度に対する砥粒濃度、並びにエッチング量を示す。 Table 1 below shows the abrasive grain concentration, the TOC concentration (total organic carbon concentration), the abrasive grain concentration with respect to the TOC concentration, and the etching amount for each Example and Comparative Example.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
 [評価]
 実施例及び比較例のエッチングする工程後の各ウェーハに対し、KLA株式会社製のSurfscanシリーズSP3にて評価を実施し、LLS欠陥を評価した。その結果を以下の表2及び図2に示す。
[evaluation]
Each wafer after the etching process of Examples and Comparative Examples was evaluated by Surfscan series SP3 manufactured by KLA Corporation, and LLS defects were evaluated. The results are shown in Table 2 and FIG. 2 below.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
 表2及び図2に示した結果、並びに表1に示した情報から、研磨用組成物中の全有機体炭素の濃度(ppmw)に対する砥粒の濃度(ppmw)の比が30以下のものである実施例1~5の研磨用組成物を用いた実施例1~5は、上記比が30を超えた比較例1の研磨用組成物を用いた比較例1よりも良好な欠陥レベルを達成できたことが分かる。 From the results shown in Table 2 and FIG. 2 and the information shown in Table 1, the ratio of the concentration of abrasive grains (ppmw) to the concentration of total organic carbon (ppmw) in the polishing composition is 30 or less. Examples 1 to 5 using the polishing compositions of Examples 1 to 5 achieved better defect levels than Comparative Example 1 using the polishing composition of Comparative Example 1 in which the ratio exceeded 30. You can see that it was done.
 また、図1に示した2つのSEM像において、白く見えている部分が砥粒である。この図1に示した2つのSEM像の比較からも明らかなように、実施例2で研磨する工程後に得られたウェーハの表面に残留していた砥粒の量は、0.42pcs/μmであり、比較例1において残留砥粒量である8.5pcs/μmよりも格段に少なかった。実施例1、3~5における残留砥粒量も、実施例2と同程度であった。すなわち、研磨用組成物中の全有機体炭素の濃度(ppmw)に対する砥粒の濃度(ppmw)の比が30以下のものである実施例1~5の研磨用組成物を用いることにより、上記比が30を超えていた比較例1の研磨組成物を用いた場合よりも、研磨後のウェーハ上に残留する砥粒の量を減らすことができたことが分かる。この作用が、表2及び図2に示した欠陥数の差の結果に結びついたと考えられる。 Further, in the two SEM images shown in FIG. 1, the portion that looks white is the abrasive grain. As is clear from the comparison of the two SEM images shown in FIG. 1, the amount of abrasive grains remaining on the surface of the wafer obtained after the polishing step in Example 2 is 0.42 pcs / μm 2 . In Comparative Example 1, the amount of residual abrasive grains was 8.5 pcs / μm 2 , which was significantly smaller than that of 8.5 pcs / μm 2. The amount of residual abrasive grains in Examples 1 and 3 to 5 was also about the same as in Example 2. That is, by using the polishing compositions of Examples 1 to 5, wherein the ratio of the concentration (ppmw) of the abrasive grains to the concentration (ppmw) of the total organic carbon in the polishing composition is 30 or less. It can be seen that the amount of abrasive grains remaining on the polished wafer could be reduced as compared with the case of using the polishing composition of Comparative Example 1 having a ratio of more than 30. It is considered that this effect led to the result of the difference in the number of defects shown in Table 2 and FIG.
 また、実施例1と実施例2~5との比較から、本発明の研磨用組成物を用い、なおかつエッチングする工程における総エッチング量を5nm以下にした実施例2~5は、総エッチング量を5nmよりも大きくした実施例1よりも更に良好な欠陥レベルを達成できたことが分かる。 Further, from the comparison between Examples 1 and Examples 2 to 5, in Examples 2 to 5 in which the polishing composition of the present invention was used and the total etching amount in the etching step was 5 nm or less, the total etching amount was determined. It can be seen that a better defect level could be achieved than in Example 1 having a size larger than 5 nm.
 なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。 The present invention is not limited to the above embodiment. The above-described embodiment is an example, and the present invention can be anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. Is included in the technical scope of.

Claims (4)

  1.  研磨用組成物であって、
     砥粒と、
     水溶性高分子及び界面活性剤の少なくとも1種と
    を含み、
     前記研磨用組成物中の全有機体炭素の濃度(ppmw)に対する前記砥粒の濃度(ppmw)の比が30以下のものであることを特徴とする研磨用組成物。
    A polishing composition
    Abrasive grains and
    Containing at least one of a water-soluble polymer and a surfactant,
    A polishing composition, wherein the ratio of the concentration (ppmw) of the abrasive grains to the concentration (ppmw) of total organic carbon in the polishing composition is 30 or less.
  2.  ウェーハの加工方法であって、
     前記ウェーハの両面又は片面を、請求項1に記載の研磨用組成物を用いて研磨する工程と、
     O及びHの少なくとも1種を含む薬液により研磨後の前記ウェーハ上の有機物を分解する工程と、
     NH及びHFの少なくとも1種を含む薬液により研磨後のウェーハをエッチングする工程と
    を含み、
     前記エッチングする工程を、総エッチング量が5nm以下となるように行うことを特徴とするウェーハの加工方法。
    Wafer processing method
    A step of polishing both sides or one side of the wafer using the polishing composition according to claim 1.
    A step of decomposing an organic substance on the wafer after polishing with a chemical solution containing at least one of O 3 and H 2 O 2 .
    Including a step of etching a wafer after polishing with a chemical solution containing at least one of NH 3 and HF.
    A method for processing a wafer, wherein the etching step is performed so that the total etching amount is 5 nm or less.
  3.  前記研磨する工程を、研磨後の前記ウェーハの表面上の砥粒付着量が5個/μm以下となるように行うことを特徴とする請求項2に記載のウェーハの加工方法。 The wafer processing method according to claim 2, wherein the polishing step is performed so that the amount of abrasive grains adhered on the surface of the wafer after polishing is 5 pieces / μm 2 or less.
  4.  研磨用組成物を用いて研磨されたシリコンウェーハであって、研磨後の表面上の砥粒付着量が5個/μm以下のものであることを特徴とするシリコンウェーハ。 A silicon wafer polished using a polishing composition, wherein the amount of abrasive grains adhered on the surface after polishing is 5 pieces / μm 2 or less.
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WO2007046420A1 (en) * 2005-10-19 2007-04-26 Hitachi Chemical Co., Ltd. Cerium oxide slurry, cerium oxide polishing liquid, and method for polishing substrate by using those
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JP2019145750A (en) * 2018-02-23 2019-08-29 株式会社Sumco Single-side polishing method of wafer

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JP2001053050A (en) * 1999-06-01 2001-02-23 Komatsu Electronic Metals Co Ltd Cleaning of semiconductor substrate
WO2007046420A1 (en) * 2005-10-19 2007-04-26 Hitachi Chemical Co., Ltd. Cerium oxide slurry, cerium oxide polishing liquid, and method for polishing substrate by using those
WO2013161701A1 (en) * 2012-04-26 2013-10-31 株式会社 フジミインコーポレーテッド Method for manufacturing polishing composition
WO2016158328A1 (en) * 2015-04-01 2016-10-06 三井金属鉱業株式会社 Abrasive, and abrasive slurry
WO2017126268A1 (en) * 2016-01-19 2017-07-27 株式会社フジミインコーポレーテッド Polishing composition and method for polishing silicon substrate
JP2019145750A (en) * 2018-02-23 2019-08-29 株式会社Sumco Single-side polishing method of wafer

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