JP5437571B2 - Polishing fluid kit - Google Patents

Description

  The present invention relates to a polishing liquid kit, a polishing liquid composition prepared using the polishing liquid kit, and a method for producing a substrate using the polishing liquid composition.

  Recent memory hard disk drives are required to reduce the flying height of the magnetic head to reduce the unit recording area in order to increase the recording density for the purpose of increasing the capacity and reducing the diameter. Along with this, the surface quality required after polishing in the manufacturing process of the magnetic disk substrate is becoming stricter year by year. That is, it is necessary to reduce the surface roughness, micro waviness, roll-off and protrusions according to the low flying height of the head, and according to the decrease in the unit recording area, the allowable number of scratches per one side of the substrate is small, Its size and depth are getting smaller and smaller.

  Also in the semiconductor field, high integration and high speed are advancing. In particular, miniaturization of wiring is required for high integration. As a result, in the manufacturing process of a semiconductor substrate, the depth of focus when exposing a photoresist becomes shallow, and further surface smoothness is desired.

  However, when the silica particle dispersion used for substrate production is stored in a container for a long time, coarse particles and the like may be generated by evaporation and drying of water from silica dispersion droplets adhering to the inner wall of the container. It was. The coarse particles or the like cause polishing scratches such as scratches generated when the object to be polished is polished.

In order to solve this problem of polishing scratches, an aqueous dispersion for chemical mechanical polishing that suppresses the generation of coarse particles using an amphiphilic compound such as an aliphatic alcohol has been proposed (Patent Document 1). Further, from the viewpoint of improving the polishing rate, surface smoothness, and substrate contamination, a polishing liquid composition using a polymer having a sulfonic acid group has been proposed (Patent Documents 2 and 3).
JP 2001-102334 A JP 2001-64631 A JP 2006-167817 A

  However, in the above-described conventional technology, the silica particles are aggregated or grown due to the transport conditions and storage conditions of the silica particle dispersion, and coarse particles are formed, and scratches are generated during substrate polishing.

  Therefore, the present invention is a polishing liquid kit that can suppress the generation of coarse silica particles and reduce scratches on the object to be polished, regardless of the transportation conditions and storage conditions of the silica particle dispersion, and is adjusted using this polishing liquid kit. A polishing liquid composition and a method for producing a substrate using the polishing liquid composition are provided.

  The polishing liquid kit of the present invention is a polishing liquid kit comprising a silica particle dispersion and an acid and / or salt thereof, wherein the silica particle dispersion and the acid and / or salt thereof are mixed with each other. The silica particle dispersion is selected from the group consisting of silica particles, sulfonic acid group-containing monomers, (meth) acrylic acid / sulfonic acid (co) polymers, and salts thereof. At least one selected from the group consisting of water and the sulfonic acid group-containing monomer, isoprenesulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid, methallylsulfonic acid, It is at least one selected from the group consisting of vinyl sulfonic acid, allyl sulfonic acid and isoamylene sulfonic acid, and the weight average molecular weight of the (co) polymer and its salt is 50 A ～7000, and said (co) polymer and the content of the constituent unit derived from a sulfonic acid group-containing monomer in the total structural units constituting the salt thereof is 15 to 100 mol%.

  The polishing liquid composition of the present invention is prepared using the polishing liquid kit of the present invention.

  The polishing liquid composition of the present invention comprises silica particles, an acid and / or a salt thereof, a sulfonic acid group-containing monomer, a (meth) acrylic acid / sulfonic acid (co) polymer, and a salt thereof. At least one selected from the group and water, and the sulfonic acid group-containing monomer is isoprenesulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid, meta It is at least one selected from the group consisting of yl sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid and isoamylene sulfonic acid, and the weight average molecular weight of the (co) polymer and its salt is 500 to 7000, And the content rate of the structural unit derived from the sulfonic acid group containing monomer in all the structural units which comprise the said (co) polymer and its salt is 15-100 mol%.

  The manufacturing method of the board | substrate of this invention includes the process of grind | polishing a to-be-polished board | substrate using the polishing liquid composition of the said invention.

  According to the polishing liquid kit of the present invention, since the aggregation or growth of silica particles can be effectively suppressed, the silica particle dispersion can be stored for a long period of time. In addition, the polishing composition of the present invention can be used to reduce scratches by using, for example, a precision component substrate polishing step for high density or high integration, and a high-quality magnetic disk substrate having excellent surface properties, Precision component substrates such as semiconductor element substrates can be manufactured. Moreover, according to the manufacturing method of the board | substrate of this invention, since the polishing liquid composition of this invention is used, the high quality board | substrate excellent in surface property can be manufactured.

  The polishing liquid kit of the present invention comprises a silica particle dispersion (hereinafter sometimes abbreviated as “dispersion”) and an acid and / or a salt thereof. The silica particle dispersion and the acid and / or salt thereof are each stored in a state where they are not mixed with each other. The silica particle dispersion is at least one selected from the group consisting of sulfonic acid group-containing monomers (monomers having sulfonic acid groups), (meth) acrylic acid / sulfonic acid (co) polymers, and salts thereof. Contains seeds and water. The (co) polymer and its salt have a weight average molecular weight of 500 to 7000, and are derived from a sulfonic acid group-containing monomer in all the structural units constituting each of the (co) polymer and its salt. The content rate of a unit is 15-100 mol%. According to the present invention, the generation of coarse particles in the dispersion can be suppressed by including at least one selected from the group consisting of the sulfonic acid-containing monomer, the (co) polymer, and salts thereof. .

  Although the suppression mechanism for the generation of coarse particles is not clear, at least selected from the group consisting of the sulfonic acid group-containing monomer, (meth) acrylic acid / sulfonic acid (co) polymer, and salts thereof in the dispersion. One type and the silanol group of the silica particles interact to suppress contact between the silica particles, thereby suppressing aggregation and / or growth of the silica particles and suppressing generation of coarse particles. .

  According to the polishing liquid kit of the present invention, it is possible to reduce scratches on an object to be polished, particularly nano scratches, even after polishing after long-term storage. Further, according to the polishing liquid kit of the present invention, since the generation of coarse particles in the dispersion liquid is suppressed, the dispersion liquid is kept at a high temperature of 40 ° C. or higher for a long period of time, for example, during the summer season or during transportation. Even when held, it exhibits excellent storage stability.

  The “nano scratch” is a fine scratch on the substrate surface having a depth of 1 nm to less than 50 nm, a width of 5 nm to less than 500 nm, and a length of 100 μm or more, and is detected by an atomic force microscope (AFM). The number can be measured by “MicroMax” manufactured by VISIONPSYTEC, which is a visual inspection apparatus described in the examples described later.

  In the present invention, the silica particle dispersion contains water and silica particles dispersed in water. Examples of the silica particles include colloidal silica and fumed silica. Among these, colloidal silica is preferable from the viewpoint of reducing nanoscratches. These silica particles may be used alone or in combination of two or more.

  Colloidal silica is, for example, a water glass method in which alkali metal silicates such as sodium silicate are used as raw materials, and a condensation reaction is carried out in an aqueous solution to grow particles, or alkoxysilanes such as tetraethoxysilane are used as raw materials, and water-soluble such as alcohol It is obtained by an alkoxysilane method or the like which is grown by condensation reaction in water containing an organic solvent.

  Fumed silica is obtained, for example, by a vapor phase method in which a volatile silicon compound such as silicon tetrachloride is used as a raw material and is hydrolyzed and grown at a high temperature of 1000 ° C. or higher with an oxygen hydrogen burner.

  In addition, silica particles that are surface-modified or surface-modified with functional groups, those that are compounded with surfactants or other particles, and the like can also be used as silica particles.

  The average particle diameter of the primary particles of the silica particles is the viewpoint of effectively suppressing the aggregation and / or growth of the silica particles and the surface roughness of the object to be polished (center line average roughness: Ra, Peak to Valley value: Rmax). From the viewpoint of reducing the thickness, it is preferably 1 to 50 nm. At the same time, from the viewpoint of improving the polishing rate, it is more preferably 3 to 50 nm, still more preferably 5 to 40 nm, and even more preferably 5 to 30 nm. If the silica particles have a small particle size, specifically, the particle size is 30 nm or less, the reason is not clear, but coarse particles are likely to be generated in the dispersion, so the average particle size of the primary particles of the silica particles. When the diameter is 30 nm or less, the dispersion contains at least one selected from the group consisting of the above sulfonic acid group-containing monomer, (meth) acrylic acid / sulfonic acid (co) polymer, and salts thereof. As a result, the generation of coarse particles can be suppressed, but the polishing rate can be improved.

  In addition, the average particle diameter of the primary particle of a silica particle can be calculated | required as an average particle diameter when it measures by the method calculated | required from the observation image with a transmission electron microscope (TEM). Specifically, a photograph obtained by observing silica particles with a transmission electron microscope (JEM-2000FX, manufacturer: JEOL) under the conditions of an acceleration voltage of 80 kV and a photographing magnification of 1 to 50,000 times is captured as image data by a scanner. Using the image analysis software (WinROOF, distributor: Mitani Shoji), the equivalent circle diameter of each silica particle (the diameter of the circle having the same area as the image area of the silica particle) is regarded as the diameter of the silica particle, 1000 After accumulating data on equivalent circle diameters of one or more silica particles, the primary particle size (D50) with a cumulative volume from the small particle size side of 50% is calculated with spreadsheet software “EXCEL” (manufactured by Microsoft). The average particle size is calculated. The photographing magnification is appropriately selected according to the size of the silica particles.

  The content of the silica particles in the silica particle dispersion is 0.1 to 0.1% from the viewpoint of aggregation and / or growth suppression of the silica particles, the viewpoint of reducing the surface roughness of the object to be polished, and the economical efficiency. 50 weight% is preferable, 1-45 weight% is more preferable, and 5-40 weight% is further more preferable.

  The silica particle dispersion contains at least one selected from the group consisting of sulfonic acid group-containing monomers, (meth) acrylic acid / sulfonic acid (co) polymers, and salts thereof.

  Examples of the sulfonic acid group-containing monomer include isoprene sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, styrene sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, and isoamylene. A sulfonic acid etc. are mentioned. Of these, isoprenesulfonic acid and 2- (meth) acrylamide-2-methylpropanesulfonic acid are preferable from the viewpoint of aggregation of silica particles and / or suppression of growth.

  The (meth) acrylic acid / sulfonic acid (co) polymer in the present invention is a copolymer containing a structural unit derived from (meth) acrylic acid and a structural unit derived from a sulfonic acid group-containing monomer, and contains a sulfonic acid group It contains at least one selected from the group consisting of homopolymers containing structural units derived from monomers. The (meth) acrylic acid / sulfonic acid (co) polymer may contain one or more structural units derived from the sulfonic acid group-containing monomer.

  Further, the (meth) acrylic acid / sulfonic acid (co) polymer in the present invention is a single amount other than the sulfonic acid group-containing monomer and the (meth) acrylic acid monomer within the scope of the effects of the present invention. The structural unit component derived from the body may be contained. In this specification, (meth) acrylic acid refers to acrylic acid or methacrylic acid, and 2- (meth) acrylamido-2-methylpropanesulfonic acid refers to 2-acrylamido-2-methylpropanesulfonic acid or 2- Refers to methacrylamide-2-methylpropane sulfonic acid.

  The content of the structural unit derived from the sulfonic acid group-containing monomer in all the structural units constituting each of the (meth) acrylic acid / sulfonic acid (co) polymer or salt thereof is the silica particles during transportation and storage. From the viewpoint of effectively suppressing the generation of coarse particles in the dispersion and from the viewpoint of effectively reducing nanoscratches, it is from 15 to 100 mol%, more preferably from 40 to 100 mol%, still more preferably from 50 to 100. Mol%. Here, the (meth) acrylic acid monomer containing a sulfonic acid group is counted as a sulfonic acid group-containing monomer.

  As a preferable (meth) acrylic acid / sulfonic acid (co) polymer from the viewpoint of effectively suppressing the generation of coarse particles in the silica particle dispersion during transportation and storage, and from the viewpoint of effectively reducing nanoscratches Are, for example, (meth) acrylic acid / isoprenesulfonic acid (co) polymer, (meth) acrylic acid / 2- (meth) acrylamido-2-methylpropanesulfonic acid (co) polymer, (meth) acrylic acid / And isoprenesulfonic acid / 2- (meth) acrylamide-2-methylpropanesulfonic acid (co) polymer.

  The weight average molecular weight of the (meth) acrylic acid / sulfonic acid (co) polymer and its salt is the viewpoint of suppressing the generation of coarse particles in the silica particle dispersion during transportation and storage, and the viewpoint of reducing nanoscratches From 500 to 7000, 500 to 6000 is more preferable, 500 to 5000 is more preferable, 500 to 3000 is still more preferable, and 500 to 1900 is even more preferable.

  The weight average molecular weight of the (meth) acrylic acid / sulfonic acid (co) polymer and its salt was measured by gel permeation chromatography (GPC), and a calibration curve prepared using sodium polystyrene sulfonate as a standard sample. Convert using. The GPC conditions are shown below.

[GPC conditions]
Column: G4000PWXL (manufactured by Tosoh Corporation) + G2500PWXL (manufactured by Tosoh Corporation)
Eluent: 0.2M phosphate buffer / acetonitrile = 9/1 (volume ratio)
Flow rate: 1.0 mL / min
Temperature: 40 ° C
Detection: 210nm
Sample: concentration 5 mg / mL (injection volume 100 μL)

  Further, from the viewpoint of improving the substrate contamination and reducing the surface roughness, the (meth) acrylic acid / sulfonic acid (co) polymer having a content of the structural unit derived from the sulfonic acid group-containing monomer of less than 15 mol% and / or Or it is preferable to further contain 0.001% by weight or more thereof, more preferably 0.01% by weight or more, and from the viewpoint of improving the polishing rate, the content is 10% by weight or less. Is preferably 5% by weight or less, more preferably 3% by weight or less, still more preferably 1% by weight or less, and even more preferably 0.5% by weight or less. That is, from the viewpoint of improving substrate contamination, reducing the surface roughness, and improving the polishing rate, the content is preferably 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, 0.01 to 3% by weight is more preferred, 0.01 to 1% by weight is even more preferred, and 0.01 to 0.5% by weight is even more preferred. A polishing liquid kit containing a (meth) acrylic acid / sulfonic acid (co) polymer and / or a salt thereof having a content of a structural unit derived from a sulfonic acid group-containing monomer of less than 15 mol% is such that the object to be polished is glass It is suitably used when it is a substrate or a silicon wafer substrate.

  The sulfonic acid group-containing monomer (meth) acrylic acid / sulfonic acid (co) polymer is preferably water-soluble and a salt thereof in order to be a constituent of the polishing composition. Is preferred.

  Although the counter ion for forming the said salt is not specifically limited, 1 or more types can be used from ion of alkali metals, such as sodium and potassium, ammonium ion, alkylammonium ion, etc.

  The (meth) acrylic acid / sulfonic acid (co) polymer used in the present invention is obtained by, for example, using a base polymer containing a diene structure or an aromatic structure by a known method, for example, edited by The Chemical Society of Japan, a new experiment. It is obtained by sulfonation by the method described in Chemical Lecture 14 (Synthesis and Reaction of Organic Compounds III, 1773, 1978).

  The content of at least one selected from the group consisting of a sulfonic acid group-containing monomer, a (meth) acrylic acid / sulfonic acid (co) polymer, and a salt thereof in the silica particle dispersion is during transportation and storage. From the viewpoint of suppressing the generation of coarse particles in the silica particle dispersion and from the viewpoint of reducing nanoscratches, the content is preferably 0.0001 to 10% by weight, more preferably 0.001 to 5% by weight, and still more preferably 0. 0.005 to 1% by weight.

  Further, a group consisting of silica particles, a sulfonic acid group-containing monomer, a (meth) acrylic acid / sulfonic acid (co) polymer, and salts thereof in a silica particle dispersion and a polishing liquid composition described later. Concentration ratio with at least one selected from [Concentration of silica particles (% by weight) / Sulphonic acid group-containing monomer, (meth) acrylic acid / sulfonic acid (co) polymer, and salts thereof The at least one concentration (% by weight)] is preferably from 10 to 100,000, more preferably from 100 to 80,000, more preferably from the viewpoint of suppressing aggregation and / or growth of silica particles and improving economy. 60,000 is more preferable.

  Examples of water used in the silica particle dispersion and the polishing composition described later include distilled water, ion exchange water, and ultrapure water. From the viewpoint of the surface cleanliness of the substrate to be polished, ion-exchanged water and ultrapure water are preferable, and ultrapure water is particularly preferable. The content of water in the silica particle dispersion is preferably 50 to 95% by weight, and more preferably 55 to 90% by weight. The content of water in the polishing composition described later is preferably 55 to 99% by weight, and more preferably 60 to 95% by weight. Moreover, you may mix | blend organic solvents, such as alcohol, in the range which does not inhibit the effect of this invention.

  The pH of the silica particle dispersion is preferably away from the isoelectric point of the silica particles from the viewpoint of improving the dispersion stability of the silica particles and reducing nanoscratches. For example, since the isoelectric point of colloidal silica is 1 to 4, the pH during storage is preferably 7 or more, more preferably 8 or more, still more preferably 8.5 or more, and even more preferably 9 or more. . Moreover, from a viewpoint of improving the solubility of colloidal silica, 12 or less is preferable, More preferably, it is 11 or less, More preferably, it is 10.5 or less. The pH can be adjusted with, for example, sodium hydroxide, potassium hydroxide, ammonia or the like.

  From the viewpoint of reducing nanoscratches, the content of coarse particles in the silica particle dispersion is preferably less than 50000 in 1 mL of the silica particle dispersion, more preferably 40000 or less, still more preferably 30000 or less, and even more preferably. The number is 25000 or less, and more preferably 20000 or less.

  In the present invention, the coarse particles are coarse particles having a particle size of 0.56 μm or more, and include not only primary particles but also secondary particles in which primary particles are aggregated. The particle size and the number of coarse particles in the dispersion can be measured by a number counting method (Sizing Particle Optical Sensing method), specifically, “Accumizer” manufactured by Particle Sizing Systems, USA. 780 ".

  The storage temperature of the silica particle dispersion is preferably 5 to 50 ° C., more preferably 10 to 40 ° C., and further preferably 15 to 30 ° C. from the viewpoint of aggregation and / or growth prevention of silica particles.

  The silica particle dispersion is stored in a container, and examples of the container for storing the silica particle dispersion include a bag-in-box, a can, a drum, and a container. Among these, from the viewpoint of preventing aggregation and / or growth of silica particles due to elution of metal ions, the material of the wall surface portion in contact with the silica particle dispersion in the container is preferably an organic polymer. Furthermore, it is more preferable that the material is polyethylene, polypropylene, or poly (tetrafluoroethylene) from the viewpoint of reducing the remaining adhesion of the dispersion.

  From the viewpoint of suppressing aggregation and / or growth of silica particles, the organic polymer preferably has a content of an additive having a melting point of 60 ° C. or less of 500 ppm by weight or less. When the dispersion is stored in the container, an additive such as an antioxidant is eluted from the organic polymer material constituting the inner wall of the container into the dispersion, and the silica particles in the dispersion are based on the eluted additive. Is considered to aggregate and / or grow, but if the additive content is 500 ppm by weight or less, the amount of additive eluting into the dispersion can be reduced, so that the generation of coarse particles in the dispersion is suppressed. be able to. In order to more effectively suppress the generation of coarse particles, the additive content is preferably 400 ppm by weight or less, more preferably 300 ppm by weight or less, and even more preferably 100 ppm by weight or less. Even more preferably, the additive is not contained. Moreover, in order to suppress generation | occurrence | production of a coarse particle more effectively, it is preferable that content of the additive whose melting | fusing point in organic polymer material is 5-60 degreeC is 500 weight ppm or less, and melting | fusing point is 25-60. It is more preferable that the content of the additive at 5 ° C. is 500 ppm by weight or less, and it is further preferable that the content of the additive having a melting point of 40-60 ° C. is 500 ppm by weight or less. In addition, content of the additive in organic polymer material can be measured with the following measuring methods.

  First, the organic polymer material is dissolved in xylene heated to 100 ° C. Subsequently, this solution is dropped into ethanol to recrystallize the polymer component. At this time, the additive is dissolved in ethanol. Next, after removing the recrystallized product by filtration, ethanol is evaporated by an evaporator. The concentrated additive solution is analyzed by gas chromatography, and the additive content is calculated from the peak area.

  Examples of the additive include an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, a dye, a nucleating agent, a filler, a lubricant, a flame retardant, and a plasticizer. Among these, antioxidants are likely to become the starting point for crystal growth of silica particles, and phenolic antioxidants are more likely to become the starting point for crystal growth.

  The polishing liquid kit of the present invention contains an acid and / or a salt thereof as a constituent component from the viewpoint of improving the polishing rate and reducing nanoscratches. Examples of acids and / or salts thereof include inorganic acids such as nitric acid, sulfuric acid, nitrous acid, persulfuric acid, hydrochloric acid, perchloric acid, phosphoric acid, phosphonic acid, phosphinic acid, pyrophosphoric acid, tripolyphosphoric acid, amidosulfuric acid, and the like. 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), ethane-1,1 -Diphosphonic acid, ethane-1,1,2-triphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid, ethane-1,2-di Carboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid , 1-phosphonobutane-2,3,4-tricarboxylic acid, organic phosphonic acids such as α-methylphosphonosuccinic acid or salts thereof; aminocarboxylic acids such as glutamic acid, picolinic acid, aspartic acid or salts thereof; oxalic acid , Carboxylic acids such as nitroacetic acid, maleic acid, oxaloacetic acid or salts thereof. Among these, inorganic acids and / or organic phosphonic acids and salts thereof are preferable from the viewpoint of reducing nanoscratches.

  Of the inorganic acids and / or their salts, nitric acid, sulfuric acid, hydrochloric acid, perchloric acid or their salts are more preferred. Among the organic phosphonic acids or their salts, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) or their salts are More preferred. These acids or their salts may be used alone or in admixture of two or more.

  The counter ion (cation) constituting these salts is not particularly limited, and examples thereof include metal ions, ammonium ions, alkylammonium ions, and the like. Examples of the metal ions include ions of metals belonging to groups 1A, 1B, 2A, 2B, 3A, 3B, 4A, 6A, 7A, or 8 of the periodic table (long-period type). From the viewpoint of reducing nanoscratches, the counter ion is preferably an ammonium ion or a metal ion belonging to Group 1A.

  In the polishing liquid kit, the acid and / or salt thereof may be in a state where it is not mixed with the silica particle dispersion liquid, and is a container separate from the container in which the silica particle dispersion liquid is put before use. It is preferable to store in a container with

  The polishing liquid composition of the present invention is prepared using the above-described polishing liquid kit of the present invention. That is, the polishing liquid composition of the present invention is prepared by mixing the above-described silica particle dispersion and an acid and / or a salt thereof. That is, the polishing composition of the present invention is prepared by mixing the above-described silica particle dispersion and acid and / or a salt thereof to adjust to a desired pH. This can reduce scratches, especially nano scratches, on the object to be polished even after polishing after long-term storage.

  The method for preparing the polishing composition is not particularly limited, but from the viewpoint of enhancing the dispersion stability of the silica particles, the acid and / or salt thereof is dissolved in water, and then the silica particle dispersion is added to the aqueous solution. It is preferable to mix these. Furthermore, when mixing the silica particle dispersion, it is preferable to mix at a speed at which the silica particles do not dry from the viewpoint of preventing aggregation due to drying of the silica particles. In addition, when mixing the silica particle dispersion, from the viewpoint of enhancing the dispersibility of the silica particles, the silica particle dispersion is added thereto while stirring the aqueous solution in which the components other than the silica particles are dissolved. It is preferable to mix.

  The pH of the polishing composition is determined according to the type of the object to be polished and the required characteristics. When the material of the object to be polished is a metal material, it is preferably 4 or less from the viewpoint of improving the polishing rate. More preferably, it is 3 or less, More preferably, it is 2 or less. Further, from the viewpoint of preventing adverse effects on the human body and corrosion of the polishing apparatus, the pH is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1 or more. In particular, in the case of an aluminum alloy substrate plated with Ni—P (nickel-phosphorus), the pH is preferably 0.1 to 4, more preferably 0.5 to 3, and even more preferably 1 in consideration of the above viewpoint. ~ 2.

  A general dispersion or particle removal method can be used for the purpose of efficiently and economically removing coarse particles contained in the silica particle dispersion during or after the production of the polishing composition. For example, a dispersion method using a high-pressure dispersion device such as a high-speed dispersion device or a high-pressure homogenizer, a sedimentation method using a centrifugal separator or the like, or a filtration method such as microfiltration or ultrafiltration using a filter medium can be used. When processing using these, you may process individually or in combination of 2 or more types, and there is no restriction | limiting also about the order of a combination. Also, the processing conditions and the number of processing can be appropriately selected and used according to the method.

  Among these methods, microfiltration using a filter that makes it possible to remove coarse particles contained in the polishing liquid composition more efficiently and more economically is preferable.

  A depth type filter or a pleat type filter can be used as a filtering material for microfiltration. As the depth type filter, in addition to a bag type filter (manufactured by Sumitomo 3M Co., Ltd.), a cartridge type filter (manufactured by Advantech Toyo Co., Ltd., Nippon Pole Co., CUNO Co., Ltd., Daiwabo Co., Ltd.) can be used.

  The depth type filter is characterized in that the pore structure of the filter medium is rough at the inlet, finer at the outlet side, and finer continuously or stepwise from the inlet side toward the outlet side. That is, among coarse particles, large particles are collected near the inlet side, and small particles are collected near the outlet side. Further, coarse particles are easily removed because they are collected in multiple stages in the thickness direction of the filter. The shape of the depth filter may be a bag-like bag type or a hollow cylindrical cartridge type.

  A pleated filter is a hollow cylindrical cartridge type formed by filtering a filtering material into a pleat shape. Unlike depth-type filters that collect in each part in the thickness direction, pleated filters are said to be mainly collected on the filter surface because the filter material is thin and generally has high filtration accuracy. It is a feature. In addition, as a filter medium, a filter having an intermediate structure between a depth type and a pleat type can also be used.

  The filtration method may be a circulation type that repeatedly filters or a one-pass method. Alternatively, a batch method that repeats the one-pass method may be used. As for the liquid passing method, in the case of pressurization, a pump is preferably used in the circulation method, and in addition to using a pump in the one-pass method, a pressure filtration method in which air pressure or the like is introduced into the tank can be used.

  By appropriately selecting the pore structure of the filter, the particle size of the coarse particles to be removed can be controlled. The filter system may be single-stage filtration or multistage filtration by combination. For multi-stage filtration, it is possible to control the particle size (filtration accuracy) of coarse particles to be removed by appropriately selecting the pore size of the filter and the structure of the filter medium, and further selecting the processing order of the filter. , Can improve economy. That is, if a filter having a large pore structure is used in the former stage and a fine filter is used in the latter stage, the life of the filter can be extended as a whole. In the structure of the filter medium, if a depth type is used at the front stage and a pleat type is used at the rear stage, the life of the filter can be extended as a whole.

  In the polishing composition, at least one content selected from the group consisting of a sulfonic acid group-containing monomer, a (meth) acrylic acid / sulfonic acid (co) polymer, and a salt thereof is silica. From the viewpoint of suppressing aggregation and / or growth of particles and improving economy, 0.0001 to 1% by weight is preferable, more preferably 0.0001 to 0.3% by weight, and still more preferably 0.001 to 0.001%. 0.1% by weight.

  The content of the silica particles in the polishing composition is preferably 0.5% by weight or more, more preferably 1% by weight or more, further preferably 3% by weight or more, and still more preferably from the viewpoint of improving the polishing rate. 5% by weight or more. Further, from the viewpoint of economically improving the surface quality, it is preferably 20% by weight or less, more preferably 15% by weight or less, still more preferably 13% by weight or less, and even more preferably 10% by weight or less. Therefore, from the viewpoint of improving the polishing rate and economically improving the surface quality, the content is preferably 0.5 to 20% by weight, more preferably 1 to 15% by weight, and still more preferably 3 to 13%. % By weight, still more preferably 5-10% by weight.

  It is preferable that the polishing composition further contains an oxidizing agent. Examples of the oxidizing agent include peroxides, metal peroxo acids or salts thereof, oxygen acids or salts thereof, and the like. In addition, the oxidizing agent is roughly classified into an inorganic oxidizing agent and an organic oxidizing agent, which can further improve the polishing rate, is easily available, and can be easily handled such as solubility in water. Therefore, an inorganic oxidizing agent is preferable.

  Examples of the inorganic oxidant include hydrogen peroxide, alkali metal or alkaline earth metal peroxide, peroxocarbonate, peroxosulfuric acid or salt thereof, peroxophosphoric acid or salt thereof, peroxoborate, peroxochromate, Examples thereof include permanganates, halogen-containing oxyacid salts, and inorganic acid metal salts.

  Examples of the alkali metal or alkaline earth metal peroxide include sodium peroxide, potassium peroxide, calcium peroxide, barium peroxide, and magnesium peroxide. Examples of the peroxocarbonate include sodium peroxocarbonate and potassium peroxocarbonate. Examples of peroxosulfuric acid or a salt thereof include ammonium peroxodisulfate, sodium peroxodisulfate, potassium peroxodisulfate, and peroxomonosulfuric acid. Examples of peroxophosphoric acid or a salt thereof include sodium peroxophosphate, potassium peroxophosphate, and ammonium peroxophosphate. Examples of peroxoborate include sodium peroxoborate and potassium peroxoborate. Examples of the peroxochromate include sodium peroxochromate and potassium peroxochromate. Examples of permanganate include sodium permanganate and potassium permanganate. Examples of the oxyacid salt containing halogen include sodium perchlorate, potassium perchlorate, sodium hypochlorite, sodium periodate, potassium periodate, sodium iodate, and potassium iodate. Examples of inorganic acid metal salts include iron (III) chloride and iron (III) sulfate.

  Examples of the organic oxidant include percarboxylic acids, peroxides, and organic acid iron (III) salts. Examples of the percarboxylic acids include peracetic acid, performic acid, perbenzoic acid, and the like. Examples of the peroxide include t-butyl peroxide and cumene peroxide. The organic acid iron (III ) Examples of the salt include iron (III) citrate.

  Among these, hydrogen peroxide, sodium peroxoborate, sodium iodate, and potassium iodate are preferable from the viewpoint of improving the polishing rate. These oxidizing agents may be used alone or in combination of two or more.

  The content of the oxidizing agent in the polishing liquid composition is preferably 0.01 to 20% by weight, more preferably 0.01 to 15% by weight, from the viewpoint of further reducing nanoscratches and improving the polishing rate. Preferably it is 0.01 to 10 weight%.

  The polishing liquid composition may further contain a bactericidal agent, an antibacterial agent, a thickener, a dispersant, a rust preventive agent, a basic substance, a surfactant, a pH adjuster, and the like. The content of these components in the polishing composition is 10% by weight from the viewpoint of improving polishing characteristics (for example, polishing rate, surface roughness of the object to be polished, surface waviness, roll-off (end face droop), etc.). The following is preferable, more preferably 8% by weight or less, and still more preferably 6% by weight or less.

  The polishing composition is suitable for the production of precision component substrates. For example, it is suitable for polishing precision component substrates such as magnetic disk substrates such as magnetic disks and magneto-optical disks, optical disks, photomask substrates, optical lenses, optical mirrors, optical prisms, and semiconductor substrates. Is preferred.

  Suitable materials for the object to be polished by the polishing composition include, for example, metals or metalloids such as silicon, aluminum, nickel, tungsten, copper, tantalum, and titanium, or alloys thereof; glass, glassy carbon, Examples thereof include glassy substances such as amorphous carbon; ceramic materials such as alumina, silicon dioxide, silicon nitride, tantalum nitride, and titanium carbide; resins such as polyimide resins. Among these, it is suitable for polishing an object to be polished containing a metal such as aluminum, nickel, tungsten, copper, or an alloy containing these metals as a main component, and an Ni-P plated aluminum alloy substrate or crystallized glass. It is more suitable for a glass substrate such as tempered glass, and more suitable for a Ni-P plated aluminum alloy substrate.

  There is no particular limitation on the shape of the object to be polished. For example, the above-mentioned polishing composition can be used for a shape having a flat portion such as a disk shape, a plate shape, a slab shape, a prism shape, or a shape having a curved surface portion such as a lens. A thing is used suitably. Among these, the polishing liquid composition is more suitable for polishing a disk-shaped workpiece.

  As described above, since the polishing liquid composition of the present invention is prepared using the polishing liquid set of the present invention, the polishing liquid composition of the present invention includes silica particles, an acid and / or a salt thereof, and a sulfone. And at least one selected from the group consisting of an acid group-containing monomer, a (meth) acrylic acid / sulfonic acid (co) polymer and salts thereof, and the sulfonic acid group-containing monomer. Is at least selected from the group consisting of isoprene sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, styrene sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid and isoamylene sulfonic acid 1 type, the weight average molecular weight of said (co) polymer and its salt is 500-7000, and all the structural units which comprise each of said (co) polymer and its salt Content of the constituent unit derived from a sulfonic acid group-containing monomer to total is 15 to 100 mol%.

  Therefore, the polishing composition of the present invention can reduce scratches, especially nano scratches, on the object to be polished even after polishing after long-term storage.

  Next, the manufacturing method of the board | substrate of this invention is demonstrated.

The manufacturing method of the board | substrate of this invention includes the process of grind | polishing a to-be-polished substrate (to-be-polished object) using the polishing liquid composition of this invention mentioned above. In the above step, for example, the substrate to be polished is sandwiched with a surface plate to which a polishing pad such as a nonwoven organic polymer polishing cloth is attached, and the polishing liquid composition is applied to the substrate to be polished with a polishing pressure of 3 to 50 kPa. The substrate to be polished is polished by moving at least one of the surface plate and the substrate to be polished while supplying at a supply rate of 0.05 to 15 mL / min per 1 cm ^{2 of} the surface to be polished.

  The polishing pressure refers to the pressure of the surface plate applied to the surface to be polished of the substrate to be polished during polishing. The polishing pressure is preferably 3 kPa or more, more preferably 4 kPa or more, further preferably 5 kPa or more, and even more preferably 5.5 kPa or more from the viewpoint of improving the polishing rate and economically polishing. In the polishing composition of the present invention, since the generation of coarse particles is suppressed, nanoscratches are hardly generated, and the substrate can be polished with a high polishing pressure. Further, from the viewpoint of improving the surface quality and relaxing the residual stress of the polished product, the polishing pressure is preferably 20 kPa or less, more preferably 18 kPa or less, and further preferably 16 kPa or less. Therefore, from the viewpoint of improving the polishing rate and surface quality, the polishing pressure in the production method of the present invention is preferably 3 to 20 kPa, more preferably 4 to 20 kPa, further preferably 5 to 18 kPa, and even more preferably 5.5 to 16 kPa. . The polishing pressure can be adjusted by applying air pressure or weight to at least one of the surface plate and the polishing object.

From the viewpoint of improving the polishing rate, the supply rate of the polishing composition is preferably 0.05 mL / min or more, more preferably 0.06 mL / min or more, more preferably 0.07 mL / min per 1 cm ^{2 of the} surface to be polished of the substrate to be polished. Minutes or more are more preferable, 0.08 mL / min or more is even more preferable, and 0.09 mL / min or more is even more preferable. From the viewpoint of improving surface quality and improving economic efficiency, the supply rate of the polishing liquid composition is preferably 15 mL / min or less, more preferably 10 mL / min or less, further preferably 5 mL / min or less, per 1 cm ^{2 of the} surface to be polished. 4 mL / min or less is even more preferable, and 3 mL / min or less is even more preferable. Therefore, from the viewpoint of achieving both improvement in polishing rate and improvement in surface quality, the supply rate of the polishing composition is preferably 0.05 to 15 mL / min per 1 cm ^{2 of the} surface to be polished of the substrate to be polished, 0.06 10 mL / min is more preferable, 0.07-5 mL / min is more preferable, 0.08-4 mL / min is still more preferable, and 0.09-3 mL / min is still more preferable.

  Examples of a method for supplying the polishing composition between the polishing pad and the substrate to be polished include a method in which the polishing composition is continuously supplied using a pump or the like. When supplying the polishing liquid composition between the polishing pad and the substrate to be polished, in addition to the method of supplying a single liquid containing all the components, considering the quality stability of the polishing liquid composition, for example, It can also be divided into a plurality of component liquids for blending and supplied in two or more liquids. In the latter case, for example, the plurality of compounding component liquids are mixed in the supply pipe or on the substrate to be polished to obtain the polishing liquid composition of the present invention.

  There is no restriction | limiting in particular as a polishing pad used by this invention, Polishing pads, such as a suede type, a nonwoven fabric type, a polyurethane independent foam type, or the two-layer type which laminated | stacked these, can be used.

  The substrate manufacturing method of the present invention is suitable for manufacturing a precision component substrate. In the manufacture of a semiconductor substrate, the polishing liquid of the present invention is used in a polishing process of a silicon wafer (bare wafer), a formation process of an embedded element isolation film, a planarization process of an interlayer insulating film, a formation process of an embedded metal wiring, a formation process of an embedded capacitor, etc. Compositions can be used. In the substrate manufacturing process, when there are a plurality of polishing processes, it is preferable that the polishing composition of the present invention is used in the second and subsequent processes, which significantly reduces nanoscratches and surface roughness, and has excellent surface smoothness. More preferably, it is used in the final polishing step from the viewpoint of obtaining the above. The finish polishing step refers to the last polishing step when there are a plurality of polishing steps.

Example 1
(Silica particle dispersion)
To a commercially available colloidal silica dispersion (manufactured by DuPont, average particle size of primary particles 16 nm, silica particle concentration 40 wt%, pH 9.5), 300 g of the AMPS / AA copolymer shown in the column of Example 1 in Table 1 ( 2-acrylamido-2-methylpropanesulfonic acid / acrylic acid copolymer, AMPS content 30 mol%, weight average molecular weight 1300, solid content concentration 40 wt%, sodium neutralized product) 0.03 g (0.01 wt. %) Was added with stirring, and then filtered through a 0.45 μm absolute filter (Advantech Toyo MCS-045-C10S) and placed in a polyethylene container (Fujimori Kogyo bag-in-box cubitner 15SC) to disperse silica particles. A liquid was obtained. When the number of coarse particles of 0.56 μm or more in 1 mL of this dispersion was measured under the following measurement conditions, it was 15000.

Next, the container containing the dispersion was placed in a thermostatic bath and stored at 60 ° C. for 72 hours. Next, the number of coarse particles in the silica particle dispersion after storage was similarly measured under the following measurement conditions. Then, the amount of increase in the number of coarse particles in the dispersion before and after storage was calculated from the following formula. The results are shown in Table 1.
Increase in number of coarse particles (number / mL) = number of coarse particles after storage (number / mL) −number of coarse particles before storage (number / mL)

(Conditions for measuring the number of coarse particles)
Measuring equipment: “Accuriser 780APS” manufactured by PSS
Injection loop volume: 1 mL
Flow rate: 60 mL / min Data collection time (Data Collection Time): 60 seconds Number of channels: 128

(Method for preparing polishing liquid composition)
To ultrapure water, sulfuric acid (made by Wako Pure Chemicals, reagent grade) as an acid and / or a salt thereof is 0.6% by weight in terms of effective component, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP, Sorcia) Japan Co., Ltd. (solid content concentration: 60% by weight) is mixed with 0.1% by weight in terms of effective component while stirring, and hydrogen peroxide (35% hydrogen peroxide manufactured by ADEKA) is added as an oxidant. After adding 0.6% by weight in terms of conversion and stirring well, 17.5% by weight of the silica particle dispersion after storage at 60 ° C. for 72 hours described above was mixed and stirred well to prepare a polishing composition. The resulting polishing composition had a pH of 1.5.

Example 2
Instead of the AMPS / AA copolymer used in Example 1, the AMPS / AA copolymer shown in the column of Example 2 in Table 1 (AMPS content 30 mol%, weight average molecular weight 4500, solid content concentration 40) A polishing composition was prepared in the same manner as in Example 1 except that the weight percent, sodium neutralized product) was used. The resulting polishing composition had a pH of 1.5.

Example 3
Instead of the AMPS / AA copolymer used in Example 1, the AMPS / AA copolymer shown in the column of Example 3 in Table 1 (AMPS content 55 mol%, weight average molecular weight 1000, solid content concentration 40) A polishing composition was prepared in the same manner as in Example 1 except that the weight percent, sodium neutralized product) was used. The resulting polishing composition had a pH of 1.5.

Example 4
Instead of the AMPS / AA copolymer used in Example 1, the AMPS / AA copolymer shown in the column of Example 4 in Table 1 (AMPS content 90 mol%, weight average molecular weight 1300, solid content concentration 40) A polishing composition was prepared in the same manner as in Example 1 except that the weight percent, sodium neutralized product) was used. The resulting polishing composition had a pH of 1.5.

Example 5
Instead of the AMPS / AA copolymer used in Example 1, the AMPS monomer shown in the column of Example 5 in Table 1 (sodium 2-acrylamido-2-methylpropanesulfonate, molecular weight 230.2, solid content) A polishing composition was prepared in the same manner as in Example 1 except that the concentration was 40% by weight. The resulting polishing composition had a pH of 1.5.

《Reference example》
A polishing composition was obtained in the same manner as in Example 1 except that the AMPS / AA copolymer was not added and the storage test was not performed at 60 ° C. for 72 hours. The resulting polishing composition had a pH of 1.5.

<< Comparative Example 1 >>
A polishing composition was obtained in the same manner as in Example 1 except that the AMPS / AA copolymer was not added. The resulting polishing composition had a pH of 1.5.

<< Comparative Example 2 >>
Instead of the AMPS / AA copolymer used in Example 1, an AA polymer (weight average molecular weight 16200, solid content concentration 40% by weight, sodium neutralized product) was used in the same manner as in Example 1. Thus, a polishing liquid composition was prepared. The resulting polishing composition had a pH of 1.5.

<< Comparative Example 3 >>
Instead of the AMPS / AA copolymer used in Example 1, the AMPS / AA copolymer shown in the column of Comparative Example 3 in Table 1 (AMPS content 20 mol%, weight average molecular weight 8400, solid content concentration 40) A polishing composition was prepared in the same manner as in Example 1 except that the weight percent, sodium neutralized product) was used. The resulting polishing composition had a pH of 1.5.

<< Comparative Example 4 >>
Instead of the AMPS / AA copolymer used in Example 1, the AMPS / AA copolymer shown in the column of Comparative Example 4 in Table 1 (AMPS content 11 mol%, weight average molecular weight 1800, solid content concentration 40) A polishing composition was prepared in the same manner as in Example 1 except that the weight percent, sodium neutralized product) was used. The resulting polishing composition had a pH of 1.5.

  Polishing was performed under the following conditions using the polishing composition obtained in Reference Examples, Examples 1 to 5 and Comparative Examples 1 to 4, and nanoscratch evaluation was performed.

(Polishing conditions)
・ Polishing test machine: Speedfam, double-sided 9B polishing machine ・ Polishing pad: Fujibow, urethane finish polishing pad ・ Upper surface plate rotation speed: 32.5 r / min
Abrasive liquid composition supply amount: 100 mL / min (0.15 mL / cm ^{2 of} substrate to be polished)
Min)
Polishing time: 4 minutes Polishing load: 7.8 kPa
・ Number of substrates to be polished: 10

(Substrate to be polished)
A Ni—P plated aluminum alloy substrate, which was rough polished in advance with a polishing liquid containing an alumina abrasive and the surface roughness Ra by an atomic force microscope (AFM) was 1 nm, was used as the substrate to be polished. The substrate to be polished had a thickness of 1.27 mm, an outer diameter of 95 mm, and an inner diameter of 25 mm.

(Nano scratch measurement conditions)
Measuring instrument: “MicroMax VMX-2100CSP” manufactured by VISION PSYTEC
-Light source: 100% for both 2Sλ (250W) and 3Pλ (250W)
-Tilt angle: -6 degrees-Magnification: Maximum (Field range: 1 / 120th of the total area)
・ Observation area: total area (substrate with outer diameter of 95 mm and inner diameter of 25 mm)
・ Iris: notch
Evaluation: Randomly select 4 substrates from the polished substrates (10), measure the number of nano scratches on both sides of each substrate, and total the number of nano scratches on 4 substrates (total 8) Was divided by 8 to calculate the number of nanoscratches per side of the substrate (lines / surface). And the relative value of each Example and each comparative example was computed by making the number of nano scratches (30 / surface) of a reference example into 1.0. The results are shown in Table 1.

(Evaluation of polishing rate)
The polishing rate when the polishing liquid compositions obtained in Reference Examples, Examples 1 to 5 and Comparative Examples 1 to 4 were used was evaluated by the following method. First, weigh each substrate before and after polishing (measured by “BP-210S” manufactured by Sartorius) to determine the weight change of each substrate, and use the average value of 10 substrates as the weight reduction amount. The value divided by time was defined as the weight reduction rate. This weight reduction rate was introduced into the following formula and converted into a polishing rate (μm / min). Then, the relative polishing speed of each experimental example was determined with the polishing speed of the reference example being the reference value 1.0. The results are shown in Table 1.
Polishing rate (μm / min) = weight reduction rate (g / min) / substrate single-sided area (mm ² ) / Ni-P plating density (g / cm ³ ) × 10 ⁶
(Calculated as substrate one side area: 6597 mm ² , Ni-P plating density: 7.9 g / cm ³ )

  From the result of Table 1, Example 5 containing a sulfonic acid group containing monomer, the weight average molecular weight is 500-7000, and the content rate of the structural unit derived from AMPS which occupies in all the structural units is 15-100. In Examples 1 to 4 containing an AMPS / AA copolymer in mol%, the generation of coarse particles in the dispersion is significantly suppressed as compared with Comparative Examples 1 to 4, and the number of nano scratches is also reduced. I understand that. In Examples 1 to 5, polishing performance equivalent to that before storage of the dispersion was shown.

  The polishing liquid kit of the present invention is suitable for polishing, for example, disk substrates such as magnetic disks and magneto-optical disks or polishing precision component substrates such as optical disks, photomask substrates, optical lenses, optical mirrors, optical prisms, and semiconductor substrates. Can be used for

Claims (9)

A polishing solution kit for an aluminum alloy substrate plated with Ni-P , comprising a silica particle dispersion and an acid and / or a salt thereof,
The silica particle dispersion and the acid and / or salt thereof are stored in a state where they are not mixed with each other,
The silica particle dispersion contains silica particles, at least one selected from the group consisting of a copolymer of 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid, and a salt thereof , and water.
The copolymer and a weight average molecular weight of the salt is 500 to 7000, and the copolymer and in the whole structural units constituting the salt of 2-acrylamido-2-methylpropane sulfonic acid-derived constitutional unit A polishing solution kit for an aluminum alloy substrate plated with Ni—P having a content of 15 to 90 mol%. The silica particles, Ni-P plated aluminum alloy substrate for a polishing solution kit according to claim 1 is colloidal silica. The polishing solution kit for an Ni-P plated aluminum alloy substrate according to claim 1 or 2 , wherein the number of coarse particles having a particle size of 0.56 µm or more in 1 mL of the silica particle dispersion is less than 50,000. The content of silica particles in the silica particle dispersion is 5 to 40% by weight,
4. The content according to claim 1, wherein the content of at least one selected from the group consisting of the copolymer and a salt thereof in the silica particle dispersion is 0.005 to 1% by weight. Polishing liquid kit for Ni-P plated aluminum alloy substrate. A polishing composition for a Ni-P plated aluminum alloy substrate prepared using the polishing kit for a Ni-P plated aluminum alloy substrate according to any one of claims 1 to 4 .   The Ni-P plated aluminum alloy substrate according to claim 5, wherein the content of at least one selected from the group consisting of the copolymer and a salt thereof is 0.001 to 0.1 wt%. Polishing liquid composition. The polishing composition for an aluminum alloy substrate plated with Ni-P according to claim 5 or 6 , wherein the polishing composition further contains an oxidizing agent. The polishing composition for a Ni-P plated aluminum alloy substrate according to any one of claims 5 to 7 , having a pH of 1 to 4. A method for producing a substrate, comprising a step of polishing a Ni-P plated aluminum alloy substrate using the polishing composition for a Ni-P plated aluminum alloy substrate according to any one of claims 5 to 8 .