Method for producing polishing composition

Abstract

The method for manufacturing the grinding composition of the present invention includes: mixing a dispersion containing silicon dioxide with a solution containing a silane coupling agent having a cationic group at a concentration of 0.03% by mass or more but less than 1% by mass, to obtain a dispersion containing cationic modified silicon dioxide.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a grinding composition. Prior Technology

[0002] In semiconductor device manufacturing processes, as semiconductor device performance improves, a technology for manufacturing wiring with higher density and higher integration is needed. In this semiconductor device manufacturing process, CMP (Chemical Mechanical Polishing) has become an essential process. With the miniaturization of semiconductor circuits, the flatness requirements for the bumps and depressions of patterned wafers are increasing, and CMP is used to achieve nanometer-level smoothness. To achieve high smoothness through CMP, it is preferable to polish the bumps of the patterned wafer at high polishing speeds, while the depressions are essentially not polished.

[0003] In CMP (Continuous Metallurgy), a composition (grinding composition) is typically used. This composition contains not only an abrasive called abrasive grains, but also various additives such as abrasion accelerators and pH adjusters. The abrasive grains are particles that adhere to the surface of the object being ground, thus grinding the surface through physical action. Furthermore, the raw materials for the abrasive grains in the grinding composition are typically silica dispersions, such as colloidal silica, in which silica (silica; SiO2) particles, which can serve as abrasive grains, are used as the dispersion phase.

[0004] Regarding this silica dispersion, it is known that silica particles aggregate with each other under acidic conditions, resulting in poor stability. Previously, a silica dispersion with excellent stability over a wide pH range has been sought.

[0005] Colloidal silica with improved stability includes, for example, colloidal silica obtained by treating aqueous colloidal silica with an aqueous solution of alkaline aluminum chloride; and colloidal silica obtained by treating aqueous colloidal silica with an aqueous solution of alkaline aluminum salt and then stabilizing it with a water-soluble organic aliphatic polycarboxylic acid.

[0006] However, although the stability of these colloidal silicon dioxides is improved, their high content of metallic impurities presents the following problem: they cannot be used for applications requiring high purity, such as abrasive particles (grinding agents) for grinding semiconductor wafers.

[0007] As a technique for reducing the amount of such metallic impurities, Japanese Patent Application Publication No. 2005-162533 discloses a method that uses modifiers such as silane coupling agents to modify colloidal silica produced by hydrolyzing hydrolyzable silica compounds, thereby manufacturing modified colloidal silica. According to Japanese Patent Application Publication No. 2005-162533, this method can produce high-purity modified colloidal silica that does not aggregate or gel, can be stably dispersed over a long period, and has extremely low metallic impurity content. Summary of the Invention

[0008] However, after studying the technology described in Japanese Patent Application Publication No. 2005-162533, the inventors discovered that coarse particles are sometimes generated after adding a silane coupling agent. When such coarse particles are generated, the productivity of the modified colloidal silica decreases.

[0009] Therefore, the object of the present invention is to provide a method for manufacturing a grinding composition, the method comprising modifying silicon dioxide by using a silane coupling agent having a cationic group, and the method being able to suppress the generation of coarse particles after adding a silane coupling agent having a cationic group.

[0010] To solve the aforementioned problems, the inventors have conducted repeated and intensive research. As a result, it was discovered that the aforementioned problems can be solved by the following method for manufacturing a grinding composition, thereby completing the present invention. The method for manufacturing the grinding composition includes mixing a dispersion containing silicon dioxide with a solution containing a silane coupling agent having a cationic group at a concentration of 0.03% by mass or more but less than 1% by mass, to obtain a dispersion containing cationic modified silicon dioxide. Implementation

[0011] The embodiments of the present invention will now be described. However, the present invention is not limited to the embodiments described below. Furthermore, unless otherwise specified, all measurements of operation and physical properties in this specification are performed at room temperature (20°C to 25°C) and relative humidity (40%RH to 50%RH).

[0012] A method for manufacturing a grinding composition according to one embodiment of the present invention includes: mixing a dispersion containing silica with a solution containing a silane coupling agent having a cationic group at a concentration of 0.03% by mass or more but less than 1% by mass, to obtain a dispersion containing cationic modified silica. According to the manufacturing method of one embodiment of the present invention having this configuration, the generation of coarse particles after adding a silane coupling agent having a cationic group can be suppressed. Furthermore, according to the manufacturing method of one embodiment of the present invention, a cationic modified silica aqueous dispersion with excellent filterability can be used, and when filtering the grinding composition, a filter with fine pores can be used, which is beneficial to reducing the number of coarse particles in the grinding composition.

[0013] Furthermore, in this specification, cationic modified silica refers to a compound of silica (preferably colloidal silica) with cationic groups (e.g., amino or quaternary ammonium groups) bonded to its surface. According to a preferred embodiment of the present invention, the cationic modified silica is amino-modified silica, more preferably amino-modified colloidal silica.

[0014] [Silicon dioxide dispersion] In one embodiment of the manufacturing method of the present invention, a dispersion containing silicon dioxide (hereinafter also referred to as "silicon dioxide dispersion") is used as a raw material. The silicon dioxide contained in the silicon dioxide dispersion is the raw material before cationic modification (remodeling) using the silane coupling agent having a cationic group described below.

[0015] The silicon dioxide used as a raw material in this invention can be any one of natural crystalline silicon dioxide, natural amorphous silicon dioxide, synthetic crystalline silicon dioxide, and synthetic amorphous silicon dioxide. However, amorphous silicon dioxide is preferred, and synthetic amorphous silicon dioxide is even more preferred. Furthermore, one type of silicon dioxide can be used alone, or two or more types can be used in combination. Also, commercially available silicon dioxide or synthetic silicon dioxide can be used.

[0016] There are no particular limitations on the methods for manufacturing amorphous silica. Examples include wet methods such as neutralizing sodium silicate with mineral acid (sodium silicate method) and hydrolyzing alkoxysilanes (sol-gel method); dry methods such as vaporizing silicon chloride and synthesizing silica particles through a gas-phase reaction in a high-temperature hydrogen flame (gas-phase method, gas combustion method); and dry methods such as heat-treating a mixture of pulverized silica, metallic silica powder or carbon powder, a reducing agent, and water to form a slurry in a reducing atmosphere at high temperature to generate SiO gas and then cooling the SiO gas in an oxygen-containing atmosphere (melting method). However, from the viewpoint of reducing metallic impurities, amorphous silica is preferably colloidal silica, and even more preferably colloidal silica manufactured by the sol-gel method. Colloidal silicon dioxide produced by the sol-gel method is preferred because it contains less diffusible metallic impurities and corrosive ions such as chloride ions in semiconductors. The production of colloidal silicon dioxide using the sol-gel method can be carried out using previously known methods. Specifically, colloidal silicon dioxide can be obtained by hydrolyzing and condensing a hydrolyzable silicon compound (e.g., alkoxysilanes or their derivatives) in water or a mixture of water and an organic solvent. The obtained colloidal silicon dioxide can be directly mixed with solutions containing cationic silane coupling agents, or it can be diluted using a dispersion medium.

[0017] Water, or a mixture of water and an organic solvent, can be used as the dispersion medium for silica dispersions. Examples of organic solvents include hydrophilic organic solvents such as methanol, ethanol, isopropanol, n-butanol, tributanol, pentanol, ethylene glycol, propylene glycol, and 1,4-butanediol; and hydrophilic organic solvents such as ketones such as acetone and methyl ethyl ketone. One of these organic solvents can be used alone, or two or more can be used in combination. There are no particular restrictions on the mixing ratio of water to organic solvents; it can be adjusted arbitrarily.

[0018] The silica contained in the silica dispersion typically exists in the form of aggregates of primary particles, i.e., secondary particles. There is no particular limitation on the lower limit of the average particle size (average secondary particle size) of the silica secondary particles, but it is preferably 10 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more. Furthermore, the upper limit of this average secondary particle size is preferably 300 nm or less, more preferably 100 nm or less, and even more preferably 60 nm or less. That is, the average secondary particle size of silica is preferably 10 nm or more and 300 nm or less, more preferably 15 nm or more and 100 nm or less, and even more preferably 20 nm or more and 60 nm or less. If the average secondary particle size is 10 nm or more, dispersibility can be sufficiently ensured even at high silica concentrations; on the other hand, if the average secondary particle size is 300 nm or less, the formation of coarse particles can be prevented. Furthermore, the value of this average secondary particle size can be obtained by measuring the volume average particle size using dynamic light scattering.

[0019] The lower limit of the average primary particle size of the silica contained in the silica dispersion is preferably 5 nm or more, more preferably 7 nm or more, and even more preferably 10 nm or more. Furthermore, the upper limit of the average primary particle size of the silica is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 30 nm or less. That is, the average primary particle size of the silica is preferably 5 nm or more and 100 nm or less, more preferably 7 nm or more and 50 nm or less, and even more preferably 10 nm or more and 30 nm or less. Regarding the average primary particle size of the silica, it can be calculated based on the specific surface area (SA) of the silica, assuming that the silica particles are truly spherical, using the formula SA = 4πR² (where R is the radius). Furthermore, the degree of association (average secondary particle size / average primary particle size) calculated based on these values ​​is not particularly limited, but is preferably around 1.0 to 5.0.

[0020] There is no particular limitation on the specific surface area of ​​the silica contained in the silica dispersion, and it can be appropriately selected according to the intended use of the cationic modified silica. Preferably, the specific surface area is 10 m² / g or more and 600 m² / g or less, more preferably 15 m² / g or more and 300 m² / g or less, and even more preferably 20 m² / g or more and 200 m² / g or less. Furthermore, this specific surface area value can be calculated using the nitrogen adsorption method (BET method).

[0021] There is no particular limitation on the lower limit of the concentration (content) of silicon dioxide in the silicon dioxide dispersion, but from a production point of view, it is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more. Furthermore, the upper limit of the concentration (content) of silicon dioxide in the silicon dioxide dispersion is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. That is, the concentration (content) of silicon dioxide in the silicon dioxide dispersion is preferably 5% by mass or more and 40% by mass or less, more preferably 8% by mass or more and 35% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less.

[0022] There are no particular limitations on the pH value of the silica dispersion, but it is preferably 5.0 to 11.0, more preferably 6.0 to 10.5, and even more preferably 7.0 to 10.0.

[0023] Furthermore, various processing steps can be performed on the prepared silica dispersion as needed. One such processing step is reducing the viscosity of the silica dispersion. For example, adding an alkaline solution (such as ammonia or other alkaline aqueous solutions) or an organic solvent to the silica dispersion can be used. The amount of alkaline solution or organic solvent added is not particularly limited; it can be appropriately set considering the viscosity of the resulting silica dispersion. By implementing the step of reducing the viscosity of the silica dispersion, the following advantages are achieved: the initial dispersibility of the cationic silane coupling agent in the silica dispersion can be improved, and the aggregation of silica particles can be suppressed.

[0024] [Silane coupling agents with cationic groups] As described above, to perform cationic modification on silica (colloidal silica), a dispersion containing silica is mixed with a solution containing a silane coupling agent with cationic groups (such as amine or quaternary ammonium groups), and the mixture is reacted at a specific temperature for a specific time. Furthermore, hereinafter, the silane coupling agent with cationic groups will be simply referred to as "silane coupling agent," and the solution containing the silane coupling agent with cationic groups will be simply referred to as "silane coupling agent solution."

[0025] Examples of silane coupling agents used include: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltris(2-propoxy)silane, 3-aminopropyldimethoxymethylsilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylethyldimethoxysilane, 3-aminopropyldimethoxysilane, and 3-aminopropyldimethoxysilane. Methylethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, 3-aminopropyldimethoxyethylsilane, trimethoxy[3-(methylamino)propyl]silane, trimethoxy[3-(phenylamino)propyl]silane, [3-(N,[N-Dimethylaminopropyl]trimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltriisopropoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, N-2-(2- [3-(6-aminohexylamino)propyl]trimethoxysilane, N-methyl-3-(triethoxysilyl)prop-1-amine, N-[3-(trimethoxysilyl)propyl]but-1-amine, (aminoethylaminoethyl)phenyltriethoxysilane, methylbenzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyltriethoxysilane, 3-ureopropyltrimethoxysilane, 3-ureopropyltriethoxysilane, (aminoethylaminoethyl)phenethyltrimethoxysilane, (aminoethylaminomethyl)phenethyltrimethoxysilane, N-[2-[3-(tri... [Methoxysilyl]propylamino]ethyl]ethylenediamine, trimethoxy[2-(2-aminoethyl)-3-aminopropyl]silane, diaminomethylmethyldiethoxysilane, methylaminomethylmethyldiethoxysilane, p-aminophenyltrimethoxysilane, N-methylaminopropyltriethoxysilane, N-methylaminopropylmethyldiethoxysilane, N-phenylaminomethyltrimethoxysilane, N-phenylaminomethyldimethoxymethylsilane, (phenylaminomethyl)trimethoxysilane, (phenylaminomethyl)methyldiethoxysilane, acetaminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-benzyl-3-amino Silanes containing amino groups include propyltrimethoxysilane, N-vinylbenzyl-3-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, (2-aminoethyl)aminomethyltrimethoxysilane, (aminomethyl)dimethoxymethylsilane, (aminomethyl)trimethoxysilane, bis(3-trimethoxysilylpropyl)amine, and N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine; silanes containing quaternary ammonium groups include octadecyldimethyl-(γ-trimethoxysilylpropyl)-ammonium chloride and N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride.

[0026] These silane coupling agents can be used alone or in combination of two or more. Furthermore, commercially available or synthetic silane coupling agents can be used.

[0027] Among the aforementioned silane coupling agents, those with high water solubility and the potential for uniform surface modification are preferably selected from 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, and 3-aminopropyldimethoxyethylsilane. At least one of the group consisting of alkyl, trimethoxy[3-(methylamino)propyl]silane, trimethoxy[3-(phenylamino)propyl]silane, [3-(N,N-dimethylamino)propyl]trimethoxysilane, [3-(6-aminohexylamino)propyl]trimethoxysilane, N-methyl-3-(triethoxysilyl)propyl-1-amine, N-[3-(trimethoxysilyl)propyl]but-1-amine, and bis[(3-trimethoxysilyl)propyl]amine. The silane coupling agent is preferably selected from at least one of the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, 3-aminopropyldimethoxyethylsilane, trimethoxy[3-(methylamino)propyl]silane, trimethoxy[3-(phenylamino)propyl]silane, [3-(N,N-dimethylamino)propyl]trimethoxysilane, [3-(6-aminohexylamino)propyl]trimethoxysilane, N-methyl-3-(triethoxysilyl)propyl-1-amine, N-[3-(trimethoxysilyl)propyl]but-1-amine, and bis[(3-trimethoxysilyl)propyl]amine.

[0028] A silane coupling agent solution can be obtained by mixing and stirring a solvent with a silane coupling agent. In this case, the solvent used for the silane coupling agent solution is only required to dissolve the silane coupling agent; there are no particular restrictions. Examples of solvents include water and organic solvents, which were listed as dispersion media in the section on [dispersions containing silicon dioxide] above.

[0029] In the manufacturing method of the present invention, the concentration (content) of the silane coupling agent in the silane coupling agent solution is 0.03% by mass or more but less than 1% by mass. When the concentration (content) is less than 0.03% by mass, the surface modification effect cannot be sufficiently obtained. Furthermore, when the concentration (content) is 1% by mass or more, coarse particles increase, and the productivity of cationic modified silica decreases. The lower limit of the concentration (content) of the silane coupling agent in the silane coupling agent solution is preferably 0.04% by mass or more, more preferably 0.05% by mass or more. Furthermore, the upper limit of the concentration (content) of the silane coupling agent in the silane coupling agent solution is preferably 0.8% by mass or less, more preferably 0.5% by mass or less, further preferably 0.3% by mass or less, and most preferably 0.15% by mass or less. That is, the concentration (content) of the silane coupling agent in the silane coupling agent solution is preferably 0.04% by mass or more and 0.8% by mass, more preferably 0.05% by mass or more and 0.5% by mass, further preferably 0.05% by mass or more and 0.3% by mass, and most preferably 0.05% by mass or more and 0.15% by mass.

[0030] [A mixture of a dispersion containing silicon dioxide and a silane coupling agent solution] The cationic modified silica of this embodiment can be obtained by mixing the aforementioned silica-containing dispersion with a silane coupling agent solution having cationic groups. Specifically, through this mixing, silica reacts with the silane coupling agent having cationic groups, and the cationic groups, acting as modifying groups, are introduced onto the surface of the silica particles to generate cationic modified silica, thereby obtaining a dispersion containing the cationic modified silica.

[0031] In the manufacturing method of this invention, there are no particular limitations on the method of mixing the silica dispersion and the silane coupling agent solution. For example, the silane coupling agent solution can be added to the silica dispersion, or the silica dispersion can be added to the silane coupling agent solution. Alternatively, both the silica dispersion and the silane coupling agent solution can be added simultaneously. Regarding the mixing method, from the viewpoint of further suppressing the generation of coarse particles, it is preferable to add a solution containing the silane coupling agent to the silica dispersion. In this case, the silane coupling agent solution can be added all at once, in several portions, or continuously. In the case of continuous addition, the addition rate can be appropriately adjusted according to the concentration of the silica dispersion, the concentration of the silane coupling agent solvent, etc. For example, when the total amount added is about 10 mL, the addition rate is 1 mL / min or more and 10 mL / min or less.

[0032] The mixing mass ratio of silicon dioxide to the silane coupling agent with cationic groups (silicon dioxide / silane coupling agent with cationic groups) can be appropriately adjusted according to the amount of cationic groups introduced, etc., preferably 100 / 0.01 to 100 / 1, more preferably 100 / 0.05 to 100 / 0.8. If the mixing mass ratio is within this range, the generation of coarse particles can be further suppressed.

[0033] When mixing, the temperature of the silica dispersion and the silane coupling agent solution is not particularly limited, but is preferably in the range from room temperature to the boiling point of the solvent (dispersion medium). In this embodiment, the reaction between silica and the silane coupling agent can proceed at around room temperature, therefore it is preferable to carry out the reaction at a temperature near room temperature (e.g., above 20°C and below 35°C). Even at temperatures near room temperature (e.g., above 20°C and below 35°C), there is an advantage that the added silane coupling agent reacts with the silica in almost all of its quantity by simply stirring the reaction system for several hours, leaving almost no unreacted silane coupling agent residue. In other words, in this embodiment, it is preferable not to include the step of heating the reaction system of the silica dispersion and the silane coupling agent solution.

[0034] The reaction time between silicon dioxide and the silane coupling agent (the mixing time of the silicon dioxide dispersion and the silane coupling agent solution) is not particularly limited, but is preferably 10 minutes to 10 hours, and more preferably 30 minutes to 5 hours. From the viewpoint of making the reaction efficient, it is preferable to carry out the reaction while stirring. The stirring method and stirring conditions used are not particularly limited, and can be appropriately referred to previously known views. As an example, from the viewpoint of making the components uniformly dispersed, the stirring speed is usually 20 rpm (0.33 s -1) to 800 rpm (13.3 s -1) and less, preferably 50 rpm (0.83 s -1) to 700 rpm (11.7 s -1) and less.

[0035] The pressure of the reaction system is not particularly limited and can be any of atmospheric pressure, under pressure, or under reduced pressure. Since the reaction of the present invention can be carried out under atmospheric pressure, it is preferred to carry out the reaction under atmospheric pressure.

[0036] When the cationic modified silica obtained by the above method contains a dispersion medium other than water, in order to improve the long-term storage stability of the cationic modified silica, the dispersion medium other than water can be replaced with water as needed. There are no particular limitations on the method of replacing the dispersion medium other than water with water. For example, a method in which a certain amount of water is added dropwise while heating the cationic modified silica can be exemplified. Alternatively, a method in which the cationic modified silica is separated from the dispersion medium other than water by precipitation, separation, centrifugation, etc., and then the cationic modified silica is redispersed in water can also be exemplified.

[0037] The lower limit of the zeta potential of the obtained cationic modified silicon dioxide is preferably 6 mV or more, more preferably 8 mV or more, and even more preferably 10 mV or more. Furthermore, the upper limit of the zeta potential of the obtained cationic modified silicon dioxide is preferably 70 mV or less, more preferably 60 mV or less, and even more preferably 50 mV or less. That is, the zeta potential of the obtained cationic modified silicon dioxide is preferably 6 mV or more and 70 mV or less, more preferably 8 mV or more and 60 mV or less, and even more preferably 10 mV or more and 50 mV or less. Moreover, in this specification, the zeta potential of the cationic modified silicon dioxide is a value measured by the method described in the examples. The zeta potential of the cationic modified silicon dioxide can be adjusted according to the amount of cationic groups present in the cationic modified silicon dioxide.

[0038] [Number of coarse particles] According to the manufacturing method of the present invention, the generation of coarse particles after adding a silane coupling agent with a cationic group can be suppressed. Specifically, the number of coarse particles with a particle size exceeding 0.7 μm present in the cationic modified silica aqueous dispersion per unit volume (1 mL), as measured by the following method, is preferably 2,000,000 particles / mL or less, more preferably 1,000,000 particles / mL or less, further preferably 500,000 particles / mL or less, further preferably 100,000 particles / mL or less, particularly preferably 50,000 particles / mL or less, especially more preferably 10,000 particles / mL or less, particularly more preferably 8,000 particles / mL or less, and most preferably 5,000 particles / mL or less.

[0039] (Methods for determining the number of coarse particles) A cationic modified silica was dispersed in water at a concentration of 0.27% by mass, and the pH was adjusted to 4.0 to prepare an aqueous dispersion. The number of coarse particles with a diameter greater than 0.7 μm per unit volume in the obtained cationic modified silica aqueous dispersion was determined using a liquid particle counter. Furthermore, the details of the method for determining the number of coarse particles are as described in the examples.

[0040] [Other steps] The method for manufacturing the grinding composition of the present invention may further include other steps without hindering the effects of the present invention. Examples of such other steps include: filtering the dispersion containing cationic modified silica; mixing the dispersion containing cationic modified silica with other additives (preferably pH adjusters); and further filtering the dispersion containing cationic modified silica after mixing with other additives. These steps will be described below.

[0041] <Steps for filtering a dispersion containing cationic modified silica (stage 1 filtration)> In this step, the dispersion containing cationic modified silica obtained above is filtered. By performing this step, the number of coarse particles in the dispersion can be further reduced.

[0042] In the manufacturing method of the present invention, the filtering step may include only one stage, or it may include multiple stages of two or more stages. The technical content described herein applies to filtering when the filtering step includes only one stage, and to the first stage of filtering when the filtering step includes multiple stages. The technical content of filtering after the second stage when the filtering step includes multiple stages will be described below.

[0043] There are no particular restrictions on the shape of the filter media used in this step; filters with various structures, shapes, and functions can be appropriately employed. Specifically, pleated or deep-layer filters, deep-layer pleated filters, membrane filters, and adsorption filters with excellent filtration performance are preferred. The filter structure is not particularly limited; it can be a bag-type filter or a hollow cylindrical filter. Cylindrical filters can be gasket-type or O-ring-type. Regarding filtration conditions (e.g., filtration differential pressure, filtration velocity), appropriate settings can be made based on technical common sense in this field, taking into account the target quality and production efficiency.

[0044] Regarding the pore size (pore diameter) of the filter used in this step, from the viewpoint of improving yield, it is preferably 0.05 μm or more, more preferably 0.1 μm or more, and even more preferably 0.2 μm or more. Furthermore, from the viewpoint of improving the removal effect of foreign matter and agglomerates, the pore size (pore diameter) of the filter used in this step is preferably 100 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less.

[0045] That is, the pore size (pore diameter) of the filter used in this step is preferably 0.05 μm to 100 μm, more preferably 0.1 μm to 30 μm, and even more preferably 0.2 μm to 20 μm.

[0046] There are no particular restrictions on the material of the filter used in this step. Examples include cellulose, nylon, polyurethane, polyether urethane, polypropylene, polytetrafluoroethylene (PTFE), polycarbonate, and glass.

[0047] There are no particular restrictions on filtration methods. For example, in addition to natural filtration at normal pressure, known filtration methods such as suction filtration, pressure filtration, and centrifugal filtration can also be used appropriately.

[0048] The filters used in this step can be commercially available products. Examples of commercially available filters include: Nuclepore membrane filters (manufactured by Whatman), and ROKI TECHNO Co., Ltd.'s HC series, BO series, SLF series, SRL series, and MPX series filters, which use polypropylene nonwoven fabric as the filter medium.

[0049] <Steps for mixing other additives> In this step, the dispersion containing cationic modified silica obtained above is mixed with other additives. This step can be performed before or after the step of filtering the dispersion containing cationic modified silica. From the viewpoint of minimizing the entrainment of foreign matter into subsequent steps, it is preferable to perform this step after the step of filtering the dispersion containing cationic modified silica.

[0050] Examples of other additives include pH adjusters, dispersion media, preservatives, rust inhibitors, antioxidants, stabilizers, and pH buffers, which can be components of grinding compositions. Among these, pH adjusters will be explained.

[0051] (pH adjuster) The pH adjuster has the function of adjusting the pH value of the grinding composition of the present invention to the desired value.

[0052] There are no particular limitations on the pH adjuster used; any known pH adjuster used in the field of grinding compositions can be used. Among these, known acids, bases, salts, amines, chelating agents, etc., are preferred. Examples of pH adjusters include: formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, pearlitic acid, stearic acid, oleic acid, linolenic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, lactic acid, malic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, hexacarboxylic acid, cinnamic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, aconitic acid, amino acids, o-aminobenzoic acid, nitrocarboxylic acid, etc. Carboxylic acids; sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, 10-camphorsulfonic acid, hydroxyethanesulfonic acid, and taurine; inorganic acids such as carbonic acid, hydrochloric acid, nitric acid, phosphoric acid, hypophosphoric acid, phosphorous acid, phosphonic acid, sulfuric acid, boric acid, hydrofluoric acid, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, and hexametaphosphoric acid; hydroxides of alkali metals such as potassium hydroxide (KOH); hydroxides of Group 2 elements; ammonia; organic bases such as quaternary amine hydroxide; amines such as aliphatic amines and aromatic amines; N-methyl-D-glucosamine, D-glucosamine, N-ethyl-D-glucosamine, N-propyl-D-glucosamine, and N-octyl- D-glucosamine, N-acetylglucosamine, tris(hydroxymethyl)aminomethane, bis(2-hydroxyethyl)amino-tris(hydroxymethyl)methane, iminodiacetic acid, N-(2-acetylglucosamine)iminodiacetic acid, hydroxyethyliminodiacetic acid, N,N-di(2-hydroxyethyl)glycine, N-[tris(hydroxymethyl)methyl]glycine, azirtriacetic acid, diethyltriaminepentaacetic acid, ethylenediaminetetraacetic acid, N,N,N-trimethylenephosphonic acid, ethylenediamine-N,N,N',N'-tetramethylenesulfonic acid, trans-cyclohexanediaminetetraacetic acid, 1,2-propanediaminetetraacetic acid, ethylene glycol ether Diaminetetraacetic acid, ethylenediamineo-o-hydroxyphenylacetic acid, ethylenediaminedisuccinic acid (SS), N-(2-carboxylic acid ethyl ester)-L-aspartic acid, β-alanine diacetic acid, phosphonobutane tricarboxylic acid (2-phosphonobutane-1,2,4-tricarboxylic acid), hydroxyethylidene diphosphonic acid (HEDP) (1-hydroxyethylidene-1,1-diphosphonic acid), nitrotrimethylenephosphonic acid, N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid, 1,2-dihydroxybenzene-4,6-disulfonic acid, polyamines, polyphosphonic acids, polyaminocarboxylic acids, polyaminophosphonic acids, and other chelating agents, or their salts, etc. These pH adjusters can be used alone or in combination of two or more. Among these pH adjusters, from the viewpoint of inhibiting the removal rate of silicon nitride and / or TEOS-type silicon oxide films, strong acids with a large-volume skeleton, such as 10-camphorsulfonic acid, p-toluenesulfonic acid, and hydroxyethanesulfonic acid, are preferred.

[0053] Regarding the amount of pH adjuster to add, select an appropriate amount to achieve the desired pH value of the grinding composition.

[0054] Furthermore, the aforementioned pH adjuster, in addition to adjusting the pH of the grinding composition, can also be used to adjust the pH of the dispersion containing cationic modified silica for storage. That is, besides this step, the storage process may also include adding a pH adjuster to the dispersion containing cationic modified silica. In this storage step, from the viewpoint of maintaining the dispersibility of the filtered cationic modified silica, it is preferable to add the pH adjuster so that the pH of the dispersion at the time of storage is acidic.

[0055] <Further filtration of the dispersion containing cationic modified silica (filtration after stage 2)> In this step, the dispersion containing cationic modified silica obtained above is further filtered. The technical content described herein applies to filtration after the second stage when the filtration process includes multiple stages (two or more stages).

[0056] Regarding the shape, structure, material, filtration conditions, and filtration method of the filter used in this step, the same descriptions as those in the section "Steps for Filtrizing a Dispersion Containing Cationic Modified Silica (Stage 1 Filtration)" above can be used.

[0057] In industrial applications, from the perspective of production efficiency, the media shape of the filter is preferably pleated or deep-layered, or deep-pleated. Furthermore, from the perspective of simultaneously improving yield and the removal of foreign matter and agglomerates, it is preferable to use the aforementioned pleated or deep-layered, or deep-pleated filters in multiple filtration stages.

[0058] At this point, it is preferable that the pore size of the filter is the same or gradually decreases from the beginning to the end of the filtration process in multiple stages.

[0059] From the perspective of improving yield, the pore size (pore diameter) of the filter used in this step is preferably 0.05 μm or more, more preferably 0.1 μm or more, and even more preferably 0.15 μm or more. Furthermore, from the perspective of improving the removal efficiency of foreign matter and agglomerates, the pore size (pore diameter) of the filter used in this step is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 1 μm or less, even more preferably 0.7 μm or less, and particularly preferably 0.4 μm or less. That is, the pore size (pore diameter) of the filter used in this step is preferably 0.05 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less, even more preferably 0.15 μm or more and 1 μm or less, even more preferably 0.15 μm or more and 0.7 μm or less, and particularly preferably 0.15 μm or more and 0.4 μm or less.

[0060] Commercially available filters may also be used in this step. Examples of commercially available filters used in this step include Ultipleat (registered trademark) P-Nylon66 and Ultipor (registered trademark) N66 manufactured by Nihon Pall Inc.

[0061] [Grinding Composition] The number of coarse particles in the grinding composition obtained by the above manufacturing method is reduced. Specifically, according to a preferred embodiment of the present invention, a grinding composition is provided comprising cationic modified silica having a cationic group and a dispersion medium, wherein the number of coarse particles with a particle size exceeding 0.7 μm in the cationic modified silica, as measured by the following method, is 500,000 particles / mL or less. Preferably, the number of coarse particles in the grinding composition is 100,000 particles / mL or less, more preferably 10,000 particles / mL or less, and even more preferably 5,000 particles / mL or less. [, , ]

[0062] (Methods for determining the number of coarse particles) A cationic modified silica was dispersed in water at a concentration of 0.27% by mass, and the pH was adjusted to 4.0 to prepare an aqueous dispersion. The number of coarse particles with a diameter greater than 0.7 μm per unit volume in the obtained cationic modified silica aqueous dispersion was determined using a liquid particle counter.

[0063] As a dispersion medium contained in the grinding composition, the dispersion mediums listed in the section on [dispersion containing silicon dioxide] can be similarly cited.

[0064] The cationic modified silicon dioxide contained in the grinding composition of this embodiment functions as abrasive particles. The lower limit of the content of the cationic modified silicon dioxide in the grinding composition relative to the total mass of the grinding composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more. Furthermore, the upper limit of the content of the cationic modified silicon dioxide in the grinding composition relative to the total mass of the grinding composition is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. That is, the content of cationic modified silicon dioxide relative to the total mass of the grinding composition is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.2% by mass or more and 10% by mass or less, and even more preferably 0.5% by mass or more and 5% by mass or less.

[0065] The grinding composition of this embodiment may, as needed, further include known additives that can be used in grinding compositions, such as pH adjusters, chelating agents, preservatives, and fungicides, without hindering the effects of the present invention.

[0066] The polishing composition of this embodiment can be suitably used for polishing, for example, polycrystalline silicon, silicon nitride, silicon carbonitride (SiCN), silicon oxide, metals, SiGe, etc.

[0067] Examples of grinding objects containing silicon oxide include TEOS-type silicon oxide surfaces (hereinafter also referred to as "TEOS") generated using tetraethyl orthosilicate as a precursor, HDP (High Density Plasma) films, USG (Undoped Silicate Glass) films, PSG (Phosphorus Silicate Glass) films, BPSG (Boron-Phospho Silicate Glass) films, and RTO (Rapid Thermal Oxidation) films.

[0068] Examples of such metals include tungsten, copper, aluminum, cobalt, hafnium, nickel, gold, silver, platinum, palladium, rhodium, ruthenium, iridium, and osmium.

[0069] The embodiments of the present invention have been described in detail, but they are illustrative and exemplary embodiments, not limiting embodiments. Obviously, the scope of protection of the present invention should be interpreted by the appended patent application claims.

[0070] The present invention includes the following forms and shapes. 1. A method for manufacturing a grinding composition, comprising: mixing a dispersion containing silicon dioxide with a solution containing a silane coupling agent having a cationic group at a concentration of 0.03% by mass or more but less than 1% by mass, to obtain a dispersion containing cationic modified silicon dioxide; 2. The manufacturing method as described in 1. above, wherein the mass ratio of the silicon dioxide to the silane coupling agent having a cationic group (silicon dioxide / silane coupling agent having a cationic group) is 100 / 0.05 to 100 / 0.8; 3. The manufacturing method as described in 1. or 2. above, wherein the concentration of the silane coupling agent having a cationic group in the above solution is 0.05% by mass or more and 0.6% by mass or less; 4. The manufacturing method as described in any one of 1. to 3. above, wherein the mixing includes adding the solution containing the silane coupling agent having a cationic group to the dispersion containing silicon dioxide; 5. The manufacturing method as described in any one of 1. to 4. above, wherein the silicon dioxide is colloidal silicon dioxide; 6. The manufacturing method as described in any one of 1. to 5. above, wherein the silane coupling agent having a cationic group is selected from 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, 3-aminopropyldimethoxymethylsilane, and 3-aminopropyldimethoxymethylsilane. At least one of the group consisting of alkyl, trimethoxy[3-(methylamino)propyl]silane, trimethoxy[3-(phenylamino)propyl]silane, [3-(N,N-dimethylamino)propyl]trimethoxysilane, [3-(6-aminohexylamino)propyl]trimethoxysilane, N-methyl-3-(triethoxysilyl)propyl-1-amine, N-[3-(trimethoxysilyl)propyl]but-1-amine, and bis[(3-trimethoxysilyl)propyl]amine; 7. The manufacturing method as described in any one of 1. to 6. above, further comprising filtering the dispersion containing cationic modified silica; 8. The manufacturing method according to any one of 1. to 7. above further includes mixing the dispersion liquid containing cation-modified silica with a pH adjuster; 9. A polishing composition comprising cation-modified silica having a cationic group and a dispersion medium, and in the above cation-modified silica, the number of coarse particles having a particle diameter exceeding 0.7 μm measured by the following measurement method is 500,000 / mL or less, (Measurement method) After dispersing cation-modified silica in water at a concentration of 0.27% by mass and adjusting the pH to 4.0 to prepare an aqueous dispersion, use a particle counter in the liquid to measure the number per unit volume (1 mL) of coarse particles having a particle diameter exceeding 0.7 μm present in the obtained aqueous dispersion of cation-modified silica.

[0071] [Examples] The present invention will be described in further detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. Furthermore, unless otherwise specified, “%” and “parts” respectively mean “mass %” and “mass parts”.

[0072] [Measurement methods for various physical properties] In this example, various physical properties were measured by the following methods.

[0073] <Measurement of particle diameter> The value of the average primary particle diameter of silica used as a raw material is calculated based on the specific surface area (SA) of silica calculated by the BET method, assuming the shape of silica is a true sphere, and using the formula SA = 4πR2 (R is the radius).

[0074] <Measurement of pH value> The pH of various aqueous dispersions and aqueous solutions was confirmed using a pH meter (manufactured by Horiba, Ltd., model: F-71).

[0075] [Manufacture of cation-modified silica] (Example 1) In a 2 L plastic container, deionized water was mixed with synthetic amorphous silica (colloidal silica; average primary particle size of silica: 24 nm; average secondary particle size of silica: 47 nm; zeta potential: 5.5 mV) to obtain an aqueous dispersion of synthetic amorphous silica with a final concentration of 19.88% by mass (pH 7.5).

[0076] In addition, 0.771 g of 3-aminopropyltriethoxysilane (APTES) was mixed with 231 g of deionized water to prepare an APTES aqueous solution with a concentration of 0.33% by mass (pH 7.0).

[0077] While stirring 1000 g of silica aqueous dispersion at 230 rpm, all of the APTES aqueous solution prepared above was added dropwise at a rate of 12 mL / min. Subsequently, the mixture was stirred at room temperature (25°C) for 50 minutes to obtain an aqueous dispersion of cation-modified silica (amine-modified) with amine groups introduced onto the silica surface.

[0078] (Examples 2-3, Examples 5-20, Comparative Examples 1-3) Except for changing the average primary particle size of the synthesized amorphous silica, the concentration of silica in the silica aqueous dispersion, the type and amount of silane coupling agent, and the amount of water used when preparing the silane coupling agent aqueous solution as shown in Table 1 below, the cationic modified silica aqueous dispersion was prepared in the same manner as in Example 1.

[0079] (Example 4) In a 2L plastic container, 0.771 g of 3-aminopropyltriethoxysilane (APTES) and 0.771 g of deionized water were mixed to prepare an APTES aqueous solution with a concentration of 0.10% by mass.

[0080] In addition, deionized water was mixed with synthetic amorphous silica (average primary particle size: 24 nm; average secondary particle size: 47 nm) to prepare a silica aqueous dispersion (pH 7.46) with a final concentration of 19.88% by mass.

[0081] While stirring the entire APTES aqueous solution prepared above at 230 rpm, 1000 g of the silica aqueous dispersion prepared above was added dropwise at a rate of 16 mL / min. Subsequently, the mixture was stirred at room temperature (25°C) for 50 minutes to obtain an aqueous dispersion of cation-modified silica (amine-modified) with amine groups introduced onto the silica surface.

[0082] The composition of the silica aqueous dispersion and silane coupling agent aqueous solution used in each embodiment and comparative example is shown in Table 1 below.

[0083] [Table 1] Table 1 Synthetic amorphous silica aqueous dispersion Silane coupling agent aqueous solution Silicon dioxide Primary particle size (nm) concentration (quality%) Silicon dioxide Aqueous dispersion Usage (g) pH value type Silane coupling agent usage (g) Water usage (g) Concentration (mass %) pH value Example 1 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 231 0.33 7.0 Example 2 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 385 0.20 7.0 Example 3 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 771 0.10 7.0 Example 4 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 771 0.10 7.0 Example 5 twenty four 10.00 1000 7.4 3-Aminopropyltriethoxysilane 0.771 771 0.10 7.0 Example 6 35 19.50 1000 7.5 3-Aminopropyltriethoxysilane 0.757 756 0.10 7.0 Example 7 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 867 0.09 7.0 Example 8 twenty four 19.88 1000 7.5 3-Aminopropyldimethoxymethylsilane 0.771 771 0.10 7.0 Example 9 twenty four 19.88 1000 7.5 3-(2-aminoethylamino)propyltriethoxysilane 0.771 771 0.10 7.0 Example 10 twenty four 19.88 1000 7.5 bis[3-(trimethoxysilyl)propyl]amine 0.771 771 0.10 7.0 Example 11 twenty four 19.88 1000 7.5 3-(2-aminoethylamino)propyltrimethoxysilane 0.771 771 0.10 7.0 Example 12 twenty four 19.88 1000 7.5 3-(2-aminoethylamino)propyldimethoxymethylsilane 0.771 771 0.10 7.0 Example 13 twenty four 19.88 1000 7.5 [3-(6-aminohexylamino)propyl]trimethoxysilane 0.771 771 0.10 7.0 Example 14 twenty four 19.88 1000 7.5 Trimethoxy[3-(phenylamino)propyl]silane 0.771 771 0.10 7.0 Example 15 twenty four 19.88 1000 7.5 N-Methyl-3-(triethoxysilyl)prop-1-amine 0.771 771 0.10 7.0 Example 16 twenty four 19.88 1000 7.5 [3-(N,N-dimethylamino)propyl]trimethoxysilane 0.771 771 0.10 7.0 Example 17 twenty four 19.88 1000 7.5 3-Aminopropyldiethoxymethylsilane 0.771 771 0.10 7.0 Example 18 twenty four 19.88 1000 7.5 N-[3-(trimethoxysilyl)propyl]but-1-amine 0.771 771 0.10 7.0 Example 19 twenty four 19.88 1000 7.5 3-Aminopropyltrimethoxysilane 0.771 771 0.10 7.0 Example 20 twenty four 19.88 1000 7.5 Trimethoxy[3-(methylamino)propyl]silane 0.771 771 0.10 7.0 Comparative Example 1 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 - 100 - Comparative Example 2 twenty four 19.88 1000 7.5 3-Aminopropyltriethoxysilane 0.771 76 1.0 7.0 Comparative Example 3 twenty four 10.00 1000 7.5 3-Aminopropyltriethoxysilane 0.771 - 100 -

[0084] [Evaluate]

[0085] <Determination of the number of coarse particles> The following aqueous dispersion was used as the sample. The aqueous dispersion was obtained by dispersing cationic modified silica in deionized water at a concentration of 0.27% by mass, and then adjusting the pH value to 4.0 with sulfuric acid.

[0086] The number of coarse particles larger than 0.7 μm per unit volume (1 mL) in the obtained cationic modified silica aqueous dispersion was determined using a liquid particle counter (LPC, AccuSizer (registered trademark) FX (manufactured by Nihon Entegris Inc.)). The average value for n=3 was then calculated and rounded to the nearest decimal.

[0087] <Measurement of ζ-potential> The zeta potential of the obtained cationic modified silica was determined using a zeta potential measuring device (trade name "ELS-Z") manufactured by Otsuka Electronics Co., Ltd. An aqueous dispersion was used as the sample, in which cationic modified silica was dispersed in deionized water at a concentration of 1.8% by mass, and then the pH was adjusted to 3.0 using sulfuric acid.

[0088] <Filtration speed> The cationic modified silica aqueous dispersions obtained in the above examples and comparative examples were subjected to suction filtration using a Nuclepore membrane filter (manufactured by Whatman Corporation) with a pore size of 3.0 μm and a diameter of 47 mm, and the filtration rate (the amount filtered per unit time (1 minute)) was measured. Furthermore, the filtration rate is the average rate after 5 minutes of filtration.

[0089] The above assessment results are shown in Table 2 below. Furthermore, blank columns in Table 2 indicate that no assessment was conducted.

[0090] [Table 2] Table 2 Coarse particles (>0.7 μm) (pcs / mL) ζ potential (mV) Filtration speed (g / min) Example 1 20858 24.2 950 Example 2 18698 26.4 975 Example 3 7131 27.2 1098.7 Example 4 1570407 25.0 Example 5 6531 27.2 Example 6 12531 28.0 Example 7 5092 31.0 Example 8 9318 Example 9 9500 Example 10 7583 Example 11 7222 30.5 Example 12 7435 Example 13 8132 Example 14 8765 Example 15 8356 Example 16 8646 Example 17 8124 28.7 Example 18 7323 Example 19 7213 Example 20 7493 21.0 Comparative Example 1 3020956 23.7 1.18 (Congestion) Comparative Example 2 5844796 26.1 0.32 (blocked) Comparative Example 3 2720956 23.6

[0091] As shown in Table 2 above, compared to the zeta potential of the synthesized amorphous silica used as a raw material, the zeta potential of the cationic modified silica in the aqueous dispersion obtained in the examples is higher. Therefore, it can be concluded that the manufacturing method of the examples can produce cationic modified silica with cationic groups bonded to its surface, synthesized amorphous silica.

[0092] Regarding the cationic modified silica aqueous dispersions of Comparative Examples 1 and 2, the filters became clogged and the filtration rate was low during the 5-minute filtration process. On the other hand, it was found that, compared to the aqueous dispersions of the comparative examples, the cationic modified silica aqueous dispersions obtained in the examples had fewer coarse particles and exhibited excellent filterability. Therefore, if the cationic modified silica aqueous dispersions of the examples with excellent filterability are used when manufacturing grinding compositions, fine-pore filters can be used, which helps to reduce the number of coarse particles in the grinding compositions.

[0093] (Example 21, Comparative Example 4) The cationic modified silica aqueous dispersion obtained in Example 7 was filtered using a 10 μm pore size filter (SLF type (deep type), manufactured by ROKI TECHNO Co., Ltd.). The filtered cationic modified silica aqueous dispersion was then dispersed in deionized water at a cationic modified silica concentration of 5.4% by mass, and the pH was adjusted to 4.0 using 10-camphor sulfonic acid. Furthermore, the cationic modified silica aqueous dispersion was filtered using a 0.2 μm pore size filter (Ultipor N66 (pleated type), manufactured by Nihon Pall Co., Ltd.) to prepare the grinding composition (slurry) of Example 21.

[0094] Furthermore, the cationic modified silica aqueous dispersion obtained in Comparative Example 1 was filtered using a 10 μm pore size filter (SLF type (deep type), manufactured by ROKI TECHNO Co., Ltd.). The filtered cationic modified silica aqueous dispersion was dispersed in deionized water at a cationic modified silica concentration of 5.4% by mass, and then the pH value was adjusted to 4.0 using 10-camphor sulfonic acid. Next, the cationic modified silica aqueous dispersion was filtered using a 3.0 μm pore size filter (SLF type (deep type), manufactured by ROKI TECHNO Co., Ltd.) to prepare the grinding composition (slurry) of Comparative Example 4.

[0095] Similarly, the number of coarse particles present in the grinding compositions of Example 21 and Comparative Example 4 was determined by LPC.

[0096] [Table 3] Table 3 Coarse particles (>0.7 μm) (pcs / mL) Example 21 3846 Comparative Example 4 1262791

[0097] As shown in Table 3 above, the number of coarse particles in the grinding composition of Example 21, which was obtained by adjusting the cationic modified silica aqueous dispersion in the aqueous dispersion obtained in the usage examples, is less than that in Comparative Example 4. By using a grinding composition with fewer coarse particles, defects during grinding can be suppressed.

[0098] This application is based on Japanese Patent Application No. 2021-86075 filed on May 21, 2021 and Japanese Patent Application No. 2022-36107 filed on March 9, 2022, the disclosures of which are incorporated herein by reference in their entirety.

Claims

1. A method for manufacturing a grinding composition, comprising: A dispersion containing silicon dioxide is mixed with a solution containing a solvent and a silane coupling agent having a cationic group at a concentration of 0.03% to 0.8% by mass to obtain a dispersion containing cationic modified silicon dioxide. The mixing includes adding the solution containing the silane coupling agent having a cationic group to the dispersion containing silicon dioxide. The solvent is water or a mixture of water and an organic solvent.

2. The manufacturing method of claim 1, wherein the mass ratio of the silicon dioxide and the silane coupling agent having a cationic group (silicon dioxide / silane coupling agent having a cationic group) is 100 / 0.05 to 100 / 0.

8.

3. The manufacturing method of claim 1 or 2, wherein the concentration of the silane coupling agent having a cationic group in the above solution is 0.05% by mass or more and 0.6% by mass or less.

4. The manufacturing method as claimed in claim 1 or 2, wherein the aforementioned silicon dioxide is colloidal silicon dioxide.

5. The manufacturing method as claimed in claim 1 or 2, wherein the aforementioned silane coupling agent having a cationic group is selected from 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, 3-aminopropyldimethoxymethylsilane, tri- At least one of the group consisting of methoxy[3-(methylamino)propyl]silane, trimethoxy[3-(phenylamino)propyl]silane, [3-(N,N-dimethylamino)propyl]trimethoxysilane, [3-(6-aminohexylamino)propyl]trimethoxysilane, N-methyl-3-(triethoxysilyl)propyl-1-amine, N-[3-(trimethoxysilyl)propyl]but-1-amine, and bis[(3-trimethoxysilyl)propyl]amine.

6. The manufacturing method of claim 1 or 2 further includes filtering the dispersion containing cationic modified silica.

7. The manufacturing method of claim 1 or 2, further comprising mixing the above-mentioned dispersion containing cationic modified silica with a pH adjuster.

8. The manufacturing method of claim 1 or 2, wherein the number of coarse particles with a particle size greater than 0.7 μm in the dispersion containing the above-mentioned cationic modified silica, as determined by the following determination method, is 500,000 particles / mL or less. (Determination method) After preparing an aqueous dispersion containing cationic modified silica by dispersing cationic modified silica in water at a concentration of 0.27% by mass and adjusting the pH value to 4.0, the number of coarse particles with a particle size greater than 0.7 μm present in the obtained aqueous dispersion containing the above-mentioned cationic modified silica per unit volume (1 mL) is determined using a liquid particle counter.

9. The manufacturing method of claim 6, wherein the filtration comprises a first stage filtration and a second stage filtration, wherein the pore size of the filter used in the second stage filtration is smaller than the pore size of the filter used in the first stage filtration.

10. The manufacturing method of claim 6, wherein the filtration comprises a first stage of filtration and a second stage of filtration, wherein the filter used in the second stage of filtration has a pore size of 0.05 μm or more and 0.4 μm or less.