Method for manufacturing chemical mechanical polishing compositions

Abstract

To provide a method for manufacturing a chemical mechanical polishing composition that can polish a semiconductor substrate containing a silicon nitride film at high speed while reducing the occurrence of surface defects on the polished surface after polishing.SOLUTION: A method for manufacturing a chemical mechanical polishing composition including (A) abrasive grains and (B) a liquid medium and having a pH of 1 or more and 5 or less, includes a first step of adding an acid to a composition containing the component (A) and the component (B) to prepare a dispersion liquid in which the zeta potential of the component (A) is 0 mV or more, and a second step of adding a phosphoric acid ester to the dispersion liquid obtained in the first step to prepare a composition for chemical mechanical polishing in which the zeta potential of the component (A) is less than 0 mV.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a method for producing chemical mechanical polishing compositions. [Background technology]

[0002] Chemical mechanical polishing (CMP) is used in semiconductor manufacturing processes, particularly in the planarization of interlayer insulating films, metal plug formation, and damascene wiring formation in multilayer wiring formation processes. In such semiconductor manufacturing processes, silicon oxide films and dense silicon nitride films with high dielectric constants are used as insulating film materials, and polishing characteristics that not only allow for high-speed polishing of these materials but also balance high flatness and low defect levels are required.

[0003] To achieve such balanced polishing characteristics, polishing compositions (slurries) for polishing silicon nitride films, for example, are being investigated (see, for example, Patent Documents 1-2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2008-235652 [Patent Document 2] International Publication No. 2017-057155 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] With the increasing miniaturization of semiconductor substrates in recent years, there is a need to polish semiconductor substrates containing silicon nitride films at high speed while simultaneously reducing the occurrence of surface defects on the polished surface after polishing. Therefore, there is a demand for chemical mechanical polishing compositions that can achieve both of these characteristics.

[0006] Some aspects of the present invention provide a method for manufacturing a chemical mechanical polishing composition that can reduce the generation of surface defects on the polished surface after polishing a semiconductor substrate containing a silicon nitride film at high speed by solving at least part of the above problems.

Means for Solving the Problems

[0007] The present invention has been made to solve at least part of the above problems and can be realized as any of the following aspects.

[0008] One aspect of the method for manufacturing a chemical mechanical polishing composition according to the present invention is a method for manufacturing a chemical mechanical polishing composition containing (A) abrasive grains and (B) a liquid medium and having a pH of 1 or more and 5 or less, a first step of adding an acid to the composition containing the component (A) and the component (B) to create a dispersion in which the zeta potential of the component (A) is 0 mV or more; a second step of adding a phosphate ester to the dispersion obtained in the first step to create a chemical mechanical polishing composition in which the zeta potential of the component (A) is less than 0 mV; and having.​​​​​​​​​​​​​​​​​​​​​​​The phosphate ester may be a compound represented by the following general formula (5). [ka] (In formula (5), R 4 (where n represents a hydrocarbon group with 2 or more carbon atoms but less than 7, n is between 0 and 2, and m is 1 or 2.) [Effects of the Invention]

[0013] According to the chemical mechanical polishing composition produced by the method of the present invention, semiconductor substrates containing silicon nitride films can be polished at high speed, and the occurrence of surface defects on the polished surface after polishing can be reduced. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic cross-sectional view showing a workpiece suitable for use with a chemical mechanical polishing composition produced by the method according to this embodiment. [Figure 2] This is a schematic cross-sectional view of the workpiece at the end of the first polishing process. [Figure 3] This is a schematic cross-sectional view of the workpiece at the end of the second polishing process. [Figure 4] This is a schematic perspective view of a chemical mechanical polishing apparatus. [Modes for carrying out the invention]

[0015] Preferred embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and includes various modifications that do not alter the essence of the invention.

[0016] In this specification, "wiring material" refers to conductive metal materials such as aluminum, copper, cobalt, titanium, ruthenium, and tungsten. "Insulating film material" refers to materials such as silicon oxide, silicon nitride, and amorphous silicon. "Barrier metal material" refers to materials such as tantalum nitride and titanium nitride that are used in lamination with wiring materials to improve the reliability of the wiring.

[0017] In this specification, numerical ranges described using "X~Y" are interpreted as including the numerical value X as the lower limit and the numerical value Y as the upper limit.

[0018] 1. Method for producing chemical mechanical polishing compositions A method for producing a chemical mechanical polishing composition according to one embodiment of the present invention is a method for producing a chemical mechanical polishing composition containing (A) abrasive grains (hereinafter also referred to as "component (A)") and (B) a liquid medium (hereinafter also referred to as "component (B)"), wherein the pH is 1 or more and 5 or less, A first step involves adding an acid to a composition containing component (A) and component (B) to prepare a dispersion in which the zeta potential of component (A) is 0 mV or higher; The phosphate ester is added to the dispersion obtained in the first step, and the phosphate of component (A) is added. The second step is to create a chemical mechanical polishing composition with a potential of less than 0 mV; It has.

[0019] The chemical mechanical polishing composition produced by the method according to this embodiment can be prepared as a concentrated stock solution and diluted with a liquid medium such as water before use.

[0020] The method for producing the chemical mechanical polishing composition according to this embodiment will be described step by step below.

[0021] 1.1.First step The first step is to add acid to a dispersion containing (A) abrasive particles and (B) a liquid medium that has been prepared in advance, in order to create a dispersion in which the zeta potential of component (A) is 0 mV or higher. In the first step, after adding acid to the dispersion containing (A) abrasive particles and (B) a liquid medium, it is desirable to stir at a temperature of preferably 10°C to 60°C, more preferably 20°C to 55°C, and particularly preferably 25°C to 50°C. The stirring method is not particularly limited, and any method can be applied as long as each component described later is uniformly dissolved or dispersed. Furthermore, there are no particular restrictions on the mixing order or mixing method of each component described later. The components that may be contained in the dispersion will be described in detail below.

[0022] 1.1.1. (A) Component (A) Component is preferably a particle mainly composed of silica. Examples of silica include fumed silica and colloidal silica, but colloidal silica is more preferred. Colloidal silica is preferably used from the viewpoint of reducing polishing defects such as scratches. As colloidal silica, for example, one manufactured by the method described in Japanese Patent Application Publication No. 2003-109921 can be used.

[0023] The shape of component (A) may be any of the following: spherical, cocoon-shaped, chain-sphere, or confetti-like with multiple protrusions on the surface. However, among these, it is preferable that it be a chain-sphere formed by three or more connected particles. "Chain-sphere" refers to a group of particles formed by three or more particles being linked together in one or more rows, and includes not only linear structures but also branched structures. When component (A) is a chain-sphere formed by three or more connected particles, the contact resistance with the silicon nitride film to be polished increases, enabling high-speed polishing of the silicon nitride film and potentially obtaining an appropriate selectivity ratio. To confirm whether component (A) is a chain-sphere formed by three or more connected particles, a sample of component (A) can be prepared by a conventional method and observed using a transmission electron microscope.

[0024] (A) The average primary particle diameter of the component is preferably 10 nm or more and 300 nm or less, more preferably 15 nm or more and 200 nm or less, and particularly preferably 20 nm or more and 100 nm or less. When the average primary particle diameter of the component (A) is within the above range, a sufficient polishing rate can be obtained, and a chemical mechanical polishing composition excellent in stability that does not cause sedimentation and separation of particles may be obtained. The average primary particle diameter of the component (A) can be determined by, for example, observing at 30,000 times with a transmission electron microscope (manufactured by Hitachi High-Technologies Corporation, model "H-7000"), measuring the particle diameters of arbitrarily selected 50 primary particles, and calculating from the measured values.

[0025] (A) At least a part of the surface of the component may be modified with a functional group as shown below.

[0026] (A) The component can have a functional group represented by the following general formula (1). -SO3 - M + ·····(1) (M + represents a monovalent cation.)

[0027] In the above formula (1), M + The monovalent cation represented by is not limited to these, and examples include H + , Li + , Na + , K + , NH4 + . That is, the functional group represented by the above general formula (1) can also be paraphrased as "at least one functional group selected from the group consisting of a sulfo group and its salts". Here, the "salt of a sulfo group" means that the hydrogen ion contained in the sulfo group (-SO3H) is replaced with Li + , Na + , K + , NH4 +This refers to a functional group substituted with a monovalent cation such as . Component (A) having the functional group represented by the above general formula (1) is an abrasive grain in which the functional group represented by the above general formula (1) is fixed to its surface via covalent bonds, and does not include abrasive grains in which a compound having the functional group represented by the above general formula (1) is physically or ionically adsorbed to its surface.

[0028] Component (A), having the functional group represented by the above general formula (1), can be produced, for example, by applying the method described in Japanese Patent Application Publication No. 2010-269985.

[0029] Component (A) may have a functional group represented by the following general formula (2). -COO - M + ...(2) (M + (This represents a monovalent cation.)

[0030] In the above formula (2), M + The monovalent cations represented by are not limited to these, but for example, H + Li + kaNa + , K + NH4 + These are examples. In other words, the functional group represented by the above general formula (2) can also be rephrased as "at least one functional group selected from the group consisting of carboxyl groups and their salts." Here, "salt of a carboxyl group" means a salt in which the hydrogen ions contained in the carboxyl group (-COOH) are Li + kaNa + , K + NH4 + This refers to a functional group substituted with a monovalent cation such as . Component (A) having the functional group represented by the above general formula (2) is an abrasive grain in which the functional group represented by the above general formula (2) is fixed to its surface via covalent bonds, and does not include abrasive grains in which a compound having the functional group represented by the above general formula (2) is physically or ionically adsorbed to its surface.

[0031] Component (A), having the functional group represented by the above general formula (2), can be manufactured, for example, by applying the method described in Japanese Patent Application Publication No. 2010-105896.

[0032] Component (A) may have a functional group represented by the following general formula (3) or the following general formula (4). -NR 1 R 2 ...(3) -N + R 1 R 2 R 3 M - ...(4) (In equations (3) and (4) above, R 1 , R 2 and R 3 Each of these independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group. - (This represents an anion.)

[0033] The functional group represented by the above general formula (3) represents an amino group, and the functional group represented by the above general formula (4) represents a salt of an amino group. Therefore, the functional group represented by the above general formula (3) and the functional group represented by the above general formula (4) can be collectively rephrased as "at least one functional group selected from the group consisting of amino groups and salts thereof." Component (A) having the functional group represented by the above general formula (3) or the above general formula (4) is an abrasive grain in which the functional group represented by the above general formula (3) or the above general formula (4) is fixed to its surface via covalent bonds, and does not include abrasive grains in which a compound having the functional group represented by the above general formula (3) or the above general formula (4) is physically or ionically adsorbed to its surface.

[0034] In the above formula (4), M - The anions represented by these are not limited to these, but for example, OH - F - Cl - , Br - , I - 5CN - In addition to anions such as those mentioned above, anions derived from acidic compounds Ions are one example.

[0035] In equations (3) and (4) above, R 1 ~R 3 Each of these independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, but R 1 ~R 3 Two or more of these may be bonded together to form a ring structure.

[0036] R 1 ~R 3 The hydrocarbon group represented by may be any of the following: an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an aromatic aliphatic hydrocarbon group, or an alicyclic hydrocarbon group. Furthermore, the aliphatic group of the aliphatic hydrocarbon group and the aromatic aliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or branched. Examples of these hydrocarbon groups include linear, branched, and cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups.

[0037] As the alkyl group, a lower alkyl group having 1 to 6 carbon atoms is preferred, and a lower alkyl group having 1 to 4 carbon atoms is more preferred. Examples of such alkyl groups include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group, iso-hexyl group, sec-hexyl group, tert-hexyl group, cyclopentyl group, and cyclohexyl group.

[0038] As the alkenyl group, a lower alkenyl group having 1 to 6 carbon atoms is preferred, and a lower alkenyl group having 1 to 4 carbon atoms is more preferred. Examples of such alkenyl groups include vinyl group, n-propenyl group, iso-propenyl group, n-butenyl group, iso-butenyl group, sec-butenyl group, tert-butenyl group, and the like.

[0039] As the aralkyl group, those having 7 to 12 carbon atoms are preferred. Examples of such aralkyl groups include benzyl group, phenethyl group, phenylpropyl group, phenylbutyl group, phenylhexyl group, methylbenzyl group, methylphenethyl group, and ethylbenzyl group.

[0040] The aryl group is preferably one having 6 to 14 carbon atoms. Examples of such aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,5-xylyl, naphthyl, and anthyl groups.

[0041] The aromatic rings of the aryl and aralkyl groups described above may have substituents such as lower alkyl groups like methyl or ethyl groups, halogen atoms, nitro groups, amino groups, or hydroxyl groups.

[0042] Component (A), having a functional group represented by the above general formula (3) or (4), can be produced by preparing silica by applying the methods described in Japanese Patent Publication No. 2007-153732 and Japanese Patent Publication No. 2013-121631, then thoroughly stirring the silica and an amino group-containing silane coupling agent in an acidic medium to covalently bond the amino group-containing silane coupling agent to the surface of the silica. Examples of amino group-containing silane coupling agents include 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

[0043] A commercially available product of component (A) having a functional group represented by the above general formula (3) or the following general formula (4) is KLEBOSOL® 1598-B25 surface-modified colloidal silica particles (manufactured by AZ Electronics Materials, available from The Dow Chemical Company, Midland, MI). Examples include FUSO® BS-3 and PL-3 (Fuso Chemical Co., Ltd., Osaka, Japan).

[0044] The content of component (A) in the dispersion used in the first step is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and particularly preferably 0.5 parts by mass or more, when the total mass of the dispersion is 98 parts by mass. The content of component (A) in the dispersion is preferably 15 parts by mass or less, more preferably 8 parts by mass or less, and particularly preferably 5 parts by mass or less, when the total mass of the dispersion is 98 parts by mass. When the content of component (A) in the dispersion is within the above range, aggregation of components (A) can be prevented, and a dispersion with excellent dispersibility can be easily obtained.

[0045] 1.1.2.(B) Liquid media (B) Examples of component (B) include water, a mixed medium of water and alcohol, and a mixed medium containing water and an organic solvent that is compatible with water. Among these, it is preferable to use water, a mixed medium of water and alcohol, and it is more preferable to use water. There are no particular restrictions on the type of water, but pure water is preferred. Water only needs to be included as the remainder of the components of the dispersion, and there are no particular restrictions on the water content.

[0046] 1.1.3. Acids In the first step, by adding acid to a dispersion containing the pre-prepared components (A) and (B) to adjust the pH to between 1 and 5, the zeta potential of the dispersion of component (A) can be adjusted to 0 mV or higher.

[0047] Examples of acids include organic acids, inorganic acids, and their salts.

[0048] The organic acids and their salts are preferably compounds having a carboxyl group or a sulfo group. Examples of compounds having a carboxyl group include stearic acid, lauric acid, oleic acid, myristic acid, alkenyl succinic acid, lactic acid, tartaric acid, fumaric acid, glycolic acid, phthalic acid, maleic acid, formic acid, acetic acid, oxalic acid, citric acid, malic acid, malonic acid, glutaric acid, succinic acid, glycolic acid, benzoic acid, phthalic acid, trimellitic acid, quinolinic acid, quinaldic acid, propionic acid, trifluoroacetic acid; amino acids such as glycine, alanine, aspartic acid, glutamic acid, lysine, arginine, tryptophan, dodecylaminoethylaminoethylglycine, aromatic amino acids, heterocyclic amino acids, etc.; imino acids such as alkyliminodicarboxylic acids; and salts thereof. Examples of compounds having a sulfo group include alkylbenzenesulfonic acids such as dodecylbenzenesulfonic acid and p-toluenesulfonic acid; alkylnaphthalenesulfonic acids such as butylnaphthalenesulfonic acid; α-olefin sulfonic acids such as tetradecenesulfonic acid; amide sulfonic acid; and salts thereof. These compounds may be used individually or in combination of two or more.

[0049] Examples of inorganic acids and their salts include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and salts thereof. These compounds may be used individually or in combination of two or more.

[0050] In the first step, the amount of acid added to the dispersion is preferably 0.001 parts by mass or more, and more preferably 0.01 parts by mass or more, when the total mass of the dispersion is 98 parts by mass. In the first step, the amount of acid added to the dispersion is preferably 5 parts by mass or less, and more preferably 1 part by mass or less, when the total mass of the dispersion is 98 parts by mass. When the amount of acid added to the dispersion in the first step is within the above range, the pH of the dispersion can be easily adjusted to 1 or more and 5 or less.

[0051] In the first step, the pH of the dispersion is 5 or less, preferably 4 or less. In the first step, the pH of the dispersion is 1 or more, preferably 2 or more, and particularly preferably 2.5 or more. When the pH of the dispersion in the first step is within the above range, the zeta potential of component (A) in the dispersion can be made 0 mV or more.

[0052] In this invention, pH refers to the hydrogen ion concentration, and its value can be measured using a commercially available pH meter (for example, a benchtop pH meter manufactured by Horiba, Ltd.) under conditions of 25°C and 1 atmosphere.

[0053] The zeta potential of component (A) is 0 mV or higher in the dispersion after acid addition. The zeta potential of component (A) is preferably +1 mV or higher, more preferably +3 mV or higher, and particularly preferably +6 mV or higher in the dispersion after acid addition. When the zeta potential of component (A) is within the above range, aggregation of particles can be prevented in the dispersion due to electrostatic repulsion between abrasive grains. Examples of zeta potential measuring devices include the "ELSZ-2000ZS" manufactured by Otsuka Electronics Co., Ltd. and the "Zetasizer nano Ultra" manufactured by Malvern.

[0054] 1.2.Second process The second step is to add a phosphate ester to the dispersion obtained in the first step to create a chemical mechanical polishing composition in which the zeta potential of component (A) is less than 0 mV. It is presumed that the phosphate ester adsorbs to component (A), thereby lowering and reversing the zeta potential of component (A). In the second step, after adding the phosphate ester to the dispersion obtained in the first step, it is desirable to stir the mixture at a temperature of preferably 10°C to 40°C, more preferably 15°C to 40°C, and particularly preferably 20°C to 35°C. The stirring method is not particularly limited, and any method that can uniformly dissolve or disperse the phosphate ester may be applied.

[0055] The content of component (A) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and particularly preferably 0.5 parts by mass or more, when the total mass of the chemical mechanical polishing composition is 100 parts by mass. The content of component (A) is preferably 15 parts by mass or less, more preferably 8 parts by mass or less, and particularly preferably 5 parts by mass or less, when the total mass of the chemical mechanical polishing composition is 100 parts by mass. When the content of component (A) in the chemical mechanical polishing composition is within the above range, aggregation of components (A) can be prevented, and a chemical mechanical polishing composition with excellent dispersibility can be easily obtained.

[0056] The following describes in detail the components that may be included in chemical mechanical polishing compositions.

[0057] 1.2.1. Phosphate Esters Generally, "phosphate ester" refers to a group of compounds having a structure in which all or some of the three hydrogen atoms of phosphoric acid (O=P(OH)3) are replaced by organic groups. The phosphate ester used in the second step is not particularly limited as long as it has such a structure, but it is preferably a compound represented by the following general formula (5).

[0058] [ka] (In formula (5), R 4 (where n represents a hydrocarbon group with 2 or more carbon atoms but less than 7, n is between 0 and 2, and m is 1 or 2.)

[0059] In the above equation (5), R 4R is a hydrocarbon group having 2 or more carbon atoms but less than 7 carbon atoms, preferably an alkyl group having 4 or more carbon atoms but less than 6 carbon atoms. Specific examples of hydrocarbon groups having 2 or more carbon atoms but less than 7 carbon atoms include ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group, iso-hexyl group, sec-hexyl group, tert-hexyl group, etc. In formula (5) above, when m=2, there are two R 4 These may be the same group, different groups, or two groups combined.

[0060] Specific examples of phosphate esters include monoethyl phosphate, ethyl acid phosphate, mono-n-butyl phosphate, dibutyl phosphate, butyl acid phosphate, butoxyethyl acid phosphate, mono(2-ethylhexyl) phosphate, bis(2-ethylhexyl) phosphate, 2-ethylhexyl acid phosphate, and mono-n-lauryl phosphate. These phosphate esters may be used individually or in combination of two or more. Furthermore, these phosphate esters include monoesters and diesters, and monoesters or diesters may be used individually or as a mixture of monoesters and diesters.

[0061] The amount of phosphate ester added is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and particularly preferably 0.1 parts by mass or more, when the total mass of the chemical mechanical polishing composition is 100 parts by mass. The amount of phosphate ester added is preferably 5 parts by mass or less, more preferably 1 part by mass or less, and particularly preferably 0.5 parts by mass or less, when the total mass of the chemical mechanical polishing composition is 100 parts by mass. When the amount of phosphate ester added is within the above range, the zeta potential of component (A) in the chemical mechanical polishing composition can be easily reversed to less than 0 mV.

[0062] The pH of the chemical mechanical polishing composition obtained through the second step is preferably 7 or less, more preferably 6 or less, and particularly preferably 4 or less. The pH of the chemical mechanical polishing composition obtained through the second step is preferably 1 or more, more preferably 2 or more, and particularly preferably 3 or more. When the pH of the obtained chemical mechanical polishing composition is within the above range, the absolute value of the zeta potential of component (A) in the chemical mechanical polishing composition increases, improving dispersibility, and thus enabling high-speed polishing while reducing the occurrence of surface defects in semiconductor substrates containing silicon nitride films.

[0063] 1.2.2. Other Ingredients In the second step, in addition to the phosphate ester, the above-mentioned acids, water-soluble polymers, nitrogen-containing heterocyclic compounds, surfactants, basic compounds, etc. may be added as needed.

[0064] <Water-soluble polymer> Water-soluble polymers can adsorb to the surface of the surface being polished, reducing polishing friction and potentially minimizing the occurrence of dishing on the polished surface.

[0065] Specific examples of water-soluble polymers include polycarboxylic acids, polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polyethers, polyacrylamide, polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, polyethyleneimine, polyallylamine, and hydroxyethylcellulose. These may be used individually or in combination of two or more.

[0066] The weight-average molecular weight (Mw) of the water-soluble polymer is preferably between 5,000 and 1,500,000, and more preferably between 20,000 and 1,000,000. Here, "weight-average molecular weight" refers to the weight-average molecular weight in terms of polyethylene glycol, measured by GPC (gel permeation chromatography).

[0067] The amount of water-soluble polymer added is preferably 0.001 parts by mass or more, and more preferably 0.002 parts by mass or more, when the total mass of the chemical mechanical polishing composition is 100 parts by mass. The amount of water-soluble polymer added is preferably 0.1 parts by mass or less, and more preferably 0.01 parts by mass or less, when the total mass of the chemical mechanical polishing composition is 100 parts by mass.

[0068] <Nitrogen-containing heterocyclic compounds> A "nitrogen-containing heterocyclic compound" refers to an organic compound containing at least one heterocyclic ring selected from heterocyclic five-membered rings and heterocyclic six-membered rings, each having at least one nitrogen atom. Specific examples of the heterocyclic rings include heterocyclic five-membered rings such as pyrrole structures, imidazole structures, and triazole structures; and heterocyclic six-membered rings such as pyridine structures, pyrimidine structures, pyridazine structures, and pyrazine structures. These heterocyclic rings may form fused rings. Specifically, examples include indole structures, isoindole structures, benzimidazole structures, benzotriazole structures, quinoline structures, isoquinoline structures, quinazoline structures, cinnoline structures, phthalazine structures, quinoxaline structures, and acridine structures. Among heterocyclic compounds having such structures, heterocyclic compounds having pyridine structures, quinoline structures, benzimidazole structures, and benzotriazole structures are preferred.

[0069] Specific examples of nitrogen-containing heterocyclic compounds include aziridine, pyridine, pyrimidine, pyrrolidine, piperidine, pyrazine, triazine, pyrrole, imidazole, indole, quinoline, isoquinoline, benzoisoquinoline, purine, pteridine, triazole, triazolidine, benzotriazole, carboxybenzotriazole, and derivatives having these skeletons. Among these, it is preferable to use at least one selected from benzotriazole and triazole. These nitrogen-containing heterocyclic compounds may be used individually or in combination of two or more.

[0070] <Surfactants> The surfactant is not particularly limited, and anionic surfactants, cationic surfactants, nonionic surfactants, etc., can be used. Examples of anionic surfactants include sulfates such as alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates; and fluorine-containing surfactants such as perfluoroalkyl compounds. Examples of cationic surfactants include aliphatic amine salts and aliphatic ammonium salts. Examples of nonionic surfactants include nonionic surfactants having triple bonds such as acetylene glycol, acetylene glycol ethylene oxide adducts, and acetylene alcohols; and polyethylene glycol-type surfactants. These surfactants may be used individually or in combination of two or more.

[0071] <Basic compounds> Basic compounds include organic bases and inorganic bases. Preferred organic bases are amines, such as triethylamine, monoethanolamine, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, benzylamine, methylamine, ethylenediamine, diglycolamine, and isopropylamine. Examples of inorganic bases include ammonia, potassium hydroxide, and sodium hydroxide. Among these basic compounds, ammonia and potassium hydroxide are preferred. These basic compounds may be used individually or in combination of two or more.

[0072] 1.3.Applications The chemical mechanical polishing composition produced by the method according to this embodiment is suitable as a polishing material for chemical mechanical polishing semiconductor substrates having multiple types of materials constituting a semiconductor device. The semiconductor substrate to be polished may have insulating film materials such as silicon oxide, silicon nitride, and amorphous silicon, as well as wiring materials such as tungsten and cobalt, and barrier metal materials such as titanium, titanium nitride, and tantalum nitride.

[0073] The target of polishing with the chemical mechanical polishing composition produced by the method according to this embodiment is preferably a semiconductor substrate having a portion containing a silicon nitride film. A specific example of such a semiconductor substrate is, for example, a semiconductor substrate in which a silicon oxide film is applied as a substrate to the silicon nitride film, as shown in Figure 1. The chemical mechanical polishing composition produced by the method according to this embodiment can polish the silicon nitride film on the silicon oxide film at high speed and reduce the occurrence of surface defects on the polished surface after polishing.

[0074] 2. Polishing method A polishing method according to one embodiment of the present invention includes the step of polishing a semiconductor substrate using a chemical mechanical polishing composition manufactured by the method described above. The chemical mechanical polishing composition manufactured by the method described above can polish a semiconductor substrate having a portion containing a silicon nitride film at high speed and can reduce the occurrence of surface defects on the polished surface after polishing. Therefore, the polishing method according to this embodiment is particularly suitable when polishing a semiconductor substrate in which a silicon oxide film is applied as a base for a silicon nitride film. A specific example of the polishing method according to this embodiment will be described in detail below with reference to the drawings.

[0075] 2.1. Object to be processed Figure 1 is a schematic cross-sectional view showing a workpiece suitable for use in a polishing method using a chemical mechanical polishing composition manufactured by the method according to this embodiment. The workpiece 100 is formed by going through the following steps (1) to (4).

[0076] (1) First, a substrate 10 is prepared as shown in Figure 1. The substrate 10 may consist of, for example, a silicon substrate and a silicon oxide film formed thereon. Furthermore, functional devices such as transistors (not shown) may be formed on the substrate 10. Next, a first silicon oxide film (thermal oxide film) 12, which is an insulating film, is formed on the substrate 10 using a thermal oxidation method.

[0077] (2) Next, a second silicon oxide film 14 is formed on the first silicon oxide film 12. The second silicon oxide film 14 can be formed, for example, by chemical vapor deposition (CVD).

[0078] (3) Next, a photosensitive resist film is deposited on the second silicon oxide film 14 using a spin coater, selectively exposed with a photomask, and developed. Then, plasma is irradiated to etch the areas without resist. After that, the protected resist is removed.

[0079] (4) Next, a silicon nitride film 16 with a thickness of 1,500 to 2,500 Å is deposited by chemical vapor deposition (CVD). By going through steps (1) to (4) as described above, the workpiece 100 can be manufactured.

[0080] 2.2. Polishing method 2.2.1.First polishing process Figure 2 is a schematic cross-sectional view showing the workpiece 100 at the end of the first polishing process. As shown, the first polishing step is a step of roughly polishing the silicon nitride film 16 using a chemical mechanical polishing composition that can polish the silicon nitride film 16 at high speed. In the first polishing step, because a chemical mechanical polishing composition that can polish the silicon nitride film at high speed is used, surface defects called dishing, as shown in Figure 2, may occur on the surface of the silicon nitride film 16.

[0081] 2.2.2.Second polishing process Figure 3 is a schematic cross-sectional view of the workpiece 100 at the end of the second polishing step. As shown in Figure 3, the second polishing step is a step in which the second silicon oxide film 14 and the silicon nitride film 16 are polished to planarize them using a chemical mechanical polishing composition manufactured by the method according to this embodiment. The above-mentioned chemical mechanical polishing composition can control the polishing speed of the silicon nitride film 16 in a balanced manner, thereby reducing the occurrence of dishing of the silicon nitride film 16, and the exposed second silicon oxide film 14 and silicon nitride film 16 can be planarized by polishing them at high speed and in a balanced manner. In addition, since the above-mentioned chemical mechanical polishing composition has good dispersibility of component (A), the occurrence of polishing scratches on the polished surface can be reduced.

[0082] 2.3.Chemical mechanical polishing equipment For the first and second polishing steps described above, a polishing apparatus 200, such as the one shown in Figure 4, can be used. Figure 4 is a schematic perspective view of the polishing apparatus 200. The first and second polishing steps described above are performed by supplying slurry (composition for chemical mechanical polishing) 44 from a slurry supply nozzle 42 and rotating a turntable 48 to which an abrasive cloth 46 is attached, while bringing a carrier head 52 holding a semiconductor substrate 50 into contact with it. A water supply nozzle 54 and a dresser 56 are also shown in Figure 4.

[0083] The polishing load of the carrier head 52 can be selected within the range of 0.7 to 70 psi, preferably 1.5 to 35 psi. The rotational speed of the turntable 48 and the carrier head 52 can be appropriately selected within the range of 10 to 400 rpm, preferably 30 to 150 rpm. The flow rate of the slurry (chemical mechanical polishing composition) 44 supplied from the slurry supply nozzle 42 can be selected within the range of 10 to 1,000 mL / min, preferably 50 to 400 mL / min.

[0084] Examples of commercially available polishing equipment include models "EPO-112" and "EPO-222" from Ebara Corporation; models "LGP-510" and "LGP-552" from Lappmaster SFT Corporation; models "Mirra," "Reflexion," and "Reflexion LK" from Applied Materials Corporation; and models "POLI-400L" and "POLI-762" from G&P Technology Corporation.

[0085] 3. Examples The present invention will be described below with reference to examples, but the present invention is not limited in any way by these examples. In these examples, "parts" and "%" are based on mass unless otherwise specified.

[0086] 3.1. Preparation of abrasive grains <Preparation of abrasive grain A> 102.6 g of tetramethyl orthosilicate (TMOS) was weighed into a 300 mL Erlenmeyer flask. This TMOS was added to 347.4 g of pure water weighed into a 1 L Erlenmeyer flask while stirring. The reaction solution, which was initially opaque, became a clear, homogeneous solution after 15 minutes due to the progression of the hydrolysis reaction. The reaction was continued for 1 hour to prepare 450 g of TMOS hydrolysate with a silica concentration of 9% by mass.

[0087] A four-necked flask (3L) equipped with a thermometer, a Liebig condenser, a distilling head with a thermometer for checking the steam temperature, an activated silicate aqueous solution feed tube, and a stirrer was prepared by adding 2250g of pure water and a predetermined amount of ethylenediamine as an alkaline catalyst to a mother liquor. This was heated, and when it reached a flux state, the feeding of the TMOS hydrolysate was started. The addition rate was 2.5 mL / min (5.9 g silica / hour / kg mother liquor). After the feeding of the hydrolysate was completed, it was held in that state for 30 minutes. Then, 4.5 g of a 1 mmol / g aqueous solution of the above alkaline catalyst was added to adjust the pH to 8-9. Thereafter, while adding the alkaline catalyst aqueous solution as needed to maintain a pH of 8, the TMOS hydrolysate was prepared and added in the above manner every 3 hours. A total of 12 TMOS hydrolysates were prepared and added. After that, residual methanol was replaced / removed with water, and the solution was heated and concentrated until the silica concentration reached 20%. After concentration, the mixture was filtered through a 3 μm mixed cellulose membrane filter (manufactured by Toyo Roshi Co., Ltd.) to obtain an aqueous dispersion containing abrasive particles A.

[0088] The abrasive particles A contained in the aqueous dispersion were observed at 30,000x magnification using a transmission electron microscope (Hitachi High-Tech Corporation, model "H-7000"). When 50 particles were randomly selected and observed, it was confirmed that all of them were in a chain-spherical shape formed by the linkage of three or more particles. Furthermore, the average primary particle size of the 50 randomly selected abrasive particles A was measured to be 28 nm.

[0089] <Preparation of abrasive grain B> Capacity 2000cm 3 In a flask, 70 g of 25% by mass aqueous ammonia, 40 g of deionized water, 175 g of ethanol, and 21 g of tetraethoxysilane were added, and the mixture was heated to 60°C while stirring at 180 rpm. After stirring at 60°C for 1 hour, the mixture was cooled to obtain a colloidal silica / alcohol dispersion. Next, using an evaporator, the alcohol was removed from the dispersion by repeatedly adding deionized water at 80°C to the dispersion, thereby preparing an aqueous dispersion containing abrasive particles B with a solid content of 15%.

[0090] The abrasive particles B contained in the aqueous dispersion were observed at 30,000x magnification using a transmission electron microscope (Hitachi High-Tech Corporation, model "H-7000"). Fifty particles were randomly selected and observed, and it was confirmed that all of them were cocoon-shaped. Furthermore, the average primary particle size of the 50 randomly selected abrasive particles B was measured to be 35 nm.

[0091] <Preparation of abrasive grain C> An aqueous dispersion containing abrasive particles C with a silica concentration of 13.7% by mass and a pH of 7.7 was prepared according to Example 7 described in Japanese Patent Publication No. 2007-153732.

[0092] The abrasive particles C contained in the aqueous dispersion were observed at 30,000x magnification using a transmission electron microscope (Hitachi High-Tech Corporation, model "H-7000"). When 50 particles were randomly selected and observed, it was confirmed that they had a shape with multiple protrusions on their surface. Furthermore, the average primary particle size of the 50 randomly selected abrasive particles C was measured to be 30 nm.

[0093] <Preparation of abrasive grain D> 5000 g of the aqueous dispersion containing abrasive grain A obtained above was mixed with 2 g of 3-aminopropyltrimethoxysilane, and heated under reflux for 4 hours to obtain an aqueous dispersion containing 19% by mass of abrasive grain D, in which amino groups are immobilized on the surface of abrasive grain A.

[0094] The abrasive particles D contained in the aqueous dispersion were observed at 30,000x magnification using a transmission electron microscope (Hitachi High-Tech Corporation, model "H-7000"), and the average primary particle size of 50 randomly selected abrasive particles D was measured to be 28 nm.

[0095] <Preparation of abrasive grains E> 5000 g of the aqueous dispersion containing abrasive grain A obtained above was mixed with 2 g of 3-mercaptopropyltrimethoxysilane and heated under reflux for 2 hours to obtain a thiolated silica sol. Hydrogen peroxide was added to the silica sol and heated under reflux for 8 hours to obtain an aqueous dispersion containing 19% by mass of abrasive grain E, in which sulfo groups were immobilized on the surface of abrasive grain A.

[0096] The abrasive particles E contained in the aqueous dispersion were observed at 30,000x magnification using a transmission electron microscope (Hitachi High-Tech Corporation, model "H-7000"), and the average primary particle size of 50 randomly selected abrasive particles E was measured to be 29 nm.

[0097] <Preparation of abrasive grains F> 5000 g of the aqueous dispersion containing the abrasive grains A obtained above was mixed with 5 g of (3-triethoxysilyl)propyl succinic anhydride, heated under reflux for 4 hours, and then cooled to obtain an aqueous dispersion containing 20% ​​by mass of abrasive grains F, on which carboxyl groups are immobilized on the surface of abrasive grains A.

[0098] The abrasive particles F contained in the aqueous dispersion were observed at 30,000x magnification using a transmission electron microscope (Hitachi High-Tech Corporation, model "H-7000"), and the average primary particle size of 50 randomly selected abrasive particles F was measured to be 29 nm.

[0099] 3.2. Preparation of chemical mechanical polishing compositions 3.2.1. Examples 1-12 and Comparative Examples 1-4 <First step> The dispersions for each example and comparative example were prepared by adding abrasive grains to a 10L polyethylene bottle to a predetermined concentration in the first step described in Table 1 or Table 2, adding acid to achieve the composition shown in Table 1 or Table 2, further adjusting with an aqueous ammonia solution to achieve the pH shown in Table 1 or Table 2, and finally adding (B) pure water as a liquid medium to adjust the total volume of the resulting dispersion to 98 parts by mass. The zeta potential of the abrasive grains was measured for each dispersion obtained in this way using a zeta potential measuring device (Malvern, model "Zetasizer Ultra") and the results are shown in Table 1 or Table 2.

[0100] <Second process> The chemical mechanical polishing compositions for each example and comparative example were prepared by adding each component to the dispersion prepared in "3.2.1. First Step" in order to achieve the content shown in Table 1 or Table 2, further adjusting the pH with an aqueous ammonia solution to the pH shown in Table 1 or Table 2, and finally adding (B) pure water as a liquid medium to adjust the total amount of the chemical mechanical polishing composition obtained to 100 parts by mass. The zeta potential of the abrasive grains was measured for each chemical mechanical polishing composition obtained in this way using a zeta potential measuring device (Malvern, model "Zetasizer Ultra") and the results are shown in Table 1 or Table 2.

[0101] 3.2.2. Comparative Examples 5-6 The mixture was added to a 10L polyethylene bottle and mixed with acid, phosphate ester, other additives, and pure water to achieve the composition shown in Table 3. The pH was then adjusted with an aqueous ammonia solution to the level shown in Table 3. Finally, abrasive grains were added to obtain a chemical mechanical polishing composition containing abrasive grains synthesized in a single step without going through the first and second steps. The zeta potential of the abrasive grains was measured for each obtained chemical mechanical polishing composition using a zeta potential measuring device (Malvern, model "Zetasizer Ultra"), and the results are shown in Table 3.

[0102] 3.3. Evaluation Method 3.3.1. Polishing Speed ​​Evaluation Using the chemical mechanical polishing composition obtained above, a 12-inch diameter wafer with a 200nm silicon nitride film and a 12-inch diameter wafer with a 1000nm silicon oxide film were prepared respectively. The workpiece was subjected to a 60-second chemical mechanical polishing test under the following polishing conditions. <Polishing conditions> • Polishing equipment: Applied Materials, model "Reflexion LK" • Polishing pad: Nitta DuPont, "IC1000XYP" ·Chemical mechanical polishing composition supply rate: 300mL / min • Plate rotation speed: 87 rpm • Head rotation speed: 93 rpm • Head pressure: 2 psi Polishing speed (Å / min) = (Thickness of film before polishing (Å) - Thickness of film after polishing (Å)) / Polishing time (minutes)

[0103] The thicknesses of the silicon nitride film and silicon oxide film were calculated by measuring the refractive index using a non-contact optical film thickness measuring device (SCREEN Holdings Co., Ltd., model "VM-1310").

[0104] The evaluation criteria for polishing speed are as follows. The polishing speeds of silicon nitride films and silicon oxide films, along with their evaluation results, are shown in Tables 1 to 3. (Evaluation Criteria) • "A"...When the polishing speed of the silicon nitride film is 100 Å / min or more, the polishing time in actual semiconductor polishing can be significantly reduced, so it was judged to be good. • "B" ... If the polishing speed of the silicon nitride film is less than 100 Å / min, the polishing speed is too low and it is difficult to use in practical applications, so it was judged to be defective.

[0105] 3.3.2. Defect Assessment Using the chemical mechanical polishing composition obtained above, a 12-inch diameter wafer with a 200 nm silicon nitride film was used as the workpiece, and a chemical mechanical polishing test was performed for 60 seconds under the following polishing conditions. Subsequently, a surface cleaning treatment was performed under the following conditions, and finally, brush scrubbing was performed under the following conditions. <Chemical mechanical polishing conditions> • Polishing equipment: Applied Materials, model "Reflexion LK" • Polishing pad: Nitta DuPont, "IC1000XYP" ·Chemical mechanical polishing composition supply rate: 300mL / min • Plate rotation speed: 87 rpm • Head rotation speed: 93 rpm • Head pressure: 2 psi <Conditions for cleaning the surface plate> • Treatment agent: Ultrapure water • Head rotation speed: 70 rpm • Head load: 100g / cm2 • Plate rotation speed: 71 rpm • Treatment agent supply rate: 300 mL / min Processing time: 30 seconds <Brush scrub cleansing> • Treatment agent: Ultrapure water • Upper brush rotation speed: 400 rpm Lower brush rotation speed: 400 rpm • Board rotation speed: 50 rpm • Treatment agent supply rate: 1200 mL / min • Processing time: 40 seconds

[0106] The wafer surface obtained after this processing was then inspected for defects using a wafer defect inspection device (KLA-Tencor, model number "SP-1") to measure the number of defects on the entire wafer surface. The results are shown in Tables 1 to 3. The evaluation criteria are as follows.

[0107] The evaluation criteria for defect assessment are as follows. The evaluation results are shown in Tables 1 to 3. (Evaluation Criteria) • "A" ... If the number of defects is less than 100, it is judged to be good. • "B" ... If the number of defects is 100 or more, it is judged to be defective.

[0108] 3.4. Evaluation Results Tables 1 to 3 show the composition and evaluation results of the chemical mechanical polishing compositions obtained in each example and comparative example.

[0109] [Table 1]

[0110] [Table 2]

[0111] [Table 3]

[0112] Each component in Tables 1 to 3 was obtained using the following products or reagents. <Abrasive grains> • Abrasive grain A: Chain-spherical colloidal silica prepared above, average primary particle size 28 nm • Abrasive grain B: Cocoon-shaped colloidal silica prepared as described above, with an average primary particle size of 35 nm. • Abrasive grain C: Colloidal silica with multiple protrusions on the surface prepared above, with an average primary particle size of 30 nm • Abrasive grain D: Colloidal silica with the surface of abrasive grain A modified with amino groups, average primary particle size 28 nm • Abrasive grain E: Colloidal silica with the surface of abrasive grain A modified with sulfo groups, average primary particle size 29 nm • Abrasive grain F: Colloidal silica with the surface of abrasive grain A modified with carboxyl groups, average primary particle size 29 nm <acid> • Maleic acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Maleic acid" • Citric acid: Manufactured by Fuso Chemical Industry Co., Ltd., product name "Purified Citric Acid (Crystals) L" ·Malonic acid: Manufactured by Tokyo Kasei Kogyo Co., Ltd., product name “Malonic Acid” • Sulfuric acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Sulfuric Acid" (10% aqueous solution) • Nitric acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Nitric Acid (1.38)" (60% aqueous solution) • Phosphoric acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Phosphoric Acid" <Phosphate esters> • Butoxyethyl acid phosphate: Manufactured by Johoku Chemical Co., Ltd., product name "JP-506H" • Monoethyl phosphate: Manufactured by Johoku Chemical Co., Ltd., product name "JAMP-2" • Mono-n-butyl phosphate: Manufactured by Johoku Chemical Co., Ltd., product name "JAMP-4" • 2-Ethylhexyl acid phosphate: Manufactured by Johoku Chemical Co., Ltd., product name "JP-508" • Mono-n-lauryl phosphate: Manufactured by Johoku Chemical Co., Ltd., product name "JAMP-12" <Other additives> (organic acid) • Acetic acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Acetic Acid" Glycolic acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Glycolic Acid" • Trimellitic acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "Trimellitic acid" (Water-soluble polymer) • Polyethylene glycol: Manufactured by Toho Chemical Industry Co., Ltd., product name "PEG-400" • Polyacrylic acid: Manufactured by Toagosei Co., Ltd., product name "Jurimar AC-10L"

[0113] Examples 1 to 12 show that by using a chemical mechanical polishing composition manufactured by the method of the present invention, silicon nitride films can be polished at high speed, and surface defects on the polished surface can be reduced.

[0114] Comparative Examples 1 and 2 are examples in which abrasive grains with an absolute value of 0 mV or higher zeta potential in the chemical mechanical polishing composition were used instead of using phosphate ester in the second step. In this case, the polishing speed of the silicon nitride film decreased, resulting in unsatisfactory results.

[0115] Comparative Examples 3 and 4 are examples in which abrasive grains with a zeta potential of less than 0 mV in the dispersion obtained after the first step were used. In this case, the phosphate ester does not adsorb to the abrasive grains, and the abrasive grains themselves have high anionic properties, resulting in a large electrostatic attraction with the positively charged silicon nitride film. As a result, the interaction becomes high, leading to many defects due to abrasive grain residue on the silicon nitride film and unsatisfactory results.

[0116] Furthermore, Comparative Examples 5 and 6 are examples in which the chemical mechanical polishing composition had the same composition as Example 3 and Example 1, respectively, but was prepared without going through the first and second steps. In these cases, the phosphate ester did not adsorb efficiently to the abrasive grains, causing the abrasive grains to aggregate. The aggregated abrasive grains resulted in many surface defects on the silicon nitride film, leading to unsatisfactory results.

[0117] From the above results, it was found that the chemical mechanical polishing composition produced by the method of the present invention can polish semiconductor substrates containing silicon nitride films at high speed and reduce surface defects on the polished surface.

[0118] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes configurations that are substantially identical to the configurations described in the embodiments (for example, configurations with the same function, method and result, or configurations with the same purpose and effect). The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as the configurations described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configurations described in the embodiments. [Explanation of Symbols]

[0119] 10...Substrate, 12...First silicon oxide film (thermal oxide film), 14...Second silicon oxide film, 16...Silicon nitride film, 42...Slurry supply nozzle, 44...Composition for chemical mechanical polishing (slurry) ), 46... Abrasive cloth, 48... Turntable, 50... Semiconductor substrate, 52... Carrier head, 54... Water supply nozzle, 56... Dresser, 100... Workpiece, 200... Chemical mechanical polishing equipment

Claims

1. A method for producing a chemical mechanical polishing composition for chemical mechanical polishing of semiconductor substrates, comprising (A) abrasive particles and (B) a liquid medium, and having a pH of 1 to 7, A first step is to add an acid to a composition containing component (A) and component (B) to prepare a dispersion in which the zeta potential of component (A) is 0 mV or higher; A second step involves adding a phosphate ester to the dispersion obtained in the first step to prepare a chemical mechanical polishing composition in which the zeta potential of component (A) is less than 0 mV; A method for producing a chemical mechanical polishing composition having the following characteristics.

2. A method for producing a chemical mechanical polishing composition according to claim 1, wherein in the first step, the pH of the dispersion is 4 or less.

3. A method for producing a chemical mechanical polishing composition according to claim 1, wherein the first step involves stirring at 10°C to 60°C.

4. A method for producing a chemical mechanical polishing composition according to claim 1, wherein the second step involves stirring at 10°C to 40°C.

5. A method for producing a chemical mechanical polishing composition according to any one of claims 1 to 4, wherein the phosphate ester is a compound represented by the following general formula (5). 【Chemistry 1】 (In formula (5), R ４ represents a hydrocarbon group with 2 or more carbon atoms but less than 7 carbon atoms, and n is 0 or more but less than 2. (m is either 1 or 2.)

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