Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
  • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
  • C09K3/1463—Aqueous liquid suspensions
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P95/00—Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
  • H10P95/06—Planarisation of inorganic insulating materials
  • H10P95/062—Planarisation of inorganic insulating materials involving a dielectric removal step
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
  • B24B37/042—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor
  • B24B37/044—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor characterised by the composition of the lapping agent
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices
  • H10P52/40—Chemomechanical polishing [CMP]
  • H10P52/403—Chemomechanical polishing [CMP] of conductive or resistive materials

Definitions

• a polishing composition using silica-based abrasive grains is used for polishing a silicon wafer. Further, in recent years, along with the multi-layer wiring on the surface of a semiconductor substrate, when forming a device, a silicon oxide film or a metal wiring is embedded on a stepped substrate, flattened, and further lithography is performed on the surface, and multi-layer wiring is applied and integrated. Manufactures circuits.
• the pattern becomes more integrated, the pattern becomes finer, and the chemical rays used for lithography become near-ultraviolet, far-ultraviolet, and extreme-ultraviolet, and the exposure wavelength of the resist is as short as 248 nm, 193 nm, 157 nm, and 13.6 nm. Wavelengths have been adopted, and electron beam lithography has also come to be used.
• the exposure wavelength used for lithography is short, the exposure light will be diffusely reflected at the interface between the resist and the substrate unless the polished surface is highly flattened. The resulting rectangular resist pattern cannot be formed, and the resist pattern cannot be transferred to the lower layer.
• polishing composition not only improves the polishing rate but also reduces defects caused by scratches and residual foreign substances on the polished surface.
• These polishing compositions contain silica-based abrasive grains, an alkaline component, a water-soluble compound, a chelating agent, an oxidizing agent, a metal corrosive agent, and the like in an aqueous medium.
• a polishing composition in which silica particles, which are abrasive grains, are defined by using a function indicating the affinity with water obtained from the relationship between the reciprocal of the relaxation time of pulse NMR and the total surface area of the silica particles (). See Patent Document 1).
• a polishing composition that defines the relationship between the BET specific surface area of silica particles contained in abrasive grains and the specific surface area by pulse NMR is disclosed (see Patent Document 2).
• a polishing composition in which the solvent affinity of the abrasive grains is evaluated by the NMR relaxation time is disclosed (see Patent Documents 3 and 4).
• the silica particles used for the abrasive grains are focused on the affinity with the aqueous medium in the aqueous medium of the polishing composition, and the value of the parameter which is an index of the affinity is determined. .. Then, from the combination of the silica particles and the basic nitrogen-containing organic compound, it was found that the polishing speed is improved and the polishing surface is improved by the combination with the optimum value of the affinity. That is, it is an object to suppress the generation of defects (residual foreign matter remaining on the polished surface and scratches) when used for CMP polishing of a device wafer.
• the Rsp value represented by the following formula (1) which contains silica particles, a basic nitrogen-containing organic compound and water as a solvent and is calculated from the measured values of pulse NMR, is 0.7.
• Rsp (Rav-Rb) / (Rb) ... (1)
• Rav is the reciprocal of the relaxation time of the polishing composition
• Rb is the reciprocal of the relaxation time of water as the solvent of the polishing composition.
• the average primary particle size of the silica particles measured by the nitrogen gas adsorption method is 5 to 80 nm, and the average particle size of the silica particles measured by the dynamic light scattering method is 12 to 200 nm.
• the polishing composition according to one aspect As a third aspect, the basic nitrogen-containing organic compound is an aliphatic linear or cyclic amine which may contain a hydroxyl group, a carboxyl group, or a combination thereof, and the amine is a primary amine.
• the polishing composition according to the first or second aspect which is a secondary amine, a tertiary amine, or a combination thereof.
• the polishing composition according to any one of the first to third aspects wherein the basic nitrogen-containing organic compound is a molecule having a molecular weight of 60 to 350.
• the polishing composition according to any one of the first to fourth aspects wherein the basic nitrogen-containing organic compound is a secondary or tertiary linear aliphatic amine.
• the polishing composition according to the first or second aspect wherein the basic nitrogen-containing organic compound is N-ethylethylenediamine or triethylamine.
• it contains an alkaline component composed of an alkali metal hydroxide or ammonia composed of NaOH or KOH and an alkaline component composed of a basic nitrogen-containing organic compound or a salt thereof, and (of a basic nitrogen-containing organic compound or a salt thereof).
• the relationship is (number of moles)> (number of moles of alkali metal hydroxide consisting of NaOH or KOH or ammonia or a salt thereof), and the electrical conductivity is 100 to 650 ⁇ S / cm when the SiO 2 concentration is 10% by mass.
• the polishing composition according to any one of the first to sixth viewpoints.
• the polishing according to any one of the first to seventh aspects further comprising a pH adjuster composed of an inorganic acid, an organic acid, an alkali metal hydroxide, an ammonium salt, ammonia, or a combination thereof.
• a pH adjuster composed of an inorganic acid, an organic acid, an alkali metal hydroxide, an ammonium salt, ammonia, or a combination thereof.
• Composition As a ninth aspect, the polishing composition according to any one of the first to eighth aspects, further comprising an aminocarboxylic acid-based chelating agent, a phosphonic acid-based chelating agent, or a chelating agent comprising a combination thereof.
• the polishing composition according to any one of the first to ninth aspects which has a pH of 1 to 12.
• the polishing composition according to any one of the first to tenth viewpoints used for polishing a silicon wafer, a device wafer, or a Si-containing substrate.
• the method for producing a polishing composition according to any one of the first to eleventh viewpoints which comprises a method (B) of dispersing a basic nitrogen-containing organic compound in an aqueous medium.
• the method for producing a polishing composition according to the twelfth viewpoint wherein the sodium silicate aqueous solution and / or the active silicic acid aqueous solution used in the step (a) is filtered in advance with a filter.
• the polishing according to the twelfth aspect or the thirteenth aspect, wherein the rate of change of the average particle size value measured by the dynamic light scattering method before and after the addition of the basic nitrogen-containing organic compound is less than 20%.
• Method of manufacturing composition for As a fifteenth viewpoint a wafer with a TEOS film is polished for 60 seconds using the polishing composition according to any one of the first to eleventh viewpoints, and the number of defects of 180 nm or more per square centimeter is determined.
• the silica particles used for the abrasive grains are focused on the affinity (water affinity) with the aqueous medium in the aqueous medium of the polishing composition, and the value of the parameter which is an index of the affinity is determined. Then, from the combination of the silica particles and the basic nitrogen-containing organic compound, it was found that the polishing rate can be improved and the defects generated on the polishing surface can be reduced by the combination with the optimum value of the affinity. Defects are caused by scratches or foreign matter adhering on the stepped substrate, and the cause of scratches has not been clarified, but it is thought that they are caused by abrasive grains and objects to be polished. Are mixed.
• the polishing composition contains silica particles as polishing abrasive grains. Depending on the surface condition, the silica particles interact with the aqueous medium in the polishing composition, which affects the polishing rate and the flatness to the polished surface.
• the water involved in the surface of the silica particles in the polishing composition is divided into free water and bound water. Free water exists around the silica particles, but does not bind to the silica particles and exists in a free state.
• the bound water is one that is bonded to the silica particles by hydrogen bonds due to the silanol groups on the surface of the silica particles. Bound water plays an important role in ensuring good contact of silica particles with water.
• the state of water can be known from the measurement of the relaxation time of protons in water molecules. Relaxation includes the process of releasing absorbed energy and the process of separating the precession movements of nuclear spins from the aligned state.
• the former is spin-lattice relaxation (longitudinal relaxation)
• the relaxation time is T1
• the latter is Spin-spin relaxation (lateral relaxation), the relaxation time is called T2.
• T1 relaxation relaxation is most likely to occur when the speed of molecular motion is about the same as the resonance frequency, and the magnetic field changes between free water molecules that are not in contact with silica particles and water molecules that are in contact with silica particles.
• the response time to, that is, the relaxation time is different.
• the fact that the relaxation time is short means that the surface of the particles that come into contact with water is large, and it is considered that the particles have high dispersibility.
• T2 relaxation is relaxed by magnetic interaction. It can be said that the measurement of relaxation time by pulse NMR is a measurement method using the difference in T2 relaxation.
• the presence of the bound water and additives in a specific range effectively functions in polishing, reducing the polishing speed, scratches on the polished surface, and reducing defects.
• the pulse NMR method has different responses to changes in the magnetic field between the solvent molecules adsorbed on the particle surface (water in this case) and the solvent molecules in a free state not adsorbed on the silica particle surface. This is an analysis method that utilizes the fact that the relaxation time is different. The movement of the solvent molecules adsorbed on the surface of the silica particles is constrained, but the solvent molecules not adsorbed on the surface of the silica particles can move freely.
• the relaxation time of the solvent molecules adsorbed on the surface of the silica particles is shorter than the relaxation time of the solvent molecules not adsorbed on the surface of the silica particles. Therefore, the Rsp value of pulse NMR becomes high in a state where many water molecules are adsorbed on the surface of silica particles.
• the basic nitrogen-containing organic compound promotes the polarization of the silanol group and adsorbs more water molecules on the surface of the silica particles.
• Silica particles having an Rsp value within the range of the present invention have a certain amount of silanol groups exhibiting hydrophilicity on the surface of the silica particles, which adsorb water molecules and amine molecules by hydrogen bonds to coat the silica particles.
• silica particles coated with water molecules or amine molecules are considered to suppress the occurrence of defects because they do not cause scratches or scratches on the polished surface regardless of the size of the particles. Even in that case, a certain constant electric conductivity is more preferable because water molecules and amine molecules are separated from the silica particles by a certain change in the electric conductivity.
• the present invention by preparing a polishing composition containing silica particles having a specific Rsp value and amine molecules, water molecules and amine molecules coat the surface of the silica particles and suppress the occurrence of scratches and defects on the polished surface.
• the addition of the basic nitrogen-containing organic compound contributes to the improvement of the dispersibility of the silica particles and causes less aggregation. Since the silica particles are present in a state close to monodisperse, the number of silanol groups on the surface of the silica particles increases, which also leads to an increase in the Rsp value.
• the rate of change in the average particle size by the dynamic light scattering method before and after the addition of the basic nitrogen-containing organic compound is within 20% or within 15%. It is considered that these factors suppress the generation of scratches on the polished surface and residual foreign matter.
• the polished wafer with a TEOS film can have a defect number of 180 nm or more of 1000 or less per 300 mm wafer. That is, the number of defects of 180 nm or more per polished surface (1 square centimeter) can be 1.4 or less, 1.2 or less, or 0.7 or less.
• the TEOS film can be applied by a plasma CVD method, a reduced pressure CVD method, a sputtering method, or an EB vapor deposition method.
• the present invention contains silica particles, a basic nitrogen-containing organic compound, and water as a solvent, and the Rsp value represented by the following formula (1) calculated from the measured values of pulse NMR exceeds 0.7, 6
• the following is a polishing composition.
• Rsp (Rav-Rb) / (Rb) ... (1)
• Rav is the reciprocal of the relaxation time of the polishing composition
• Rb is the reciprocal of the relaxation time of water as the solvent of the polishing composition.
• the silica particles are colloidal silica particles and have an average particle diameter of 12 to 200 nm or 20 to 150 nm measured by a dynamic light scattering method, and the silica particles in the dispersion are averages measured by a nitrogen gas adsorption method.
• the primary particle size is 5 to 80 nm, or 10 to 80 nm, or 15 to 70 nm.
• the measurement principle of this method is that the magnetic field changes between the solvent molecules that are in contact with or adsorbed on the particle surface and the solvent molecules in the solvent bulk (solvent molecules that are not in contact with the particle surface). Is based on different responses to. Generally, the movement of liquid molecules adsorbed on the particle surface is restricted, but it is free to move in bulk liquid. As a result, the NMR relaxation time of the liquid molecules adsorbed on the particle surface is shorter than the relaxation time of the molecules in the bulk liquid.
• the relaxation time measured by the particle dispersion is two relaxations that reflect the liquid volume concentration on the particle surface and the liquid volume concentration in the free state (the liquid in the bulk liquid but not adsorbed on the particle surface). It is the average value of time.
• the relaxation time constant R is the reciprocal of the relaxation time.
• Rav PsRs + PbRb Demanded by.
• Rav The average relaxation time constant, that is, the reciprocal of the relaxation time of the colloidal silica dispersion.
• Ps The volume concentration of the liquid on the particle surface, that is, the volume concentration of the colloidal silica dispersion liquid.
• Rs The relaxation time constant of the adsorption phase liquid molecule on the particle surface, that is, the reciprocal of the relaxation time of the colloidal silica dispersion.
• Pb The volume concentration of the bulk liquid, that is, the volume concentration of the blank aqueous solution excluding the silica particles in the colloidal silica dispersion liquid.
• Rb The relaxation time constant of the bulk liquid molecule, that is, the reciprocal of the relaxation time of the blank aqueous solution excluding the silica particles in the colloidal silica dispersion.
• Rav and Rb are relaxation times (lateral relaxation time T2, specifically, NMR relaxation time after dispersing silica abrasive grains, and silica) measured using a pulse NMR apparatus Acorn area manufactured by Xigo nanotools (USA). It is the inverse of the NMR relaxation time before dispersing the abrasive grains (dispersion medium only).
• the measurement conditions can be magnetic field: 0.3 T, measurement frequency: 13 MHz, measurement nucleus: 1 H NMR, measurement method: CPMG pulse sequence method, sample volume: 0.4 mL, temperature: 30 ° C.
• Rsp is an index of water affinity of the particle surface. When the specific surface area is the same, the larger this value (Rsp) is, the higher the water affinity is.
• the basic nitrogen-containing organic compound used in the present invention is an aliphatic linear or cyclic amine which may contain a hydroxyl group, a carboxyl group, or a combination thereof, and the amine is a primary amine, the first amine.
• the amine may contain a hydroxyl group, a carboxyl group, or a combination thereof. It also contains an aliphatic linear structure or an aliphatic cyclic structure. Further, the structure may contain a primary amine, a secondary amine, a tertiary amine, or a combination thereof.
• the amine preferably contains a secondary or tertiary linear aliphatic amine.
• the secondary structure and the tertiary structure can be contained individually in one molecule, or the secondary structure and the tertiary structure can be contained at the same time.
• the amine molecule contains a secondary or tertiary linear aliphatic amine, but can also contain a primary amine.
• Examples of the basic nitrogen-containing organic compound include N-ethylethylenediamine, N- (2-hydroxyethyl) piperazine, triethylamine, and 2-aminoethanol, and particularly N-ethylethylenediamine and triethylamine. You can, but you are not limited to these.
• As the basic nitrogen-containing organic compound it is preferable to use a low molecular weight amine having a molecular weight of 60 to 350, 60 to 150, or 80 to 110. These amines can be used alone or in admixture of a plurality of types.
• examples thereof include, but are not limited to, amines, cyclohexylamines, heptylamines, octylamines, nonylamines, decylamines, dodecylamines, cetylamines, methylenediamines, ethylenediamines and tetraethylenepentamines.
• Secondary aliphatic amines include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine, Dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine, disetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepentamine, N-ethylethylenediamine, Examples include, but are not limited to, N- (2-hydroxyethyl) piperazine.
• examples of the mixed amines include, but are not limited to, dimethylethylamine, methylethylpropylamine, benzyl
• nitrogen-containing compounds having a carboxy group examples include aminobenzoic acid, indolecarboxylic acid, and amino acid derivatives (for example, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, and phenylalanine. , Threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine) and the like, but are not limited thereto.
• Examples of the nitrogen-containing compound having a hydroxy group (hydroxyl group), the nitrogen-containing compound having a hydroxyphenyl group, and the alcoholic nitrogen-containing compound include 2-aminoethanol, 2-hydroxypyridine, aminocresol, 2,4-quinolindiol, and 3-.
• Indolmethanol Hydrate Monoethanolamine, Diethanolamine, Triethanolamine, N-Ethyldiethanolamine, N, N-diethylethanolamine, Triisopropanolamine, 2,2'-Iminodiethanol, 2-Aminoethanol, 3-Amino- 1-propanol, 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholin, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2- (2-) Hydroxyethoxy) ethyl] piperazine, piperidine ethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2-hydroxyethyl) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1, 2-Propanediol, 8-Hydroxyurodil, 3-Quinucridinol, 3-Tropanol, 1-Methyl
• an alkali metal hydroxide or ammonia composed of NaOH or KOH and an alkaline component composed of a basic nitrogen-containing organic compound or a salt thereof are contained, and the electrical conductivity when the SiO 2 concentration is 10% by mass is high. It can be 100 to 650 ⁇ S / cm.
• the above-mentioned basic nitrogen-containing organic compound is added to an acidic aqueous silica sol (a trace amount of alkali metal ions remains) obtained by removing alkaline ions from an alkaline aqueous silica sol stabilized with an alkali metal hydroxide. Is added until the pH reaches 8-11. Therefore, the relationship is (number of moles of basic nitrogen-containing organic compound or salt thereof)> (number of moles of alkali metal hydroxide composed of NaOH or KOH or ammonia or salt thereof).
• an acid hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid
• an acid hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid
• a combination of cation exchange and anion exchange is used to obtain an acidic silica sol having a pH of 1 to 6. Therefore, the relationship is (number of moles of basic nitrogen-containing organic compound or salt thereof)> (number of moles of alkali metal hydroxide consisting of NaOH or KOH or ammonia or salt thereof), and the SiO 2 concentration is 10 mass by mass.
• the electrical conductivity is preferably 100 to 650 ⁇ S / cm.
• the polishing composition was selected from the group consisting of silica particles as abrasive grains, an aqueous medium, a pH adjuster (alkaline component and water-soluble compound), a chelating agent, an oxidizing agent, and a metal corrosion inhibitor. It can contain at least one additive.
• the component (S) excluding the aqueous medium from the polishing composition is 0.01 to 20% by mass or 0.1 to 10% by mass, and the silica content in the component (S) is 80 to 99. It is 9% by mass, or 90 to 99.9% by mass, and the content of the basic nitrogen-containing organic compound in the above component (S) is 0.01 to 20% by mass, or 0.01 to 10% by mass. %.
• alkaline component examples include alkali metal hydroxides (sodium hydroxide, potassium hydroxide), ammonia, and amines.
• the amine is present in the aqueous medium in the form of a corresponding ammonium salt.
• the pH of the polishing composition of the present invention can be set to 1-12.
• the pH can be adjusted to the range of 7 to 12 or 8 to 11 by adding these alkaline components. Further, the pH can be adjusted in the range of 1 to 7 or 1 to 6 by exchanging cations or adding an acid (hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid).
• Any water-soluble compound can be used as the water-soluble compound.
• monomers having a carboxylic acid group such as acrylic acid, methacrylic acid, and maleic acid, polyacrylic acid and polymethacrylic acid as their polymers, and ammonium polyacrylate, potassium polyacrylate, and polymethacrylic acid as their salts. Examples include ammonium and polypotassium methacrylate.
• alginic acid, pectinic acid, carboxymethyl cellulose, polyaspartic acid, polyglutamic acid, polyamic acid, ammonium polyamic acid, polyvinylpyrrolidone, hydroxyethyl cellulose, glycerin, polyglycerin, polyvinyl alcohol, or carboxy group or sulfonic acid group modified polyvinyl alcohol is used. You can, but you are not limited to these.
• the water-soluble compound can be contained in a proportion of 0.01 to 10% by mass with respect to the silica particles.
• an aminocarboxylic acid-based chelating agent or a phosphonic acid-based chelating agent can be used as the chelating agent.
• the chelate resin can be contained in a proportion of 0.01 to 10% by mass with respect to the silica particles.
• the oxidizing agent include hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid, ozone water and the like.
• the oxidizing agent can be contained in a proportion of 0.01 to 10% by mass with respect to the silica particles, but is not limited thereto.
• Examples of the metal corrosive agent include, but are not limited to, triazole compounds, pyridine compounds, pyrazole compounds, pyrimidine compounds, imidazole compounds, guanidine compounds, thiazole compounds, tetrazole compounds, triazine compounds, and hexamethylenetetramine.
• Examples of the triazole compound include 1,2,3-triazol, 1,2,4-triazol, 3-amino-1H-1,2,4-triazol, benzotriazole (BTA), 1-.
• pyridine compound examples include pyridine, 8-hydroxyquinoline, prothionamide, 2-nitropyridine-3-ol, pyridoxamine, nicotine amide, iproniazide, isonicotic acid, benzo [f] quinoline, 2,5-pyridinedicarboxylic acid, 4-.
• Styrylpyridine anabacin, 4-nitropyridine-1-oxide, pyridine-3-ethyl acetate, quinoline, 2-ethylpyridine, quinophosphate, alecholine, citrazic acid, pyridine-3-methanol, 2-methyl-5-ethylpyridine , 2-Fluoridine, pentafluoropyridine, 6-methylpyridin-3-ol, pyridine-2-ethyl acetate and the like, but are not limited thereto.
• Examples of the pyrazole compound include pyrazole, 1-allyl-3,5-dimethylpyrazole, 3,5-di (2-pyridyl) pyrazole, 3,5-diisopropylpyrazole, 3,5-dimethyl-1-hydroxymethylpyrazole, 3 , 5-Dimethyl-1-phenylpyrazole, 3,5-dimethylpyrazole, 3-amino-5-hydroxypyrazole, 4-methylpyrazole, N-methylpyrazole, 3-aminopyrazole, 3-aminopyrazole and the like. , Not limited to these.
• Examples of the pyrimidine compound include pyrimidine, 1,3-diphenyl-pyrimidine-2,4,6-trione, 1,4,5,6-tetrahydropyrimidine, 2,4,5,6-tetraaminopyrimidinesulfate, 2, 4,5-Trihydroxypyrimidine, 2,4,6-triaminopyrimidine, 2,4,6-trichloropyrimidine, 2,4,6-trimethoxypyrimidine, 2,4,6-triphenylpyrimidine, 2,4 Examples of, but not limited to, -diamino-6-hydroxypyrimidine, 2,4-diaminopyrimidine, 2-acetamidopyrimidine, 2-aminopyrimidine, 4-aminopyrazolo [3,4-d] pyrimidine and the like.
• imidazole compound examples include imidazole, 1,1'-carbonylbis-1H-imidazole, 1,1'-oxalyldiimidazole, 1,2,4,5-tetramethylimidazole, 1,2-dimethyl-5-nitroimidazole. , 1,2-dimethylimidazole, 1- (3-aminopropyl) imidazole, 1-butyl imidazole, 1-ethyl imidazole, 1-methyl imidazole, benzimidazole and the like, but are not limited thereto.
• guanidine compound examples include guanidine, 1,1,3,3-tetramethylguanidine, 1,2,3-triphenylguanidine, 1,3-di-o-tolylguanidine, 1,3-diphenylguanidine and the like. However, it is not limited to these.
• Examples of the thiazole compound include, but are not limited to, thiazole, 2-mercaptobenzothiazole, 2,4-dimethylthiazole and the like.
• Examples of the tetrazole compound include, but are not limited to, tetrazole, 5-methyltetrazole, 5-amino-1H-tetrazole, 1- (2-dimethylaminoethyl) -5-mercaptotetrazole and the like.
• triazine compound examples include, but are not limited to, triazine, 3,4-dihydro-3-hydroxy-4-oxo-1,2,4-triazine and the like.
• the metal corrosive agent can be added at a ratio of 0.0001 to 10% by mass with respect to the silica particles.
• the silica used in the present invention is the method (A) of mixing the silica sol obtained by any one of the following production methods (a) to (d) with the basic nitrogen-containing organic compound, or the silica sol and the above.
• a polishing composition can be produced by a production method including a method (B) of dispersing a basic nitrogen-containing organic compound in an aqueous medium.
• Method (A) is a method of mixing a silica source (silica sol or a polishing composition containing silica sol) and a basic nitrogen-containing organic compound.
• the method (B) is a method of dispersing the silica source and the basic nitrogen-containing organic compound in an aqueous medium.
• the silica source can be added as a silica sol (B1), or the silica sol can be made into silica powder and then dispersed in an aqueous medium (B2).
• Examples of the method for producing the silica source include any one of the following steps (a) to (d).
• the method is roughly divided into a step of obtaining active silicic acid (a-I), a step of heating and sizing the active silicic acid (a-II), and a step of adjusting the concentration of the obtained silica sol (a-III). Can be done.
• the steps of obtaining active silicic acid (a-I) include a step of obtaining active silicic acid (a-I), a step of purifying it (a-I-I), and a highly purified active silicic acid. Is divided into steps (a-I-II) of collecting. (A-1) is indispensable, and (a-I-I) and (a-I-II) are arbitrary steps.
• Step (a-II) of heating and sizing the active silicic acid include the following steps (a-II-I) and (a-II-II).
• Aqueous acid salt solution, ammonia silicate aqueous solution, or alkali metal silicate aqueous solution having pH 10 to 12.5 and SiO 2 concentration 0.1 to 8% by mass obtained by concentrating or diluting this aqueous solution, or ammonia.
• the temperature of the obtained mixed solution of the silicate aqueous solution or the active silicic acid aqueous solution obtained in the same manner as in the above step (a-II-I) is 110 to less than 150 ° C, or 110 to 145 ° C, or 110.
• Examples thereof include a step of supplying the mixture at ⁇ 140 ° C., 110 to 135 ° C., or 110 to 130 ° C. for 1 to 30 hours until the pH in this mixed solution reaches 9 to 12 under sufficient stirring. ..
• the step (a-III) of adjusting the concentration of the obtained silica sol is a step of concentrating the silica sol to 10 to 50% by mass, but impurities can be removed before and after the concentration. This step (a-III) is not essential but is performed if desired. Then, the stable aqueous silica sol obtained in the steps (a-IV): (a-III) is brought into contact with the hydrogen type strong acid cation exchange resin, and then the aqueous silica sol produced by this contact is subjected to the hydroxyl group type strong base. A step of producing an acidic aqueous silica sol that is substantially free of polyvalent metal oxides other than silica by contacting with a sex anion exchange resin.
• alkali include a step of producing a stable aqueous silica sol having a SiO 2 concentration of mass%, substantially free of polyvalent metal oxides other than silica, and having an average particle size of colloidal silica of 10 to 30 nm.
• step (aI) it is preferable to use sodium water glass having a SiO 2 / Na 2 O molar ratio of about 2 to 4, which is an inexpensive industrial product.
• the main ones of relatively high multivalent metals are aluminum, iron, calcium, magnesium and the like.
• the alkali metal silicate aqueous solution is brought into contact with the hydrogen type strong acid cation exchange resin. This contact can be preferably performed by passing the liquid through the column filled with the ion exchange resin, and the column passing liquid is made of active silicic acid having a SiO 2 concentration of 1 to 6% by mass, preferably 2 to 6% by mass. It is recovered as an aqueous solution.
• the amount of the hydrogen-type cation exchange resin used may be a sufficient amount to exchange all the alkali metal ions in the alkali metal silicate aqueous solution with hydrogen ions.
• the speed of passing through the column is preferably a space speed of about 1 to 10 per hour.
• the strong acid used in the step (aII) examples include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, but nitric acid is most preferable for increasing the removal rate of aluminum and iron.
• the aqueous solution obtained in the step (a-II) is first brought into contact with the hydrogen-type strongly acidic cation exchange resin. This contact can be preferably carried out by passing the liquid through the column filled with the hydrogen-type strong acid cation exchange resin at 0 to 60 ° C., preferably 5 to 50 ° C. at a space velocity of 2 to 20 per hour. .. Then, the aqueous solution obtained by this liquid passing is preferably brought into contact with the hydroxyl group type strongly basic anion exchange resin at 0 to 60 ° C., preferably 5 to 50 ° C. immediately after the acquisition.
• the aqueous solution of alkali hydroxide used in the step (a-II) preferably dissolves alkali hydroxide of a commercially available industrial product having a component concentration of 95% or more in ion-exchanged water so as to have a concentration of preferably 2 to 20% by mass. Obtained by The device used in the step (a-III) is equipped with a stirrer, a temperature control device, a liquid level sensing device, a depressurizing device, a liquid supply device, the above cooling device, etc. in a normal acid-resistant, alkali-resistant and pressure-resistant container. It is possible to use the one that has been made. In step (a-III), the temperature inside the container is kept below 110 to 150 ° C.
• the contact between the stable aqueous sol and the ion exchange resin in the step (a-IV) can be performed in the same manner as the contact in the step (a-I).
• the alkali used in the step (av) may be a commercially available industrial product, but a high-purity alkali is preferably used, and in the case of ammonia, it is preferably used as about 5 to 28% by mass of ammonia water. Instead of this ammonia, quaternary ammonium hydroxide, guanidine hydroxide, water-soluble amine and the like can also be used. Potassium hydroxide can be preferably used in the present invention.
• a silica sol obtained by hydrolyzing alkoxysilane can be used. Hydrolysis is carried out by adding alkoxysilane in an organic solvent containing a catalyst or water (in methanol).
• alkoxysilane tetramethoxysilane and tetraethoxysilane are used. Ammonia and alkali metal hydroxides are used as catalysts, but ammonia is used as a volatile catalyst for high purity.
• the silica bower can be produced by a method of wet pulverization in an aqueous medium.
• silica powder obtained by crushing natural silica sand or the like can be used to distinguish it from the raw material of the method of the following step (d).
• acid or alkali can be added for wet pulverization.
• step (d) As the method of step (d) as the silica source of the present invention, it is obtained by a method of wet pulverizing silica obtained by combustion hydrolysis of silicon tetrachloride in a flame. At the time of wet pulverization, acid or alkali can be added for wet pulverization. In the wet pulverization, it is preferable to pulverize the primary particle size to a colloidal region suitable as the silica source used in the present invention using a ball mill, a colloidal mill, a sand mill, a disper, or the like and disperse it in an aqueous medium.
• the value of the average particle size of the silica source by the dynamic light scattering method is used.
• the rate of change is preferably within 20% or within 15% before the addition.
• the sodium silicate aqueous solution and / or the active silicate aqueous solution used is previously filtered through a filter.
• the silica concentration of the sodium silicate aqueous solution is adjusted to 0.5 to 10.0% by mass, and the removal rate of particles having a primary particle diameter of 1.0 ⁇ m is 50% or more, 60% or more, or 80% or more. It is possible to filter with a filter having a filtration rate of 13 liters / minute to 400 liters / minute per 1 m 2 of filtration area.
• an active sodium silicate aqueous solution was prepared by removing an alkaline component from a sodium silicate aqueous solution adjusted to a silica concentration of 0.5% by mass to 10.0% by mass by cation exchange, and the active silicic acid aqueous solution was used as primary particles.
• colloidal silica which is abrasive grains and fine particles are removed by cleaning.
• Spherical particles are easily removed by cleaning after polishing, but plate-shaped particles are difficult to be removed by cleaning after polishing.
• the particles to be removed by the filter are particles mainly composed of fine flat silica present in an aqueous solution of sodium silicate or an aqueous solution of active silicic acid, which is a raw material in the silica sol manufacturing process.
• Silica sol is manufactured and prepared into a polishing composition, but coarse particles (mainly silica-based) that may cause defects during polishing can be removed in advance during the manufacturing process of silica sol.
• the filter include a membrane type filter, a pleated type filter, a depth type filter, a pincushion type filter, a surface type filter, a roll type filter, a depth pleated type filter, a diatomaceous earth containing type filter and the like.
• a membrane type filter having an absolute pore size of 0.3 to 3.0 ⁇ m can be preferably mentioned.
• a membrane filter (filtration area 4.90 cm 2 ) having an absolute pore size of 0.4 ⁇ m. After that, when the membrane type filter was observed with a scanning electron microscope at a magnification of 5000 times, a rectangular observation area of 15 ⁇ m in length and 20 ⁇ m in width was regarded as one field, and one flat particle was formed in this one field.
• the polishing composition of the present invention can be used for polishing semiconductor wafers, semiconductor devices (device wafers), and Si-containing substrates such as quartz substrates.
• the polishing used for semiconductor devices is CMP (Chemical Mechanical Polishing), which can be applied to form wiring for semiconductor substrates.
• the object to be polished include a conductive material layer (wiring layer), a barrier layer (a layer made of a barrier metal, for example, titanium nitride, tantalum nitride, etc. for preventing copper from diffusing into an insulating layer. ), It can be applied to the polishing of an insulating layer (a layer composed of an interlayer insulating material, a low-k material, for example, SiO 2 , SiOC, porous silica, etc.).
• examples of the material constituting the conductive material layer include copper-based metals such as copper, copper alloys, copper oxides, and copper alloy oxides; and tungsten such as tungsten, tungsten nitride, and tungsten alloys.
• at least one copper-based metal selected from the group consisting of copper, copper alloys, copper oxides and copper alloy oxides is preferable, and copper is more preferable.
• the conductive substance can be formed by a known sputtering method, plating method, or the like.
• the barrier metal constituting the barrier layer is formed in order to prevent the conductive substance from diffusing into the insulating material and to improve the adhesion between the insulating material and the conductive substance.
• the barrier metal material constituting the barrier metal is preferably at least one selected from the group consisting of tantalum-based metals, titanium-based metals, tungsten-based metals, ruthenium-based metals, cobalt-based metals and manganese-based metals.
• tantalum-based metals such as tantalum, tantalum nitride, and tantalum alloy
• titanium-based metals such as titanium, titanium nitride, and titanium alloys
• tungsten-based metals such as tungsten and tungsten alloys
• ruthenium such as ruthenium and ruthenium alloys.
• cobalt-based metals such as cobalt and cobalt alloys
• manganese-based metals such as manganese and manganese alloys, but are not limited thereto.
• the constituent material of the insulating material include, but are not limited to, silicon-based materials and organic polymers.
• the insulating material may be in the form of a film (insulating film, for example, an interlayer insulating film).
• insulating film examples include, but are not limited to, a silicon-based film and an organic polymer film.
• the insulating film can be formed by a CVD method, a spin coating method, a dip coating method, a spray method, or the like.
• the silicon-based material examples include silica-based materials and low-k materials (low dielectric constant materials).
• silica-based material examples include silicon dioxide; fluorosilicate glass; organosilicate glass obtained from trimethylsilane or dimethoxydimethylsilane as a starting material; porous organosilicate glass; silicon oxynitride; hydride silsesquioxane and the like.
• low-k material examples include, but are not limited to, silicon carbide and silicon nitride.
• a conductive thin film made of a conductive substance is formed on a silicon substrate, a resist film is formed on the conductive thin film, and a circuit pattern is masked by lithography to expose and develop a resist layer.
• the pattern is transferred to the resist layer.
• the conductive film is dry-etched with an ionic gas having strong anisotropy.
• the gas types used are, for example, tetrafluoromethane (CF 4 ), perfluorocyclobutane (C 4 F 8 ), perfluoropropane (C 3 F 8 ), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, hexafluoride. Gases such as sulfur, difluoromethane, nitrogen trifluoride and chlorine trifluoride, chlorine, trichloroborane and dichloroborane can be used, but are not limited thereto. Further, the resist film is ashed with oxygen gas to remove the resist layer. The resist layer can also be removed by a chemical solution (for example, a mixed solution of sulfuric acid and hydrogen peroxide, or a mixed solution of ammonia and hydrogen peroxide) to protect the substrate.
• a chemical solution for example, a mixed solution of sulfuric acid and hydrogen peroxide, or a mixed solution of ammonia and hydrogen peroxide
• an insulating film is formed to prevent a short circuit with the upper layer wiring.
• the surface of the wafer on which the interlayer insulating film is formed reflects the pattern of the lower layer wiring, and the insulating film has irregularities of various sizes.
• the wafer surface is flattened. The flattening of this interlayer insulating film is performed by CMP.
• BET nitrogen gas adsorption method
• DLS dynamic light scattering method
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 1 was 98.2% by mass, and the content of the basic nitrogen-containing organic compound was 1.8% by mass. ..
• the average primary particle size of the BET method in the polishing composition of Example 1 after the addition of the basic nitrogen-containing organic compound was 20 nm, and the average particle size of the DLS method was 31.9 nm.
• Example 2 A polishing composition was obtained in the same manner as in Example 1 except that the basic nitrogen-containing organic compound was changed to that shown in Table 1.
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 2 was 93.7% by mass, and the content of the basic nitrogen-containing organic compound was 6.3% by mass. ..
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 3 was 97.7% by mass, and the content of the basic nitrogen-containing organic compound was 2.3% by mass. ..
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 4 was 97.9% by mass, and the content of the basic nitrogen-containing organic compound was 2.1% by mass. ..
• the average primary particle size of the BET method in the polishing composition of Example 2 after the addition of the basic nitrogen-containing organic compound was 20 nm, and the average particle size of the DLS method was 31.7 nm.
• the average primary particle size of the BET method in the polishing composition of Example 3 after the addition of the basic nitrogen-containing organic compound was 20 nm, and the average particle size of the DLS method was 31.5 nm.
• the average primary particle size of the BET method in the polishing composition of Example 4 after the addition of the basic nitrogen-containing organic compound was 20 nm, and the average particle size of the DLS method was 31.8 nm.
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 5 was 96.4% by mass, and the content of the basic nitrogen-containing organic compound was 3.6% by mass. ..
• the average primary particle size of the BET method and the average particle size of the DLS method in the polishing composition of Example 5 after the addition of the basic nitrogen-containing organic compound were 20 nm.
• Example 6 A polishing composition was obtained in the same manner as in Example 5 except that the basic nitrogen-containing organic compound was changed to that shown in Table 1.
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 6 was 91.5% by mass, and the content of the basic nitrogen-containing organic compound was 8.5% by mass. ..
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 7 was 97.8% by mass, and the content of the basic nitrogen-containing organic compound was 2.2% by mass. ..
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 8 was 97.7% by mass, and the content of the basic nitrogen-containing organic compound was 2.3% by mass. ..
• the average primary particle size of the BET method and the average particle size of the DLS method in the polishing composition of Example 6 after the addition of the basic nitrogen-containing organic compound were 20 nm.
• the average primary particle diameter of the BET method in the polishing composition of Example 7 after the addition of the basic nitrogen-containing organic compound was 20 nm, and the average particle diameter of the DLS method was 29.8 nm.
• the average primary particle size of the BET method in the polishing composition of Example 8 after the addition of the basic nitrogen-containing organic compound was 20 nm, and the average particle size of the DLS method was 29.2 nm.
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 9 was 97.9% by mass, and the content of the basic nitrogen-containing organic compound was 2.1% by mass. ..
• the average primary particle size of the BET method in the polishing composition of Example 9 after the addition of the basic nitrogen-containing organic compound was 17 nm, and the average particle size of the DLS method was 27.4 nm.
• Example 10 A polishing composition was obtained in the same manner as in Example 9 except that the basic nitrogen-containing organic compound was changed to that shown in Table 1.
• the content of SiO 2 in the component (S) excluding the aqueous medium from the polishing composition of Example 10 was 97.6% by mass, and the content of the basic nitrogen-containing organic compound was 2.4% by mass. ..
• the average primary particle size of the BET method in the polishing composition of Example 10 after the addition of the basic nitrogen-containing organic compound was 17 nm, and the average particle size of the DLS method was 27.1 nm.
• the measurement was performed using an electric conductivity meter (model number: CM-30R manufactured by DKK-TOA Corporation) and an electric conductivity cell (model number: CT57101B manufactured by DKK-TOA Corporation). (Measurement of average particle size by dynamic light scattering method) The measurement was performed using a particle size / zeta potential / molecular weight measuring device (Zetasizer Nano ZS manufactured by Malvern).
• Polishing machine ChaMP332 manufactured by Tokyo Seimitsu Co., Ltd. (for 12 inches) Machining pressure: 1.7 psi Surface plate rotation speed: 90 rpm Head rotation speed: 90 rpm Polishing pad: Nitta & Haas IC1400XY + Performate Dresser: 3M A2865 (# 80 diamond) Supply amount of polishing diluent: 300 mL / min Polishing time: 60 sec Substrate: Wafer with TEOS film
• Rsp indicates the Rsp value calculated from the measured value of pulse NMR
• LPC indicates the count number (pieces / mL) of coarse particles of 0.16 ⁇ m or more contained in the polishing composition
• the defect number is a unit.
• pH indicates the adjusted pH value of the polishing composition
• the electrical conductivity is the electrical conductivity when the SiO 2 concentration of the polishing composition is 10% by mass ( ⁇ S / cm) was shown
• the DLS change rate was the rate (%) of change in the average particle size (nm) by the dynamic light scattering method before the addition of the basic nitrogen-containing organic compound.
• the Rsp value of pulse NMR has a specific numerical range, and these are used as the polishing composition for the device wafer.
• the occurrence of defects can be suppressed.
• the LPC value is increased, the effect of reducing the defect, which is not normally expected, is also found.
• the Rsp value showing affinity is high in Comparative Examples 1 and 3, the occurrence of defects is not suppressed.
• the polishing composition of the present invention can be used not only for polishing device wafers for CMP, but also as a polishing agent for silicon wafers and a polishing agent for quartz substrates for photomasks.
• the object to be polished is a metal or semi-metal such as silicon, aluminum, nickel, tungsten, copper, tantalum, titanium, stainless steel, or an alloy thereof; quartz glass, aluminosilicate glass.
• Glassy substances such as glassy carbon; Ceramic materials such as alumina, silica, sapphire, silicon nitride, tantalum nitride, titanium carbide; Compound semiconductor substrate materials such as silicon carbide, gallium nitride, gallium arsenide; Resins such as polyimide resin It can be used for polishing materials, etc. Further, it can be applied to a polishing object composed of a plurality of these materials.

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