# US 7,744,666 B2 · Polishing medium for chemical-mechanical polishing, and method of polishing substrate member > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,666 B2 - Document ID: US7744666B2 - Status: Granted - Kind: B2 - Application number: 11/201,242 - Filed: 2005-08-11 - Published: 2006-02-23 - Granted: 2010-06-29 - Earliest claimed: 1999-08-17 - Assignees: Hitachi Chemical Company, Ltd. - Inventors: Yasushi Kurata; Yasuo Kamigata; Takeshi Uchida; Hiroki Terasaki; Akiko Igarashi - Web page: https://patentgrep.com/patent/US7744666B2 ## CPC - C03C 15/00: Surface treatment of glass, not in the form of fibres or filaments, by etching (etching or surface-brightening compositions, in general C09K13/00) - C09G 1/02: containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} - C09K 3/1463: {Aqueous liquid suspensions} - C23F 3/06: with acidic solutions - H10P 52/403: {of conductive or resistive materials} - H10W 20/062: {by smoothing of conductive parts, e.g. by planarisation} - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - C09G: POLISHING COMPOSITIONS (French polish C09F11/00); SKI WAXES - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract This invention provides a polishing medium for chemical-mechanical polishing, comprising an oxidizing agent for a conductor, a protective-film-forming agent for protecting a metal surface, an acid, and water; (1) the polishing medium having a pH of 3 or less, and the oxidizing agent being in a concentration of from 0.01 to 3% by weight, or (2) the polishing medium containing abrasive grains having an average particle diameter of 50 nm or less, and the abrasive grains having standard deviation of particle size distribution in a value of more than 5 nm. ## Claims ### Claim 1 A polishing medium having a property of chemical-mechanical polishing of a surface, and comprising: abrasive grains, an oxidizing agent for a conductor; a protective-film-forming agent for protecting a metal surface; an acid; and water, wherein: said abrasive grains have an average particle diameter of 50 nm or less and a standard deviation of particle size distribution in a value of more than 5 nm, said polishing medium has a pH of 3 or less, and said polishing medium has a property of chemical-mechanical polishing of a surface having at least one of tantalum, tantalum alloy and a tantalum compound which is on silicon dioxide and which is originally covered by copper or copper alloy, and is exposed after polishing of the copper or copper alloy, the polishing medium having a property of chemical-mechanical polishing said at least one of tantalum, tantalum alloy and a tantalum compound exposed after polishing of the copper or copper alloy, and chemical-mechanical polishing said at least one of tantalum, tantalum alloy and the tantalum compound at a higher polishing rate than a polishing rate of said silicon dioxide by said polishing medium. ### Claim 2 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein: said oxidizing agent for a conductor is in a concentration of from 0.01% by weight to 3% by weight. ### Claim 3 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein: said abrasive grains are at least one selected from the group consisting of silica, alumina, ceria, titania, zirconia and germania. ### Claim 4 (depends on 3) The polishing medium having a property of chemical-mechanical polishing according to claim 3, wherein said abrasive grains are colloidal silica or colloidal alumina. ### Claim 5 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein said abrasive grains are mixed in an amount of from 0.1% by weight to 5% by weight. ### Claim 6 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, which further comprises a water-soluble polymer. ### Claim 7 (depends on 6) The polishing medium having a property of chemical-mechanical polishing according to claim 6, wherein said water-soluble polymer is at least one selected from the group consisting of polyacrylic acid, a polyacrylic acid salt, polymethacrylic acid, a polymethacrylic acid salt, polyamic acid, a polyamic acid salt, polyacrylamide, polyvinyl alcohol and polyvinylpyrrolidone. ### Claim 8 (depends on 6) The polishing medium having a property of chemical-mechanical polishing according to claim 6, wherein said oxidizing agent is in a concentration of from 0.01% by weight to 1.5% by weight. ### Claim 9 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein said acid is an organic acid. ### Claim 10 (depends on 9) The polishing medium having a property of chemical-mechanical polishing according to claim 9, wherein said acid is at least one selected from the group consisting of malonic acid, malic acid, tartaric acid, glycolic acid and citric acid. ### Claim 11 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein said protective-film-forming agent is at least one selected from the group consisting of benzotriazole and a derivative thereof. ### Claim 12 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein said oxidizing agent for a conductor is at least one selected from the group consisting of hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid and ozone water. ### Claim 13 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, which has: a polishing-rate ratio (Ta/Cu) between tantalum and copper or a copper alloy of more than 1; a polishing-rate ratio (TaN/Cu) between tantalum nitride and copper or a copper alloy of more than 1; a polishing-rate ratio (Ta/SiO2) between tantalum and silicon dioxide of more than 10; and a polishing-rate ratio (TaN/SiO2) between tantalum nitride and silicon dioxide of more than 10. ### Claim 14 (depends on 1) A method of polishing a substrate member comprising a step of polishing a barrier layer containing tantalum, a tantalum alloy or a tantalum compound, by the use of the polishing medium having a property of chemical-mechanical polishing according to claim 1. ### Claim 15 (depends on 1) A method of polishing a substrate member comprising a step of polishing a surface including a wiring layer and a barrier layer, by the use of the polishing medium having a property of chemical-mechanical polishing according to claim 1. ### Claim 16 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, wherein said medium has a property that said at least one of tantalum, tantalum alloy and tantalum compound is selectively polished by said polishing medium relative to polishing of said copper or copper alloy by said polishing medium. ### Claim 17 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, which consists essentially of said abrasive grains, said oxidizing agent, said protective-film-forming agent, said acid and water, and wherein the polishing medium has a property that a polishing-rate ratio of the at least one of tantalum, tantalum alloy and tantalum compound by the polishing medium to the copper or copper alloy by the polishing medium is greater than 1. ### Claim 18 (depends on 17) The polishing medium having a property of chemical-mechanical polishing according to claim 17, wherein the polishing medium has a further property that a polishing-rate ratio of the at least one of tantalum, tantalum alloy and tantalum compound by the polishing medium to silicon dioxide by the polishing medium is more than 10. ### Claim 19 (depends on 1) The polishing medium having a property of chemical-mechanical polishing according to claim 1, which consists of said abrasive grains, said oxidizing agent, said protective-film-forming agent, said acid and water. ### Claim 20 A polishing medium having a property of chemical-mechanical polishing of a surface, and comprising: abrasive grains, an oxidizing agent for a conductor: a protective-film-forming agent for protecting a metal surface; an acid; and water, wherein: said abrasive grains have an average particle diameter of 50 nm or less and a standard deviation of particle size distribution in a value of more than 5 nm, said oxidizing agent is included in the polishing medium in a concentration from 0.01% to 3% by weight, and said polishing medium has a property of chemical-mechanical polishing of a surface having at least one of tantalum, tantalum alloy and a tantalum compound which is on silicon dioxide and which is originally covered by copper or copper alloy, and is exposed after polishing of the copper or copper alloy, the polishing medium having a property of chemical-mechanical polishing said at least one of tantalum, tantalum alloy and a tantalum compound exposed after polishing of the copper or copper alloy, and chemical-mechanical polishing said at least one of tantalum, tantalum alloy and the tantalum compound at a higher polishing rate than a polishing rate of said silicon dioxide by said polishing medium. ### Claim 21 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, wherein: said abrasive grains are at least one selected from the group consisting of silica, alumina, ceria, titania, zirconia and germania. ### Claim 22 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, wherein said abrasive grains are mixed in an amount of from 0.1% by weight to 5% by weight. ### Claim 23 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, which further comprises a water-soluble polymer. ### Claim 24 (depends on 23) The polishing medium having a property of chemical-mechanical polishing according to claim 23, wherein said oxidizing agent is in a concentration of from 0.01% by weight to 1.5% by weight. ### Claim 25 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, wherein said acid is an organic acid. ### Claim 26 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, which has: a polishing-rate ratio (Ta/Cu) between tantalum and copper or a copper alloy of more than 1; a polishing-rate ratio (TaN/Cu) between tantalum nitride and copper or a copper alloy of more than 1; a polishing-rate ratio (Ta/SiO2) between tantalum and silicon dioxide of more than 10; and a polishing-rate ratio (TaN/SiO2) between tantalum nitride and silicon dioxide of more than 10. ### Claim 27 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, wherein said medium has a property that said at least one of tantalum, tantalum alloy and tantalum compound is selectively polished by said polishing medium relative to polishing of said copper or copper alloy by said polishing medium. ### Claim 28 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, which consists essentially of said abrasive grains, said oxidizing agent, said protective-film-forming agent, said acid and water, and wherein the polishing medium has a property that a polishing-rate ratio of the at least one of tantalum, tantalum alloy and tantalum compound by the polishing medium to the copper or copper alloy by the polishing medium is greater than 1. ### Claim 29 (depends on 28) The polishing medium having a property of chemical-mechanical polishing according to claim 28, wherein the polishing medium has a further property that a polishing-rate ratio of the at least one of tantalum, tantalum alloy and tantalum compound by the polishing medium to silicon dioxide by the polishing medium is more than 10. ### Claim 30 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, wherein the medium has a pH of 3 or less. ### Claim 31 (depends on 20) The polishing medium having a property of chemical-mechanical polishing according to claim 20, which consists of said abrasive grains, said oxidizing agent, said protective-film-forming agent, said acid and water. ### Claim 32 A polishing medium for chemical-mechanical polishing, comprising: an oxidizing agent; a protective-film-forming agent; abrasive grains, wherein said abrasive grains have a standard deviation of particle size distribution in a value of more than 5 nm; an acid; and water, wherein: said polishing medium has a pH of 3 or less, said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight, said polishing medium has a property of being capable of polishing a barrier layer of tantalum, a tantalum alloy or a tantalum compound, which is a barrier layer for a conductor of copper, copper alloy or copper oxide, and said polishing medium has a property that a ratio of a polishing rate of the barrier layer of tantalum, a tantalum alloy or a tantalum compound using the polishing medium, to a polishing rate of the conductor of copper, copper alloy or copper oxide using the polishing medium, is greater than 1. ### Claim 33 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said abrasive grains have an average particle diameter of 50 nm or less. ### Claim 34 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said abrasive grains are mixed in an amount of from 0.1% by weight to 5% by weight. ### Claim 35 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, which further comprises a water-soluble polymer, wherein the concentration of the oxidizing agent in the polishing medium is in a range of from 0.01% by weight to 1.8% by weight. ### Claim 36 (depends on 35) The polishing medium for chemical-mechanical polishing according to claim 35, wherein said water-soluble polymer is at least one selected from the group consisting of polyacrylic acid, a polyacrylic acid salt, polymethacrylic acid, a polymethacrylic acid salt, polyamic acid, a polyamic acid salt, polyacrylamide, polyvinyl alcohol and polyvinylpyrrolidone. ### Claim 37 (depends on 35) The polishing medium for chemical-mechanical polishing according to claim 35, wherein said oxidizing agent is in a concentration of from 0.01% by weight to 1.5% by weight. ### Claim 38 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said acid is an organic acid. ### Claim 39 (depends on 38) The polishing medium for chemical-mechanical polishing according to claim 38, wherein said acid is at least one selected from malonic acid, malic acid, tartaric acid, glycolic acid and citric acid. ### Claim 40 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said protective-film-forming agent is at least one selected from benzotriazole and a derivative thereof. ### Claim 41 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid and ozone water. ### Claim 42 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said barrier layer is a barrier layer for preventing copper atoms from diffusing. ### Claim 43 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said abrasive grains are made of colloidal silica or colloidal alumina. ### Claim 44 (depends on 32) The polishing medium for chemical-mechanical polishing according to claim 32, wherein said medium has a pH of 2.49 to 2.95. ### Claim 45 (depends on 32) As polishing condition, polishing pressure is 25 kPa and relative speed of substrate member to polishing platen is 18 m/minute, the polishing medium for chemical-mechanical polishing according to claim 32, which has: a polishing-rate ratio (Ta/Cu) between tantalum and copper or a copper alloy of more than 1; a polishing-rate ratio (TaN/Cu) between tantalum nitride and copper or a copper alloy of more than 1; a polishing-rate ratio (Ta/SiO2) between tantalum and silicon dioxide of more than 10; and a polishing-rate ratio (TaN/SiO2) between tantalum nitride and silicon dioxide film of more than 10. ### Claim 46 A polishing medium comprising: an oxidizing agent; a protective-film-forming agent; an acid; and water; wherein: said polishing medium includes abrasive grains, said abrasive grains having a standard deviation of particle size distribution in a value of more than 5 nm, said polishing medium has a pH of 3 or less, said oxidizing agent is in a concentration of from 0.01% by weight to 3.0% by weight, said polishing medium has a property of being capable of chemical-mechanical polishing a surface having at least one of tantalum, a tantalum alloy and a tantalum compound, and said polishing medium has a property that a polishing rate of said surface having at least one of tantalum, a tantalum alloy and a tantalum compound, using the polishing medium, to a polishing rate of a conductor selected from the group consisting of copper, copper alloy and copper oxide, using the polishing medium, is greater than 1. ### Claim 47 (depends on 46) The polishing medium for chemical-mechanical polishing according to claim 46, wherein said abrasive grains have an average particle diameter of 50 nm or less. ### Claim 48 A polishing medium for chemical-mechanical polishing of a surface having at least one of tantalum, tantalum alloy and a tantalum compound, comprising: an oxidizing agent for a conductor; a protective-film-forming agent for protecting a metal surface; an acid; water; and abrasive grains, wherein said abrasive grains have a standard deviation of particle size distribution in a value of more than 5 nm, and wherein: said polishing medium has a pH of 3 or less; said oxidizing agent is in a concentration of from 0.01% by weight to 3.0% by weight, said polishing medium has a property of being capable of chemical-mechanical polishing a surface having at least one of tantalum, a tantalum alloy and a tantalum compound, and said polishing medium has a property that a polishing rate of said surface having at least one of tantalum, a tantalum alloy and a tantalum compound, using the polishing medium, to a polishing rate of a conductor selected from the group consisting of copper, copper alloy and copper oxide, using the polishing medium, is greater than 1. ### Claim 49 (depends on 48) The polishing medium for chemical-mechanical polishing according to claim 48, wherein said abrasive grains have an average particle diameter of 50 nm or less. ### Claim 50 A polishing medium for chemical-mechanical polishing, comprising: at least one selected from the group consisting of hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid and ozone water; at least one selected from benzotriazole and a derivative thereof; abrasive grains, wherein said abrasive grains have a standard deviation of particle size distribution in a value of more than 5 nm; an acid; and water, wherein: said polishing medium has a pH of 3 or less, said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight, said polishing medium has a property of being capable of polishing a barrier layer of tantalum, a tantalum alloy or a tantalum compound, which is a barrier layer for a conductor of copper, copper alloy or copper oxide, and said polishing medium has a property that a ratio of a polishing rate of the barrier layer of tantalum, a tantalum alloy or a tantalum compound using the polishing medium, to a polishing rate of the conductor of copper, copper alloy or copper oxide using the polishing medium, is greater than 1. ### Claim 51 (depends on 50) The polishing medium for chemical-mechanical polishing according to claim 50, wherein said abrasive grains have an average particle diameter of 50 nm or less. ### Claim 52 A polishing medium comprising: at least one selected from the group consisting of hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid and ozone water; at least one selected from benzotriazole and a derivative thereof; an acid; and water, wherein: said polishing medium includes abrasive grains, said abrasive grains having standard deviation of particle size distribution in a value of more than 5 nm, said polishing medium has a pH of 3 or less, said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight, said polishing medium has a property of being capable of chemical-mechanical polishing a surface having at least one of tantalum, a tantalum alloy and a tantalum compound, and said polishing medium has a property that a polishing rate of said surface having at least one of tantalum, a tantalum alloy and a tantalum compound, using the polishing medium, to a polishing rate of a conductor selected from the group consisting of copper, copper alloy and copper oxide, using the polishing medium, is greater than 1. ### Claim 53 (depends on 52) The polishing medium for chemical-mechanical polishing according to claim 52, wherein said abrasive grains have an average particle diameter of 50 nm or less. ### Claim 54 A polishing medium comprising: at least one selected from the group consisting of hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid and ozone water; at least one selected from benzotriazole and a derivative thereof; an acid; water; and abrasive grains, wherein said abrasive grains have a standard deviation of particle size distribution in a value of more than 5 nm, and wherein: said polishing medium has a pH of 3 or less; said oxidizing agent is in a concentration of from 0.01% by weight to 3.0% by weight, said polishing medium has a property of being capable of polishing a surface having at least one of tantalum, a tantalum alloy and a tantalum compound, and said polishing medium has a property that a polishing rate of said surface having at least one of tantalum, a tantalum alloy and a tantalum compound, using the polishing medium, to a polishing rate of a conductor selected from the group consisting of copper, copper alloy and copper oxide, using the polishing medium, is greater than 1. ### Claim 55 (depends on 54) The polishing medium for chemical-mechanical polishing according to claim 54, wherein said abrasive grains have an average particle diameter of 50 nm or less. ### Claim 56 A polishing medium for chemical-mechanical polishing, comprising: an oxidizing agent; a protective-film-forming agent; abrasive grains; an acid; and water, wherein: said polishing medium has a pH of 3 or less, said oxidizing agent is in a concentration of from 0.01% by weight to 3% by weight, said polishing medium has a property of being capable of polishing a barrier layer of tantalum, a tantalum alloy or a tantalum compound, which is a barrier layer for a conductor of copper, copper alloy or copper oxide, said polishing medium has a property that a ratio of a polishing rate of the barrier layer of tantalum, a tantalum alloy or a tantalum compound using the polishing medium, to a polishing rate of the conductor of copper, copper alloy or copper oxide using the polishing medium, is greater than 1, and said polishing medium has a property that a ratio of a polishing rate of the barrier layer of tantalum, a tantalum alloy or a tantalum compound using the polishing medium, to a polishing rate of silicon dioxide using the polishing medium, is greater than 10.