# US 2010/0163785 A1 · Dispersion comprising cerium oxide, silicon dioxide and amino acid > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0163785 A1 - Document ID: US20100163785A1 - Status: Published application - Kind: A1 - Application number: 12/600,954 - Filed: 2008-05-05 - Published: 2010-07-01 - Earliest claimed: 2007-05-25 - Assignees: Evonik Degussa GmbH - Inventors: Michael Kroell; Stefan Heberer; Katharina Dauth - Web page: https://patentgrep.com/patent/US20100163785A1 ## CPC - C09G 1/02: containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} - C09K 3/1409: {Abrasive particles per se (preparation of diamond C01B32/25)} - C09K 3/1463: {Aqueous liquid suspensions} - C09G: POLISHING COMPOSITIONS (French polish C09F11/00); SKI WAXES - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract A dispersion comprising particles of cerium oxide and colloidal silicon dioxide and in each case one or more aminocarboxylic acids and/or salts thereof, where the zeta potential of the silicon dioxide particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, the mean diameter of the • cerium oxide particles is not more than 200 nm silicon dioxide particles is less than 100 nm, the content, based in each case on the total amount of the dispersion, of • cerium oxide particles is from 0.1 to 5% by weight silicon dioxide particles is from 0.01 to 10% by weight and • aminocarboxylic acid or salt thereof is from 0.01 to 5% by weight and —the pH of the dispersion is from 7.5 to 10.5. ## Claims ### Claim 1 A dispersion comprising particles of cerium oxide and colloidal silicon dioxide and one or more aminocarboxylic acids and/or salts thereof, wherein the zeta potential of the silicon dioxide particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, the mean diameter of the cerium oxide particles is not more than 200 nm and of the silicon dioxide particles is less than 100 nm, the content, based in each case on the total amount of the dispersion, of cerium oxide particles is from 0.1 to 5% by weight, silicon dioxide particles is from 0.01 to 10% by weight and aminocarboxylic acid or salt thereof is from 0.01 to 5% by weight, and the pH of the dispersion is from 7.5 to 10.5. ### Claim 2 (depends on 1) The dispersion as claimed in claim 1, wherein the zeta potential of the dispersion is from −20 to −100 mV. ### Claim 3 (depends on 1) The dispersion as claimed in claim 1, wherein the pH is from 9 to 10. ### Claim 4 (depends on 1) The dispersion as claimed in claim 1, wherein the content of cerium oxide is from 0.2 to 1% by weight, based on the dispersion. ### Claim 5 (depends on 1) The dispersion as claimed in claim 1, wherein the content of colloidal silicon dioxide is from 0.05 to 0.5% by weight, based on the dispersion. ### Claim 6 (depends on 1) The dispersion as claimed in claim 1, wherein the cerium oxide/silicon dioxide weight ratio is from 1.1:1 to 100:1. ### Claim 7 (depends on 1) The dispersion as claimed in claim 1, wherein cerium oxide particles and silicon dioxide particles are the only particles in the dispersion. ### Claim 8 (depends on 1) The dispersion as claimed in claim 1, wherein the mean particle diameter of the cerium oxide particles is from 40 to 90 nm. ### Claim 9 (depends on 1) The dispersion as claimed in claim 1, wherein the cerium oxide particles are present in the form of aggregated primary particles. ### Claim 10 (depends on 1) The dispersion as claimed in claim 1, wherein the cerium oxide particles contain carbonate groups on their surface and in layers close to the surface. ### Claim 11 (depends on 1) The dispersion as claimed in claim 1, wherein the colloidal silicon dioxide particles have a mean particle diameter of from 3 to 50 nm. ### Claim 12 (depends on 1) The dispersion as claimed in claim 1, wherein the amino acid is selected from the group consisting of alanine, 4-aminobutanecarboxylic acid, 6-aminohexanecarboxylic acid, 12-aminolauric acid, arginine, aspartic acid, glutamic acid, glycine, glycylglycine, lysine and proline. ### Claim 13 (depends on 1) The dispersion as claimed in claim 1, wherein the amino acid or salt thereof is present in the dispersion with a content of from 0.1 to 0.6% by weight. ### Claim 14 (depends on 1) The dispersion as claimed in claim 1, wherein water is the main constituent of the liquid phase of the dispersion. ### Claim 15 (depends on 1) The dispersion as claimed in claim 1, which comprises acids, bases, salts, oxidizing agents, oxidation catalysts and/or corrosion inhibitors. ### Claim 16 (depends on 1) A process for producing the dispersion as claimed in claim 1, which comprises introducing and subsequently dispersing cerium oxide particles in powder form into a predispersion comprising colloidal silicon dioxide particles or combining and subsequently dispersing a predispersion comprising cerium oxide particles and a predispersion comprising colloidal silicon dioxide particles and then adding one or more amino acids in solid, liquid or dissolved form and then optionally oxidizing agent, oxidation catalyst and/or corrosion inhibitor. ### Claim 17 (depends on 16) The process as claimed in claim 16, wherein the zeta potential of the colloidal silicon dioxide particles is from −20 to −100 mV at a pH of from 7.5 to 10.5. ### Claim 18 (depends on 16) The process as claimed in claim 16, wherein the zeta potential of the cerium oxide particles is from 0 to 40 mV at a pH of from 7.5 to 10.5. ### Claim 19 (depends on 1) A composition for polishing dielectric surfaces comprising the dispersion as claimed in claim 1.