RASPBERRY-TYPE METAL OXIDE NANOSTRUCTURES COATED WITH CeO2 NANOPARTICLES FOR CHEMICAL MECHANICAL PLANARIZATION

摘要

Raspberry-type coated particles comprising a core selected from the group consisting of metal oxides of Si, Ti, Zr, Al, Zn and mixtures thereof with a core size of from 20 to 100 nm wherein the core is coated with CeCO2 particles having a particle size below 10 nm; process for preparing raspberry type coated particles comprising the steps of i) providing a mixture containing: a) core particles selected from the group of metal oxides of Si, Ti, Zr, Al, Zn and mixtures thereof, with a particle size of from 20 to 100 nm; b) a water soluble Ce-salt and c) water; ii) adding an organic or inorganic base to the mixture of step i) at temperatures of from 10 to 90° C. and iii) aging the mixture at temperatures of from 10 to 90° C.; and polishing agents containing the particles and their use for polishing surfaces.