CERIA-BASED COMPOSITE FINE PARTICLE DISPERSION, PRODUCTION METHOD THEREOF, AND ABRASIVE GRAIN DISPERSION FOR POLISHING INCLUDING THE CERIA-BASED COMPOSITE FINE DISPERSION

摘要

To provide a ceria-based composite particle dispersion capable of polishing at a high speed silica films, Si wafers and even hard-to-process materials and simultaneously attaining a high surface precision.SOLUTION: Provided is a dispersion of ceria-based composite fine particles 20 that include ceria-based composite fine particles having an average particle diameter of 30 to 1000 nm and that have the following characteristics (1) to (5): (1) mother particles 10 and child particles 14 are contained, the child particles being dispersed on a cerium-containing silica layer 12 on the surface of the mother particles 10 and within the cerium-containing silica layer 12, and the mother particles 10 have amorphous silica as a main component and the child particles 12 have crystalline ceria as a main component; (2) the surface covering ratio of the child particles 12 in the ceria-based composite fine particles is 40% or more; (3) the mass ratio between silica and ceria is 100:50-400; (4) subjecting the ceria-based composite fine particles to X-ray diffractometry results in the detection of a crystalline phase alone of ceria; and (5) the average crystal diameter of the crystalline ceria measured by X-ray diffractometry is 10 to 50 nm.SELECTED DRAWING: Figure 1