Patent ID: 8439995

Claim:
A method for producing a polishing slurry for semiconductor planarization, comprising mechanically grinding cerium oxide particles, mixing at least a dispersing agent and water with the cerium oxide particles to prepare a polishing slurry, filtering the polishing slurry through a filter wherein holes of the filter are formed by superposing filter fibers and reducing the diameter of the holes continuously from the outside of the filter to the inside, wherein the filter fibers are not mutually fixed, and performing said filtering multiple times until the content of cerium oxide particles having a diameter of at least 3 μm is not more than 500 ppm, calculated based on the weight of particles obtained by filtering with a film filter for analysis on which hole diameters of 3 μm are formed by punching the film and the weight of all the solids in the polishing slurry, wherein said polishing slurry is capable of semiconductor planarization.