Patent Number: 7,708,788

Title: Cerium oxide abrasive and method of polishing substrates

Abstract: A cerium oxide abrasive slurry having, dispersed in a medium, cerium oxide particles whose primary particles have a median diameter of from 30 nm to 250 nm, a maximum particle diameter of 600 nm or smaller, and a specific surface area of from 7 to 45 m..sup.2/g, and slurry particles have a median diameter of from 150 nm to 600 nm. The cerium oxide particles have structural parameter Y, representing an isotropic microstrain obtained by an X-ray Rietveld method (with RIETAN-94), of from 0.01 to 0.70, and structural parameter X, representing a primary particle diameter obtained by an X-ray Rietveld method (with RIETAN-94), of from 0.08 to 0.3. The cerium oxide abrasive slurry is made by a method of obtaining particles by firing at a temperature of from 600.degree. C. to 900.degree. C. and then pulverizing, then dispersing the resulting cerium oxide particles in a medium.

Inventors: Yoshida; Masato (Tsukuba, JP), Ashizawa; Toranosuke (Hitachinaka, JP), Terazaki; Hiroki (Tsukuba, JP), Kurata; Yasushi (Tsukuba, JP), Matsuzawa; Jun (Tsukuba, JP), Tanno; Kiyohito (Hitachi, JP), Ootuki; Yuuto (Hitachi, JP)

Assignee: Hitachi Chemical Co, Ltd.

International Classification: C09G 1/02 (20060101); C09G 1/04 (20060101); C09K 3/14 (20060101)

Expiration Date: 5/04/12018