The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 24, 2001
Filed:
Aug. 10, 1999
Masato Yoshida, Tsukuba, JP;
Toranosuke Ashizawa, Hitachinaka, JP;
Hiroki Terazaki, Tsukuba, JP;
Yasushi Kurata, Tsukuba, JP;
Jun Matsuzawa, Tsukuba, JP;
Kiyohito Tanno, Hitachi, JP;
Yuuto Ootuki, Hitachi, JP;
Abstract
This invention provides a cerium oxide abrasive with which the surfaces of substrates such as SiO,insulating films can be polished at a high rate without causing scratches. The abrasive of the present invention comprises a slurry comprising cerium oxide particles whose primary particles have a diameter of from 10 nm to 600 nm and a median diameter of from 30 nm to 250 nm and slurry particles have a median diameter of from 150 nm to 600 nm and a maximum diameter of 3,000 nm or smaller, the cerium oxide particles being dispersed in a medium.