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:
Jun. 04, 2002
Filed:
Jun. 29, 2000
Isao Ota, Funabashi, JP;
Tohru Nishimura, Funabashi, JP;
Yoshitane Watanabe, Funabashi, JP;
Yoshiyuki Kashima, Funabashi, JP;
Kiyomi Ema, Funabashi, JP;
Yutaka Ohmori, Funabashi, JP;
Nissan Chemical Industries, LTD., Tokyo, JP;
Abstract
The present invention relates to a polishing composition for polishing alumina disks, polishing substrates having silica surfaces and semiconductor wafers, comprising a stable aqueous silica sol containing moniliform colloidal silica particles having a ratio (D /D ) of a particle diameter D nm (as measured by dynamic light scattering method) to a mean particle diameter D (as measured by nitrogen absorption method) of 3 or more, wherein D is between 50 to 800 nm and D is between 10 to 120 nm, said moniliform colloidal silica particles being composed of spherical colloidal silica particles and a metal oxide-containing silica bond which bonds these spherical colloidal silica particles together, wherein the spherical colloidal silica particles are linked together in rows in only one plane by observation through an electron microscope, and further wherein said polishing composition contains 0.5 to 50% by weight of said moniliform colloidal silica particles.