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:
Oct. 09, 2001
Filed:
Apr. 22, 1999
Applicant:
Inventors:
Assignee:
SpeedFam Co Ltd, Kanagawa-pref, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1302 ; H01L 2/1461 ;
U.S. Cl.
CPC ...
H01L 2/1302 ; H01L 2/1461 ;
Abstract
The present invention is a polishing compound comprising a colloidal solution containing 1˜15 wt. % of silicon oxide particles of 8˜500 nanometer average diameter, wherein said colloidal solution is prepared as a buffer solution which has buffering action between pH 8.7˜10.6 by the addition of one combination selected from groups composed by weak acid and strong base, strong acid and weak base or weak acid and weak base, and logarithms of reciprocal number of acid dissociation constant at 25° C. of said weak acid and/or weak base is 8.0˜12.0.