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:
Jan. 19, 1999
Filed:
Nov. 27, 1996
Scott B Loncki, Lincoln University, PA (US);
Lee Melbourne Cook, Steelville, PA (US);
James Shen, Bear, DE (US);
Keith G Pierce, Newark, DE (US);
Rodel, Inc., Newark, DE (US);
Abstract
An improved slurry composition and methods of using it are provided for final polishing of silicon wafers. The composition comprises water, submicron silica particles at about 0.02 to about 0.5 percent by weight of this composition, a salt at a concentration of about 100 to about 1000 ppm, an amine compound at a concentration sufficient to effect a composition pH of about 8 to about 11, and a polyelectrolyte dispersion agent at a concentration of about 20 to about 500 ppm, wherein the composition has a total sodium and potassium content below about 1 ppm and an iron, nickel and copper content each below about 0.1 ppm, all ppm being parts per million by weight of the composition.