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:
Nov. 03, 2015
Filed:
Sep. 14, 2012
Russell Herbert Arndt, Fishkill, NY (US);
Paul F. Findeis, Verbank, NY (US);
Charles Jesse Taft, Wappingers Falls, NY (US);
Russell Herbert Arndt, Fishkill, NY (US);
Paul F. Findeis, Verbank, NY (US);
Charles Jesse Taft, Wappingers Falls, NY (US);
GLOBALFOUNDRIES INC., Grand Cayman, KY;
Abstract
An etching method. The method includes etching a first plurality of silicon wafers in a first enchant, each silicon wafer having SiOand SiNdeposited thereon, where the etching includes dissolving a quantity of the SiOand a quantity of the SiNin the first etchant. A quantity of insoluble SiOprecipitates. A ratio of a first etch rate of SiNto a first etch rate of SiOis determined to be less than a predetermined threshold. A portion of the first etchant is combined with a second etchant to form a conditioned etchant. A second plurality of silicon wafers is etched in the conditioned etchant. A ratio of a second etch rate of SiNto a second etch rate of SiOin the conditioned etchant is greater than the threshold. A method for exchanging an etching bath solution and a method for forming a selective etchant are also disclosed.