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:
Jul. 13, 1999
Filed:
Sep. 16, 1997
Applicant:
Inventors:
Brian V Jenkins, LaGrange Park, IL (US);
John E Hoots, St. Charles, IL (US);
Assignee:
Nalco Chemical Company, Naperville, IL (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
436 55 ; 134-13 ; 134-2 ; 134 18 ; 436 56 ; 436172 ; 438-5 ; 438 14 ; 438 16 ; 438906 ;
Abstract
A method for determining wafer cleanliness by fluorometric monitoring of the impurities in the semiconductor chip wafer rinse solution. A clean chip is indicated by a leveling off of increased concentration of impurities as the rinsing of the chip progresses. A method for optimizing reuse or recyling of the water discharged from the rinse process which accurately measures the contaminants in that water.