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:
Feb. 21, 2012
Filed:
Jan. 31, 2008
Eugene Shalyt, Washington Township, NJ (US);
Victor Ososkov, Springfield, NJ (US);
Michael Pavlov, Fairlawn, NJ (US);
Peter Bratin, Flushing, NY (US);
Eugene Shalyt, Washington Township, NJ (US);
Victor Ososkov, Springfield, NJ (US);
Michael Pavlov, Fairlawn, NJ (US);
Peter Bratin, Flushing, NY (US);
ECI Technology, Inc., Totowa, NJ (US);
Abstract
A simple titration method involving a single copper ion titrant detected by a copper ion specific electrode provides the concentrations of both copper ions and bath complexing agent (ethylene diamine, for example) in alkaline copper electroplating baths of the type used to deposit or thicken copper seed layers on silicon wafers. Standard addition of an excess of a strong complexing agent (EDTA, for example) and back-titration with the copper ion titrant yields the bath copper ion concentration, and continued titration to a second endpoint, preferably after addition of hydroxide to adjust the pH of the analysis solution, yields the total concentration of bath complexing agent. Based on these analyzes, the concentration of free bath complexing agent may be calculated. The method also provides direct determination of the free bath complexing agent concentration via standard addition of excess bath complexing agent to a sample of the plating bath and titration with the copper ion titrant.