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. 10, 2001
Filed:
Nov. 01, 1999
William Graham Easter, Orlando, FL (US);
Sudhanshu Misra, Orlando, FL (US);
Pradip Kumar Roy, Orlando, FL (US);
Susan Clay Vitkavage, Orlando, FL (US);
Agere Systems Guardian Corp., Allentown, PA (US);
Abstract
An apparatus for determining the endpoint in a chemical mechanical polishing operation used for polishing a metal-containing material includes an electrochemical cell and an electronic circuit. An acidic polishing slurry is used to oxidize the metal and the oxidized metal is included in an effluent slurry stream, a sample of which is provided to the apparatus. The apparatus includes a liquid-phase working electrode, a reference electrode and a solid electrolyte which allows for the interchange of ions between the electrodes. An electronic circuit is coupled to the electrode for monitoring the component activity of the effluent slurry stream by measuring the electric potential across the electrodes. When the measured electric potential changes, indicating a change in the composition of the effluent slurry, endpoint is indicated.