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:
Sep. 25, 2001
Filed:
Oct. 14, 1999
William Graham Easter, Orlando, FL (US);
John Albert Maze, Orlando, FL (US);
Frank Miceli, Orlando, FL (US);
Sudhanshu Misra, Orlando, FL (US);
Allen Yen, Orlando, FL (US);
Agere Systems Guardian Corp., Allentown, PA (US);
Abstract
An apparatus for determining endpoint in the chemical mechanical polishing of a metal film using an acidic slurry includes a hydrogen sensor which senses the amount of hydrogen vapor being produced as a result of the reaction between the metal film and the acidic slurry. When the concentration of hydrogen vapor in the reaction area drops, endpoint is attained and the polishing operation may be terminated or otherwise adjusted. Hydrogen sensing elements include a palladium gate MOS transistor, expandable plastics and a tungsten oxide film.