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. 08, 1998
Filed:
Jun. 20, 1997
Konstantin Volodarsky, San Francisco, CA (US);
David E Weldon, Los Gatos, CA (US);
OnTrak Systems, Inc., Fremont, CA (US);
Abstract
A polishing head for polishing a semiconductor wafer includes a housing, a wafer carrier movably mounted to the housing, and a wafer retainer movably mounted to the housing. The wafer carrier forms a wafer supporting surface, and the wafer retainer is shaped to retain a wafer in place on the wafer-supporting surface. A first fluid actuator is coupled to the wafer carrier to bias the wafer carrier in a selected direction with respect to the housing, and a second fluid actuator is coupled to the wafer retainer to bias the wafer retainer in a second selected direction with respect to the housing. First and second fluid conduits are coupled to the first and second actuators, respectively, such that fluid pressures in the first and second actuators are separately and independently adjustable with respect to one another. Biasing forces on the retainer can thereby be dynamically adjusted with respect to biasing forces on the carrier during the polishing operation.