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:
Jun. 12, 2012
Filed:
Jan. 18, 2011
Robert John Wilby, Bristol, GB;
Adrian Kiermasz, Bristol, GB;
Robert John Wilby, Bristol, GB;
Adrian Kiermasz, Bristol, GB;
Metryx Limited, Bristol, GB;
Abstract
Measuring apparatus for monitoring the position of the center of mass of a semiconductor wafer is disclosed. The apparatus includes a wafer support () with a ledge for supporting an edge of a wafer () when it is lifted at a detection point by a probe (). The probe () is connected to a force sensor () which senses a force due to a moment of the wafer about a fulcrum () on the wafer support (). Moment measurements are taken at a plurality of detection points and a processing unit calculates the position of the center of mass from the moment measurements. Changes in wafer mass distribution (e.g. due to faulty treatment steps) which cause movement of the center of mass can be detected.