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. 13, 2004
Filed:
Jan. 15, 2003
Robert Martinson, San Mateo, CA (US);
Dhairya Shrivastava, Los Altos, CA (US);
Matthew Weis, San Jose, CA (US);
Novellus Systems, Inc., San Jose, CA (US);
Abstract
A method for a robotic semiconductor wafer processing system to correct for wafers that have become offset or off-center during wafer processing. This is accomplished by determining the amount of offset and re-centering the wafer during wafer transport to the next process station using a single station sensor to locate the wafer center point. Each single sensor located at each station activates when the wafer's edge traverses through the sensor's path. Directional coordinates for the measured designated points on the wafer's edge are calculated, and the intersection points of two circles, analytically derived from using the measured designated points as their centers, are determined. The intersection point closest to the true wafer center position represents the measured wafer's center point. This point is compared to the true wafer center position, and the wafer is then adjusted for this difference.