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:
Oct. 03, 2000
Filed:
Nov. 26, 1997
Martin N Scales, San Jose, CA (US);
David A Pechin, Santa Clara, CA (US);
Jeffrey C Benzing, Saratoga, CA (US);
R Marshall Stowell, Lakeworth, FL (US);
Novellus Systems, Inc., San Jose, CA (US);
Abstract
A passive mechanism for centering a wafer on a chuck and with respect to a backside exclusion gas ring includes a plurality of wheels that are rotatably mounted in a circular pattern at the top surface of a chuck. The axis of rotation of each wheel is parallel to the top surface of the chuck and perpendicular to a radius extending outward from the centerpoint of the chuck surface. When a wafer is placed on the chuck, its edge contacts the wheels and, by its own weight, the wafer moves toward the center of the chuck, thereby centering itself. The wafer either slides on the wheels or, if the frictional force between the wafer and one or more of the wheels is great enough, the wafer causes the wheel to turn. The wheels may be mounted on the chuck, a carrier ring or a wafer transfer arm for moving wafers between processing stations. In one embodiment the alignment wheels are mounted on a carrier ring, and a second alignment mechanism aligns the carrier ring to the chuck.