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:
May. 30, 1989
Filed:
May. 11, 1987
Robert M Spencer, San Juan Capistrano, CA (US);
Christopher O Lada, Palo Alto, CA (US);
Lam Research, Fremont, CA (US);
Abstract
A system for locating and positioning wafers includes a wafer shuttle, a spindle, and a position sensor. The wafer shuttle retrieves wafers from a storage location, typically a wafer cassette, and transports the wafers to the spindle. The wafers are then incrementally rotated on the spindle, and the distance between the center of rotation and the periphery of the wafer along a linear path is measured. By using three such measurements, the distance and angle with which the center of the wafer is offset from the center of rotation may be calculated. The wafer can then be centered on the spindle by rotation and translated a proper distance by the wafer shuttle. Usually, the wafers will be further rotationally oriented so that the crystal lattice lies in a desired direction.