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:
Apr. 25, 2017
Filed:
Apr. 16, 2015
Varian Semiconductor Equipment Associates, Inc., Gloucester, MA (US);
Morgan D. Evans, Manchester, MA (US);
Jason M. Schaller, Austin, TX (US);
Ala Moradian, Beverly, MA (US);
D. Jeffrey Lischer, Acton, MA (US);
Gregory D. Thronson, Groveland, MA (US);
Varian Semiconductor Equipment Associates, Inc., Gloucester, MA (US);
Abstract
An electrostatic clamp having improved temperature uniformity is disclosed. The electrostatic clamp includes an LED array mounted along an annular ring so as to illuminate the outer edge of the workpiece. The LEDs in the LED array may emit light at a wavelength readily absorbed by the workpiece, such as between 0.4 μm and 1.0 μm. The center portion of the workpiece is heated using conductive heating provided by the heated electrostatic clamp. The outer portion of the workpiece is heated by light energy from the LED array. The LED array may be disposed on the base of the electrostatic clamp, or may be disposed on a separate ring. The diameter of the upper dielectric layer of the electrostatic clamp may be modified to accommodate the LED array.