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. 23, 2020
Filed:
Dec. 05, 2017
Axcelis Technologies, Inc., Beverly, MA (US);
Edward K. McIntyre, Franklin, MA (US);
William P. Reynolds, Canton, MA (US);
Axcelis Technologies, Inc., Beverly, MA (US);
Abstract
An electrostatic clamp monitoring system has an electrostatic clamp configured to selectively electrostatically clamp a workpiece to a clamping surface associated therewith via one or more electrodes. A power supply is electrically coupled to the electrostatic clamp and configured to selectively supply a clamping voltage at a clamping frequency to the electrostatic clamp. A data acquisition system measures a current supplied to the one or more electrodes, and a controller integrates the measured current over time, therein determining a charge value associated a clamping force between the workpiece and electrostatic clamp. The controller is further configured to selectively vary one or more of the clamping voltage and clamping frequency based on the determined charge value, thereby maintaining a desired clamping force between the workpiece and electrostatic clamp.