公开(公告)号：US10324121B2

公开(公告)日：2019-06-18

申请号：US13729524

申请日：2012-12-28

Applicant: Axcelis Technologies, Inc.

Inventor： Edward K. McIntyre ,  Edward J. Ladny ,  Nathaniel Robinson ,  William Davis Lee

IPC: G01R29/24 ,  H01L21/687 ,  H01L21/67 ,  H01L21/683

Abstract: An electrostatic clamp monitoring system has an electrostatic clamp configured to selectively electrostatically clamp a workpiece to a clamping surface via one or more electrodes. A power supply electrically coupled to the electrostatic clamp is configured to selectively supply a clamping voltage to the one or more electrodes. A data acquisition system is coupled to the power supply and configured to measure a current supplied to the one or more electrodes, therein defining a measured current. A controller integrates the measured current over time, therein determining a charge value associated a clamping force between the workpiece and electrostatic clamp. A memory stores the charge value associated with the clamping force over a plurality of clamping cycles, therein defining a plurality of charge values, and the controller determines a clamping capability of the electrostatic clamp based on a comparison of a currently determined charge value to the plurality of charge values.