Electrostatic chuck having electrode with rounded edge

摘要

An electrostatic chuck provides reduced electric field effects about its peripheral edge. The chuck comprises a dielectric covering an electrode having a central planar portion with top and bottom surfaces. In one version, the electrode also has a wire loop extending about its perimeter, the wire loop having a radially outwardly facing surface that is substantially rounded. Altematively, the electrode has a peripheral arcuate portion having a tip with a curvature length of at least about pi /8 radians between a normal to the top surface of the central planar portion and a normal to the upper surface of the tip. A dielectric covers the electrode. The electrostatic chuck is used to hold a substrate in a process chamber of a substrate processing apparatus.