Abstract: A control circuit configured to control a reference voltage of a reference node of an electrostatic chuck power supply is disclosed. The electrostatic chuck power supply is configured to clamp a substrate to a bipolar electrostatic chuck. The electrostatic chuck has a first buried conductor and a second buried conductor. The electrostatic chuck power supply has a first output configured for being coupled with the first buried plate. The first output has a first output voltage referenced to the reference voltage of the reference node. The electrostatic chuck power supply also has a second output configured for being coupled with the second buried plate. The first output has a first output voltage referenced to the reference voltage of the reference node.

Abstract: An apparatus and method in a plasma processing chamber for reducing charging of a wafer is described. A plasma generating element is configured to cause a plasma including ions and free radicals to be formed in a plasma generating region. A plasma diffusion region is configured so that plasma generated in the plasma generating region can diffuse through the plasma diffusion region. A conductive grid is positioned within the plasma diffusion region between the wafer and the plasma generating region. The conductive grid includes a mesh which is configured to trap a portion of the ions so that a portion of the ions are prevented from diffusing through the diffusion region to reach the wafer.