Patent ID: 8721836

Claim:
A system for plasma processing of a microelectronic workpiece, the system comprising: a reaction chamber configured to produce a plasma in an interior volume of the chamber; a gas distributor in the reaction chamber for delivering a non-dissociated and non-ionized process gas to the interior volume of the chamber; a support element in the reaction chamber for positioning a microelectronic workpiece adjacent to the plasma; a cathode discharge assembly in the reaction chamber, the cathode discharge assembly being spaced apart from the gas distributor and proximate to a perimeter of the microelectronic workpiece, the cathode discharge assembly having a flow port with an outlet, the cathode discharge assembly being configured to deliver at least one of an at least partially dissociated and ionized tuning gas along a peripheral edge of the workpiece through the outlet of the flow port to the workpiece separate from the process gas; and a power supply connected to the cathode discharge assembly and configured to: at least dissociate the tuning gas or ionize the tuning gas, or dissociate and ionize the tuning gas.