Patent ID: 8343592

Claim:
A method of coupling RF power to a plasma chamber, comprising the steps of: providing a plasma chamber having a workpiece passageway; providing an electrode positioned so as to couple electrical power from the electrode to a plasma within the plasma chamber, wherein a first half of the electrode is closer to the workpiece passageway than a second half of the electrode; providing one or more RF drive points on the first half of the electrode and one or more RF drive points on the second half of the electrode; connecting at least a first capacitor between a supply of RF power and one or more of the RF drive points on the first half of the electrode; connecting at least a second capacitor between said supply of RF power and one or more of the RF drive points on the second half of the electrode; supplying a first time-averaged level of RF power to the first half of the electrode; and supplying a second time-averaged level of RF power to the second half of the electrode; wherein the second time-averaged level of RF power is greater than or equal to zero; wherein the first time-averaged level of RF power is greater than the second time-averaged level of RF power; and wherein the sum of the capacitances of the capacitors connected to RF drive points on the first half of the electrode is less than the sum of the capacitances of the capacitors connected to RF drive points on the second half of the electrode.