Patent ID: 8366829

Claim:
A plasma processing chamber having at least two processing regions to enable individual or simultaneous processing of at least two wafers, comprising: a chamber body having a grounded wall defining at least two plasma processing regions, each processing region having a cathode situated at a lower part thereof and an anode situated in a ceiling thereof, said chamber body defining an evacuation path; at least one vacuum pump coupled to the evacuation path; at least two RF match circuits, each RF match circuit simultaneously coupling at least a first RF frequency and a second RF frequency to a corresponding one of the cathodes, wherein the first frequency is higher than the second frequency; and, two movable dielectric isolation rings, each provided at one processing region and each being vertically movable between loading/unloading position and processing position, each isolation ring defining peripheral boundary of each processing region when the isolation ring assumes its processing position, wherein each isolation ring has a thickness, T, such that it prevents return path from the plasma via the grounded wall, whereby the RF return path is controlled to flow via the anode.