| 摘要 |
RF power is coupled to one or more RF drive points (50-56) on an electrode (20-28) of a plasma chamber such that the level of RF power coupled to the RF drive points (51-52, 55-56) on the half (61) of the electrode that is closer to the workpiece passageway (12) exceeds the level of RF power coupled to the RF drive points (53-54), if any, on the other half (62) of the electrode. Alternatively, RF power is coupled to one or more RF drive points on an electrode of a plasma chamber such that the weighted mean of the drive point positions is between the center (60) of the electrode and the workpiece passageway. The weighted mean is based on weighting each drive point position by the time-averaged level of RF power coupled to that drive point position. The invention offsets an increase in plasma density that otherwise would exist adjacent the end of the electrode closest to the passageway.
|
