Methods and apparatus for selectively modulating azimuthal non-uniformity in a plasma processing system

A plasma processing system having a plasma processing chamber, comprising:

• an upper electrode;
• and
• a magnet ring disposed off-center relative to a center of said upper electrode, said magnet ring further disposed in one of a first position and a second position, the first position being above said upper electrode, the second position being around an outer periphery of said upper electrode.

The plasma processing system of claim it wherein said plasma processing chamber is an inductively coupled chamber.

A plasma processing system having a plasma processing chamber, comprising:

• a upper electrode;
• and
• a ring comprising a plurality of electromagnets disposed in a ring-like configuration, said ring being disposed off-center relative to a center of said upper electrode, each of said plurality of electromagnets having its coil current individually controllable, said ring further disposed in one of a first position and a second position, the first position being above said upper electrode, the second position being around an outer periphery of said upper electrode.