Apparatus, systems, and methods for controlling azimuthal uniformity of an etch process in a plasma processing chamber are provided. In one embodiment, a plasma processing apparatus can include a plasma processing chamber and an RF cage disposed above the plasma processing chamber. A dielectric window can separate the plasma processing chamber and the RF cage. The apparatus can include a plasma generating coil disposed above the dielectric window. The plasma generating coil can be operable to generate an inductively coupled plasma in the plasma processing chamber when energized. The apparatus further includes a conductive surface disposed within the RF cage proximate to at least a portion of the plasma generating coil. The conductive surface is arranged to generate an azimuthally variable inductive coupling between the conductive surface and the plasma generating coil when the plasma generating coil is energized.