Plasma uniformity control system and methods

A method of processing a substrate, comprising performing a processing sequence on the substrate disposed within a processing region of a plasma processing chamber, wherein the processing sequence comprises:

• biasing, with a power supply circuit, at least three of a plurality of concentric coils to adjust a generated magnetic field in a region of control of a plasma in the plasma processing chamber to control a plasma density of the plasma by changing an absolute magnitude of a current applied to the at least three of the plurality of concentric coils to change a radial flux in the region of control, wherein the biasing the at least three of the plurality of concentric coils comprises:
• delivering a first bias signal to a coil of a first concentric coil of the plurality of concentric coils;
• delivering a second bias signal to a coil of a second concentric coil of the plurality of concentric coils;
• and
• delivering a third bias signal to a coil of a third concentric coil of the plurality of concentric coils, and wherein at least one of the at least three of the plurality of concentric coils is biased oppositely of the other concentric coils.

A method of processing a substrate, comprising performing a processing sequence on the substrate disposed within a processing region of a plasma processing chamber, wherein the processing sequence comprises:

• biasing, with a power supply circuit, at least two of a plurality of concentrically aligned coils to adjust a generated magnetic field in a region of control of a plasma in the plasma processing chamber to control a plasma density of the plasma by changing an absolute magnitude of a current applied to the at least two of the plurality of concentrically aligned coils to change a radial flux in the region of control, wherein the biasing the at least two of the plurality of concentrically aligned coils comprises:
• delivering a first bias signal to a coil of a first concentric coil of the plurality of concentrically aligned coils at a first time;
• and
• delivering a second bias signal to a coil of a second concentric coil of the plurality of concentrically aligned coils at a second time.