Systems and methods for controlling directionality of ions in an edge region by using an electrode within a coupling ring

A system for controlling directionality of ion flux at an edge region within a plasma chamber, comprising:

• a first radio frequency (RF) filter that is configured to output a first filtered RF signal;
• a second RF filter coupled to the first RF filter for receiving the first filtered RF signal to output a second filtered RF signal;
• and
• a plasma chamber including:
• an edge ring;
• and
• a coupling ring located below the edge ring and coupled to the second RF filter, wherein the coupling ring includes an electrode configured to receive the second filtered RF signal to further generate a capacitance between the electrode and the edge ring to control the directionality of the ion flux upon receiving the second filtered RF signal.

A system for controlling directionality of ion flux at an edge region within a plasma chamber, comprising:

• a radio frequency (RF) filter that is configured to output a filtered RF signal;
• a plasma chamber including:
• an edge ring;
• and
• a coupling ring located below the edge ring and coupled to the RF filter to receive the filtered RF signal, wherein the coupling ring includes an electrode configured to generate a capacitance between the electrode and the edge ring to control the directionality of the ion flux upon receiving the filtered RF signal.