Tuning voltage setpoint in a pulsed RF signal for a tunable edge sheath system

A method for tuning a voltage setpoint for a multi-state pulsed RF signal in a plasma processing system, comprising:

• applying a RF power from a first generator to an ESC electrostatic chuck (ESC), the RF power from the first generator defining a first pulsed RF signal having a first state and a second state;
• applying a RF power from a second generator to an edge electrode that surrounds the ESC and is disposed below an edge ring that surrounds the ESC, the RF power from the second generator defining a second pulsed RF signal having a first state and a second state, wherein the second generator automatically introduces a first phase adjustment to substantially match phase of the first state of the second pulsed RF signal with the first state of the first pulsed RF signal, and wherein the second generator automatically introduces a second phase adjustment to substantially match phase of the second state of the second pulsed RF signal with the second state of the first pulsed RF signal, the second phase adjustment being tuned to a target phase adjustment setting;
• and,
• responsive to detecting a change in the second phase adjustment away from the target phase adjustment setting, adjusting a voltage setpoint for the second state of the second pulsed RF signal to return the second phase adjustment to the target phase adjustment setting.