US Patent 11610761 Synchronization between an excitation source and a substrate bias supply

Systems and methods for plasma processing are disclosed. A method includes applying pulsed power to a plasma processing chamber with an excitation source during a first processing step with a first duty cycle and applying, during the first processing step, an asymmetric periodic voltage waveform to a substrate support to produce a first plasma sheath voltage between a substrate and a plasma. Pulsed power is applied to the plasma processing chamber with the excitation source during a second processing step with a second duty cycle and during the second processing step, a different asymmetric periodic voltage waveform is applied to the substrate support to produce a different plasma sheath voltage between the substrate and the plasma.