Synchronization between an excitation source and a substrate bias supply

A plasma processing system, the system comprising:

• a bias supply configured to apply and modify an asymmetric periodic voltage waveform to a substrate support to modify a plasma sheath voltage between the plasma and a substrate within a plasma processing chamber;
• and
• at least one controller configured to:
• synchronize the bias supply with an excitation source during a first processing step to produce a plasma sheath voltage while the excitation source is producing pulsed power with a first duty cycle;
• and
• synchronize the bias supply with the excitation source during a second processing step while the excitation source is producing pulsed power with a second duty cycle and apply the asymmetric periodic voltage waveform to produce a different magnitude of the plasma sheath voltage during the second processing step.

A non-transitory computer-readable medium comprising instructions stored thereon, for execution by a processor, or for configuring a field programmable gate array, to perform plasma processing, the instructions including instructions to:

• apply pulsed power to a plasma processing chamber with an excitation source during a first processing step with a first duty cycle;
• apply, 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;
• apply pulsed power to the plasma processing chamber with the excitation source during a second processing step with a second duty cycle, wherein the second processing step follows the first processing step;
• and
• apply, during the second processing step, a different asymmetric periodic voltage waveform to the substrate support to produce a different plasma sheath voltage between the substrate and the plasma.