Semiconductor processing with DC assisted RF power for improved control

A semiconductor processing system comprising:

• a processing chamber that includes:
• a lid assembly defining a precursor inlet through which precursor species may be delivered;
• a ground electrode;
• a grid electrode disposed between the lid assembly and the ground electrode, and defining a first plasma region within the chamber between the grid electrode and the lid assembly and a second plasma region within the chamber between the grid electrode and the ground electrode;
• a conductive insert disposed between the lid assembly and the grid electrode at a periphery of the first plasma region and at least partially defining a section of a sidewall of the processing chamber;
• an insulation member positioned to electrically isolate the grid electrode from the conductive insert;
• a first power supply electrically coupled with the lid assembly;
• and
• a second power supply electrically coupled with at least one of the lid assembly, the grid electrode, or the conductive insert.