Dc plasma control for electron enhanced material processing

A direct-current (DC) plasma system for processing of a substrate, comprising:

• a DC plasma reaction chamber configured to contain a DC plasma that is generated between an anode and a cathode of the DC plasma reaction chamber;
• an adjustable DC voltage source having an output that is electrically coupled to the anode;
• a DC current source that is electrically coupled to the cathode;
• and
• a substrate support stage arranged in a region of the DC plasma reaction chamber that contains a positive column of the DC plasma,
• wherein
• the adjustable DC voltage source and the DC current source are electrically coupled to a reference ground,
• the DC current source is configured to set a constant DC current that flows between the anode and the cathode, and
• the adjustable DC voltage source is configured to adjust, independently from the constant DC current, an electrical potential at the anode to set a substrate floating potential at a surface of the substrate support stage to a specific potential relative to a potential of the reference ground.