Apparatus and methods for manipulating power at an edge ring in plasma process device

A process chamber comprising:

• a chamber body;
• a lid disposed on the chamber body;
• an inductively coupled plasma apparatus positioned above the lid;
• and
• a substrate support positioned within the chamber body, the substrate support comprising:
• a vertical stack comprising:
• an electrostatic chuck having a substrate electrode embedded therein for chucking a substrate to an upper surface of the electrostatic chuck, wherein the electrostatic chuck includes one or more channels through which a fluid is provided to facilitate temperature control of the substrate support,
• a ground plate surrounding an insulating layer, wherein the insulating layer is below the electrostatic chuck,
• a baseplate underneath the electrostatic chuck to feed power to the substrate, the baseplate positioned between a lower portion of the ground plate and the electrostatic chuck,
• a quartz pipe ring circumscribing the baseplate and the electrostatic chuck;
• an edge ring disposed over the electrostatic chuck and circumscribes the substrate;
• an edge ring electrode located about a periphery of the baseplate, wherein the edge ring electrode is located underneath the edge ring;
• and
• a tuning circuit configured to couple a first pulsed DC power source to the substrate electrode and to the edge ring electrode through transmission lines spaced about the substrate support at evenly spaced intervals, the tuning circuit comprising:
• a first circuit coupled to the edge ring electrode through the collection of transmission lines by attachment to the feed transmission line before it is split,
• the first circuit comprises:
• a first variable capacitor coupled to the edge ring electrode.