Edge ring assembly for a substrate support in a plasma processing chamber

A processing chamber, comprising:

• a chamber body;
• and
• a substrate support positioned within the chamber body, the substrate support comprising:
• an electrostatic chuck comprising a chucking electrode;
• an edge ring assembly positioned exterior to the electrostatic chuck, the edge ring assembly comprising an edge ring electrode;
• an outer silicon ring positioned above the edge ring assembly;
• an inner silicon ring positioned above the edge ring assembly within the outer silicon ring;
• an insulating ring positioned above the edge ring assembly between the outer silicon ring and the inner silicon ring;
• and
• an outer insulating ring positioned exterior to the edge ring assembly to encircle the edge ring assembly, wherein:
• the insulating ring comprises an inner recess formed within an inner surface of the insulating ring and an outer recess formed within an outer surface of the insulating ring,
• the inner silicon ring is at least partially positioned within the inner recess,
• the outer silicon ring is at least partially positioned within the outer recess,
• the outer silicon ring is positioned above the outer insulating ring, and
• the outer insulating ring comprises an upper recess formed within an upper surface of the outer insulating ring with the outer silicon ring positioned within the upper recess of the outer insulating ring.

A method of processing substrates, comprising:

• processing a first substrate within a processing chamber comprising a substrate support using a plasma sheath, the substrate support comprising:
• an electrostatic chuck comprising a chucking electrode;
• an edge ring assembly positioned exterior to the electrostatic chuck, the edge ring assembly comprising an edge ring electrode;
• an outer silicon ring positioned above the edge ring assembly;
• an inner silicon ring positioned above the edge ring assembly within the outer silicon ring;
• an insulating ring positioned above the edge ring assembly between the outer silicon ring and the inner silicon ring;
• and
• an outer insulating ring positioned exterior to the edge ring assembly to encircle the edge ring assembly, wherein:
• the outer silicon ring is positioned above the outer insulating ring, and
• the outer insulating ring comprises an upper recess formed within an upper surface of the outer insulating ring with the outer silicon ring positioned within the upper recess of the outer insulating ring;
• adjusting the plasma sheath within the processing chamber with the edge ring electrode;
• and
• processing a second substrate within the processing chamber using the adjusted plasma sheath.