Bottom and middle edge rings

A bottom ring configured to support a moveable edge ring, wherein the moveable edge ring is configured to be raised and lowered relative to a substrate support, the bottom ring comprising:

• an annular body defining an upper surface, a lower surface, a lower annular inner diameter, and a lower annular outer diameter;
• a plurality of vertical guide channels extending through the bottom ring from the lower surface to the upper surface, wherein each of the plurality of vertical guide channels includes a first region having a smaller diameter than a diameter of the plurality of vertical guide channels, and wherein the plurality of vertical guide channels are configured to receive respective lift pins for raising and lowering the moveable edge ring;
• and
• a raised annular rim extending upwardly along the upper surface and having an inner annular diameter located radially inwardly from the lower annular inner diameter and an outer annular diameter located radially inwardly from the lower annular outer diameter, and
• wherein the plurality of vertical guide channels extend through the raised annular rim between the inner annular diameter and outer annular diameter of the raised annular rim.