Bottom and middle edge rings
A bottom ring is configured to support a moveable edge ring that is configured to be raised and lowered relative to a substrate support. The bottom ring includes an upper surface that is stepped, an annular inner diameter, an annular outer diameter, a lower surface, a plurality of vertical guide channels provided through the bottom ring from the lower surface to the upper surface of the bottom ring, each of the guide channels including a first region having a smaller diameter than the guide channel and being configured to receive respective lift pins for raising and lowering the edge ring, and a guide feature extending upward from the upper surface of the bottom ring.
1 . 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.
2 . The bottom ring of claim 1 , wherein the diameter of the plurality of vertical guide channels is between 0.063″ and 0.067″.
3 . The bottom ring of claim 1 , further comprising a plurality of cavities surrounding the plurality of vertical guide channels, respectively, on the lower surface of the bottom ring, wherein the plurality of cavities have a diameter greater than the plurality of vertical guide channels.
4 . The bottom ring of claim 3 , wherein transitions between the plurality of vertical guide channels and the plurality of cavities are chamfered.
5 . The bottom ring of claim 4 , wherein the chamfered transitions have a height and width between 0.020″ and 0.035″ and an angle between 40° and 50°.
6 . The bottom ring of claim 1 , wherein the raised annular rim is configured to extend into a groove in a lower surface of the moveable edge ring.
7 . The bottom ring of claim 1 , wherein the first region of the plurality of vertical guide channels is arranged in the raised annular rim.
8 . The bottom ring of claim 1 , wherein the upper surface includes an inner annular rim extending radially inwardly and upwardly relative to the lower annular inner diameter, and wherein the raised annular rim and the inner annular rim define a groove.
9 . The bottom ring of claim 8 , wherein a height of the raised annular rim is less than a height of the inner annular rim.
10 . The bottom ring of claim 8 , wherein the inner annular rim is configured to support an edge of a substrate.
11 . The bottom ring of claim 1 , wherein at least one of a first upper corner and a second upper corner of the raised annular rim is chamfered.
12 . The bottom ring of claim 1 , wherein the upper surface includes at least five changes of direction.
13 . The bottom ring of claim 1 , wherein the upper surface includes at least five alternating vertical and horizontal paths.
14 . The bottom ring of claim 1 , wherein the lower surface includes a plurality of cavities configured to be aligned with bolt holes in a baseplate of the substrate support.
15 . The bottom ring of claim 1 , wherein the outer annular diameter of the raised annular rim is located radially outwardly from the lower annular inner diameter.
16 . The bottom ring of claim 1 , wherein the diameter of the plurality of vertical guide channels extending above and below the first region through the annular body is constant above and below the first region.
17 . The bottom ring of claim 1 , wherein the raised annular rim being offset relative to the lower inner annular diameter and the lower outer annular diameter of the annular body.
18 . The bottom ring of claim 1 , wherein the outer annular diameter of the raised annular rim and the lower outer annular diameter form a step to support a radially outer portion of the moveable edge ring.