Minimization of ring erosion during plasma processes
A ring assembly for a substrate support is disclosed herein. The ring assembly has a ring shaped body. The ring shaped body has an inner diameter and an outer diameter, a top surface, an inner portion at the inner diameter, and an outer portion at the outer diameter. A carbon based coating is disposed on the top surface of the ring shaped body, wherein the carbon based coating is thicker on the inner portion of the ring shaped body than the outer portion of the ring shaped body.
1 . A process kit ring for a substrate support of a plasma etch chamber, the ring comprising:
a first ring having a first ring shaped body having a first inner diameter and a first outer diameter, the first ring shaped body comprising:
a step along the first inner diameter; and
a first top surface having a first inner top surface on the step and a first outer top surface extending from the first outer diameter to the step, wherein a first vertical surface of the step connects the first inner top surface to the first outer top surface;
a second ring having a second ring shaped body having a second inner diameter and a second outer diameter, wherein the second inner diameter abuts the first outer diameter of the first ring, the second ring shaped body comprising:
a second top surface extending from the second inner diameter to the second outer diameter, wherein the second top surface is configured to be coplanar with the first outer top surface; and
a carbon based coating disposed in contact with the first ring and the second ring, wherein the carbon based coating disposed on the first top surface is thicker and denser than the carbon based coating disposed on the second top surface.
2 . The process ring of claim 1 , wherein the first ring shaped body is formed from a silicon containing material and the second ring shaped body is formed from quartz.
3 . The process ring of claim 1 , wherein the carbon based coating on the first top surface is about 10 times to about 30 times denser than the carbon based coating formed on the second top surface.
4 . The process ring of claim 1 , wherein the first ring shaped body is separable from the second ring shaped body.
5 . The process ring of claim 1 , wherein the carbon based coating is formed from process gasses comprising O 2 and SiCl 4 .
6 . The process ring of claim 1 , wherein the first ring shaped body further comprises:
a bottom surface, wherein the bottom surface does not have the carbon based coating.
7 . A substrate support for a plasma etch chamber, the substrate support comprising:
a support body, the support body having a top surface suitable for supporting a substrate thereon;
an electrode disposed in the support body;
an edge ring disposed on the top surface of the support body, the edge ring further comprising:
a first ring having a first ring shaped body having a first inner diameter and a first outer diameter, the first ring shaped body comprising:
a step along the first inner diameter; and
a first top surface having a first inner top surface on the step and a first outer top surface extending from the first outer diameter to the step, wherein a first vertical surface of the step connects the first inner top surface to the first outer top surface;
a second ring having a second ring shaped body having a second inner diameter and a second outer diameter, wherein the second inner diameter abuts the first outer diameter of the first ring, the second ring shaped body comprising:
a second top surface extending from the second inner diameter to the second outer diameter, wherein the second top surface is configured to be coplanar with the first outer top surface; and
a carbon based coating disposed in contact with the first ring and the second ring, wherein the carbon based coating disposed on the first top surface is thicker and denser than the carbon based coating disposed on the second top surface.
8 . The substrate support of claim 7 , wherein the first ring shaped body is formed from a silicon containing material and the second ring shaped body is formed from quartz.
9 . The substrate support of claim 7 , wherein the carbon based coating on the first top surface is about 10 times to about 30 times denser than the carbon based coating formed on the second top surface.
10 . The substrate support of claim 7 , wherein the first ring shaped body is separable from the the second ring shaped body.
11 . The substrate support of claim 7 , wherein the carbon based coating is formed from process gasses comprising O 2 and SiCl 4 .
12 . The substrate support of claim 7 , wherein the first ring shaped body further comprises:
a lip disposed on the inner portion and configured to support a substrate thereon; and
a bottom surface extending across both the inner portion and the outer portion of the first ring shaped body, wherein the lip has the carbon based coating disposed thereon and the bottom surface does not have the carbon based coating.