Plasma density control on substrate edge

A plasma processing apparatus, comprising:

• a chamber body;
• a lid coupled to the chamber body;
• wherein the chamber body and the lid define a processing volume therebetween;
• a substrate support disposed in the processing volume;
• and
• an edge ring disposed on the substrate support, the edge ring comprising:
• an inner lip extending radially inward;
• a top surface connected to the inner lip, wherein the top surface of the edge ring is inclined;
• a bottom surface opposite the top surface and extending radially outward from the substrate support;
• and
• an inner step between the bottom surface and the inner lip disposed on the substrate support.

A plasma processing apparatus, comprising:

• a chamber body;
• a lid coupled to the chamber body;
• wherein the chamber body and the lid define a processing volume therebetween;
• a substrate support disposed in the processing volume;
• and
• an edge ring disposed on the substrate support, the edge ring comprising:
• an inner lip extending radially inward;
• a top surface connected to the inner lip, wherein the top surface of the edge ring is chamfered;
• a bottom surface opposite the top surface and extending radially outward from the substrate support;
• and
• an inner step between the bottom surface and the inner lip disposed on the substrate support.