Lower plasma-exclusion-zone rings for a bevel etcher

A lower plasma-exclusion-zone ring for a bevel etcher that is configured to etch a bevel edge of a substrate, the lower plasma-exclusion-zone ring comprising:

• a ring-shaped body of the lower plasma-exclusion-zone ring defining:
• an upper surface;
• a lower surface;
• a radially inner surface;
• and
• a radially outer surface;
• and
• a radially-inner stepped surface of the lower plasma-exclusion-zone ring extending inwardly into the ring-shaped body between the radially inner surface of the ring-shaped body and the lower surface of the ring-shaped body,
• wherein
• a height of the radially-inner stepped surface and a height of the ring- shaped body define a size of a gap between an electrode of the bevel etcher and the substrate,
• the size of the cap is greater than zero such that at least a portion of the substrate over the cap does not contact an upper most surface of the electrode, and
• the ring-shaped body is made of a material selected from a group consisting of aluminum oxide, aluminum nitride, silicon, silicon carbide, silicon nitride, and yttria.

A system for a bevel etcher that is configured to etch a bevel edge of a substrate, the system comprising:

• the substrate;
• and
• a lower plasma-exclusion-zone ring supporting the substrate and comprising
• a ring-shaped body of the lower plasma-exclusion-zone ring defining
• an upper surface,
• a lower surface,
• a radially inner surface, and
• a radially outer surface, and
• a radially-outer stepped surface of the lower plasma-exclusion-zone ring extending inwardly into the ring-shaped body between the radially outer surface of the ring-shaped body and the upper surface of the ring-shaped body;
• and
• an upper plasma-exclusion-zone ring disposed above the substrate and having a radially outer stepped surface,
• wherein
• a portion of the radially-outer stepped surface of the lower plasma-exclusion-zone ring is disposed under the substrate,
• the radially inner surface is more radially inward than the radially- outer stepped surface of the upper plasma-exclusion-zone ring,
• the radially outer surface of the ring-shaped body is more radially outward than the bevel edge of the substrate, and
• the ring-shaped body is made of a material selected from a group consisting of aluminum oxide, aluminum nitride, silicon, silicon carbide, silicon nitride, and yttria.