Edge ring for a thermal processing chamber

A substrate support, comprising:

• a body forming a closed loop, wherein the body is equal in width around the closed loop;
• a lip extending inward from the body, wherein the lip has an upper surface configured to receive a substrate around an outer edge of the substrate, and the body surrounds the substrate when the substrate is disposed on the lip;
• and
• one or more surface area increasing structures extending from an upper surface or a lower surface of the body, wherein the one or more surface increasing structures has at least one sloped side relative to the body.

A chamber for processing a substrate, comprising:

• a chamber body defining a processing volume, where the chamber body has a window formed therethrough;
• a substrate support base disposed in the processing volume;
• an energy source disposed outside the window to direct radiant energy towards the processing volume through the window;
• and
• an edge ring disposed on the substrate support base for supporting substrate thereon, wherein the one or more surface area increasing structure of the edge ring faces the energy source, and the edge ring comprises:
• a ring shaped body having an inner edge, an outer edge, an upper side and a lower side, wherein the inner edge and outer edge are concentric about a central axis;
• a lip extending radially inward from the inner edge of the ring shaped body, wherein at least a portion of an upper surface of the lip is substantially parallel to a major plane that is perpendicular to the central axis;
• and
• one or more surface area increasing structures extending from at least one of the upper side or lower side of the ring shaped body, wherein the one or more surface area increasing structures has at least one sloped side relative to the ring shaped body.