Abstract: A substrate support includes a body and a thermal void. The body is configured to support a substrate during processing of the substrate. The body includes plates including a top plate, a first intermediate plate, a second intermediate plate and a bottom plate. The plates are arranged to form a stack. The first intermediate plate is disposed on the second intermediate plate. The thermal void is defined by an upper surface of the second intermediate plate and at least one of a lower surface of the first intermediate plate or a lower surface of the top plate. The thermal void is annular-shaped.

Abstract: In some examples, an exclusion ring locates a substrate on a substrate-support assembly in a processing chamber. An example exclusion ring comprises an inner edge portion to cover an edge of a substrate in the processing chamber and an outer edge portion to support the exclusion ring on the substrate support assembly in the processing chamber. The outer edge portion may include an outer edge of the exclusion ring. A separation zone extending between the inner edge portion and the outer edge of the exclusion ring includes an undercut in an undersurface of the exclusion ring. In some examples, a cooling gas is directed at the exclusion ring while the exclusion ring is located at a station or during an indexing operation performed by the exclusion ring within a processing tool.