A focus ring configured to be coupled to a substrate holder comprises a first surface exposed to a process; a second surface, opposite the first surface, for coupling to an upper surface of the substrate holder; an inner radial edge for facing a periphery of a substrate; and an outer radial edge. The second surface further comprises one or more contact features, each of which is configured to mate with one or more receiving features formed within the upper surface of the substrate holder. The focus ring can further comprise a clamping feature for mechanically clamping the focus ring to the substrate holder. Furthermore, a gas can be supplied to the contact space residing between the one or more contact features on the focus ring and the one or more receiving features on the substrate holder.