A baffle plate assembly, configured to be coupled to a substrate holder in a plasma processing system, comprises a baffle plate having one or more openings to permit the passage of gas there through, wherein the coupling of the baffle plate to the substrate holder facilitates auto-centering of the baffle plate in the plasma processing system. For example, a centering ring mounted in the substrate holder can comprise a centering feature configured to couple with a mating feature on the baffle plate. After initial assembly of the plasma processing system, the baffle plate can be replaced and centered within the plasma processing system without disassembly and re-assembly of the substrate holder.