A processing chamber may include a gas distribution member, a substrate support, and a pumping liner. The gas distribution member and the substrate support may at least in part define a processing volume. The pumping liner may define an internal volume in fluid communication with the processing volume via a plurality of apertures of the pumping liner circumferentially disposed about the processing volume. The processing chamber may further include a flow control mechanism operable to direct fluid flow from the internal volume of the pumping liner into the processing volume via a subset of the plurality of apertures of the pumping liner during fluid distribution into the processing volume from the gas distribution member.