An apparatus for fabricating a semiconductor device has a housing defining a buffer chamber, a plurality of reactor ports formed in the housing for establishing interfaces with a plurality of process chambers that are to receive a wafer during a fabrication process to fabricate the semiconductor device, a wafer positioning robot positioned within the buffer chamber to transport the wafer between the plurality of process chambers through the plurality of reactor ports, a purge port formed in the housing for introducing a purge gas into the buffer chamber, a pump port formed in the housing for exhausting a portion of the purge gas from the buffer chamber, and a first flow enhancer that directs the purge gas flowing in an axial direction along a longitudinal axis of the purge port into the buffer chamber in a plurality of radial directions relative to the longitudinal axis.