A cylindrical pump baffle fitted to a semiconductor processing chamber is
disclosed. The pump baffle contains a screen with bores therethrough to
allow process gasses from the process chamber to be exhausted from the
chamber at a reduced rate. This decreases process discrepancies to the
wafer due to the prejudice of gas concentration as a result of the
pressure differential imposed upon the gas and thereby the wafer brought
about by the rapid and relatively unimpeded exit flow of process gasses
when no restrictive member is in place. The pump baffle is also machined
such that it does not block the placement and removal of wafers by the
platform robot arm.
