摘要 |
<p>A pressure sealed chamber (15) such as load lock or processing chamber of an apparatus for processing substrates is operated with a guide plate (30) spaced from a substrate (20) supported in the chamber to form a gap (31) that covers the substrate surface (28) to be protected from contamination by moisture (27a) condensing in the chamber during the rapid evacuation thereof or particulates (27) picked up by the gaz during turbulent flow into or out of the chamber. During the evacuation of the chamber, by either pumping or venting, clean dry gas is introduced through an orifice (35) in the center of the plate so as to flow outwardly from the edge of the gap at a pressure sufficient to displace or otherwise prevent gas borne moisture condensate and particulates in the chamber from entering the gap and contaminating the surface to be protected of the substrate. During evacuation of the chamber, gas is introduced through the gap at a flow rate less that of the evacuating gas. During filling of the chamber, at least some of the filling clean gas is introduced through the orifice in the plate at a sufficient rate to prevent gas borne particulates from entering the gap.</p> |