An apparatus for processing semiconductors includes a processing chamber including a plurality of chamber walls, a substrate holder, positioned within the processing chamber and configured to support the substrate, and a linear displacement device, coupled between a base wall of the plurality of walls and the substrate holder and configured to move the substrate holder relative to the base wall. A shielding part extending from the substrate holder to be in close parallel relation with at least one of the plurality of walls such that a first area of the processing chamber is substantially shielded from a processing environment to which the substrate is exposed.