NOVELTY - An isolation chamber for separating adjacent deposition zones used in the production of solar cell material where the deposition zones are at different pressures, comprises chambers for receiving the substrate; sources of vacuum acting to withdraw volatiles and unreacted volatiles from the respective chambers; and at least one differential insert defining a slot (70), the slot functioning to restrict the unreacted volatiles from the first chamber from entering the second chamber.    USE - The isolation chamber is used for separating adjacent deposition zones used in the production of solar cell material (claimed).    ADVANTAGE - The apparatus and method are used for the continuous formation of solar cell material including an isolation chamber that reduces cross contamination between adjacent formation zones that are at different pressures.    DETAILED DESCRIPTION - An isolation chamber for separating adjacent deposition zones used in the production of solar cell material where the deposition zones are at different pressures, comprises a first chamber for receiving the substrate; the substrate being at a first pressure in the first chamber; a source of vacuum being connected to the first chamber, the source of vacuum acting to withdraw volatiles from the first chamber; a second chamber positioned adjacent the first chamber for receiving the substrate, the substrate entering the second chamber at substantially the pressure at which the web leaves the first chamber; at least one differential insert positioned in the second chamber, the at least one differential insert having a first side made of a low friction material, the low friction material first side being disposed to engage the substrate; the second side of the at least one differential inserts being an adjustable block, the adjustable block being disposed adjacent the web, the at least one differential insert defining a slot (70), the slot functioning to restrict the unreacted volatiles from the first chamber from entering the second chamber; and a source of vacuum being connected to the second chamber, the source of vacuum acting to withdraw unreacted volatiles from the second chamber, the source of vacuum reducing the pressure in the second chamber from the pressure in the first chamber. An INDEPENDENT CLAIM is a method for reducing cross contamination in the inline production of solar cell material.    DESCRIPTION OF DRAWING(S) - The drawing shows an exploded perspective view of the isolation chamber.    Outer wall (40)    Reinforcing rib (41)    Slot (70)    Passageway (87)    Gas source (89)