sleeves 47 and 48 in their raised and sealed position with a wafer 18 inside the resulting chamber ready for processing the cylindrical metal sleeves 46 49 are lowered to allow the transfer of wafers 18 between adjacent processing stations 31 34 by the wafer transfer carousel 30 the cylindrical metal sleeves 46 49 are raised and sealed to allow the wafers 18 to be exposed through a corresponding port 51 54 to a particular removable process module tops 39 42 each of the four processing station positions 31 34 can be independently populated with wafer heating and cooldown etching ashing amp cleaning chemical vapor deposition cvd physical vapor deposition pvd and other types of hot and cold semiconductor process modules in paired top and bottom parts any of the four processing station positions 31 34 may receive conventional semiconductor process reactors for photoresist removal cleaning plasma etching sputtering vapor deposition and or the deposition on uniform silicon nitride films on large sized wafers for example a wafer 18 is placed in a deposition zone and a process gas comprising a silicon containing gas and a nitrogen containing gas is introduced into the deposition zone through an inlet gas conduit the wafer 18 is heated to a temperature t d that is sufficiently high to cause the process gas to deposit silicon nitride on the wafer 18 with the resultant formation of process gas byproducts the process gas byproducts are exhausted through an exhaust gas conduit as further example any of the four processing station positions 31 34 may receive a conventional semiconductor process reactor for physical vapor deposition pvd or sputtering such stations may be used to deposit a metallic layer on the surface of the silicon wafer 18 pvd is frequently used to deposit metallic layers.