Abstract: Semiconductive wafers are processed, i.e., etched or layers deposited thereon, by means of a plasma enhanced chemical vapor processing system. The processing system includes an evacuable horizontal tubular envelope disposed within a surrounding heater or furnace for maintaining, the case of deposition, a region of uniform temperature within the central region of the elongated tubular envelope. Two sets of interleaved generally planar electrodes are disposed within the evacuable envelope for establishing an electrical plasma discharge in the process gaps defined between the interleaved electrodes. Wafers are loaded into the processing gaps vertically with the major face of each wafer facing into the process gap. The mutually opposed surfaces of the interleaved electrodes are preferably lined with a material of the same conductivity as that of the bulk material of the wafer to enhance the uniformity of the processing.