Abstract: A surface processing apparatus is provided for use in the surface processing of a substrate. The surface processing apparatus comprises a plasma source and processing chamber in which a substrate is mounted in use. The processing chamber is operatively connected to the plasma source and the surface processing apparatus is characterised by a transmission plate for the transmission of plasma in use between the plasma source and processing chamber. The transmission plate comprises one or more apertures wherein the physical form of the one or more apertures and/or the distribution of the one or more apertures is adapted to provide a predetermined processing pattern upon the surface of the substrate. Typically the design of the apertures is adapted to provide a substantially uniform deposition rate across a wafer substrate.