Plasma reactor for the treatment of large size substrates

A process for treating at least one substrate in a radiofrequency plasma reactor, comprising the steps of:

• locating the at least one substrate between two electrodes in the reactor, the two electrodes defining an internal process space there between;
• circulating a reactive gas within the reactor so that the reactive gas is present in the internal process space;
• connecting at least one radiofrequency generator to at least one of the electrodes at a connection location;
• operating the radiofrequency generator to create a plasma discharge in at least one zone of the internal process space to expose the substrate to a processing action of the plasma discharge;
• providing capacitor means having an electrical capacitance acting in series with the substrate and the plasma discharge, the capacitor means having a profile along the at least one substrate between the electrodes;
• and
• defining the profile so that a capacitance of the capacitor means varies along the at least one substrate in a location-dependant manner along the substrate for generating a selected RF voltage distribution in the plasma discharge along the substrate.