US Patent 7618686 Method and apparatus for sequential plasma treatment

An apparatus for plasma treatment of a non-conductive hollow substrate, including a plurality of ionization energy sources disposed adjacent to each other all along the part of the substrate to be treated. The apparatus also includes a processor to sequentially power the plurality of ionization energy sources from a radio frequency power source. Each ionization energy source includes two parts sandwiching the substrate. The ionization energy sources can be capacitively or inductively coupled plasma sources.