ION-BOMBARDMENT EFFECTS IN CONDUCTING POLYMERS

The modification of properties of conducting polymers by ion bombardment offers interesting possibilities for their application in the field of microelectronics and electrochemistry. Therefore foils of intrinsically conducting polymers (polypyrrole and polythiophene) were modified by noble gas ion implantation. By ion bombardment the resistivity can be increased by several orders of magnitude. This effect depends on the species, energy and ion fluence. Cyclovoltammetric experiments show the same electrochemical features for the modified foils as the untreated polymers, but the observed currents are smaller by two orders of magnitude. The conductivity of the virgin foil (sigma = 100 S/cm) is sufficient for galvanic metal deposition. The bombardment induced change of resistivity causes an inhibition of electrochemical deposition. By using masks lateral structures in the range of several mum can be produced. During implantation the black colour of the untreated foil changes to brown depending on the implanted dose. The associated changes of the chemical structures, investigated by XPS, are discussed.