AFM surface morphology investigation of ion beam modified polyimide

Polyimide Upilex R was irradiated with 90 keV N+ ions to the fluences of 1 x 10(14)-2 x 10(17) cm(-2), The surface morphology and the structure of the ion beam modified PI were examined using atomic force microscopy and X-ray difraction, Sheer resistance as a function of the ion fluence and the sample temperature was measured by standard two point technique, Significant changes of the surface morphology and production of graphitic phase in the sample surface layer modified by the ion irradiation were observed. Strong decrease of the sheet resistance (by 11 orders of magnitude) in the ion beam modified samples is connected with progressive carbonization and graphitization of the degraded polymer, Electrical charge transport is mediated by variable-range hopping mechanism. Drastic structural changes initiated by the ion irradiation to high fluences are similar to those observed in polymer pyrolysis.