V. Svorcik et al., AFM SURFACE-MORPHOLOGY INVESTIGATION OF ION-BEAM MODIFIED POLYIMIDE, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 122(4), 1997, pp. 663-667
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 struct
ure of the ion beam modified PI were examined using atomic force micro
scopy 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 productio
n of graphitic phase in the sample surface layer modified by the ion i
rradiation 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 poly
mer, Electrical charge transport is mediated by variable-range hopping
mechanism. Drastic structural changes initiated by the ion irradiatio
n to high fluences are similar to those observed in polymer pyrolysis.