Partially cured and cured PF-resin samples were prepared at 150°C, 170°C and at 200°C in an inert environment and then bombarded by MeV ion beams using protons, alphas and nitrogen. Using low ion beam current density, 100 to 500 pA/mm2 for the nitrogen ions, 10 to 20 nA/mm2 for the alpha ions, and 50 to 500 nA/mm2 for protons, we have produced buried carbon layers without breakdown i.e., crack formation. The thicknesses of the carbon layers produced were of the order of a few tens of nanometers at a depth of a few nanometers to several micrometers depending on the energy, the type of bombarding ions and the curing temperature of the precursor. The electrical resistivity of these layers was measured in situ and was reduced from 109 Ω-cm to 10 Ω-cm. The lowest resistivity, 10 Ω-cm, was measured in the alpha bombarded, 150°C heat-treated resin. The carbonized volumes were analyzed by Raman microprobe spectroscopy which showed that the strongest graphitic (G-line) and distorted (D-line) Raman signals observed were from the nitrogen and alpha irradiated samples.