Low-resistivity ( < 0.1 Omegacm at room temperature), p-type SiC layers were produced by the combination of high dose At implantation in n-type, 6H-SiC at low temperature, subsequent ion-beam-induced crystallization by means of Si irradiation at 500degreesC and high temperature annealing at 1500degreesC. The implanted SiC layers have a nanocrystalline structure consisting of randomly oriented grains of 3C-SiC. The electrical properties of the nanocrystalline and single-crystalline reference samples were investigated by sheet resistance and Hall effect measurements in dependence on temperature. In comparison with the standard doping process the hole concentration in nanocrystalline SiC is enhanced by more than one order of magnitude. This can be explained by a higher solid solubility of At in nanocrystalline SiC. Current-voltage measurements across the vertical p-n-junction in the heavily doped nanocrystalline and single-crystalline samples demonstrated the equivalence of the diode quality.