  As demonstrated in previous works, implantation with a MeV ion microbeam
through masks with graded thickness allows the formation of conductive
micro-channels in diamond which are embedded in the insulating matrix at
controllable depths [P. Olivero et al., Diamond Relat. Mater. 18 (5-8), 870-876
(2009)]. In the present work we report about the systematic electrical
characterization of such micro-channels as a function of several implantation
conditions, namely: ion species and energy, implantation fluence. The
current-voltage (IV) characteristics of the buried channels were measured at
room temperature with a two point probe station. Significant parameters such as
the sheet resistance and the characteristic exponent (alpha) of the IV
power-law trend were expressed as a function of damage density, with
satisfactory compatibility between the results obtained in different
implantation conditions.
