An apparatus and method is disclosed for increasing the thermal conductivity in a substrate of a non-wide bandgap material comprising the steps of directing a thermal energy beam onto the substrate in the presence of a first doping gas for converting a region of the substrate into a wide bandgap material to enhance the thermal conductivity of the substrate for cooling the non-wide bandgap material. In one example, the invention is incorporated into a carbon rich layer formed within the wide bandgap material. In another example, the invention is incorporated into a carbon rich layer formed within the wide bandgap material having basal planes disposed to extend generally outwardly relative to an external surface of the substrate to enhance the cooling of the substrate.