Electrical characterization of C-coated nickel silicide nanowires grown on Ni-loaded Si substrate

Carbon-coated nickel silicide nanowires (C-coated NiSi NWs) were grown in a home-made chemical vapor deposition (CVD) reactor. The coating of semiconductor or metal nanowires with nano-sized carbon layer is effective to prevent the oxidation of the nanowires, resulting in the stabilization of electrical properties of nanodevices. The growth of the NiSi nanowires and the coating of the NWs with carbon layers simultaneously took place in the reaction. The current-voltage curve of individual NiSi nanowire showed highly linear behavior, indicating the good ohmic contact without the insulating layer. The resistivity of the NiSi nanowire was about 370 μΩ-cm at room temperature, decreased monotonically as the temperature was lowered, and became saturated at low temperatures, indicating the growth of metallic NiSi nanowires. Field emission measurements showed that the C-coated NiSi nanowires were an excellent field emitter with large emission current densities at very low electric field.