The Effect of Bonding Structure of Diamond Like Carbon (DLC) Film with Surface Nickel Coating upon Laser Annealing

Previous work has shown that the bonding structure and phase of amorphous carbon (a-C) can be modified by laser annealing. In this work, the effect of surface modification by metal coating on a-C during laser annealing was studied. A-C film was deposited by the filtered cathodic vacuum arc (FCVA) technique onto n-type (100) silicon substrate at room temperature. Nickel (Ni) was deposited on the surface of a-C films by electron beam (e-beam) evaporation method, and laser annealing with different laser energy density was performed on the a-C films with and without Ni coating. Visible Raman spectroscopy was used to examine the bonding structure evolution upon laser annealing and the effect on the bonding structure of a-C by introducing Ni onto the DLC film surface. The Raman spectra shows more pronounced change for a-C films with Ni coating than those without Ni coating upon laser annealing, and the Raman features also suggest that the Ni surface coating can enhance formation of the six-ring graphitic-like sp2 ordering. Electrical measurement shows a low resistive characteristic for both set of films due to laser induced conducting sp2 clusters formation.