Effect of Electrical Spark Discharging Parameters on the Etching of Chemical Vapor Deposition (CVD) Diamond Film

In this article electrical spark discharging was used to etch the diamond film synthesized by chemical vapor deposition (CVD) in order to obtain flatten and smooth surface. The effects of parameters in electrical spark discharging such as the pulse width, electrode shape, metal layer thickness, and the polarity on diamond removal height were investigated. The etched surface of diamond film was examined by scanning electron microscopy (SEM), Raman spectrum analysis. It was found that higher peak current, pulse width of 400 μs, smaller electrode cross section, thinner metal layer, and negative polarity of the diamond film could benefit the material removal process. An etching mechanism model was also proposed that the material removal of diamond is the compound effects of vaporization, graphitization, cleavage fracture, oxidation of diamond in the electrical spark discharging.