Deposition of polycrystalline diamond films by a new type MPCVD reactor at high power density

Polycrystalline diamond films were grown by using H2-CH4 as the source gas in a new type microwave plasma CVD reactor with an input power of 5kW,gas pressure of 13.33 and 26.66kPa and different methane concentrations.Optical emission spectroscopy was used to evaluate the concentrations of H atoms and carbon active groups in the plasma.The surface morphology,fracture morphology and the quality of the films were examined by using scanning electron microscope and Raman spectrum.Experimental results showed that the new type microwave plasma CVD reactor was able to form diamond films in the condition of high power density.The concentrations of H atoms and carbon active groups were obviously increased by enhancing the power density,and hence the deposition rates of diamond films will be increased while keeping the quality of the diamond films as well.