Technique of preparing diamond films on poly-substrate by DC-arc plasma jet CVD for surface acoustic wave devices

In order to synthesize high quality surface acoustic wave devices and explore the deposition process of diamond films, large-area high-quality diamond films were deposited on silicon substrate by DC-arc plasma jet CVD. Deformation of the silicon substrate which happened in the deposition process was eliminated by a special poly-substrate technique. The influences of the concentration of methane and the temperature of the substrate on the diamond films were studied, and the deposit process was optimized. The results showed that fine grain diamond films were gained when the volume fraction of methane was 1.8% and the temperature of the substrate was 1000℃. The roughness of the diamond films deposited under this condition is the lowest.