Abstract: The contacting interface between the substrate and water-cooled base is vital to the substrate temperature during diamond films deposition by a DC (direct current) plasma jet. The effects of the solid contacting area, conductive materials and fixing between the substrate and the base were investigated without affecting the other parameters. Experimental results indicated that the preferable solid contacting area was more than 60% of total contacting areal; the particular Sn-Pb alloy was more suitable for conducting heat and the concentric fixing ring was a better setting for controlling the substrate temperature. The result was explained in terms of the variable thermal contact resistance at the interface between substrate and base. The diamond films were analyzed by scanning electron microscopy (SEM) for morphology, X-ray diffraction (XRD) for the intensity of characteristic spectroscopy and Raman spectroscopy for structure.

Key words: diamond films, substrate temperature, contacting interface, DC arc plasma jet