THE THERMAL-CONDUCTIVITY OF CHEMICAL-VAPOR-DEPOSITED DIAMOND FILMS ON SILICON

The thermal conductivity of chemical-vapor-deposited diamond films on silicon is measured for the case of heat flow parallel to the plane of the film. A new technique uses thin-film heaters and thermometers on a portion of the film which is made to be free standing by etching away the substrate. Effects of thermal radiation are carefully avoided by choosing the length scale properly. Data for several films yield thermal conductivities in the range 2-6 W/cm degrees-C. This is comparable to copper (4 W/cm degrees-C) and is in a range that would be useful as a thin-film dielectric material, provided that the interface thermal resistance can be minimized. The conductivity varies inversely with the growth rate and the Raman linewidth.