Growth-rate dependence of the thermal conductivity of chemical-vapor-deposited diamond

The in-plane thermal diffusivity of chemical-vapor-deposited diamond films was measured as a function of diamond-growth rate. The films, 0.1-0.4 mm th ick, were prepared in microwave-plasma reactor at growth rates ranging from 1 to 10 mu m/h. A modification of Angstrom's method was used to perform th e diffusivity measurements. The thermal conductivity calculated from the th ermal diffusivity shows an inverse relationship with growth rate. Analyses of Raman spectra indicate that both the line shifts and the line widths of the diamond Raman peak are practically independent of the deposition rate, except for the specimen grown at the highest growth rate.