Thin films of carbon have been deposited at temperatures ranging from 77 to 1073 K. It has been found that diamond-like properties of the films change with the deposition temperature and the thermal conductivity of the substrate. Densities as high as 2.9 g/cc with an sp3bond content > 40% have been observed. Substrates that have been investigated include graphite, NaCl, Si, Al2O3fused quartz, and diamond. Density measurements have been made using Rutherford backscattering spectrometry and electron-energy-loss spectroscopy while hydrogen profiling was conducted using forward recoil spectrometry. © 1991, American Vacuum Society. All rights reserved.