NANOCRYSTALLINE DIAMOND FILMS DEPOSITED BY HIGH-PRESSURE SPUTTERING OF VITREOUS CARBON

Nano-diamond films were deposited at room temperature (approximate to 300 K) on quartz, Si and Mo substrates by high pressure (greater than or equal to 45 mTorr) dc magnetron sputtering of vitreous carbon targe t in an argon + hydrogen (0-10 vol%) plasma. The nanocrystallites of d iamond were embedded in a-C matrix and the ratio of sp(3) and sp(2) bo nds in the film (determined from FTIR) was dependent on the deposition conditions. Formation of nanocrystallites was examined by TEM and SAD patterns. XRD and Raman spectroscopy were also used to probe the micr ostructural characteristics of the deposited films having average grai n size approximate to 55 nm on quartz and approximate to 75 nm on Si a nd Mo substrates. The films had a surface roughness of approximate to 9 nm on quartz substrates. The sp(3) content of the film was high (> 8 0%) leading to a high band gap (E-g approximate to 4.2 eV) and hardnes s (H-V approximate to 30 GPa). E-g and H-V increased to 5 eV and 50 GP a respectively with the addition of hydrogen (approximate to 10 vol%) in the sputtering environment.