GROWTH OF DIAMOND THIN-FILMS ON NICKEL-BASE ALLOYS

Microwave plasma-assisted chemical vapor deposition has been employed to grow diamond films (thickness up to 50 mu m) using a gas mixture of hydrogen (H-2), methane (CH4), and oxygen (O-2) on various substrates such as Ni 200, MONEL 400, INCONEL 600, INVAR, single crystal nickel with orientations of (100), (111), (110), etc. Nucleation of diamond o n the substrates has been achieved by seeding with diamond particles, manual scratching, and ultrasonic agitation in methanol (CH,OH) contai ning diamond particles. The substrate underwent H-2 microwave plasma t reatment for 5-60 min to remove any oxide film present prior to 2 diam ond growth. Growth of diamond over MONEL 400 was achieved at various C H4 concentrations in H-2. As-deposited films were analyzed by scanning electron microscopy (SEM), Raman spectroscopy, secondary ion mass spe ctroscopy, X-ray photoelectron spectroscopy and Auger electron spectro scopy. According to SEM the morphology of the grown films was (100) te xture over the entire surface (<0.5 cm(2)) of Ni 200 substrate. Raman analysis of the top side of deposited film confirms for diamond and on the back side of the free-standing film shows the characteristic peak s for diamond and graphite. As-deposited films were diamond and other forms of non-diamond carbon on INCONEL 600 and on INVAR.