COMPARISON OF SILICON, NICKEL, AND NICKEL SILICIDE (NI3SI) AS SUBSTRATES FOR EPITAXIAL DIAMOND GROWTH

We carried out experimental and theoretical studies aimed at probing i nterface interactions of diamond with Si, Ni, and Ni3Si substrates. Or iented diamond films deposited on (100) silicon were characterized by polar Raman, polar XRD, and cross-sectional HRTEM. These studies show that the diamond-(100)/Si(100) interface does not adopt the 45 degrees -rotation but the 3:2-match arrangement. Our extended Huckel tight-bin ding (EHTB) electronic structure calculations for a model system show that the interface interaction favors the 3:2-match arrangement. Growt h,on polycrystalline Ni3Si resulted in oriented diamond particles whil e, under the same growth conditions, largely graphite was formed on th e nickel substrate. Our EHTB electronic structure calculations for mod el systems show that the (111) and (100) surfaces of Ni3Si have a stro ng preference for diamond-nucleation over graphite-nucleation, but thi s is not the case for the (111) and (100) surfaces of Ni.