DIAMOND DEPOSITION ON TITANIUM AND IRON SUBSTRATES PRETREATED IN N-2-C2H2 PLASMA

Diamond deposition on pure titanium and iron substrates pretreated in N-2-C2H2 plasma without any mechanical surface pretreatment was studie d. High quality diamond film was deposited on such pretreated substrat es by CVD using combustion flame. After the pretreatment, a C-C bond w as detected on the modified substrate, and graphitic carbon formation on the substrate was suppressed during diamond deposition. The surface of the modified substrate also became slightly rough, so the anchor e ffect between the film and the substrate was expected. This suppressio n and the anchor effect would indicate a remarkable improvement of adh esion of the film to the substrate. In particular, the diamond deposit ion process on the plasma-pretreated iron substrate was compared in de tail with that on the substrate scratched with diamond powder. It was found that diamond was directly grown from the carbonitrided surface l ayer of the plasma pretreated substrate. (C) 1998 Elsevier Science S.A .