CHARACTERIZATION OF DIAMOND NUCLEATION ON FE/SI SUBSTRATE BY HOT-FILAMENT CHEMICAL VAPOR-DEPOSITION

Diamond particles were grown on both iron coated substrates and pretreated substrates in a methane atmosphere, using hot-filament chemical vapor deposition. The thin iron film deposited on the silicon substrate surface influenced the diamond nucleation and the subsequent growth of diamond particles. Diamond nucleation density was enhanced by the iron film, and those on Si and quartz substrates with the iron films were a factor of about 50 and 7000 greater, respectively, than that for a normal Si substrate X-ray photoelectron spectroscopy analysis on the substrate surfaces revealed that the diffusion of the carbon atoms into the substrate is important in the diamond nucleation process. The iron has a high diffusion coefficient of carbon atoms, which includes the carbon molecules on the Si substrate surface and helps to produce the carbide layer on the substrates. Nucleation density of diamond has also been measured in order to study the role of the carbide layer and the pretreatment of substrates in the diamond nucleation mechanism. The pretreatment of the substrates for the carbonization of the substrate surface also enhanced the diamond nucleation density on both the normal Si and Fe/Si substrates.