Influence of Ti, Fe, and Cu metal submicron-particles on diamond CVD on Si substrates Original Research Article

It is known that CVD diamond nucleation densities on virgin substrates may be enhanced as a result of surface abrasion with diamond powder. Diamond debris embedded in the substrate surface (by ultrasonic agitation) serve as seeds for subsequent growth. With the aim to investigate the influence of nano-sized metal particles on diamond formation by chemical vapour deposition (CVD), Ti, Fe, and Cu powders were added to the abrasive slurry. To quantitatively compare the efficiency of these metals for diamond nucleation enhancement, the effect of equal amounts of metal debris should be compared. By varying the weight of metal particles in the abrasive slurry, we managed to control the metals atomic concentration on the substrate surface. The various atomic concentrations (as measured by Auger electron spectroscopy) were then correlated to the deposited diamond particle densities (established by a scanning electron microscope), and the relative catalytic activity of the metals towards CVD diamond formation has been established. It was found that for 1% metal atomic surface concentration the catalytic activities display the following order Ti:Fe:Cu:(no metal)≈20:9:2:1.