Influence of Ti, Fe, and Cu metal submicron-particles on diamond CVD on Sisubstrates

It is known that CVD diamond nucleation densities on virgin substrates may be enhanced as a result of surface abrasion with diamond powder. Diamond de bris embedded in the substrate surface (by ultrasonic agitation) serve as s eeds for subsequent growth. With the aim to investigate the influence of na no-sized metal particles on diamond formation by chemical vapour deposition (CVD), Ti, Fe, and Cu powders were added to the abrasive slurry. To quanti tatively compare the efficiency of these metals for diamond nucleation enha ncement, the effect of equal amounts of metal debris should be compared. By varying the weight of metal particles in the abrasive slurry, we managed t o control the metals atomic concentration on the substrate surface. The var ious atomic concentrations (as measured by Auger electron spectroscopy) wer e 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 di splay the following order Ti:Fe:Cu:(no metal)approximate to 20:9:2:1. (C) 2 000 Elsevier Science Ltd. All rights reserved.