THE EFFECT OF SUBSTRATE MATERIAL ON BIAS-ENHANCED DIAMOND NUCLEATION

Diamond has been deposited on polycrystalline copper substrates via bi as-enhanced nucleation, a pre-treatment technique to promote nucleatio n in which a negative potential is applied to the substrate. The maxim um nucleation density of the diamond on the copper substrates was appr oximately 1 X 10(6) CM-2. In contrast, typical nucleation densities of roughly 1 x 10(11) cm-2 have been observed on silicon substrates, ind icating that bias-enhanced nucleation is affected by the substrate mat erial. Auger electron spectroscopy and electron energy loss spectrosco py indicated the presence of a highly graphitic surface carbon on the copper, which was not detected on silicon. Also, deconvolution of the Cu 2p3/2 peak and micro-Auger depth profiling revealed this surface ca rbon to be 5-10 angstrom thick. The thickness and form of this surface carbon remained constant despite increasing bias-enhanced nucleation times. This is believed to be related to the slight enhancement of dia mond nuclei compared with silicon.