High resolution transmission electron microscopy study of the initial growth of diamond on silicon

A polycrystalline diamond film grown by hot filament CVD was ion-milled and thinned to the diamond/silicon-substrate interface and the structures formed during the initial stages of diamond nucleation were studied by high resolution transmission electron microscopy (HRTEM). At the interface, isolated polycrystalline islands (15-35 nm) consisting primarily of mixed phase beta-SiC and nanocrystalline diamond could be observed. The beta-SiC phase occurred mainly as isolated nano-sized domains with no evidence of a larger micron-scale coalescence. In addition to co-existing with beta-SiC in the polycrystalline islands, nanocrystalline diamond was also observed to nucleate in the amorphous carbon matrix. The density of the nanocrystalline diamond in the amorphous carbon matrix was observed to be at least an order of magnitude higher than that in the polycrystalline beta-SiC phase. The total nanocrystalline diamond nucleation density was found to be several orders of magnitude higher than the growth density of the micron-sized diamond crystallites that ultimately evolved from the interface at longer growth times. (C) 2000 Elsevier Science S.A. All rights reserved.Materials Science, MultidisciplinarySCI(E)EICPCI-S(ISTP)