BIAS-ENHANCED DIAMOND NUCLEATION ON SILICON - A TEM STUDY

The bias-enhanced nucleation and early growth of diamond on (100) sili con by microwave plasma-enhanced chemical vapour deposition (MPCVD) fr om a CH4-H-2 gas mixture were investigated by transmission electron mi croscopy (TEM). Hillocks containing beta-SiC, diamond and amorphous co mponents are the most prominent features at the substrate surface afte r bias-enhanced nucleation. The hillocks are formed not only by the de position of carbon, but also by the re-deposition of Si etched from th e substrate surface. In between the hillocks, beta-SiC clusters, with a distinct texture parallel to the heteroepitaxial orientation, are fo rmed at the interface between the silicon substrate and a thin amorpho us layer. During subsequent diamond growth, only the hillocks act as n ucleation sites.