Microstructural study of the alternating current bias-enhanced nucleation and growth of diamond on (001) silicon wafers

The bias-enhanced nucleation (BEN) and growth of diamond by microwave plasma chemical vapor deposition have been investigated using transmission electron microscopy (TEM), transmission electron diffraction (TED), atomic force microscopy (AFM), and scanning electron microscopy (SEM) full stop TED results show epitaxial relations between SIC and Si, and diamond and SiC, which depend on the BEN time. The formation of highly oriented (001) diamond films is obtained after 25 min BEN, in which the heteroepitaxially oriented beta-SiC and hence the heteroepitaxially oriented diamond crystallites play an important role. TEM reveals the beta-SiC crystallites 2-10 nm in size and the diamond crystallites 5-30 nm across. As the nucleation time increases, the density of the beta-SiC crystallites increases from similar to 2.7x10(11) to similar to 1.6x10(12) cm(-2), while that of the diamond crystallites varies from similar to 2.0x10(9) to similar to 4.1x10(10) cm(-2). Discrepancy between the densities obtained using TEM and AFM is discussed. (C) 1997 American Institute of Physics.