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

Abstract

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 β-SiC and hence the heteroepitaxially oriented diamond crystallites play an important role. TEM reveals the β-SiC crystallites 2–10 nm in size and the diamond crystallites 5–30 nm across. As the nucleation time increases, the density of the β-SiC crystallites increases from ∼2.7×1011 to ∼1.6×1012 cm−2, while that of the diamond crystallites varies from ∼2.0×109 to ∼4.1×1010 cm−2. Discrepancy between the densities obtained using TEM and AFM is discussed.