Mechanism of diamond epitaxial growth on silicon

According to this study and to our previously reported nucleation model, we can explain the mechanism of diamond heteroepitaxial growth as follows: microscopic nucleation sites, i.e. etching scars, bunching atomic steps, and grooves formed by growing SiC, are formed on the substrate surface at the beginning of the bias application and are related to the crystal orientation of the substrate. Carbon atoms that reach the substrate surface are trapped at the nucleation sites and form clusters. Since these clusters are in the embryonic form during ion irradiation, deformation, rotation and migration can easily take place to form clusters with shapes that correspond to the shapes of these sites. At the same time, the conversion from sp² to sp³ progresses, and diamond nuclei of critical sizes are thought to be formed. This phenomenon strongly suggests that the heteroepitaxial growth of diamond involves a graphoepitaxial process in the formation of a critical nucleus size. In this study, we examined in detail the effect of bias on substrates to clarify the mechanism of heteroepitaxial growth of diamond.