Continuity conditions at heterointerfaces and optimization conditions of buffer layers in SiC/Si

The optimization of Si1 − x buffer layers for growing the best quality β-SiC on Si substrate is considered in this article. This is carried out by applying the correlation theory of misfit induced interface superstructures (MIS) and of nucleation centers for misfit dislocations (NCMD) network. Depending on the carbon composition x, we identify two domains: (i) for small carbon composition, both interfaces in SiC/Si1 − xCx/Si may be matched with small size interface NCMD network, consequently, both interfaces may develop a high density of misfit dislocations; (ii) for large carbon composition, the two interfaces are geometrically mismatched with a larger NCMD network at the SiC/Si1 − xCx interface. A mechanism which shows that the incorporation of an optimized buffer layer may provide the conditions for a pseudomorphic growth of SiC on Si is discussed.