The practical importance for electronic industry of material systems which are compatible with standard Si processing technology the growth as well as the characterization of the Si1-xCx/Si structures have been extensively pursued in the last years. More recently, the optical and electronic properties of novel Si1-xCx and Si1-x-yGexCy alloy layers on Si substrates have attracted much interest. Such systems may provide high quality materials which extend the range of Si-based heterostructures. Nevertheless, the thermodynamic properties, stability and structure properties of Si1-xCx alloys is still not will understood.
In this work we report the theoretical study of epitaxialy strained Si1-xCx/Si(001) alloys. Our investigations were based on NVT molecular dynamic method with three-particle Tersoff's potential of interactions with mirror-boundary conditions.
It allows us to obtain information on the influence of external biaxial stress on the ordering. We calculated and analyzed the enthalpy of mixing epitaxialy strained ZB(zinc-blende)-ordered and RB(rhombohedral)-ordered Si1-xCx alloys. The bond-length of C-C, Si-C and Si-Si bonds as a function of the compositions is build by using the radial-distribution functions. The diagram of stability of ordered Si1-xCx/Si(001) alloys is studied. It's shown that ordered and biaxial strain increase the stability. In this way, we also gain further insight into the effect of biaxial strain and alloying on intrinsic properties of the silicon-carbon alloys materials. Our results are in a good agreement with recent experimental data.