Ab initio study of early stages of III-V epitaxy on high-index surfaces of group-IV semiconductors: In adsorption on Si(112)

We consider theoretically the early stages of the epitaxy of III-V compound semiconductors on high-index surfaces of elemental semiconductors. Specifically, we compare two models for the $7\ifmmode\times\else\texttimes\fi{}1$ indium-induced reconstruction of the silicon (112) surface. Density functional theory calculations suggest a substitutional model to be favorable when compared to on-terrace step edge adsorption in good agreement with recent low-electron-energy diffraction and scanning tunneling microscopy experiments. In addition, we report a comprehensive study of the atomic reconstruction and electronic structure of the (112) surfaces of group-IV semiconductors diamond, silicon, germanium, and $\ensuremath{\alpha}$-tin. We find the $1\ifmmode\times\else\texttimes\fi{}1$ rebonded reconstruction to be most stable for Si. For Ge and Sn the $2\ifmmode\times\else\texttimes\fi{}1$ reconstruction is most stable, and for carbon diamond it is $2\ifmmode\times\else\texttimes\fi{}2$. However, in all cases the mechanism of reconstruction is surprisingly similar to that known for the (001) surface.