Epitaxial growth of a low-density framework form of crystalline silicon: Amolecular-dynamics study

Crystal growth processes of low-density framework forms of crystalline sili con, named Si clathrates (Si-34 and Si-46), during solid phase epitaxy (SPE ) have been successfully observed in molecular-dynamics simulations using t he Tersoff potential. The activation energy of SPE for Si-34 has been found to correspond with the experimental value (approximate to2.7 eV) for the c ubit: diamond phase, while the SPE rates of Si-46 are much lower than that of Si-34. The structural transition from Si-46 to Si-34 can be also observe d during the Si-46-[001] SPE. The present results suggest that new wide-gap Si semiconductors with clathrate structures can be prepared using epitaxia l growth techniques.