Growth of Ge sub x Sn sub 1-x Semiconductor Alloys by Molecular Beam Epitaxy

Despite the immiscibility of bulk Ge and Sn, we have fabricated Ge sub x Sn sub 1-x (x>>0.01) semiconductor alloys using molecular beam epitaxy. The zinc-blende structure and lattice constant of InSb provide a template for the epitaxial stabilization of the Ge sub x Sn sub 1-x layers on (001) InSb substrates. Although the layers typically possess a 1% mismatch strain, reflection high energy electron diffraction patterns during growth indicate that we are able to fabricate Ge sub x Sn sub 1- x single crystal alloys, and that the growth proceeds by a two-dimensional- like process.