Strained Si1-xSnx alloys, where x was between 0.001 and 0.052, were prepared on (001) Si substrates by means of molecular beam epitaxy at 220 or 280C. It was found that the as-grown alloys were pseudomorphic to Si, with no sign of extended defects or Sn precipitates. Within the accuracy of the present study, the compressive strain in the alloys corresponded to that which was deduced from Vegard’s linear interpolation between the lattice parameters of Si and -Sn. Annealing experiments showed that the alloys were thermally unstable at 1000C, and that the transition of the SiSn/Si system to a lower-energy state occurred via 2 routes. These were alloy decomposition by the precipitation of Sn atoms in metallic -Sn, or the introduction of 60 misfit dislocations.

S.J.Shiryaev, J.L.Hansen, P.Kringhøj, A.N.Larsen: Applied Physics Letters, 1995, 67[16], 2287-9