Metastable pseudomorphic Si0.83Ge0.17 with thickness of 135nm was deposited onto (001) Si substrate by molecular beam epitaxy and amorphized to a depth of ~360nm, using 3 x 1015/cm2 Ge ions at 270keV. Samples were re-grown by solid phase epitaxy at 500 to 600C. The re-growth rate was measured in situ by time-resolved reflectivity, while the structure of the epilayers was investigated by transmission electron microscopy. Three regions could be distinguished in SiGe after solid phase epitaxy, independent of the annealing temperature: a 20nm defect-free layer close to the original crystal-amorphous interface, a middle region with a high density of planar defects and a layer with dislocations and stacking faults extending to the surface. The activation energy of the SiGe solid phase epitaxy was equal to the activation energy of Si except in the middle region. The amorphous-crystal interface evolution was studied by transmission electron microscopy of partially re-grown samples. In order to study the effects of dopants, some samples were also implanted with B+ and Sb+ ions. At the ion projected range (125nm for both implants) the re-growth rate increased by a factor of 3 with respect to the non-implanted SiGe, but the defect-free layer again was found to be about 20nm in all cases. Moreover, the activation energy of the solid phase epitaxy re-growth process does not depend on dopant introduction, while the only observable effect of B or Sb incorporation was a smoothness of the amorphous-crystal interface during solid phase epitaxy.

Interface Roughening and Defect Nucleation During Solid Phase Epitaxy Regrowth of Doped and Intrinsic Si0.83Ge0.17 Alloys. D.D'Angelo, A.M.Piro, A.Terrasi, M.G.Grimaldi, S.Mirabella, C.Bongiorno: Journal of Applied Physics, 2007, 101[10], 103508