Metastable pseudomorphic Si0.83Ge0.17 with thickness of 135nm was deposited on (001) Si substrate by molecular beam epitaxy and amorphized to a depth of ∼360nm, using 3×1015cm−2 Ge ions at 270keV. Samples were regrown by solid phase epitaxy in the 500–600°C temperature range. The regrowth rate was measured in situ by time resolved reflectivity, while the structure of the epilayers was investigated by transmission electron microscopy. Three regions can be distinguished in SiGe after solid phase epitaxy, independent of the annealing temperature: (1) a 20nm defect-free layer close to the original crystal-amorphous interface, (2) a middle region with a high density of planar defects, and (3) a layer with dislocations and stacking faults extending up to the surface. The activation energy of the SiGe solid phase epitaxy is equal to the activation energy of Si except in the middle region. The amorphous …