MOLECULAR-BEAM EPITAXY OF STRAINED SI1-XGEX LAYERS ON PATTERNED SUBSTRATES

Epitaxial Si1-xGex layers have been grown on patterned Si(001) substra tes. Mesa-like structures of 1.4 mum height on the surface limited by inclined {111} planes were used. Structure dimensions between 10 and 0 .2 mum were chosen to allow the mesas to relieve elastically under the strained layer. The film growth, the crystallographic perfection and the relaxation of strained Si1-xGex layers were investigated by transm ission electron microscopy (TEM) including in situ annealing. The rela xation mechanism and the control of dislocation generation on top of t he mesas are discussed.