DOPANT ACTIVATION IN SB-IMPLANTED RELAXED SI1-XGEX ALLOY LAYERS GROWNON COMPOSITIONALLY GRADED BUFFERS

Supersaturated solid solutions of substitutional, electrically active Sb have been obtained by ion implantation of relaxed epitaxial Si1-xGe x alloy layers grown on compositionally graded buffers. Substitutional and non-substitutional Sb fractions in relaxed Si0.85Ge0.15, Si0.65Ge 0.35 and Si0.50Ge0.50 alloy layers implanted to a dose of 5 x 10(15) S b cm(-2) and annealed isothermally at temperatures ranging from 400 to 850 degrees C have been studied by Rutherford backscattering/channeli ng, transmission electron microscopy and Hall-effect and sheet resisti vity measurements. A supersaturated solution of Sb corresponding to a peak carrier concentration of 4 x 10(20) cm(-3) and an electrically ac tive fraction of 40% of the implanted dose is observed by Hall measure ments for the case of Si0.85Ge0.15 and Si0.65Ge0.35 alloys annealed at 550 degrees C.