Redistribution of Cr in GaAs:Cr and of V in GaAs:V after implantation of Si, Be, or B and annealing in a controlled atmosphere

Abstract

The redistribution of V in V-doped and Cr in Cr-doped semi-insulating GaAs substrates after implantation with Si, Be, B and subsequent controlled atmosphere annealing at 840 °C for 20 min is determined using secondary ion mass spectrometry. Both V and Cr show accumulation into zones of high defect densities at ∼Rp+ΔRp of the Si, Be, or B implantation profile, respectively, and a depletion which extends beyond that zone to ∼2–4×Rp. Some surface accumulation has also been observed. For all three cases studied, the V redistribution is much smaller than the Cr redistribution. It is therefore concluded that from thermal stability point of view semi-insulating GaAs:V should be a better substrate material for implantation type devices than is GaAs:Cr.