Characterization of silicon ion-implantation damage in single-strained-layer (InGa)As/GaAs quantum wells

We have characterized the structural effects of silicon ion implantation and controlled-atmosphere annealing on single quantum wells of In_0.14Ga_0.86As strained to match the in-plane lattice spacing of bulk GaAs. Cantilever-beam techniques were applied to measure implantation-induced stresses, while Rutherford backscattering, double-crystal x-ray diffraction, and cross-sectional transmission electron microscopy were applied to characterize the resulting microstructure. Samples were examined in both the as-implanted state and also after implantation and annealing under an arsenic overpressure at 800° C for 10 minutes. For implants whose energies produced maximum implanted ion density near the center of the 20 nm-thick quantum well, a maximum in the implantation-induced stresses were observed to occur at a silicon ion fluence of 1 × 10¹⁴/cm². Annealing of the implanted samples resulted in small dislocation loops in the ion range zone with survival of the strained quantum well. Electrical activation of the implants was found to be similar to identical implants into bulk GaAs.