Chromium gettering in GaAs by oxygen implantation

Oxygen‐ion implantation has been performed in chromium‐doped GaAs substrates. Oxygen chromium profiles were measured by SIMS. Implanted oxygen profiles are observed for the first time. The chromium distribution, in annealed samples, shows an accumulation. This accumulation is shown to depend on the implanted ion and on the nature and concentration of the metallic impurity in the substrate. Thus one can no longer expect to analyze the contribution of any single impurity without taking into account other incorporated impurities.