The depth profiles measured by secondary‐ion mass spectrometry of 56 MeV oxygen ions implanted into Si, GaAs, and InP are reported. Most of the oxygen is contained within a sharp (full width at half maximum ∼2 &mgr;m) non‐Gaussian profile centered at ∼31 &mgr;m in GaAs, ∼36 &mgr;m in InP, and ∼46 &mgr;m in Si, with the distribution skewed towards greater depths. The experimental projected ranges appear to be 10% larger than theoretical predictions. Changes in the electrical, optical, and structural properties of the material were measured by transmission electron microscopy (TEM), photoluminescence, and spreading resistance profiling. In the as‐implanted Si, the maximum perturbation in the electrical properties occurs at ∼37 &mgr;m. No defects are visible by TEM in any of the as‐implanted semiconductors for oxygen ion doses of 1.35×1015cm−2but the photoluminescent intensity in GaAs and InP is reduced by more than an order of magnitude as a result of this type of implantation.