The annealing behavior of Si crystals, implanted with ∼1015Sb ions/cm2at 40 keV, has been studied by observing the orientation dependence of the scattering yield of 1.0‐MeV protons and also by electrical measurements. The scattering measurements provide information on the sites of the implanted atoms and on the extent of lattice disorder. After a room temperature implant, the lattice is heavily damaged, with the Sb occupying random (or interstitial) positions. After annealing at 650°C, ∼75% of the Sb is substitutional with very little damage remaining. Comparable results are obtained in a 400°C implant.