Low‐temperature anneals (500–650 °C) of 2, 4, and 8×1015cm−2As+implanted in ⟨100⟩ silicon at 50 keV were studied by x‐ray double crystal diffraction. The rocking curves were analyzed by a kinematical model. Two regions of strain were found in the solid‐phase epitaxially regrown layer. One layer was uniform and positively strained. The other was nonuniform and negatively strained. By comparing rocking curves of repeatedly etched layers it was found that the surface layer is negatively strained, corresponding largely to the substitutional As in the regrown layer. The positively strained region lies at the interface between the implanted layer and the undamaged silicon substrate.