Extended defects in GaAs are investigated following epitaxial regrowth of amorphous layers. GaAs surface layers were amorphized by Si+implants at liquid‐nitrogen temperature. Anneals were performed for 4 s to 30 min from 150 to 885 °C. Rutherford backscattering spectrometry and transmission electron microscopy were used to evaluate the results of annealing. Complete solid‐state epitaxy occurs rapidly at low temperature. Stacking faults and microtwins surrounded by dislocation networks extend to the surface following regrowth. The dislocations anneal at varying rates over intermediate temperature ranges (200–700 °C), and the microtwins climb out at higher temperatures (>700 °C). Defect depth profiles are correlated with damage and stoichiometric imbalances computed by the Boltzmann transport equation approach to ion‐implant modeling.