Ion beam induced damaging and amorphization of crystalline InP is investigated. 100 keVB+,300 keVSi+,200 keVAr+and 600 keVSe+ions are implanted into⟨100⟩InP at temperatures ranging from 80 K to 420 K. The implanted layers are analyzed using Rutherford backscattering spectrometry in channeling configuration, cross section transmission electron microscopy and optical spectroscopy in the sub-gap frequency region. The temperature dependence of damage production can be represented assuming a thermally stimulated defect diffusion within the primary collision cascades, resulting in a shrinkage of the remaining defect clusters. At a critical temperatureT∞these clusters dissolve completely and only point defect complexes nucleate. Then, amorphization occurs only at very large ion fluences(≈1016cm−2)and the process seems to be influenced by the high amount of implanted ions. A defect band forms around the projected range of the implanted ions, which may act as a diffusion barrier for point defects. The range ofT∞from≈350K forB+and≈420K forSe+ions corresponds to the annealing stage II of defects in InP, which can be related to the mobility of phosphorous interstitials. This indicates that phosphorous interstitials play an important role during ion irradiation of InP. ©1997 American Institute of Physics.