Ion mass and temperature dependence of damage production in ion implanted InP

Ion beam induced damaging and amorphization of crystalline InP is investigated. 100 keV B+, 300 keV Si+, 200 keV Ar+ and 600 keV Se+ 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 temperature T∞ 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 of T∞ from ≈350 K for B+ and ≈420 K for Se+ 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.