The thermal reaction of Ir/SiGe structures following ion implantation induced Ir grain boundary mixing has been studied. The morphology of the final interface has been investigated by Cross-sectional Transmission Electron Microscopy (XTEM) and Rutherford Backscattering Spectrometry (RBS) has been used to detect the redistribution of constituent atoms in the reacted layers. A 20 nm iridium film was deposited in vacuum by electron beam evaporation onto p-Si 1-x Ge x (x = 0.25, 0.33) fully relaxed MBE grown layers. Implantation conditions used were effective in amorphizing the interface-close region of the Ir film and the SiGe substrate. After regrowth, XTEM results show that the interface quality is improved with respect to the material that had not been implanted. RBS results on the other hand show Ge incorporation in the reacted layer to occur in contrast to the non implated case where the Ge piles up at the silicide/SiGe interface. The effect of a second anneal step at higher temperatures (in the range 800°C – 900°C) is also investigated.