Although the domination of electronic stopping over nuclear stopping may be regarded as an important practical advantage for high energy (MeV) ion processing, exact knowledge of the doping introduced into the active regions as well as of the process-associated defects and their thermal stability is essential for an understanding of device performance. In the present work we review the results of our recent investigations into lattice damage accumulation in single crystal Si resulting from high energy ion implantation in the implantation temperature (T. ) range between liquid nitrogen temperature and 200°C.The ion species used were 1 MeV 0 + , 1.25 MeV Si and a.8 MeV Er +