DAMAGE RANGES IN METALS AFTER ION-IMPLANTATION

Mo[110] single crystals were implanted with 150 keV argon ions at temp eratures between 20 and 300 K and defect profiles were determined by a -particle channelling in a backscattering geometry. Analyses of the lo w temperature implants were performed in situ at various annealing ste ps up to room temperature. At all implantation and annealing temperatu res, similar damage ranges were observed, which exceeded the TRIM esti mate by more than a factor of two. Ranges did not change during warmin g up, but the defect density started to increase significantly above a n annealing temperature of 77 K for implantation at a temperature belo w recovery stage I. The results are compared with previous studies on other metals. All available data on implantation damage in metals disa gree with the assumption that defect structures beyond projected ion r anges are a result of point defect migration. It is proposed that the observed damage range enhancement in metals is due to a mechanism base d on dislocation dynamics.