Molybdenum Concentration Depth Profile in Aluminum Implanted by Multi-charged Molybdenum Ions

In addition to the accelerating voltage of ions, ion charge state, ion sputtering, diffusion and phase change will all affect the concentration depth distribution. In order to distinguish the influence degree of the various factors, appropriate computational and experimental approaches must be put forward. Molybdenum ions from a metal vapor vacuum arc (MEVVA) ion source are implanted into aluminum to investigate the influence factors of the concentration depth profiles. The results of high voltage electron microscopy (HVEM) have showed that phase change are not induced by molybdenum ion implantation of an average current density of lower than 20μA/cm2. Rutherford backscattering spectroscopy (RBS) is used to investigate the Mo concentration depth profile in the Mo-implanted Al. RBS from Mo-implanted Al is converted to Mo concentration depth distribution considering the change of stopping cross section induced by high dose ion implantation. The measured concentration depth profile is compared with the calculation result of the TRIDYN program, in which sputtering and multi-charged state can both be considered dynamically. The deviation of the experiment and simulation results could be attributed to radiation enhanced diffusion or intense pulse beam current density implantation.