Mass transfer of metal ion implantation into metal targets at elevated temperatures

A mass transfer model for metal ion implantation into a metal target at elevated temperatures has been built up based on transport of ions in matter and radiation enhanced diffusion. It is used to calculate concentration-depth profiles and compositional changes of the implanted species. The ion implantation at elevated temperatures was simulated by a dynamic Monte Carlo (MC) method, which takes into account a local saturation in the crystalline target by using a maximum atomic fraction allowed in the matrix. For the diffusion process, the transport of the implanted species was obtained from the diffusion equations for the implanted species and nonequilibrium vacancies. The radiation enhanced diffusion coefficient was obtained by taking into account linear annealing of the defects. A nonequilibrium vacancy source function and surface sputtering were introduced into the diffusion equations. Concentration-depth profiles of Cr, Fe and Ni ions implanted into Al at a temperature range from 200 to 510 degrees C were calculated. The calculated results principally were consistent with measured concentration-depth profiles obtained by Rutherford backscattering spectroscopy (RBS). In some cases deviations occur, which are discussed. (c) 2004 Elsevier B.V. All rights reserved.