Projected range distributions of implanted ions in multilayer targets

A theoretical model is presented for the calculation of projected range distributions of energetic implanted ions in multilayer targets. In this approach, which is based on the energy distribution of the implanted ions at different depths within the target, the angular deflection of the penetrating ions is taken into account. The calculations employ the power-law approximation for the nuclear scattering cross section and results are presented for large angular scattering of 20 keV aluminium implanted into germanium and for small angular scattering of 355 keV arsenic implanted into silicon. A range profile is also derived for 20 keV boron implanted into a substrate coated with a layer of silicon nitride to demonstrate the effectiveness of the model as applied to non-uniform target substrates. These projected range distributions are compared, where possible, with other theoretical calculations and/or experimental results. (author)