B4C/Mo/Si and Ta2O5/Ta nanostructures analysed by ultra-low energy argon ion beams

Ultra-low energy ion bombardment was applied for depth profiling of B4C/Mo/Si and Ta2O5/Ta nanostructures. The experiments were performed with argon ion beams of 180, 380, 880, 2000 and 4000 eV energies and 45 deg. incidence angle. Sub-nanometer depth resolution of both structures is achieved at 880 eV. Performed MC SRIM'96 simulations allow to characterise altered layer formation during bombardment of B4C, Si, Mo, Ta and Ta2O5 matrices. Energy dependence of recoil effects and sputtering coefficient, allows suggesting suitable energies for experimental SIMS depth profiling of structures composed of these matrices. For B4C matrix the recommended argon beam energy range is 800-550 eV and for Si it is 400-200 eV. For Ta2O5, lowering energy below 600 eV does not reduce the number of recoil effects. The results generally agree with the experimental data of depth profile resolution, measured at Mo/Si and Ta2O5/Ta interfaces