Three-dimensional spatiokinetic distributions of sputtered and scattered products of Ar+ and Cu+ impacts onto the Cu surface: molecular dynamics simulations

Energy and angular distributions of reflections and sputtered atoms are essential inputs for feature profile evolution simulations. Molecular dynamics simulations are used to compute the three-dimensional energy and angular distributions for reflected and sputtered products when both Ar⁺ and Cu⁺ ions bombard a copper surface. We term these “spatiokinetic” distribution functions (SKDF´s). We show by example that SKDF´s for reflected Ar⁺ ions focus as the incident angle θ_i (normal=0°) is increased from 60-75° and broaden as the incident energy E_i is increased from 55-175 eV. We show that the SKDF´s for glancing-angle reflected Cu⁺ ions focus when E_i is increased from 55-175 eV. We show that the SKDF´s for copper atoms sputtered by 175 eV Ar⁺ are insensitive to θ_i;. We report total sputter yields for Ar⁺ and Cu⁺ ions at 55 and 175 eV for incident angles between 0° and 85°, and sticking probabilities for Cu⁺ ions for these energies and angles. Comparison to representative experimental results (Doughty et al., 1997) is given