Three-dimensional spatiokinetic distributions of sputtered and scattered products of Ar/sup +/ and Cu/sup +/ 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/sup +/ and Cu/sup +/ ions bombard a copper surface. We term these "spatiokinetic" distribution functions (SKDF's). We show by example that SKDF's for reflected Ar/sup +/ ions focus as the incident angle /spl theta//sub i/ (normal=0/spl deg/) is increased from 60-75/spl deg/ and broaden as the incident energy E/sub i/ is increased from 55-175 eV. We show that the SKDF's for glancing-angle reflected Cu/sup +/ ions focus when E/sub i/ is increased from 55-175 eV. We show that the SKDF's for copper atoms sputtered by 175 eV Ar/sup +/ are insensitive to /spl theta//sub i/;. We report total sputter yields for Ar/sup +/ and Cu/sup +/ ions at 55 and 175 eV for incident angles between 0/spl deg/ and 85/spl deg/, and sticking probabilities for Cu/sup +/ ions for these energies and angles. Comparison to representative experimental results (Doughty et al., 1997) is given.