Angle-Resolved SIMS—A New Technique for the Determination of Surface Structure

Abstract

One of the central problems in surface science is the experimental determination of surface structure. Recently we have theoretically predicted that the angular distributions of the particles that eject during ion bombardment are sensitive to the original site of the adsorbate [1]. Furthermore, we found that by analyzing only the higher energy particles (kinetic energy ≳ 10 eV) strong enhancement of the angular anisotropies occurs. Although the molecular dynamics calculations employed to predict this effect were for neutral ejected species, the ejected ions should exhibit similar angular distributions. For example, the polar deflection of a 20 eV particle due to the image force will be less than 2° [1]. Hence we feel that SIMS would be a viable technique with which to measure the angular distributions of ejected particles.