Surface structure determination using ion scattering spectroscopy

Abstract

Ion scattering spectroscopy (ISS) using low (<10 keV) energy noble gas ion beams [also known as low energy ion scattering (LEIS)] has been used for nearly a decade and a half in the study of surface composition and structure. Recent advances in both the technology associated with ISS and in the understanding of scattering from solids demonstrate that ISS is about to mature as a spectrometric technique and join LEED as an established tool for surface structure determination. The primary difficulty with ISS analysis has been bombardment damage to surfaces, which can be reduced to undetectable levels by using time-of-flight energy analysis or by monitoring the total (energy-integrated or partially filtered) yield of backscattered particles. Present technology is illustrated with an example of a shadow and blocking cone analysis of time-of-flight ISS data from a GaSb (001) surface. Near-future developments in ISS are anticipated by a computer simulation of a total-yield blocking cone analysis of scattering from a Cu (001) surface.