Surface analysis using scattered primary and recoiled secondary neutrals and ions by TOF and ESA techniques

A spectrometer system for simultaneous mass, velocity, and energy analysis of scattered and sputtered ions and velocity analysis of fast neutrals ejected from a surface by bombardment with a pulsed, mass selected ion beam is described. Combination secondary ion and scattered neutral plus ion time-of-flight (TOF) spectra are presented. Electrostatic sector analysis (ESA) coupled with the TOF technique is used to obtain energy distributions of scattered and sputtered ions and TOF/ESA spectra. The neutralization probability of scattered ions, i.e. the fraction of particles surviving a scattering collision as ions, is obtained by collection of spectra of neutrals plus ions and neutrals alone. TOF and ESA spectra are used to illustrate the measurements of particles scattered and sputtered by direct recoils and surface recoils. The feasibility of detecting such fast sputtered neutrals without postionization is demonstrated. TOF spectra of scattered primary and fast recoiled surface neutrals and ions from selected He+, Ne+, and Ar+ bombardment of CsBr, Ge, GeO2, H2O adsorbed on Ge, and clean and adsorbate covered La are presented. Ion fractions are determined for scattered and recoiled particles and the significance of Auger and resonant neutralization channels is demonstrated. Adsorbed hydrogen and oxygen are detected by surface recoiling and direct recoiling processes. (orig.)