Depth profiling of ion-implanted samples by high-energy electron scattering

For heavy ions implanted in low-Z targets it is possible to determine the depth and concentration of introduced heavy impurities by studying the energy spectra of electrons scattered from the surface. Here, we demonstrate this for the case of 30 and 300 keV Au implantation in SiO2. For high-energy incoming electrons the elastic peak splits up in different components as the recoil losses depends on the mass of the scattering atom. Heavy impurities also affect the partial intensities and hence changes in the shape of the energy loss spectra are observed. These effects are reproduced by a simple model that uses sample composition, atomic elastic scattering cross sections and target dielectric function as input.