Separation of the bulk and surface components in Auger electron spectroscopy

It is shown that a simple procedure applied to Si LVV Auger-electron (AE) spectra can be used to extract the surface-induced perturbation of the local density of states (LDOS). A weighted difference between the energy distribution of Auger electrons from the clean surface and from the surface covered by a monolayer of a properly chosen adsorbate contains information solely about the topmost atomic layer of the clean surface. As a case study, the AE difference spectra of clean and Ge-covered Si(113) surfaces are examined.