Surface Sensitivity of Auger-Electron Spectroscopy and X-ray Photoelectron Spectroscopy

Abstract

Four terms are commonly used as measures of the surface sensitivity of Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS): the inelastic mean free path (IMFP), the effective attenuation length (EAL), the mean escape depth (MED), and the information depth (ID). These terms have been defined by the International Organization for Standardization (ISO) and ASTM International, and are utilized in various ISO standards. The IMFP, EAL, MED, and ID are intended for different applications. We give information on sources of data for IMFPs, EALs, and MEDs, and present simple analytical expressions from which IMFPs, EALs, MEDs, and IDs can be determined.