EVALUATION OF VALIDITY OF THE DEPTH-DEPENDENT CORRECTION FORMULA (CF)FOR ELASTIC ELECTRON-SCATTERING EFFECTS IN AES AND XPS

Elastic electron scattering in XPS and AES vary considerably with dept h of origin of emitted electrons. To account for this, we introduced i n a recent paper a simple correction factor CF. The function CF is the ratio of emitted peak intensity from a layer of atoms located at a gi ven depth in a solid calculated from theories that take into account a nd neglect elastic electron scattering. The observed depth dependence of CF is well described by a simple analytical formula that depends on ly on the inelastic and tie transport mean free paths. In the present paper the limits of validity of the formula are determined by comparis on to results of extensive Monte Carlo simulations. It is found to be valid for most XPS and AES peaks provided that the angle of emission i s <30 degrees and the angle between x-ray anode and analyser axis is 4 5-65 degrees. The procedure for application of CF in practical surface analysis is also discussed. (C) 1998 John Wiley & Sons, Ltd.