Thickness dependence of the characteristic X-ray yield and the Auger backscattering factor

✍ Scribed by M. M. Ei Gomati; W. C. C. Ross; J. A. D. Matthew

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 642 KB
• Volume: 17
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/sia.740170404

✦ Synopsis

Abstract

A Monte Carlo model employing a screened Rutherford scattering cross‐section and the Bethe energy loss approximation has been used to investigate the thickness dependence of the backscattering coefficient, η, the depth distribution of inner shall ionization, ϕ(ρz), the surface ionization function, ϕ(0), the Auger backscatter factor, r, and the initial gradient of the ϕ(ρz) curve, dϕ(0)/dz. Backscatter coefficients obtained for thick samples are in good agreement with experiment with experimental values. The surface ionization functions for C, Al, Cu, Ag and Au display an S‐shape thickness dependence, which is explainable in terms of the different scattering behaviour for samples of high and low atomic number. A direct relationship between the normalized surface ionization function, ϕ(0), and the Auger electron backscattering enhancement factor, r, is found, and a preliminary investigation has been made into the target thickness dependence of dϕ(0)/dz.