Practical correction formula for elastic electron scattering effects in attenuation of auger electrons and photoelectrons

✍ Scribed by Jablonski, A.; Tougaard, S.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 533 KB
• Volume: 26
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199801)26:1<17::aid-sia343>3.0.co;2-z

✦ Synopsis

We deÐne a new parameter to describe the e †ects of elastic electron scattering in XPS and AES. The parameter is the ratio of emitted intensity from a layer of atoms located at a given depth in a solid calculated from theories that take into account and neglect elastic electron scattering. We have found that the correction parameter can be expressed by a simple formula. This formula is of general validity for typical experimental geometries applied in practical XPS and AES. The formula was determined by Ðtting an analytical expression to the results of extensive Monte Carlo calculations made under variation in the full relevant range of electron energy, matrix atomic number, depth of origin of emitted electrons and angular emission anisotropy. The formula depends on the inelastic and the transport mean free path for electron scattering. Three assumptions were made in the calculations, (k i ) ( k tr ) namely that the geometry is close to normal emission, that the angle between x-ray source and analyser axis is close to the magic angle (54Ä) and that the ratio is approximately constant over the analysed depth. However, k tr /k i the result is expected to vary only slightly when these assumptions are not strictly fulÐlled.

1998 John Wiley & ( Sons, Ltd.