Abstract
We describe here a novel practical approach for the quantification of AES based on normalization of the peak height to the background measured at a fixed energy.
Studies from the literature show that the background has an angular dependence close to the for the AES peak and it is directly proportional to the primary electron current. In addition, we have found that for a primary beam energy of 10 keV the background measured at 2 keV exhibits practically the same atomic number dependence as the backβscattering factor. Therefore, we have proposed that normalization of the peak height to the background allows us to determine the absolute surface concentration of an element without reference to the other elements present, provided that the mean free path is known.
This proposal has been tested buy making measurements on a range of oxides, silicon compounds and metals. A good correlation is found between the O KLL peakβtoβbackground ratio and the atomic concentration of oxygen in a series of oxides covering a wide range of atomic number (Mg to U). A similarly good correlation is observed for magnesium, silicon, iron and nickel Auger peaks.
The physical basis and the limitations of this quantitative approach are discussed.