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Investigation of thin films by soft X‐ray fluorescence and by total electron yield measurements
Author(s) -
Ebel H.,
Mantler M.,
Svagera R.,
Kaitna R.
Publication year - 1994
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.7402201128
Subject(s) - auger , yield (engineering) , x ray fluorescence , analytical chemistry (journal) , electron , thin film , excited state , chemistry , fluorescence , x ray , kinetic energy , radiation , auger electron spectroscopy , atomic physics , excitation , materials science , optics , physics , nanotechnology , chromatography , quantum mechanics , nuclear physics , metallurgy
We propose a description of the sampling depth (λ) of total electron yield experiments (TEY) in terms of kinetic Auger electron energies. This empirical response results from literature data 1 – 6 on low energy (<2 keV) and from our own experiments performed on thin layers of Cu on Fe substrates and on thin layers of Al x Ga 1 − x As on GaAs substrates at energies of approximately 5to 8 keV. From these investigations we estimate a sampling depth of 74 nm for Ga KLL Auger electrons in Al x Ga 1 − x As. For comparison, the sampling depth of x‐ray fluorescence analysis (XRF) for Al Kα radiation in Al x Ga 1 − x As is 400 nm. Both methods (XRF and TEY) were joined for quantitative determination of the thickness t and the Al content x in thin Al x Ga 1 − x As layers on GaAs substrates. Al Kα fluorescence radiation excited by polychromatic x‐radiation and the jump of the total electron yield in the vicinity of the GaK‐edge were used in our analytical model. The validity of this model is verified by a comparison of our results with the expected values (known from preparation of the layers).