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Wavelength despersive spectroscopy analysis at high spectral resolution: application to the study of Mo/Si multilayers
Author(s) -
Jonnard Philippe,
Maury Hélène,
André JeanMichel
Publication year - 2007
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/xrs.940
Subject(s) - spectroscopy , materials science , amorphous solid , analytical chemistry (journal) , resolution (logic) , emission spectrum , spectrometer , molybdenum , diffusion , electron , spectral line , atomic physics , optics , chemistry , physics , crystallography , chromatography , quantum mechanics , astronomy , artificial intelligence , computer science , metallurgy , thermodynamics
We show that x‐ray emission spectroscopy (XES) induced by electrons, analyzed at high spectral resolution by a WDS Johann‐type spectrometer, is a powerful technique to characterize in a nondestructive way the interlayers in Mo/Si multilayers. The analysis is performed using the IRIS (Instrument de Recherche sur les Interfaces et Surfaces) apparatus equipped with a curved crystal. Within those experimental conditions the spectral resolution E /Δ E is about 2000 in the 1800–1900 eV photon energy range. Because of the high resolution of the spectrometer, the evolution of the shape of the Si Kβ emission band (3p − 1s transition) as a function of the chemical environment of the Si atoms is easily evidenced. We study a series of Mo/Si multilayers, where the thickness of the Si layers is 2 nm and that of the Mo layers is 1, 2, 3 or 4 nm. It clearly appears that the emission band from the Si atoms within the multilayers is different from that of amorphous Si (a‐Si), which should be observed if no diffusion process takes place at the interfaces. By comparing the observed emission band to that of a‐Si and molybdenum silicides and using a simple diffusion model, we deduce the composition of the interlayers. Their thickness is deduced and estimated to be 0.4 ± 0.1 nm or 0.8 ± 0.2 nm depending on the samples. Copyright © 2007 John Wiley & Sons, Ltd.