Book/Report

FZJ-2018-04107

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Electronic and geometric structure of buried CoSi$_{2}$ layers investigated with photon-in photon-out spectroscopies

Eisebitt, S. (Corresponding author)FZJ*

1993
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/19288

Report No.: Juel-2715

Abstract: The electronic and geometric structure of CoSi$_{2}$ layers embedded in Si wafers by means of ion beam synthesis (IBS) has been studied. The work had two main directions: the development of methods suited to study buried structures in general and the actual investigation of the CoSi$_{2}$ layers. In order to determine the geometric structure of buried silicides, we developed a method to use EXAFS at the 3d TM L-edges. We could demonstrate that this new technique is a promisingalternative to K-EXAFS for samples in an environment of crystalline Si. The technique was established on a CoSi$_{2}$ IBS sample. XANES detected by the fluorescence yield (FY) is another technique suited to study buried structures in situ due to its deep-probing character and its atomic selectivity. The saturation effects in FY spectra of concentrated samples were analysed. Using the dependence of the FY intensity on the geometry of the experiment, we developed a new method to calculate the absorption coefficient from spectra recorded at different angles. The information depth of the technique has been investigated. We applied this method to the Co L$_{3}$ near-edge absorption in order to investigate the unoccupied electronic states of buried CoSi$_{2}$ layers by FY-XANES. Additionally, the occupied electronic states of these structures produced by IBS were studied by soft x-ray emission (SXE) spectroscopy. As a result, we obtained a complete picture of the Co d-DOS with a resolution that allowed for a detailed comparison to theoretical calculations. By investigating a CoSi$_{2}$ single crystal in addition to an as-implanted and an annealed IBS sample we gained insight into the evolution of the electronic structure upon silicide formation in the IBS process. We could proove that single crystalline CoSi$_{2}$ is indeed formed upon annealing. The results show that the experimental methods applied can be used for non-destructive investigations of buried layers in microelectronic devices.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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