Use of XPS to clarify the Hall coefficient sign variation in thin niobium layers buried in silicon

[Display omitted] •HR XPS spectra of Nb 3d, Si 2p, O 1s were probed for Si/Nb/Si trilayers prepared by magnetron sputtering to clarify the Hall coefficient variation as a function of Nb layer thickness.•Strong boundary scattering, enhanced by the presence of silicon ions in the layer close to the in...

Full description

Saved in:
Bibliographic Details
Published in:Applied surface science 2017-03, Vol.399, p.32-40
Main Authors: Demchenko, Iraida N., Lisowski, Wojciech, Syryanyy, Yevgen, Melikhov, Yevgen, Zaytseva, Iryna, Konstantynov, Pavlo, Chernyshova, Maryna, Cieplak, Marta Z.
Format: Article
Language:English
Subjects:
Hall coefficient
HR XPS
NbSi
Si/Nb/Si
Superconductivity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •HR XPS spectra of Nb 3d, Si 2p, O 1s were probed for Si/Nb/Si trilayers prepared by magnetron sputtering to clarify the Hall coefficient variation as a function of Nb layer thickness.•Strong boundary scattering, enhanced by the presence of silicon ions in the layer close to the interface/s is a main factor leading to sign change of the Hall coefficient.•Theoretical concentration/depth profile as a function of sputtering determined by SESSA after optimization of the model system gives good agreement with experiment. Si/Nb/Si trilayers formed with 9.5 and 1.3nm thick niobium layer buried in amorphous silicon were prepared by magnetron sputtering and studied using XPS depth-profile techniques in order to investigate the change of Hall coefficient sign with thickness. The analysis of high-resolution (HR) XPS spectra revealed that the thicker layer sample has sharp top interface and metallic phase of niobium, thus holes dominate the transport. In contrast, the analysis indicates that the thinner layer sample has a Nb-rich mixed alloy formation at the top interface. The authors suggest that the main effect leading to a change of sign of the Hall coefficient for the thinner layer sample (which is negative contrary to the positive sign for the thicker layer sample) may be related to strong boundary scattering enhanced by the presence of silicon ions in the layer close to the interface/s. The depth-profile reconstruction was performed by SESSA software tool confirming that it can be reliably used for quantitative analysis/interpretation of experimental XPS data.
ISSN:0169-4332
1873-5584
DOI:10.1016/j.apsusc.2016.12.028