Imperial College London
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DrAnnaRegoutz

Faculty of Engineering, Department of Materials

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Contact

 

a.regoutz Website

 
 
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Location

 

2.M14Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Kalha:2021:10.1063/5.0048304,
author = {Kalha, C and Bichelmaier, S and Fernando, NK and Berens, JV and Thakur, PK and Lee, T-L and Gutiérrez, Moreno JJ and Mohr, S and Ratcliff, LE and Reisinger, M and Zechner, J and Nelhiebel, M and Regoutz, A},
doi = {10.1063/5.0048304},
journal = {Journal of Applied Physics},
pages = {1--15},
title = {Thermal and oxidation stability of TixW1−x diffusion barriers investigated by soft and hard x-ray photoelectron spectroscopy},
url = {http://dx.doi.org/10.1063/5.0048304},
volume = {129},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The binary alloy of titanium-tungsten (TiW) is an established diffusion barrier in high-power semiconductor devices, owing to its ability to suppress the diffusion of copper from the metallization scheme into the surrounding silicon substructure. However, little is known about the response of TiW to high-temperature events or its behavior when exposed to air. Here, a combined soft and hard x-ray photoelectron spectroscopy (XPS) characterization approach is used to study the influence of post-deposition annealing and titanium concentration on the oxidation behavior of a 300 nm-thick TiW film. The combination of both XPS techniques allows for the assessment of the chemical state and elemental composition across the surface and bulk of the TiW layer. The findings show that in response to high-temperature annealing, titanium segregates out of the mixed metal system and upwardly migrates, accumulating at the TiW/air interface. Titanium shows remarkably rapid diffusion under relatively short annealing timescales, and the extent of titanium surface enrichment is increased through longer annealing periods or by increasing the bulk titanium concentration. Surface titanium enrichment enhances the extent of oxidation both at the surface and in the bulk of the alloy due to the strong gettering ability of titanium. Quantification of the soft x-ray photoelectron spectra highlights the formation of three tungsten oxidation environments, attributed to WO
AU  - Kalha,C
AU  - Bichelmaier,S
AU  - Fernando,NK
AU  - Berens,JV
AU  - Thakur,PK
AU  - Lee,T-L
AU  - Gutiérrez,Moreno JJ
AU  - Mohr,S
AU  - Ratcliff,LE
AU  - Reisinger,M
AU  - Zechner,J
AU  - Nelhiebel,M
AU  - Regoutz,A
DO  - 10.1063/5.0048304
EP  - 15
PY  - 2021///
SN  - 0021-8979
SP  - 1
TI  - Thermal and oxidation stability of TixW1−x diffusion barriers investigated by soft and hard x-ray photoelectron spectroscopy
T2  - Journal of Applied Physics
UR  - http://dx.doi.org/10.1063/5.0048304
UR  - https://aip.scitation.org/doi/10.1063/5.0048304
UR  - http://hdl.handle.net/10044/1/90461
VL  - 129
ER  -
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