Diamond Publications - Search Results

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

One item found (0 items not approved).

Instruments / Technical Area	Publication Details	Published	Actions
I09-Surface and Interface Structural Analysis	Thermal and oxidation stability of Tix W1−x diffusion barriers investigated by soft and hard x-ray photoelectron spectroscopy C. Kalha , S. Bichelmaier , N. K. Fernando , J. V. Berens , P. K. Thakur , T.-L. Lee , J. J. Gutiérrez Moreno , S. Mohr , L. E. Ratcliff , M. Reisinger , J. Zechner , M. Nelhiebel , A. Regoutz Journal Of Applied Physics 129 DOI: 10.1063/5.0048304 Diamond Proposal Number(s): [19885] Open Access Show Abstract ▼ Abstract: 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 WO2, WO3, and a WO3 oxide coordinated with a titanium environment. This combinatorial characterization approach provides valuable insights into the thermal and oxidation stability of TiW alloys from two depth perspectives, aiding the development of future device technologies.	May 2021

Instruments / Technical Area

Publication Details

Published

Actions

I09-Surface and Interface Structural Analysis

Thermal and oxidation stability of Tix W1−x diffusion barriers investigated by soft and hard x-ray photoelectron spectroscopy