European Centre Specialised in the Characterisation of Materials at Nanometre Scale

Institution CRP Gabriel Lippmann
Autres partenaire(s) Cératizit S.A. , Circuit Foil , Ecole des Mines, Nancy (F) , Goodyear S.A. , Novelis - Foil Innovation Centre , University of Louvain (B) , University of Namur (B)
Du : 16/07/2001
Au : 30/06/2008
Budget : 4 000 000,00€
Contact(s) : Migeon Henri-Noël

Summary

Elaboration of materials at submicronic and nanometric scale is today an important economic and strategic stake of innovation in fields such as health, environment, transport, information and communication technologies. These developments of new materials imply their characterization with analytical techniques adapted to their nanometric dimensions. The department Science et Analysis of Materials (SAM) is equipped with a mass spectrometer dedicated to ion imaging and an Auger spectrometer with high lateral resolutions (50nm and 20nm respectively) and works with industrial and academic partners to develop and provide a complete overview and knowledge of these new materials.
The collaboration with the industrial partners was focused on the characterization of new materials and the optimization of elaboration processes. In the case of the collaboration with the research group of Novelis, implanted in the CRP-GL site, the influence of contaminants in the aluminum alloys on the physical properties was studied. As an example the thermal treatment improving the mechanical properties of the aluminum foils leads to the segregation of some elements to the surface and results in the decrease of the adhesion properties. The efficiency of the tests to limit these diffusion phenomena was controlled by XPS. Circuit Foil deposits thin multilayers on copper foils to control the adhesion properties during the microelectronic components elaboration and to chemically stabilize the surface. In order to optimize the elaboration process and the efficiency of the deposit, the thickness of the layers, their composition and the inter-diffusion was studied by XPS and SIMS depth profiling.

The possibility to transfer samples under vacuum, to avoid surface modification and contamination between the treatment and the analyze of the specimen, using the vacuum transfer vessel developed in the framework of this project, was useful for two studies: in the case of a thesis in the “Laboratoire Interdisciplinaire de Spectroscopie Electronique” in Namur, several samples elaborated in Belgium were analyzed in the SAM department. The goal of this work was to study the ionization processes of secondary ions and clusters during ToF-SIMS analysis by cesium and xenon co-sputtering. The Cs and Xe surface concentrations were determined by AES. In the same way, an impact energy of 16 kV is required to obtain a lateral resolution of 50nm with the NanoSIMS50. The drawback of this high energy is then the impossibility to analyze the first 10nm of the surface. However, the deposition of neutral Cs on the sample before its transfer under UHV into the NanoSIMS50 increases the sputtering yield, notably for the thin thicknesses, and allowed the study of small 2D and 3D objects.

Figure: Images of the distribution of carbon, oxygen, silicon and aluminium on the surface of an aluminium foil and obtained with the NanoSIMS50.