Research

Atomic Dynamic:
Theory and computational surface and interface phenomena

SUMMARY

Since my recruiting in LAAS-CNRS, my research focuses on the development and application of multi-scale computational methods, dedicated to physical and chemical problems in material science for micro and nanotechnology applications. My challenge is to propose a predictive modeling dedicated to fill in the gaps in experiments and to guide and control technological process at the atomic scale through predictive and multiscale strategy.

My research activity develops around this major issue that is "the understanding and mastery of surfaces and interfaces". I am particularly interested in the problematic of the atomic diffusion (at the nanoscale), which is often crucial for the functional macroscopic properties.
More precisely, the atomic diffusion is a crucial process that is encountered:

• in the growth of materials in the context of their integration into microelectronics devices. When designing directly integrated materials, atomic diffusion drives the nanostructuring of the material and thus defines the morphology and composition of the achieved layers, in particular at the interfaces.
  Those topics are addressed in collaboration with Nicolas Richard (CEA-DAM-DIF, Arpajon), Sébastien Vizzini (IM2NP, Marseille), Normand Mousseau (Univ. Montréal, Canada).
  Several materials are currently under progress:
  • Thermal oxidation of silicon
  • Growth of Copper oxide on Aluminum
  • Diffusion of Copper into Aluminum from surface to bulk
  • Growth of magnesium and magnesium oxide on silicon, silver and nickel substrates
     
• in material during their use. Particularly in the context of the detection of polluting or harmful gases, the atomic diffusion occurring at the surface of the integrated sensitive layers controls the macroscopic electronic response. The competition between the chemical atomic scale reactions at the surface of the sensing layer determines this response.
  Current application: provide a fundamental description of the atomic scale reactions (physisorption, chemisorption, charge transfers) occuring during the detection of the gas.
  • A focus on the effect of the humidity on the sensing properties is currently under progress for several metal oxides (SnO2, WO3, In2O3) in collaboration the Dr Nicolae Barsan from the University of Tuebingen, in Germany.
     

• in their environment, notably in harsh environment. In aggressive environments or for specific external conditions, the intrinsic properties of the materials can be altered because the nanoscale structure of the material can be damaged.
  Current application: in embedded components for space or nuclear applications subject to irradiation; the energy particles then give rise to clusters of defects which will render the component faulty. This issue is addressed in collaboration with ISAE-SUPAERO (Toulouse), CEA-DAM-DIF (Arpajon), Université de Montréal (Canada), Université of Nova Gorica (Slovénie).