Scientific staff

HEAD: C. Robert-Goumet

•    L Bideux (Professor, UCA, CNU 28)
•    B Gruzza (Professor, UCA, CNU 28)
•    P. Hoggan (Professor, UCA, CNU 28)
•    G Monier (Engineer, UCA)
•    C. Robert-Goumet (Assistant Professor HDR, UCA, CNU 28)

•    H. Beji (PhD, IP/ICCF, fundong LabEx IMobS3, Challenge 3)
•    G. Tsamo (PhD, funding ED SPI)
•    T. R. Bure (PhD, IP/CEA LETI, funding CEA)

Abstract

The Surface and Interface group within IP is well known for electron spectroscopic techniques and surface passivation of III-V compounds.
The group’s research in recent years has mainly focused on the nanostructuring of nitrided overlayers on indium phosphide (InP) and Gallium Arsenide (GaAs) substrates for application in micro and optoelectronics. The surface restructuring effect on the nanoscale is also investigated. Development of expertise to monitor in-situ the nitridation process by electron spectroscopy is assured, mainly XPS and UPS. Various nitridated structures are studied as III-V flat, nanoporous and nanowires surfaces.
The group’s research has developed Elastic Peak Electron Spectroscopy (EPES) : a surface analysis method pioneered by the group. Monte Carlo (MC) simulations, predicting the effect of surface crystallographic orientation and/or surface nanoscale modifications on the spectroscopic response, are necessary to support the interpretation of EPES experimental results. The EPES method and associated applications, is well recognized by the NIST (US national institute for standards in technology) for determining the inelastic mean free path of electrons in solids which is a fundamental parameter for surface electron analysis. Currently, the research is focused on the development of a new non destructive technique: elastic imagery. Indeed, MC results combined with experimental elastic imagery can provide additional information to that obtained with more conventional spectroscopic methods as for example XPS method.
On the other hand, DFT calculations are performed on a plane-wave basis. (Numerical calculation on grids in k-space). Some applications to periodic solids, adatoms : potential surface of nitrogenapproaching GaAs (100). The DFT calculations confirm the N adatom diffusion in the GaAs matrix and confirm the XPS results. Diffusion studies can be simulated by Car Parrinello dynamics. This allows a reasonable approximation of experimental temperature conditions for diffusion. The process may be studied in detail by Quantum Monte Carlo simulations (QMC).

Selected papers

- M.A. Mahjoub, G. Monier, C. Robert-Goumet et al., XPS combined with MM-EPES technique for in situ study of ultra thin film deposition: application to an Au/SiO2/Si structure, Applied Surface Science 357, 1268 (2015)
- E. Gil et al., Record Pure Zincblende Phase in GaAs Nanowires down to 5 nm in Radius, Nano Letters 14, 3938 (2014)
- M.A. Mahjoub, G. Monier, C. Robert-Goumet et al., New method for the determination of the correction function of a hemisperical electron analyser based on elastic electron images, Journal of Electron Spectroscopy and Related Phenomena 197, 80 (2014)

- C. Robert-Goumet et al., Development of Monte-Carlo simulations for nano-patterning surfaces associated with MM-EPES analysis - Application to different Si(111) nanoporous surfaces, Surface Science 618, 72 (2013)
- G. Monier et al., Passivation of GaAs (001) surface by the growth of high quality c-GaN ultra-thin film using low power glow discharge nitrogen plasma source, Surface Science 606, 1093 (2012)

- M.A. Mahjoub, G. Monier, C. Robert-Goumet and al : New method for the determination of the correction function of a hemisperical electron analyser based on elastic electron images Journal of Electron Spectroscopy and Related Phenomena 197, 80 (2014)

- C. Robert-Goumet et al., Development of Monte-Carlo simulations for nano-patterning surfaces associated with MM-EPES analysis – Application to different Si(111) nanoporous surfaces, Surface Science 618, 72 (2013)

- B. Gruzza, S.Chelda, C. Robert-Goumet, L. Bideux, G. Monier, Monte Carlo simulation for Multi-Mode Elastic Peak Electron Spectroscopy of crystalline materials, effects of surface structure and excitation, Surface Science 604, 217 (2010)

- S. Chelda, C. Robert-Goumet, B. Gruzza, L. Bideux, G. Monier, Effect of surface roughness on EPES and AREPES measurements: Flat and crenels silicon surfaces, Surface Science 602, 2114 (2008)

- M.A. Mahjoub, G. Monier, C. Robert-Goumet et al., Ultramicroscopy (2016)

FLASH NEWS

We are delighted to share with you news of the installation of a new Surface Analysis and Structuring System at the Institut Pascal, University Clermont Auvergne, Clermont-Ferrand.
 
The SASS project was supported by the European Union within the context of the European Regional Development Fund (FEDER), the Auvergne-Rhone-Alpes Region and the University Clermont Auvergne. To smooth the operation, this equipment has been customized by the SPECS Group with a special design that couples our preparation chamber to the new UHV system.
 
Facilities available with equipment:
- 2 monochromatic X-ray sources (Al Kα: 1486.6 eV and Ag Lα: 2984.3 eV)
- 1 electron gun
- 1 UV source
- 1 PHOIBOS 150/2D-CMOS hemispherical analyzer
- 1 variable temperature sample holder (from -150°C to 550°C)
- 1 Argon Cluster Ion Beams (GCIB) for depth profiling
- 1 Sample storage for 4 samples

Characterisation techniques available:
- UPS and AR-XPS (Angle Resolved X-ray Photoelectron Spectroscopy)
- ARPES (Angle Resolved PhotoEmission Spectroscopy)
- REELS (Reflection Electron Energy Low Spectroscopy)
- ISS (Ion Secondary Spectroscopy)
- and LEED (Low Energy Electron Diffraction)
 
Examples of current applications including microelectronics (e.g., Metal/SC structures, MIS, PCRAM, etc.), photonics (PQs and NanoDots), photovoltaics (anti-reflective layers), biomedical and transport (polymers), among others.

International and national projects

• FUNPROB (2011-2015): FP7-PEOPLE-2010, Marie Curie Actions—International Research Staff Exchange Scheme (IRSES), proposing to use III-V semiconductor nanowires as functioning sensors at the apex of scanning probes. The primary goal of this joint research program is to develop an integrated NW scanning probe that exhibits advanced functionalities. The creation of such a probe will facilitate both fundamental and applied research. It will lead to new applications and bridge the gap between traditional divides including physical sciences and biomedical sciences. The synthesis process will consist of controlling the growth of III-V semiconductor NWs with the ability to fine tune their physical, chemical and optical properties. These NWs will subsequently be integrated into a SPM probe. We will develop new theoretical models to predict their response characteristics and optimise the growth. The results of this work will feed directly into the probe development section of the programme.
• Run to the Synchrotron SOLEIL (France : RUN on the SMIS beamline (June 2012). Studies by absorption method FTIR of the nitridation by wet and plasma N2 methods in collaboration with the LPMC (Palaiseau) and the IOFFE of St Petersburg
• Run on super computers:
  1. European: DEISA (Distributed European Infrastructure for Supercomputing Applications): Projet STOPQuaLMS (Slater Type Orbital Package for Quantum Monte Carlo on Large Molecular Systems) 2008-2009. Principle Investigator (PI): Ph Hoggan (with P Reinhardt, R Assaraf and J Toulouse de UPMC, Paris). 5 million core hours on Bluegene/P (in Jullich Germany, CHAMP software) were awarded.
  2. National: 2010-2011. DARI Demande d’Allocation de Ressources Informatique. On Bluegene/P at l’IDRIS, Orsay: CASINO (applications to adsorbed CO hydrolysis on metals). PI: Ph Hoggan (with N Drummond, Cambridge, UK and D Claves, LMI, Clermont) 1.5 Million core hours.
     GDR3314 (CNRS - DIR) Méthodes Corrélées pour la structure électronique (CORREL). The « Surface and Interface » group is an active member of the Research Group on electron correlation, national network.