Transmission electron microscopy (TEM) makes possible the visualization of the microstructure of materials from a micrometric scale down to atomic scale. At CRHEA the MET has 2 missions:

• A service mission concerning the structural and microstructural characterization of the materials elaborated in the laboratory. This includes conventional measurements for thin films of wide bandgap semiconductors :
  • Analysis of structural defects (measurement of their densities, determination of their nature...)
  • Precise measurement of thicknesses, compositions and morphology of hetero-structures having sizes from micrometer to nanometer

  This service activity is also open to laboratories and companies that wish to benefit the expertise of CRHEA.

• A research activity on the understanding of the microstructure of hetero-epitaxial thin films of wide bandgap semiconductors (GaN and ZnO, SiC ...) in relation with their growth conditions. CRHEA is recognized nationally and internationally for this activity as evidenced by the many publications and collaborations. These collaborations are at the local (see ACT-M platform), national or international levels.

For the technical aspect, CRHEA has :

• Sample preparation :
  • 2 wire saws
  • 2 polishers including a semi-automatic one (Allied Multiprep)
  • 1 grinding machine
  • 1 ionic thinning machine
  • 2 optical microscopes
• Observations:
  • CRHEA had a MET JEOL 2010 FEG high resolution. This MET was destroyed during the violent storms of October 3 2015. Since then, MET observations are performed on external MET. CRHEA benefits to the access to the MET of the IMRA Europe company installed on the Sophia Antipolis site. The experiences are also conducted on the METs of CP2M in Marseille and MINATEC in Grenoble as part of a collaboration with CEA LETI.

• Data analysis :
  • Image simulation (JEMS software)
  • Image analysis: quantitative analysis of high resolution images by the GPA method and by methods in the direct network