We have used the medium energy ion scattering (MEIS) technique to assess the strain relaxation in
molecular-beam epitaxial (MBE) grown CdTe (211)/Ge (211) system. A previous X-ray diffraction study,
on 10 samples of the same heterostructure having thicknesses ranging from 25 nm to 10 lm has allowed
the measurement of the strain relaxation on a large scale. However, the X-ray diffraction measurements
cannot achieve a stress measurement in close proximity to the CdTe/Ge interface at the nanometer scale.
Due to the huge lattice misfit between the CdTe and Ge, a high degree of disorder is expected at the interface.
The MEIS in channeling mode is a good alternative in order to profile defects with a high depth resolution.
For a 21 nm thick CdTe layer, we observed, at the interface, a high density of Cd and/or Te atoms
moved from their expected crystallographic positions followed by a rapid recombination of defects.
Strain relaxation mechanisms in the vicinity of the interface are discussed