A Transmission Electron Microscopy study of composition in Si1-xGex / Si (001) quantum dots

Yidir Androussi (1) , Tarik Benabbas (1) , Slawomir Kret (2) , Vincent Ferreiro (1) , Alain Lefebvre (1)

1 LSPES - Laboratoire de structures et propriétés de l'état solide - UMR 8008
2 Institute of Physics, Polish Academy of Sciences

A finite-element program has been developed to model strain relaxation in the case of epitaxial Si1-xGex / Si coherent quantum dots either with or without compositional inhomogeneities. The resulting elastic displacement fields are used to calculate the intensity of dynamical plan view TEM images of such quantum dots. Various types of linear or parabolic compositional inhomogeneities are studied. TEM images of quantum dots with such inhomogeneities are calculated as well as those of quantum dots with a homogeneous composition. They are then compared with experimental images. It is shown how the analysis of the main features of these experimental images (black/white lobes and moiré-like fringes) enables us to determine the conditions in which it is possible to distinguish quantum dots with a homogeneous composition from those with compositional inhomogeneity.

Mots clés: Physical Sciences

Yidir Androussi, Tarik Benabbas, Slawomir Kret, Vincent Ferreiro, Alain Lefebvre. A Transmission Electron Microscopy study of composition in Si1-xGex / Si (001) quantum dots. Philosophical Magazine, 2007, 87 (10), pp.1531-1543. ⟨10.1080/14786430601055387⟩. ⟨hal-00513799⟩