An investigation was made of Auger-electron diffraction of the L2,3VV Auger line of clean 7 x 7 reconstructed Si(111) surfaces, and the Ge/Si interface formed after a few monolayers of Ge deposition. The experimental Auger electron diffraction in the low kinetic-energy regime was interpreted within the framework of multiple-scattering theory. A comparison of Auger electron diffraction data obtained using both an X-ray source and an electron source showed that the incident beam played a negligible role when the experimental conditions required the use of an angular detector. The evolution of the Ge/Si(111) interface was studied by monitoring the intensity anisotropy of the Auger peaks of the two elements at room temperature and after 400C-annealing temperature of the substrate. The evolution of the growth mechanism underlying Ge/Si interface formation was studied by exploiting the very low electron escape depth of this technique (≤5Å). Whereas, at room temperature, 2 monolayers of Ge deposition appeared uniform and amorphous, successive annealing induced intermixing and recrystallization only in the first two layers of the interface; without any further interdiffusion. Furthermore, a Stranski-Krastanow growth mode was deduced after deposition of 4ML of Ge onto a clean Si sample kept at 400C.

Auger-Electron Diffraction in the Low Kinetic-Energy Range - the Si(111)7 x 7 Surface Reconstruction and Ge/Si Interface Formation. M.De Crescenzi, R.Gunnella, R.Bernardini, M.De Marco, I.Davoli: Physical Review B, 1995, 52, 1806-15