An Auger electron diffraction investigation was made of the L2,3VV Auger line of the clean reconstructed (111) Si surface, and of the Ge/Si interface which formed after a few monolayers of Ge deposition. 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 an X-ray source and an electron source, revealed 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 2 elements at room temperature, and after annealing (400C) the substrate. The evolution of the growth mechanism that underlay Ge/Si interface formation was studied by exploiting the very low electron escape depth (less than 0.5nm) that was associated with this technique. At room temperature, 2 monolayers of Ge deposition appeared uniform and amorphous but successive annealing caused intermixing and recrystallization only in the first 2 layers of the interface; with no further interdiffusion. A Stranski-Krastanow growth mode was detected after depositing 4 monolayers of Ge onto clean Si at 400C.

M.De Crescenzi, R.Gunnella, R.Bernardini, M.De Marco, I.Davoli: Physical Review B, 1995, 52[3], 1806-15