J. Phys. IV France 04 (1994) C9-187-C9-190
Characterization of two-dimensional Er-silicide / Si (111) interfaceM.H. Tuilier1, G. Gewinner1, C. Pirri1, P. Wetzel1, D. Bolmont1 and O. Heckmann2
1 Laboratoire de Physique et de Spectroscopie Electronique, Université de Haute-Alsace, 4 rue des Frères Lumière, 68093 Mulhouse cedex, France
2 Laboratoire pour l'Utilisation du Rayonnement Electromagnétique, Centre Universitaire Paris-Sud, Bâtiment 209D, 91405 Orsay cedex, France
Si2p core level photoemission as well as X-ray polarization dependent surface extended absorption fine structure (SEXAFS) have been used to characterize the interface of a two-dimensional erbium silicide with Si(111). This silicide, which consists of a hexagonal erbium monolayer located underneath a buckled Si top layer, was grown by deposition of one monolayer of erbium on clean Si(111) and annealing in the 400-600°C temperature range. Photoemission experiments reveal a Schottky barrier height ØB as low as 0.13 ± 0.05 eV while for thicker erbium silicide layers ØB is found to be ∅B 0.3 eV. SEXAFS measured at the Er L3 edge shows the location of erbium atoms in the eclipsed threefold hollow sites of the Si substrate.The average distance of erbium to the silicon of the substrate is found to be 3.10 ± 0.04 Å, whereas the distance of erbium atoms to their three first neighbors in the Si top layer is found to be 2.94 ± 0.04 Å.
© EDP Sciences 1994