Influence of the ultra-thin Ag layer on Si(1 1 1)7 × 7 on directional elastic peak electron spectroscopy profiles

The directional elastic peak electron spectroscopy (DEPES) polar profiles for the clean Si(1 1 1)7 × 7 surface and the Si(1 1 1)√ 3 × √3R30°-Ag system are presented. The results were obtained for the [112¯]-[1¯1¯2] and [011¯]-[01¯1] azimuths of the substrate for primary electron energies from the range 0.5-2 keV. A simple qualitative analysis of the observed profiles revealed the influence of the ultra-thin silver layer on the shape of the measured DEPES polar profiles, i.e. both on their background level and on the height of some intensity maxima. Thus, the information on the position of silver atoms in the investigated structure and other ultra-thin layers on crystalline substrates seems to be obtainable by the analysis of the DEPES profiles. The presence of numerous maxima in the measured profiles imply the application of a more advanced method in qualitative and quantitative interpretation of the DEPES profiles.