Surface structure and thermal desorption spectroscopy in Si(111)

Publisher Website
Google Scholar
Abstract
The authors studied the adsorption-desorption behaviour of Ar and Xe on the Si(111) 7*7 reconstructed surface. Using thermal desorption spectroscopy (TDS) one can clearly distinguish between adsorption in the monolayer range and higher coverage. Desorption from the second and higher layers show up in a non-saturating desorption peak of zero-order kinetic at lower temperatures while in the monolayer range they observe a saturating behaviour of the desorption rate with a complex structure at higher temperatures. Here the adsorbate-substrate interaction is dominant and different adsorption sites can be resolved demonstrating the rough character of the 7*7 reconstruction. This interpretation was confirmed by a controlled in situ change of the 7*7 reconstruction using a saturation precoverage of atomic hydrogen. The concentration and binding energy of the different binding sites are obtained by fitting a theoretical desorption model to the data. The relevance of the model and alternative models is discussed.

This publication has 22 references indexed in Scilit: