Lead growth on Si(111) surfaces reconstructed by indium

TitleLead growth on Si(111) surfaces reconstructed by indium
Publication TypeJournal Article
Year of Publication2012
AuthorsVlachos D, Kamaratos M, Foulias SD, Binz S, Hupalo M, Tringides MC
Journal TitleJournal of Physics-Condensed Matter
Volume24
Pages095006
Date Published03
Type of ArticleArticle
ISBN Number0953-8984
Accession NumberWOS:000300641000008
Keywordsadsorption, CHAINS, ENERGY ELECTRON-DIFFRACTION, LOW-TEMPERATURES, pb, x-ray-diffraction
Abstract

We study the Pb growth on both root 3 x root 3-In and 4 x 1-In reconstructed Si(111) surfaces at room and low temperature (160 K). The study takes place with complementary techniques, to investigate the role of the substrate reconstruction and temperature in determining the growth mode of Pb. Specifically, we focus on the correlation between the growth morphology and the electronic structure of the Pb films. The information is obtained by using Auger electron spectroscopy, low energy electron diffraction, soft x-ray photoelectron spectroscopy, scanning tunneling microscopy and spot profile analysis-low energy electron diffraction. The results show that, at low temperature and coverage <= 12 ML on the Si(111) root 3 x root 3-In surface, Pb does not alter the initial semiconducting character of the substrate and three-dimensional Pb islands with poor crystallinity are grown on a wetting layer. On the other hand, for the same coverage range, Pb growth on the Si(111)4 x 1-In surface results in metallic Pb(111) crystalline islands after the completion of a double incomplete wetting layer. In addition, the bond arrangement of the adatoms is studied, confirming that In adatoms interact more strongly with the silicon substrate than the Pb ones. This promotes a stronger Pb-Pb interaction and enhances metallization. The onset of the metallization is correlated with the amount of pre-deposited In on the Si(111) surface. The decoupling of the Pb film from the 4 x 1-In interface can also explain the unusual thermal stability of the uniform height islands observed on this interface. The formation of these Pb islands is driven by quantum size effects. Finally, the different results of Pb growth on the two reconstructed surfaces confirm the importance of the interface, and also that the growth morphology, as well as the electronic structure of the Pb film can be tuned with the initial substrate reconstruction.

URL<Go to ISI>://WOS:000300641000008
DOI10.1088/0953-8984/24/9/095006
Alternate JournalJ. Phys.-Condes. Matter