Effect of oxygen on the stability of Ag islands on Si(111)-7 x 7

TitleEffect of oxygen on the stability of Ag islands on Si(111)-7 x 7
Publication TypeJournal Article
Year of Publication2012
AuthorsShao DH, Liu XJ, Lu N, Wang CZ, Ho KM, Tringides MC, Thiel PA
Journal TitleSurface Science
Volume606
Pages1871-1878
Date Published12
Type of ArticleArticle
ISBN Number0039-6028
Accession NumberWOS:000309318100018
Keywordsadsorption, augmented-wave method, basis-set, density functional theory, EPOXIDATION, film growth, growth, initial-stage, microscopy, oxidation-product, Scanning tunneling, Semiconductor surfaces, si surfaces, spectroscopy, Surface structure and morphology, total-energy calculations
Abstract

We have used scanning tunneling microscopy to probe the effect of oxygen exposure on an ensemble of Ag islands separated by a Ag wetting layer on Si( 111)-7 x 7. Starting from a distribution dominated by islands that are 1 layer high (measured with respect to the wetting layer), coarsening in ultrahigh vacuum at room temperature leads to growth of 2-layer islands at the expense of 1-layer islands, which is expected. If the sample is exposed to oxygen, 3-layer islands are favored, which is unexpected. There is no evidence for oxygen adsorption on top of Ag islands, but there is clear evidence for adsorption in the wetting layer. Several possible explanations are considered. (C) 2012 Elsevier B.V. All rights reserved.

URL<Go to ISI>://WOS:000309318100018
DOI10.1016/j.susc.2012.07.030
Alternate JournalSurf. Sci.