AVS 46th International Symposium
    Surface Science Division Friday Sessions
       Session SS2-FrM

Paper SS2-FrM5
STM Study of Metal Row Growth on Si(5 5 12)

Friday, October 29, 1999, 9:40 am, Room 607

Session: Adsorption on Metals and Silicon
Presenter: K.M. Saoud, Virginia Commonwealth University
Authors: K.M. Saoud, Virginia Commonwealth University
I. Samanta, Virginia Commonwealth University
K.M. Jones, Virginia Commonwealth University
A.A. Baski, Virginia Commonwealth University
Correspondent: Click to Email
The high-index Si(5 5 12)-2x1 surface has recently gained interest as a template for overlayer growth, primarily because of its highly anisotropic row reconstruction. Our recent STM studies have shown that a noble metal such as Ag forms well-ordered overlayer rows on this surface.@footnote 1@ At coverages below 0.25 ML and moderate annealing temperatures (450°C), Ag forms monatomic rows with an inter-row spacing of ~5 nm. These Ag rows nucleate along the more reactive tetramer rows of the surface reconstruction, and are separated by isolated @pi@-chains remaining from the clean surface. At higher temperatures and coverages (>500°C, >0.25 ML), these @pi@-chains are removed and the Ag rows become wider with a strong 3x periodicity. We now have preliminary studies of more reactive metals such as Au and Ca on Si(5 5 12). At moderate annealing temperatures, both metals form overlayer rows that still preferentially nucleate along the tetramers. However, these rows are less well-ordered and are shorter at a given coverage, indicating the enhanced reactivity of these adsorbates. As expected, both metals change their growth behavior at higher annealing temperatures. The Au grows in 3x rows that become substantially more ordered and longer at a given coverage, whereas Ca rearranges the surface into a more complicated undulating row-like structure. In both cases, no remaining structures from the underlying reconstruction are visible. This work clearly demonstrates the utility of the Si(5 5 12) surface as a template for the 1D growth of a variety of metals. @FootnoteText@ @footnote 1@ H.H. Song, K.M. Jones, and A.A. Baski, J. Vac. Sci. Technol. A Jul/Aug 1999.