Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/26929

OpenURL Link
Title
Phosphine dissociation and diffusion on Si(001) observed at the atomic scale
Author/Creator
Schofield, Steven R.;  Curson, Neil J.;  Warschkow, Oliver;  Marks, Nigel A.;  Wilson, Hugh F.;  Simmons, Michelle Y.;  Smith, Phillip V.;  Radny, Marian W.;  McKenzie, David R.;  Clark, Robert G.
Description
A detailed atomic-resolution scanning tunneling microscopy (STM) and density functional theory study of the adsorption, dissociation, and surface diffusion of phosphine (PH₃) on Si(001) is presented. Adsorbate coverages from ∼0.01 monolayer to saturation are investigated, and adsorption is performed at room temperature and 120 K. It is shown that PH₃ dissociates upon adsorption to Si(001) at room temperature to produce both PH₂ + H and PH + 2H. These appear in atomic-resolution STM images as features asymmetric-about and centered-upon the dimer rows, respectively. The ratio of PH₂ to PH is a function of both dose rate and temperature, and the dissociation of PH₂ to PH occurs on a time scale of minutes at room temperature. Time-resolved in situ STM observations of these adsorbates show the surface diffusion of PH₂ adsorbates (mediated by its lone pair electrons) and the dissociation of PH₂ to PH. The surface diffusion of PH₂ results in the formation of hemihydride dimers on low-dosed Si(001) surfaces and the ordering of PH molecules along dimer rows at saturation coverages. The observations presented here have important implications for the fabrication of atomic-scale P dopant structures in Si, and the methodology is applicable to other emerging areas of nanotechnology, such as molecular electronics, where unambiguous molecular identification using STM is necessary.
Relation
Journal of Physical Chemistry B Vol. 110, Issue 7, p. 3173-3179
Publisher Link
http://dx.doi.org/10.1021/jp054646v
Date
2006
Publisher
American Chemical Society
Keyword(s)
scanning tunneling microscopy;  density functional theory;  phosphine;  Si(001);  nanotechnology
Resource Type
journal article
Identifier
http://hdl.handle.net/1959.13/26929
Identifier
ISSN:1520-5207
Reviewed
Reviewed
8 Visitors 9 Hits 0 Downloads
Save/E-mail Citation
Citation Format
E-mail Address
Subject
"Journal of Physical Chemistry B"
 
OR