Wiethoff, Christian; Ross, Frances M.; Copel, Matthew; Horn-von Hoegen, Michael; Meyer zu Heringdorf, Frank:

Au stabilization and coverage of sawtooth facets on Si nanowires grown by vapor-liquid-solid epitaxy

In: Nanoletters, Jg. 8 (2008) ; Nr. 9, S. 3065–3068
ISSN: 1530-6992, 1530-6984
Zeitschriftenaufsatz / Fach: Physik
Fakultät für Physik » Experimentalphysik
Zentrale wissenschaftliche Einrichtungen » Center for Nanointegration Duisburg-Essen (CeNIDE)
Si nanowires grown in UHV by Au-catalyzed vapor−liquid−solid epitaxy are known to exhibit sidewalls with {112}-type orientation that show faceting. To understand the origin of the faceting, Au induced faceting on Si(112) surfaces was studied in situ by spot-profile-analyzing low-energy electron diffraction. With increasing Au coverage at 750 °C, the Si(112) surface undergoes various morphological transformations until, at a critical Au coverage of about 3.1 × 1014 atoms/cm2, a phase consisting of large (111) and (113) facets forms, similar in structure to the nanowire sidewalls. This phase is stable at larger Au coverages in equilibrium with Au droplets. We suggest that Si nanowire surfaces exhibit this structure, and we derive the Au coverage on the two types of facets.