Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 30: Phenomena at Semiconductor Surfaces
O 30.6: Vortrag
Dienstag, 26. Februar 2008, 13:15–13:30, MA 041
Investigations of Ga atom wire formation on Si(112) — •Moritz Speckmann1, Thomas Schmidt1, Jan-Ingo Flege1,2, and Jens Falta1 — 1Institute of Solid State Physics, University of Bremen, 28334 Bremen — 2National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973, USA
High index surfaces are of strong interest in today’s research because they are supposed to be a candidate for self-assembling systems, e. g. nano wires.
In this work the adsorption of Ga on Si(112) has been investigated with different surface sensitive techniques. The stepped silicon surface consists of (111)- and (337)-facets. Because of the lower surface energy at the step edges growth of metals, e.g. Ga or Al, results in quasi-1D metal quantum wires along the direction of the step edges.
STM and LEED images clearly reveal a Ga:Si(112)-(6×1)-reconstruction with Ga atom rows along the step edges in [110]-direction. Using XPEEM experiments performed at NSLS, Brookhaven and comparing with the Ga:Si(111)-(√3×√3)-reconstruction we were able to determine the coverage of the Ga:Si(112)-(6×1)-reconstruction. Our results correspond to 10 Ga atoms per (6×1) unit cell and therefore confirm the model by Snijders et al. (Phys. Rev. B, 72, 2005). Furthermore we performed x-ray standing waves experiments at HASYLAB, Hamburg. The obtained positions of the Ga atoms again show a strong agreement with the proposed positions in the model.