Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 35: Poster Session I (Metal, semiconductor and oxide substrates: structure and adsorbates; Graphene)

O 35.44: Poster

Dienstag, 12. März 2013, 18:15–21:45, Poster B1

And Now For Something Completely Different: Au Induced Faceting of Si(0 8 15) — •Christian Witt, Michael Horn-von Hoegen, and Frank-J. Meyer zu Heringdorf — Faculty for Physics and Center for Nanointegration CENIDE,University Duisburg-Essen Lotharstrasse 1, 47057 Duisburg

Au and Ag are known to induce faceting on many vicinal Si surfaces. Until now, studies have focused on the faceting kinetics in one dimensional systems, where a distinct step orientation of the vicinal substrate was transformed into a faceted surface with straight step edges and a zigzag cross section. Here, we show similar experiments on a surface that exhibits two faceting directions during depositionof Au at elevated temperatures. Si(0 8 15) is a vicinal Si(0 1 2) surface with a miscut of 1.51° towards (0 2 -1). We observed the faceting kinetics of this surface by low energy electron microscopy and low energy electron diffraction. During Au adsorbtion the surface initially forms one dimensional facets. This is followed by a second faceting transformation to form an Escher-like "checkered" pattern. After completed faceting we find three different types of facets with typical facet sizes of few hundred nm. The facets angles relative to the surface normal were determined by in-situ reciprocal space mapping and independently confirmed by ex-situ AFM measurements. The Au induced faceting transformation of the (0 8 15)face of Si produces two well-ordered facets while leaving the third facet a stepped area with characteristic convex and concave areas. [1] Phys. Rev. Lett. 86 (2001) 5088; [2] J. Phys.: Cond. Matter 18 (2006) 1; [3] Surf. Rev. & Lett. 5 (1998) 1164