Dresden 2003 – wissenschaftliches Programm

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O: Oberflächenphysik

O 22: Epitaxie und Wachstum I

O 22.12: Vortrag

Dienstag, 25. März 2003, 17:45–18:00, FOE/ORG

Kinetics of the Single-Domain Formation During Si Homoepitaxy on vicinal Si(100) — •D. Thien, I. Dumkow, F.-J. Meyer zu Heringdorf, P. Kury, and M. Horn-von Hoegen — Universität Essen, 45117 Essen, Germany

The formation of a single-domain Si(100) surface from a regularly stepped low-miscut Si(100) surface provides a powerful tool to create an artificial substrate without the intrinsic anisotropy of the original surface. On the Si(100) surface, two types of terraces are present with either (2x1) or (1x2) reconstruction. Accordingly, single-steps between terraces are either straight (S_A step) or rough (S_B step), depending on the orientation of the reconstruction, i.e. the alignment of Si dimers on the terraces. During Si deposition the dimer orientation leads to a diffusion anisotropy, causing the terrace with a S_B step to grow faster than the terrace with a S_A step. We studied the single domain formation on Si(100) surfaces with a miscut of 0.2^∘ and 0.8^∘ in [110] using high resolution low energy electron diffraction (SPA-LEED) and low energy electron microscopy (LEEM). At temperatures between 450^∘C and 550^∘C the growth mode for Si changes from island growth to step flow. In this temperature regime we observe the formation of single domain surfaces after deposition of a total of ≈ 3/4ML Si.

The azimuthal misorientation of the extremely low miscut vicinal surfaces, however, is a crucial parameter for the single domain formation. We demonstrate how a slight misorientation of only 1/100^∘ can completely suppress the single domain formation.