Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 5: Epitaxie und Wachstum I

O 5.6: Vortrag

Montag, 8. März 2004, 12:30–12:45, H44

Growth of a GaSe half-sheet on Si(111) — •Bengt Jaeckel, Rainer Fritsche, Andreas Klein, and Wolfram Jaegermann — Darmstadt University of Technology, Surface Science Division, Department of Materials Science, Petersenstr. 23, 64287 Darmstadt

The evolution of the Si(111):GaSe surface termination is investigated with scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and SXPS. GaSe is evaporated from an effusion cell filled with GaSe compound as source material onto Si(111)-(7× 7) surfaces held at 540^∘C substrate temperature. Although both Gallium and Selenium are exposed during the formation process, the surface passes through different reconstructions, which are known for Ga-terminated Si(111) surfaces. The passivated surface is characterized by a three-fold symmetry of the LEED-pattern, a hexagonal periodicity of the lattice imaged with atomic resolved STM and flat-band conditions measured with SXPS.
In the beginning a √3×√3 R30^∘- Ga surface is formed, followed by a 6.3 × 6.3 and a 6.3√3× 6.3√3 - Ga surface, which corresponds to one third, 0.7 and 1 monolayer of Gallium. No Si(111)-(1× 1):GaSe terminated areas are observed below one third monolayer coverage.