Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 20: Halbleiteroberfl
ächen und -grenzfl
ächen
O 20.9: Vortrag
Dienstag, 25. März 2003, 17:00–17:15, FOE/ANOR
Step structures on differently reconstructed ZnSe(001) surfaces — •W. Weigand1, P. Bach2, T. Schallenberg2, C. Kumpf1, W. Faschinger2, M. Sokolowski3, and E. Umbach1 — 1Experimentelle Physik II, Universität Würzburg — 2Experimentelle Physik III, Universität Würzburg — 3Theoretische und Physikalische Chemie, Universität Bonn
For the formation of surface structures, and consequently for the growth of high-quality epitaxial films, the occurrence of steps and domain boundaries and their energetics play an important role [1]. To evaluate the influence of steps on ZnSe(001) we investigated the (2×1) and c(2×2) reconstructed surfaces of ZnSe thin films epitaxially grown on GaAs(001) using high resolution low energy electron diffraction (SPA-LEED). In this talk we present these results and discuss their impact for II-VI surfaces. The steps on the c(2×2) reconstructed surface run along two well defined directions, namely the [100] and [010] direction (surface units). Due to a distinct phase difference across the steps, anti-phase boundaries are induced running along the [110] direction through the terraces [2]. By annealing the surface the average domain size is increased to ≈ 1000 Å. In contrast, the steps on the (2×1) reconstructed ZnSe(001) surface are oriented in the [110] direction and cause an incommensurate diffraction pattern [3].
[1] D. Martrou, et al., Phys Rev Lett 83, 2366-2369 (1999).
[2] Z. H. Chen, et al., Europhys Lett 59, 552 (2002).
[3] R. W. Cutler, et al., Surf Sci 340, 258-264 (1995).