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  Kleinschmidt, P.; Brückner, S.; Supplie, O.; Dobrich, A.; Döscher, H.; Hannappel, T.: In-situ control and atomic imaging of double-layer steps on MOVPE-prepared Si(100). In: 14th European Workshop on Metalorganic Vapor Phase Epitaxy. EW-MOVPE 2011. June 5 -8, Wroclaw, Polen, 2011, p. [1-4]

Abstract:
Preparation of double-layer steps is thought to be essential for heteroepitaxial growth of III-V semiconductors on Si(100), as single-layer steps on Si(100) lead to the initiation of anti-phase disorder in the epitaxial III-V layer. We have investigated the surface structure of MOVPE-prepared Si(100) surfaces using in-situ reflectance anisotropy spectroscopy (RAS) and benchmarked the in-situ signals to scanning tunneling microscopy (STM) images of the surfaces. In particular, we achieved double-layer steps on differently misoriented samples by applying specific processing conditions. On 6° misoriented samples, the STM images revealed double layer steps where dimer rows were perpendicular to the step edges, so-called DB steps. The corresponding RA spectra showed a characteristic derivative-like feature at an energy of 3.4 eV at room temperature. In samples of 0.1° and 2° misorientation we also found a tendency towards double-layer in disagreement with standard results in ultra-high vacuum (UHV). The main feature in the corresponding RA spectra was a peak at 3.4 eV, in contrast to the derivative-like structure of the 6° spectrum.