Berlin 2015 – scientific programme

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O: Fachverband Oberflächenphysik

O 99: Semiconductor Substrates: Structure, Epitaxy and Growth

O 99.1: Talk

Friday, March 20, 2015, 10:30–10:45, MA 042

Surface and step conductivities at Si(111)-(7×7) surfaces investigated by multi-tip STM — •Sven Just¹, Marcus Blab¹, Stefan Korte¹, Vasily Cherepanov¹, Helmut Soltner², and Bert Voigtländer¹ — ¹Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, and JARA-Fundamentals of Future Information Technology — ²Central Institute for Engineering, Electronics and Analytics (ZEA-1), Forschungszentrum Jülich

Four point measurements using a multi-tip scanning tunneling microscope (STM) are carried out to determine surface and step conductivities at Si(111)-(7×7) reconstructed surfaces. In a first step, distance dependent linear four point measurements are used to disentangle the 2D surface conductivity from bulk and space charge layer contributions. In order to further disentangle the surface conductivity of the step free surface from the contribution due to steps, the four probe method is applied in a quadratic configuration as function of the rotation angle. In total this combined approach allows to uniquely determine the surface conductivity, as well as the step conductivity at silicon surfaces.