Appearance of effective surface conductivity - an experimental and analytic study

Abstract

Surface conductance measurements on p-type doped germanium show a small but systematic change to the surface conductivity at different length scales. This effect is independent of the structure of the surface states. We interpret this phenomenon as a manifestation of conductivity changes beneath the surface. This hypothesis is confirmed by an analysis of the classical current flow equation. We derive an integral formula for calculating of the effective surface conductivity as a function of the distance from a point source. Furthermore we derive asymptotic values of the surface conductivity at small and large distances. The actual surface conductivity can only be sampled close to the current source. At large distances, the conductivity measured on the surface corresponds to the bulk value.

11 pages, 8 figures

References in corpus (2)

• Conductivity of Si(111) - 7 x 7: the role of a single atomic step
• A multi-scale approach to the electronic structure of doped semiconductor surfaces

Cited by in corpus (3)

• Surface Conductivity of Si(100) and Ge(100) Surfaces Determined from Four-Point Transport Measurements Using an Analytical N-Layer Conductance Model
• Fermi level pinning at the Ge(001) surface - A case for non-standard explanation
• Electric Currents at Semiconductor Surfaces from the Perspective of Drift-Diffusion Equations