Polarization of electronic charge and distortion of surface geometry by a scanning tunneling microscopy tip: Si(100) Conference Paper uri icon


  • First-principles calculations have been performed of (a) the electronic structure, (b) the Hellmann-Feynman forces, and (c) the distortion of the surface geometry at a Si(100) surface when a voltage is applied by a model scanning tunneling microscopy (STM) tip. As one expects, a polarization charge forms under the tip at the semiconductor surface. For the voltages and distances typical of STM experiments, and corresponding to electric fields of — 0.1 V/A, the electronic structure is only weakly perturbed and the surface atoms are displaced by only a few hundredths of an angstrom. These results rule out tip-induced perturbations of the surface as an explanation for the symmetric dimer images seen in STM experiments on Si (100). © 1992, American Vacuum Society. All rights reserved.

author list (cited authors)

  • Huang, Z., Weimer, M., Allen, R. E., & Lim, H.

citation count

  • 16

publication date

  • July 1992