AVS 64th International Symposium & Exhibition
    Surface Science Division Thursday Sessions
       Session SS+AS+EM-ThA

Paper SS+AS+EM-ThA8
Surface-sensitive Measurement of Dielectric Screening via Atom and Electron Manipulations

Thursday, November 2, 2017, 4:40 pm, Room 25

Session: Semiconductor Surfaces
Presenter: Daejin Eom, Korea Research Institute of Standards and Science, Republic of Korea
Authors: D. Eom, Korea Research Institute of Standards and Science, Republic of Korea
E. Seo, Korea Research Institute of Standards and Science, Republic of Korea
J.-Y. Koo, Korea Research Institute of Standards and Science, Republic of Korea
Correspondent: Click to Email
Dielectric screening is essential in determining semiconductor properties. Its assessment on the surface, however, is beyond the capability of conventional capacitance and optical techniques due to their lack of surface sensitivity. Here we present the surface-sensitive measurement of the dielectric screening by using the scanning tunneling microscopy and spectroscopy. To be specific, we generate a single-atom defect on the surface and vary its ionization state by a single-electron charge. We then assess in-plane dielectric constant and Debye length at the surface by probing the surface potential modulation with atomic resolutions. Such single-atom and single-electron manipulations on B δ-doped Si(111) surface unravel that the dielectric screening on this surface is much in excess of what the classical image-charge model predicts, which we ascribe to the strained bonds and the ionic character of the surface layers. Also, as an exemplary application of the measured screening parameters, we demonstrate determining the ionization state of a surface defect from the defect-induced band bending.