The Near-Surface Electrostatic Environment of n-Doped Silicon Probed with a Moveable Dangling Bond Point Probe

With nanoelectronics reaching the limit of atom-sized devices, it has become critical to characterize how irregularities in the local environment can affect device functionality. This includes unwanted charge defects detuning binary logic atomic patterns [1], delicately coupled quantum computing states [2], and supra-layer molecular electronics [3]. In this work, we characterize charged subsurface defects on a hydrogen terminated silicon (100) sample, adding a possible explanation for a heretofore contentious negatively-charged defect. Through contact potential difference maps, taken with non-contact atomic force microscopy, variations in the electrostatic topography on a nanometer length scale are shown and correlated with alterations in the behavior of dangling bond charge state transitions. In addition, the spectroscopic signature of a single electron charge transition in a dangling bond is used as a charge sensor to directly probe the depth of charged defects, the local Debye screening length, and the effective dielectric constant close to the surface.

[1] T. Huff, H. et al. In Review at Nature Electronics. arXiv:1706.07427v3 (2017)
[2] Hollenberg, L. C. L. et al. Phys. Rev. B 69, 113301 (2004)
[3] Baris, B. et al. ACS Nano 6, 6905–6911 (2012)