Better in Vacuum – boosting the characterization of 2D semiconductors via electrical AFM in high vacuum - September 3, 2020
SPEAKERS
  • Ilka Hermes
    Park Systems Europe GmbH, Mannheim, Germany
Authors
Ilka Hermes

With ever-decreasing device sizes in the semiconductor industry, the demand for functional materials with low dimensionality continues to grow. Since the discovery of graphene in 2004,1 2D materials have caught the interest of scientific and industrial research. Among 2D materials for semiconductor applications, transition metal dichalcogenides (TMDs) are particularly promising. However, TMDs often exhibit morphological features such as grain boundaries, which affect the electronic properties locally.2 Hence, characterization of TMDs requires techniques with high spatial resolution and sensitivity for electronic properties, including conductivity and surface potential. Atomic Force Microscopy not only offers topography imaging with local resolutions on the nanoscale, but also resolves electronic properties by scanning the surface with an electrically conductive tip.
In this webinar, we will demonstrate on Park’s NX Hivac how high vacuum (10-5 Torr) significantly improves the sensitivity and the resolution of electrical AFM modes on TMDs. The removal of the surface water layer leads to an improved electrical contact between tip and sample. At the same time, the vacuum environment prevents the adverse doping effect of the TMD material, which effectively lowers the material’s conductivity. Thereby, the local electronic characterization of TMDs can be pushed to the next level.

1.Novoselov, K. S. et al. Electric Field Effect in Atomically Thin Carbon Films. Science (80-. ). 306, 666 LP – 669 (2004).
2.Ludwig, J. et al. Effects of buried grain boundaries in multilayer MoS2. Nanotechnology 30, 285705 (2019).