•Alexander Gigler1, Peter Spizig2, Stefan Walheim3,
Othmar Marti1 und Thomas Schimmel3
1Experimental Physics, University of Ulm, D-89069 Ulm, Germany
2WITec GmbH, www.WITec.de
3Institute for Nanotechnology, Forschungszentrum-Karlsruhe
GmbH, D-76021 Karlsruhe, Germany
AFM allows to measure local mechanical properties at the nanoscale. Besides looking exclusively at the surface topography, one can also determine e.g. stiffness and adhesion. The tool of choice is the force vs. distance plot (FD-plot), but acquisition of FD-plots performed concurrently with topographical imaging slows down the scanning speed by more than two orders of magnitude. The Digital-Pulsed-Force-Mode was introduced to acquire each force curve for every pixel of an image, but maintaining the scanning speed. The complete data then allows to determine material parameters from postprocessing the force curves without scanning the sample more often.
To access dynamic friction parameters and the properties accessible by PFM at the same time, the setup was extended to the COmbined-DYnamical-Mode. The concurrent measurement of both friction and adhesion is important, since both seem to be closely related.
This contribution reports on the implementation of the CODY Mode method
on a WITec a-SNOM setup and on tests with a
SAM of octadecyltrichlorosilane (OTS), which was deposited on a Si surface
in a laterally controlled manner by a lift-off technique, based on m-CP
[4].