Dresden 2006 – scientific programme
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O: Oberflächenphysik
O 27: Scanning probe techniques II
O 27.9: Talk
Tuesday, March 28, 2006, 17:45–18:00, WIL B321
Detection of electrical forces with a capacitive cantilever device — •A.-D. Müller1, F. Müller1, A. Käppel2, and M. Hietschold2 — 1Anfatec Instruments AG, Melanchthonstr.28, 08606 Oelsnitz, Europe. — 2TU Chemnitz, Solid Surfaces Analysis Group, 09107 Chemnitz, Europe.
The detection of electrical forces in dynamic mode AFM allows to observe contact potential differences between tip and sample as well as carrier concentration variations. For this, additional voltages are applied to the tip, while the additional electrical signals are evaluated with lock-in amplifiers. In order to observe locally generated potentials in its surrounding surface region, multiple tip cantilevers can be utilized.
This work investigates the applicability of multiple tip cantilever devices for electrical force microscopy. In contrast to conventional AFM, the tips in this devices are independently movable in vertical direction and the tip sample forces are sensed by displacement current detection [1]. Imaging of electrical properties with this devices is shown at the example of dopant patterns on n-silicon. In order to improve the understanding of the image contrast, the results are compared with numerical simulations of the electrical force interaction in dependence on applied voltage magnitudes.
[1] A.-D . Müller, F. Müller, M. Hietschold, Th. Gessner, Curr. Appl. Phys. 5, 629 (2005).