SIMULTANEOUS OPTICAL-DETECTION TECHNIQUES, INTERFEROMETRY, AND OPTICAL BEAM DEFLECTION FOR DYNAMIC-MODE CONTROL OF SCANNING FORCE MICROSCOPY

In dynamic mode control of scanning force microscopy (SFM), optical be am deflection and interferometry are the techniques most used for dete ction of force gradients by means of a tip and a microcantilever that usually vibrates at the first resonant mode. In order to increase the sensitivity of these kinds of microscopes, one possible means is to in vestigate the potential of the highest resonance modes which allow an increase in the operating frequencies. For these two detection techniq ues, according to the local displacement slope, care must be taken in the choice of an appropriate microcantilever point where the laser bea m is focused. In this article, an original technique based on simultan eous detection, interferometry, and the beam deflection method is intr oduced. These techniques are able to characterize within two degrees o f freedom, normal displacement and angular deflection, thus resonating the SFM cantilever. (C) 1997 American Vacuum Society. [S0734-211X(97) 10104-4].