Improving sensitivity in electrostatic force detection utilizing cantilever with tailored resonance modes

In order to increase the sensitivity of potential or capacitance measurement in Kelvin probe force microscopy or scanning capacitance force microscopy, the frequency of alternating electric field applied between the tip and the sample is tuned close to the mechanical resonance frequencies of the cantilever. The authors have designed a cantilever with a tailored resonance modes suitable for these measurements. The ratio of the first and the second resonance frequencies is optimized by the finite element method. Furthermore, they modified a commercially available cantilever according to the calculation. The performance of the modified cantilever was demonstrated in the scanning capacitance force microscopy measurement.