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Ü. Sökmen, A. Stranz, A. Waag, A. Ababneh, H. Seidel, U. Schmid, E. Peiner:
"Evaluation of resonating Si cantilevers sputter-deposited with AlN piezoelectric thin films for mass sensing applications";
Journal of Micromechanics and Microengineering, 20 (2010), 6.

We report on a micro-machined resonator for mass sensing applications which is based on a
silicon cantilever excited with a sputter-deposited piezoelectric aluminium nitride (AlN) thin
film actuator. An inductively coupled plasma (ICP) cryogenic dry etching process was applied
for the micro-machining of the silicon substrate. A shift in resonance frequency was observed,
which was proportional to a mass deposited in an e-beam evaporation process on top. We had
a mass sensing limit of 5.2 ng. The measurements from the cantilevers of the two arrays
revealed a quality factor of 155-298 and a mass sensitivity of 120.34 ng Hz−1 for the first
array, and a quality factor of 130-137 and a mass sensitivity of 104.38 ng Hz−1 for the second
array. Furthermore, we managed to fabricate silicon cantilevers, which can be improved for
the detection in the picogram range due to a reduction of the geometrical dimensions.

http://dx.doi.org/10.1088/0960-1317/20/6/064007