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A. Ababneh, A. Al-Omari, A. Dagamseh, H. Qiu, D. Feili, V Ruiz-Díez, T. Manzaneque, J. Hernando-Garcia, J.L. Sànchez-Rojas, A. Bittner, U. Schmid, H. Seidel:
"Electrical characterization of micromachined AlN resonators at various back pressures";
Microsystem Technologies - Micro- and Nanosystems - Information Storage and Processing Systems, 20 (2014), 663 - 670.

In this work, the fabrication process of piezoelectric cantilevers based on aluminum nitride films is presented. The cantilevers were electrically characterized in a vacuum chamber offering the possibility to close-loop control the back pressure from atmospheric conditions down to 10−2 mbar. The quality factor is an important figure of merit to evaluate the performance of micro resonators. In particular, three different modes were detected and analyzed: the first flexural mode, the second flexural mode and the first torsional mode. among these three investigated modes, the first torsional mode has a higher quality factor compared to the others, which makes this mode more suitable for mass change detection applications as higher sensitivities are feasible. With the first torsional mode, quality factors of up to 4,557 are achievable at low chamber pressure, where the intrinsic damping is the dominating loss mechanism. The quality factor decreased to 1,050 at atmospheric pressure and is limited by viscous losses.

In this work, the fabrication process of piezoelectric cantilevers based on aluminum nitride films is presented. The cantilevers were electrically characterized in a vacuum chamber offering the possibility to close-loop control the back pressure from atmospheric conditions down to 10−2 mbar. The quality factor is an important figure of merit to evaluate the performance of micro resonators. In particular, three different modes were detected and analyzed: the first flexural mode, the second flexural mode and the first torsional mode. among these three investigated modes, the first torsional mode has a higher quality factor compared to the others, which makes this mode more suitable for mass change detection applications as higher sensitivities are feasible. With the first torsional mode, quality factors of up to 4,557 are achievable at low chamber pressure, where the intrinsic damping is the dominating loss mechanism. The quality factor decreased to 1,050 at atmospheric pressure and is limited by viscous losses.

http://dx.doi.org/10.1007/s00542-013-2003-9

Project Head Ulrich Schmid:
Mikrosystemtechnik Projektkonto Schmid