Thickness shear mode vibrations in silicon bar resonators

Authors

Hengky Chandrahalim, Air Force Institute of TechnologyFollow
Dana Weinstein, Purdue University
Lih Feng Cheow, National University of Singapore
Sunil A. Bhave, Purdue University

Document Type

Conference Proceeding

Publication Date

2005

Abstract

This paper demonstrates a dielectrically transduced high quality factor (Q) quarter-wave thickness shear silicon resonator. Dielectric transduction provides a κ² reduction in motional impedance relative to air-gap electrostatic transduction. The resonator is fabricated on the 1.8 µm thick device layer of a heavily doped SOI wafer with 68 nm thick silicon nitride thin-film on top. The quarter-wave thickness shear mode of the silicon bar resonator has a resonant frequency of 713 MHz, a motional impedance R_x of 10.5 kΩ and Q of 1,517 in air. After partial release, the bar resonates at 723 MHz, exhibiting a motional impedance R_x of 2.4 kΩ and Q of 4,400 in air. Additionally, by varying a tuning voltage between the resonator and silicon substrate from 50 V to 150 V across a 2.5 micron gap, approximately 5 MHz of frequency tuning is observed.

Comments

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DOI

10.1109/ULTSYM.2005.1602995

Source Publication

IEEE Ultrasonics Symposium, 2005

Recommended Citation

H. Chandrahalim, D. Weinstein and S. A. Bhave, "Thickness shear mode vibrations in silicon bar resonators," IEEE Ultrasonics Symposium, 2005., Rotterdam, Netherlands, 2005, pp. 898-901, doi: 10.1109/ULTSYM.2005.1602995.