Abstract
In this paper, bidirectional and location-dependent frequency tuning of single crystal 4H silicon carbide (4H-SiC) cantilever resonators was investigated. 4H-SiC is a superior material platform for MEMS devices operated in harsh environments. A passive tuning method was employed using focused ion beam (FIB) deposition of platinum (Pt) and milling of Pt and SiC material at different locations on cantilever beams. Linear downward shifts in resonant frequency were observed with Pt films deposited at the free end of cantilever, which is attributed to the increase in effective mass. Subsequent FIB milling reduced Pt mass and therefore restored the resonant frequency to previous values, showing the advantage of FIB for fine-tuning of frequency by precise adjustment of Pt mass. Location dependence of frequency tuning was investigated by measuring frequency shifts when removing SiC material at different locations by FIB milling, which leads to changes in effective mass and effective stiffness. Results show that resonant frequency increases when removing SiC at the free end, and decreases when close to the fixed anchor. These results demonstrate the capability of bidirectional frequency tuning of SiC cantilever resonators.
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References
Abdelmoneum MA, Demirci MM, Lin YW, Nguyen CTC (2004) Location-dependent frequency tuning of vibrating micromechanical resonators via laser trimming. In: Proceedings of IEEE International frequency control symposium and exposition, pp 272–279
Adams SG, Bertsch F, Macdonald NC (1996) Independent tuning of the linear and nonlinear stiffness coefficients of a micromechanical device. In: Proceedings 9th International workshop on microelectromechanical systems, pp 32–37
Bannon FD, Clark JR, Nguyen CTC (2000) High-Q HF microelectromechanical filters. IEEE J Solid-State Circuits 35:512–526
Cabuz C, Fukatsu K, Hashimoto H, Shoji S, Kurabayashi T, Minami K et al. (1994) Fine frequency tuning in resonant sensors. In: Proceeding of the IEEE workshop on micro electro mechanical systems, pp 245–250
Enderling S (2006) Fabrication, characterisation and tuning of micromechanical resonators. PhD Dissertation, University of Edinburgh, Edinburgh
Joachim D, Lin L (2003) Characterization of selective polysilicon deposition for MEMS resonator tuning. IEEE J Microelectromech Syst 12:193–200
Moore DF, Syms RRA (2000) Tuning of vibrating micromechanical resonators using a focused ion beam. IEEE seminar on demonstrated micromachining technologies for industry 3/1–3/5
Remtema T, Lin L (2001) Active frequency tuning for micro resonators by localized thermal stressing effects. Sens Actuators A 91:326–332
Syms RRA (1998) Electrothermal frequency tuning of folded and coupled vibrating micromechanical resonators. J Microelectromech Syst 7:164–171
Syms RRA, Moore DF (1999) Focused ion beam tuning of in-plane vibrating micromechanical resonators. Electron Lett 35:1277–1278
Yi JW, Shih WY, Shih WH (2002) Effect of length, width, and mode on the mass detection sensitivity of piezoelectric unimorph cantilever. J Appl Phys 91:1680–1686
Zhao F, Islam MM, Huang CF (2011) Photoelectrochemical etching to fabricate single-crystal SiC MEMS for harsh environments. Mater Lett 65:409–412
Acknowledgments
Feng Zhao acknowledges the support from National Science Foundation (ECCS-1307237 monitored by Dr. Anupama B. Kaul).
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Zhao, F., Chen, Z. Bidirectional and location-dependent frequency tuning of single crystal 4H-SiC micromechanical cantilevers. Microsyst Technol 21, 1663–1668 (2015). https://doi.org/10.1007/s00542-014-2246-0
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DOI: https://doi.org/10.1007/s00542-014-2246-0