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Journal ArticleDOI

Design, Modeling and Fabrication of TPoS MEMS Resonators With Improved Performance at 1 GHz

22 Apr 2021-IEEE\/ASME Journal of Microelectromechanical Systems (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 30, Iss: 3, pp 375-383

Abstract: In this work, the effects of physical dimensions such as length, width and thickness as well as the mode of vibration and the number of anchors on the performance of longitudinal thin film piezoelectric on silicon (TPoS) MEMS resonators have been studied. TPoS resonators, designed for a resonant frequency of around 1 GHz, were fabricated with a 4 mask CMOS compatible process. A $225~\mu \text{m}$ wide resonator excited in its $23^{rd}$ order had an unloaded quality factor of 9453 (in vacuum), which is the highest value reported so far for similar resonators, motional resistance of $107~\Omega $ and linear thermal coefficient of frequency of -28.4 ppm. We have also studied and modeled the different loss mechanisms in these devices. The model matches well with measured results for resonators of different geometries, modes of vibrations and number of anchors. [2020-0397]
Topics: Resonator (55%), Q factor (55%)
References
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TL;DR: As vibrating RF MEMS devices are perceived more as circuit building blocks than as stand-alone devices, and as the frequency processing circuits they enable become larger and more complex, the makings of an integrated micromechanical circuit technology begin to take shape, perhaps with a functional breadth not unlike that of integrated transistor circuits.
Abstract: An overview on the vise of microelectromechanical systems (MEMS) technologies for timing and frequency control is presented. In particular, micromechanical RF filters and reference oscillators based on recently demonstrated vibrating on-chip micromechanical resonators with Q's > 10,000 at 1.5 GHz are described as an attractive solution to the increasing count of RF components (e.g., filters) expected to be needed by future multiband, multimode wireless devices. With Q's this high in on-chip abundance, such devices might also enable a paradigm shift in the design of timing and frequency control functions, where the advantages of high-Q are emphasized, rather than suppressed (e.g., due to size and cost reasons), resulting in enhanced robustness and power savings. Indeed, as vibrating RF MEMS devices are perceived more as circuit building blocks than as stand-alone devices, and as the frequency processing circuits they enable become larger and more complex, the makings of an integrated micromechanical circuit technology begin to take shape, perhaps with a functional breadth not unlike that of integrated transistor circuits. With even more aggressive three-dimensional MEMS technologies, even higher on-chip Q's are possible, such as already achieved via chip-scale atomic physics packages, which so far have achieved Q's > 107 using atomic cells measuring only 10 mm3 in volume and consuming just 5 mW of power, all while still allowing atomic clock Allan deviations down to 10-11 at one hour

727 citations


Journal ArticleDOI
G.K. Ho1, Reza Abdolvand2, A. Sivapurapu3, Shweta Humad  +1 moreInstitutions (4)
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178 citations


Proceedings ArticleDOI
21 Jun 2009-
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152 citations


Journal ArticleDOI
Brandon Harrington1, Reza Abdolvand1Institutions (1)
Abstract: In this paper, novel in-plane acoustic reflectors are proposed to enhance the quality factor (Q) in lateral-mode micromachined resonators. Finite element coupled-domain simulation is used to model anchor loss and to estimate the relative change in the resonator's performance without and with the inclusion of acoustic reflectors. Several 27 and 110 MHz AlN-on-silicon resonators are fabricated and measured to validate the theoretical and simulated data. An average Q enhancement of up to 560% is reported for specific designs with reflectors over the same resonators without reflectors. The measured results trend well with the simulated data and support that the acoustic reflectors can reduce the overall anchor loss with minimum modification in the resonator design.

132 citations


Journal ArticleDOI
08 Sep 2016-Micromachines
TL;DR: A review of the remarkable progress that has been made during the past few decades in design, modeling, and fabrication of micromachined resonators with references to the most influential contributions in the field for those interested in a deeper understanding of the material.
Abstract: This paper is a review of the remarkable progress that has been made during the past few decades in design, modeling, and fabrication of micromachined resonators. Although micro-resonators have come a long way since their early days of development, they are yet to fulfill the rightful vision of their pervasive use across a wide variety of applications. This is partially due to the complexities associated with the physics that limit their performance, the intricacies involved in the processes that are used in their manufacturing, and the trade-offs in using different transduction mechanisms for their implementation. This work is intended to offer a brief introduction to all such details with references to the most influential contributions in the field for those interested in a deeper understanding of the material.

120 citations


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