Spider Web-Shaped Phononic Crystals for Quality Factor Improvement of Piezoelectric-on-Silicon MEMS resonators

Phononic crystals (PnC) are a remarkable example of acoustic metamaterials with superior wave attenuation mechanisms for piezoelectric micro-electro-mechanical systems (MEMS) resonators to reduce the energy dissipation. Herein, a spider web-like PnC (SW-PnC) is proposed to sufficiently isolate the wave vibration. Finite-element analysis is performed to gain insight into the transmission property of finite PnC, and band characteristics by infinite periods. In comparison with the circle hole PnC at a similar bandgap, due to its already very lightweight PnC structure compared with previously reported PnCs, the proposed PnC offers a significantly lighter weight, smaller lattice constant, and greater energy leakage inhibition. More specifically, the resonator with the SW-PnC plate as the anchoring substrate exhibited a quality factor as high as 66569.7 at 75.82 MHz.

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Wafer-Level Packaged MEMS Resonators with a Highly Vacuum-Sensitive Quality Factor

JSTS Journal of Semiconductor Technology and Science ◽

10.5573/jsts.2014.14.5.632 ◽

2014 ◽

Vol 14 (5) ◽

pp. 632-639 ◽

Cited By ~ 1

Author(s):

Seok Jin Kang ◽

Young Soon Moon ◽

Won Ho Son ◽

Sie Young Choi

Keyword(s):

Quality Factor ◽

Wafer Level ◽

Mems Resonators

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Effect of curvature and electrode coverage on the quality factor of biconvex ALN-on-Si MEMS resonators

2017 19th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS) ◽

10.1109/transducers.2017.7993997 ◽

2017 ◽

Cited By ~ 1

Author(s):

Muhammad Wajih Ullah Siddiqi ◽

Cheng Tu ◽

Joshua E.-Y Lee

Keyword(s):

Quality Factor ◽

Mems Resonators ◽

Electrode Coverage

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Thermoelastic Dissipation in Composite Silicon MEMS Resonators with Thin Film Silicon Dioxide Coating

MRS Proceedings ◽

10.1557/opl.2012.1049 ◽

2012 ◽

Vol 1426 ◽

pp. 193-198 ◽

Cited By ~ 4

Author(s):

Shirin Ghaffari ◽

Thomas W. Kenny

Keyword(s):

Thin Film ◽

Silicon Dioxide ◽

Quality Factor ◽

Thermal Relaxation ◽

Oxide Coating ◽

Thermal Mode ◽

Silicon Dioxide Film ◽

Thermal Dynamics ◽

Mems Resonators ◽

Composite Silicon

ABSTRACTWe analyze thermoelastic dissipation in composite silicon MEMS resonators that exhibit multiple mechanical and thermal modes with complex dynamics. Silicon resonators that are coated with thin films of silicon dioxide can have near-zero temperature coefficients of frequency, making them attractive for use as precision time references. The quality factor of MEMS resonators can be dominated by thermoelastic dissipation (TED), which is triggered by the relaxation of mechanically induced temperature gradients. Recently, Chandorkar et al. (2009) have shown an expression of TED based on entropy generation as a weighted sum of the modal solutions of the three-dimensional heat transfer equation. This expression was obtained for weak coupling between mechanical and thermal dynamics. Applying this same technique to a fully coupled solution to the dynamics, we show that the TED contribution of the dominant thermal modes can be inhibited in the presence of a thin silicon dioxide film. Reduction of the contribution from the dominant thermal mode is shown with increasing oxide. We studied the effects of varying oxide film thickness and beam length. The quality factor was simulated for each unique case and compared to multimode energy dissipation. Our results suggest with some variability, thin film oxide coating affects the thermal relaxation of the composite resonator in the direction of lower TED and increased quality factor.

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