High C&lt;inf&gt;x&lt;/inf&gt;/Co 13nm-capacitive-gap transduced disk resonator

Nilchi, Jalal Naghsh; Liu, Ruonan; Nguyen, C.T.-C.

doi:10.1109/memsys.2017.7863560

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…The high motional resistance of several hundred kΩ to several MΩ is ascribed to the limited electromechanical coupling coefficient of the capacitive transduction. There are several methods to decrease the motional resistance, such as decreasing the spacing gap 43 , filling the gap with high-κ solid dielectric materials 44,45 , and increasing the transduction area 46 .…”

Section: Discussionmentioning

confidence: 99%

A Switchable High-Performance RF-MEMS Resonator with Flexible Frequency Generations

Chen

Kan

Yuan

et al. 2020

Sci Rep

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Resonators with multi-frequency generations at the device-level are highly desired in the future multiband, reconfigurable, and compact wireless communications. In this work, a switchable radio frequency micro-electro-mechanical system (RF-MEMS) resonator with multiple electrodes is presented. The resonator is designed to operate at the whispering gallery modes (WGMs). Simultaneous excitations of the second to seventh modes with high Q values are implemented within a single device using a pair of electrodes for driving and sensing. For effective multi-frequency excitations, the electrode span angle is optimized. The frequencies of the 37 μm and 18 μm-radius resonators range from 53 MHz to 176 MHz and 112 MHz to 366 MHz, respectively. The Q values in each mode are over 10 4 . Moreover, with the multi-electrode configurations, the specific mode can be enhanced with other modes suppressed. A more than 6 dB improvement of the spectrum peak is realized and the high Q values are maintained. A comprehensive theory is built up to clarify the driving/sensing principles under different electrode configurations. Furthermore, the air damping is found to have a significant effect on Q values for resonator with high stiffness vibrating in all the WGMs. The Q values in vacuum have at least two times improvement. The high-performance switchable resonator could dramatically reduce the power consumption, simplify the processing circuits, and occupy less footprint, which has great potential applications in future advanced RF front end systems.Future wireless communications, like 5 th generation (5 G) 1,2 , Internet of Thing (IOT) 3,4 , and tactile Internet 5 , urge for radio frequency (RF) front end transceivers with high operating frequencies, pronounced tunability and reconfigurability, reduced hardware redundancy and less power consumption 6 . Radio frequency micro-electro-mechanical system (RF-MEMS) technologies are emerging as an enabling solution to address the fast-growing demands of the advanced wireless communications 7-9 . MEMS resonators with remarkable characteristics of high f × Q products, high-level IC compatibility, small footprint, and low power consumption have great potential in communication applications, which are regarded as the key element to constitute the future RF front end transceivers 10-14 . Mechanically coupling high-Q MEMS resonators, MEMS filters with ultra-narrow passbands less than 0.1% and high stopband rejection over 50 dB have been demonstrated 15 , which are beneficial for the direct channel selection. Meanwhile, using MEMS resonators as frequency selection components, MEMS oscillators with low phase noise of −138 dBc/Hz @ 1 kHz 16 and excellent long-term frequency stability of ±0.1 ppm 17 have been implemented. The miniaturized MEMS oscillators are regarded as competitive alternatives of traditional off chip devices such as quartz crystals and surface acoustic wave (SAW) resonators 18 .Multi-frequency devices are highly desired to meet the requirements of wider frequency coverage 19 . Although...

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Section: Discussionmentioning

confidence: 99%

A Switchable High-Performance RF-MEMS Resonator with Flexible Frequency Generations

Chen

Kan

Yuan

et al. 2020

Sci Rep

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“…dx, (8) where W s and L s are the length and width of the tether, respectively, L and h refer to the length and thickness of the plate, ω denotes the angular resonance frequency. To decrease the energy dissipation while maintaining mechanical reliability and size compactness, the slots were etched on the two sides of the tether support end.…”

Section: Optimized Tethers With Reduced Anchor Lossmentioning

confidence: 99%

“…resonators, their large motional resistances require high-gain sustaining circuits [7]. Several methods have been employed, such as shrinking spacing gaps [8], using solid dielectric capacitively transduced gaps [9], and increasing the overlap areas [10]. However, the fabrication processes become more complicated, which leads to more cost and failure risks.…”

Section: Introductionmentioning

confidence: 99%

A novel piezoelectric RF-MEMS resonator with enhanced quality factor

LI¹,

Chen²,

Liu³

et al. 2022

J. Micromech. Microeng.

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This work presents a novel ultra-high frequency (UHF) Lamb mode Aluminum Nitride (AlN) piezoelectric resonator with enhanced quality factors (Q). With slots introduced in the vicinity of the tether support end, the elastic waves leaking from the tether sidewalls can be reflected, which effectively reduces the anchor loss while retaining size compactness and mechanical robustness. Comprehensive analysis was carried out to provide helpful guidance for obtaining optimal slot designs. For various resonators with frequencies ranging from 630 MHz to 1.97 GHz, promising Q enhancements up to 2 times have all been achieved. The 1.97 GHz resonator implemented excellent f × Q product up to 6.72 × 1012 and low motional resistance down to 340 Ω, which is one of the highest performances among the reported devices. The devices with enhanced Q values as well as compact size could have potential application in advanced RF front end transceivers.

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“…One of the key limitations associated with the RF MEMS resonators is their relatively high motional impedances [6][7], which can be a cumbersome bottleneck against employment of such devices in RF front-end transceivers due to the large impedance mismatch between the resonators and antenna or other frontend modules. This problem could be relaxed and partially mitigated by incorporating nanometer capacitive gap in electrostatically transduced MEMS resonators to achieve an enhanced electromechanical coupling coefficient [8]. But, the employment of nanogap capacitive transducers gives rise to higher fabrication cost, lower yield, poorer reliability and reproducibility of those devices [9][10].…”

Section: Introductionmentioning

confidence: 99%

Thin-Piezo on Single-Crystal Silicon Reactive Etched RF MEMS Resonators

et al. 2020

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This paper demonstrates how a single crystal silicon wafer can be used to fabricate thin-film piezoelectric-on-silicon (TPoS) resonators by utilizing a modified version of Single Crystal Silicon Reactive Etch and Metallization (SCREAM) process. The developed process enables the fabrication of MEMS resonators with varied device layer thicknesses ranging from sub-micrometer to tens of micrometers (one thickness per die) from a single bulk silicon wafer, while avoiding the need of costly silicon-on-insulator (SOI) substrates. The thin-film piezoelectric on single-crystal silicon reactive etched technique allows batch fabrication of TPoS resonators, while also retaining the same number of photolithography steps. To maintain a good resonator body sidewall roughness, a conformal Al2O3 thin film was deposited by atomic layer deposition to act as the sidewall protection layer. Through the developed process, resonators with varied silicon layer ranging from 0.1µm to 47µm have been successfully implemented. The measured results under different ZnO-to-Si thickness ratios have been studied, in terms of motional impedance (Rm), quality factor (Q), and resonance frequency. It is noted that TPoS MEMS resonators operating in fundamental and higher lateral extensional modes exhibit its best performance under an optimal ZnO-to-Si thickness ratio. Resonators fabricated by the modified TPoS process with a Si device layer thickness of 4-20 µm exhibits optimal performance. The highest Q of 1,567 for a disk resonator and the lowest motional impedance of 791 Ω for a square plate resonator were achieved with Si layer thicknesses of 20 m and 4 µm, respectively.

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High C<inf>x</inf>/Co 13nm-capacitive-gap transduced disk resonator

Cited by 7 publications

References 2 publications

A Switchable High-Performance RF-MEMS Resonator with Flexible Frequency Generations

A Switchable High-Performance RF-MEMS Resonator with Flexible Frequency Generations

A novel piezoelectric RF-MEMS resonator with enhanced quality factor

Thin-Piezo on Single-Crystal Silicon Reactive Etched RF MEMS Resonators

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