Resonant frequency method for monitoring MEMS fabrication

2003 ◽  
Author(s):  
Danelle M. Tanner ◽  
Albert C. Owen, Jr. ◽  
Fredd Rodriguez
Keyword(s):  
Resonant Frequency ◽  
Frequency Method ◽  
Mems Fabrication

scholarly journals A MEMS Fabrication Process with Thermal-Oxide Releasing Barriers and Polysilicon Sacrificial Layers for AlN Lamb-Wave Resonators to Achieve fs·Qm > 3.42 × 1012

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 892
Author(s):  
Jicong Zhao ◽  
Zheng Zhu ◽  
Haiyan Sun ◽  
Shitao Lv ◽  
Xingyu Wang ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Lamb Wave ◽  
Piezoelectric Layer ◽  
Sacrificial Layer ◽  
High Quality ◽  
Micro Electro Mechanical Systems ◽  
Mems Fabrication ◽  
Thermal Oxide ◽  
Series Resonant ◽  
Releasing Process

This paper presents a micro-electro-mechanical systems (MEMS) processing technology for Aluminum Nitride (AlN) Lamb-wave resonators (LWRs). Two LWRs with different frequencies of 402.1 MHz and 2.097 GHz by varying the top interdigitated (IDT) periods were designed and fabricated. To avoid the shortcomings of the uncontrollable etching of inactive areas during the releasing process and to improve the fabrication yield, a thermal oxide layer was employed below the platted polysilicon sacrificial layer, which could define the miniaturized release cavities well. In addition, the bottom Mo electrode that was manufactured had a gentle inclination angle, which could contribute to the growth of the high-quality AlN piezoelectric layer above the Mo layer and effectively prevent the device from breaking. The measured results show that the IDT-floating resonators with 12 μm and 2 μm electrode periods exhibit a motional quality factor (Qm) as high as 4382 and 1633. The series resonant frequency (fs)·Qm values can reach as high as 1.76 × 1012 and 3.42 × 1012, respectively. Furthermore, Al is more suitable as the top IDT material of the AlN LWRs than Au, and can contribute to achieving an excellent electrical performances due to the smaller density, smaller thermo-elastic damping (TED), and larger acoustic impedance difference between Al and AlN.

Assessment of human hemiplegic spasticity by a resonant frequency method

1988 ◽  
Vol 3 (3) ◽  
pp. 173-178 ◽  
Author(s):  
M. Lakie ◽  
E.G. Walsh ◽  
G.W. Wright
Keyword(s):  
Resonant Frequency ◽  
Frequency Method

scholarly journals Evaluation of the free–free resonant frequency method to determine stiffness moduli of cement-treated soil

2015 ◽  
Vol 55 (5) ◽  
pp. 943-950 ◽  
Author(s):  
R.D. Verástegui-Flores ◽  
G. Di Emidio ◽  
A. Bezuijen ◽  
J. Vanwalleghem ◽  
M. Kersemans
Keyword(s):  
Resonant Frequency ◽  
Frequency Method ◽  
Treated Soil

Relationships between Resonant Frequency and some Dynamic Properties of Marble and Brick Waste-Substituted Concrete

2011 ◽  
Vol 147 ◽  
pp. 236-240
Author(s):  
Mehmet Serkan Kirgiz
Keyword(s):  
Resonant Frequency ◽  
Dynamic Properties ◽  
Frequency Method ◽  
Dynamic Ratio

The present research determines the relationships between resonant frequency and some dynamic properties of concrete. Based on the research, new relationship equations are offered. The resonant frequency method is used to measure the resonant frequency of concrete samples from which a dynamic module of elasticity, a dynamic ratio of Poisson, and a dynamic module of shear are computed. Marble or brick waste substituted concrete in samples with water-cement ratios of 0.60 and 0.70 are cured in water and measured at 90 days.

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