Controlling Crystallization Structures in Thin Si Film for Improving Characteristics of MEMS Resonators

2012 ◽  
Vol 1427 ◽  
Author(s):  
Shinya Kumagai ◽  
Hiromu Murase ◽  
Takashi Tomikawa ◽  
Syohei Ogawa ◽  
Ichiro Yamashita ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Domain Size ◽  
Q Factor ◽  
Random Orientation ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Small Grains ◽  
Thin Polycrystalline ◽  
Lateral Crystallization ◽  
Conventional Annealing

ABSTRACTAn approach to control the tensile stress and Q factor of thin Si film beams in MEMS resonators was investigated. Metal-induced lateral crystallization (MILC) using Ni nanoparticles that were synthesized within a cage-shaped protein, apoferritin, was applied to a thin morphous Si film for making a MEMS resonator with thin film beams. The MILC produced a thin polycrystalline Si (poly-Si) film with large crystallized domain (50-60 μm) with nearly the same crystalline orientation, whereas the poly-Si film obtained by conventional annealing (without MILC) consisted of small grains (less than 1 μm) with random orientation. The MEMS resonator with a beam made of poly-Si film by MILC was fabricated. The large domain size and the improved crystallinity increased the tensile stress, and resulted in 20% increase in Q factor in the resonant characteristics.

scholarly journals Q-Factor Enhancement of Thin-Film Piezoelectric-on-Silicon MEMS Resonator by Phononic Crystal-Reflector Composite Structure

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1130
Author(s):  
Jiacheng Liu ◽  
Temesgen Bailie Workie ◽  
Ting Wu ◽  
Zhaohui Wu ◽  
Keyuan Gong ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Composite Structure ◽  
Phononic Crystal ◽  
Q Factor ◽  
Leakage Loss ◽  
One Dimensional ◽  
High Q ◽  
Mems Resonator ◽  
Mems Resonators

Thin-film piezoelectric-on-silicon (TPoS) microelectromechanical (MEMS) resonators are required to have high Q-factor to offer satisfactory results in their application areas, such as oscillator, filter, and sensors. This paper proposed a phononic crystal (PnC)-reflector composite structure to improve the Q factor of TPoS resonators. A one-dimensional phononic crystal is designed and deployed on the tether aiming to suppress the acoustic leakage loss as the acoustic wave with frequency in the range of the PnC is not able to propagate through it, and a reflector is fixed on the anchoring boundaries to reflect the acoustic wave that lefts from the effect of the PnC. Several 10 MHz TPoS resonators are fabricated and tested from which the Q-factor of the proposed 10 MHz TPoS resonator which has PnC-reflector composite structure on the tether and anchoring boundaries achieved offers a loaded Q-factor of 4682 which is about a threefold improvement compared to that of the conventional resonator which is about 1570.

Design of a MEMS Resonant Wind Sensor on Airplane Wing

2013 ◽  
Vol 562-565 ◽  
pp. 436-440
Author(s):  
Chao Wei Si ◽  
Guo Wei Han ◽  
Jin Ning ◽  
Wei Wei Zhong ◽  
Fu Hua Yang
Keyword(s):  
High Vacuum ◽  
Pressure Change ◽  
Wind Pressure ◽  
Damping Factor ◽  
Deep Reactive Ion Etching ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Element Simulation ◽  
Airplane Wing ◽  
Soi Substrates

A new kind of wind sensor made up of MEMS resonators is designed in the paper capable of sensing the lift, the resistance and the turbulence of airplane wings by mounting on the surface. The designed wind sensor is made up of four MEMS wind pressure gauges fixed around a square wind resistance block which used to block the wind to change the wind pressure on the surface, and the change of wind pressure is detected by MEMS wind pressure gauges to reveal the air condition on the surface of the airplane wings. As known, a MEMS resonator is a second-order resonant system whose damping factor is mainly dependent on the air pressure, and the characteristic is often used to detecting the airtightness of a sealed chamber for the damping factor is sensitive under high vacuum, while a MEMS resonator with the damping factor sensitive at atmospheric pressure is designed in this paper for sensing wind pressure change, and the MEMS resonator is manufactured on SOI substrates with deep reactive ion etching technology. Also relations between the wind pressure change and the wind speed around a block at atmosphere is revealed by finite element simulation. Compared to traditional wind sensors such as anemometers and Venturi tubes, the designed MEMS wind sensor with a very small size is suitable to mount on different zones of a wing with a large amount to monitor the air condition and have less influence on air flow.

ROM of Superharmonic Resonance of Second Order of Electrostatically Actuated MEMS Resonators

2015 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Christian Reyes
Keyword(s):  
Second Order ◽  
Voltage Response ◽  
Order Model ◽  
Reduced Order ◽  
Superharmonic Resonance ◽  
Electrostatically Actuated ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Method Effects ◽  
Ground Plate

This paper deals with the voltage-amplitude response (or voltage response) of superharmonic resonance of second order of MEMS resonator sensors under electrostatic actuation. The system consists of a MEMS flexible cantilever above a parallel ground plate. The AC frequency of actuation is near one fourth the natural frequency. The voltage response of the superharmonic resonance of second order of the structure is investigated using the Reduced Order Model (ROM) method. Effects of voltage and damping voltage response are reported.

Dynamic behaviours of the Double-end tuning fork based comb-driven microelectromechanical resonators for modulating the magnetic flux synchronously

2021 ◽  
Author(s):  
Zhenxi Liu ◽  
Jiamin Chen ◽  
Wuhao Yang ◽  
Tianyi Zheng ◽  
Qifeng Jiao ◽  
...  
Keyword(s):  
Detection Limit ◽  
Magnetic Flux ◽  
Resonance Frequency ◽  
Tuning Fork ◽  
Paper Making ◽  
Initial Space ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Mems Fabrication ◽  
First Time

Abstract MEMS resonators have been widely used in the magneto-resistive (MR) sensor for modulating the magnetic flux to enhance the detection limit. However, the manufacturing tolerances in MEMS fabrication processes make it challenging to fabricate the identical resonators with the same vibration frequency, which greatly decreases the detection limit of the MR sensor. To synchronize the MEMS resonators and improve the performance of the MR sensor, the double end tuning fork (DETF) based comb-driven MEMS resonators is proposed in this paper, making the system operate at the out-of-phase mode to complete the synchronization. The dynamic behaviour of the resonators is investigated through theoretical analysis, numerical solution based on MATLAB code and Simulink, and experimental verification. The results show that the transverse capacitances in the comb will significantly affect the resonance frequency due to the second-order electrostatic spring constant. It is the first time to observe the phenomenon that the resonant frequency increases with the increase of the bias, and it can also decrease with increasing the bias through adjusting the initial space between the fixed finger and the moving mass, they are different from the model about spring softening and spring hardening. Besides, the proposed DETF-based comb-driven resonators can suppress the in-phase and out-of-phase mode through adjusting the driving and sensing ports, and sensing method, meanwhile make the magnetic flux modulation fully synchronized, and maximize the modulation efficiency, and minimize the detection limit. These characteristics are appropriate for the MR sensor, even other devices that need to adjust the resonance frequency and vibration amplitude. Furthermore, the model and the design can also be extended to characteristic the single end tuning fork (SETF) based MEMS resonator and other MEMS-based MR sensors.

Voltage Response of MEMS Resonators Under Simultaneous Resonances

2014 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Christian Reyes
Keyword(s):  
Natural Frequency ◽  
Electrostatic Actuation ◽  
Voltage Response ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Simultaneous Resonances

This paper deals with MEMS resonator sensors under double electrostatic actuation. The system consists of a MEMS cantilever between two parallel fixed plates. The frequencies of actuation are AC near natural frequency, and AC half natural frequency. The voltage response of the structure is investigated, and parameter influences reported.

scholarly journals Evaluation of Residual Stress of C Oriented AlN/Si (111) and Its Impact on Mushroom Shaped Piezoelectric Resonator 

2021 ◽  
Author(s):  
AKHILESH PANDEY ◽  
Shankar Dutta ◽  
Nidhi Gupta ◽  
Davinder Kaur ◽  
R. Raman
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Mode Shapes ◽  
Quality Factors ◽  
Resonator Structure ◽  
Resonator Design ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Quality Factor Q ◽  
Preferred Oriented

Abstract Aluminum nitride-based MEMS resonators are one of the interesting recent research topics for its tremendous potential in a wide variety of applications. This paper focuses on the detrimental effect of residual stress on the AlN based MEMS resonator design for acoustic applications. The residual stress in the sputtered c axis (<001>) preferred oriented AlN layers on Si (111) substrates are studied as a function of layer thickness. The films exhibited compressive residual stresses at different thickness values: -1050 MPa (700 nm), -500 MPa (900 nm), and -230 MPa (1200 nm). A mushroom-shaped AlN based piezoelectric MEMS resonator structure has been designed for the different AlN layer thicknesses. The effect of the residual stresses on the mode shapes, resonant frequencies, and quality factor (Q) of the resonator structures are studied. The resonant frequency of the structures are altered from 235 kHz, 280 kHz, and 344 kHz to 65 kHz, 75 kHz and 371 kHz due to the residual stress of -1050 MPa (thickness: 700 nm), -500 MPa (thickness: 900 nm) and -230 MPa (thickness: 1200 nm) respectively. At no residual stress, the quality factors of the resonator structures are 248, 227, 241 corresponding to the 700 nm, 900 nm, and 1200 nm thick AlN layers respectively. The presence of the residual stress reduced the Q values from 248 (thickness: 700 nm), 227 (thickness: 900 nm), 241 (thickness: 1200 nm) to 28, 53, and 261 respectively.

Analysis of the Orbits of Electrostatic MEMS Resonators

2008 ◽  
Author(s):  
F. Najar ◽  
E. M. Abdel-Rahman ◽  
A. H. Nayfeh ◽  
S. Choura
Keyword(s):  
Initial Conditions ◽  
Order Approximation ◽  
Differential Quadrature Method ◽  
Basin Of Attraction ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Electrostatic Mems ◽  
Differential Integral Equation ◽  
First Order Approximation ◽  
The Basin Of Attraction

We study the dynamic behavior of an electrostatic MEMS resonator using a model that accounts for the system nonlinearities due to mid-plane stretching and electrostatic forcing. The partial-differential-integral equation and associated boundary conditions representing the system dynamics are discretized using the Differential Quadrature Method (DQM) and the Finite Difference Method (FDM) for the space and time derivatives, respectively. The resulting model is analyzed to determine the periodic orbits of the resonator and their stability. Simultaneous resonances are identified for large orbits. Finally, we develop a first-order approximation of the microbeam dynamic response, which reveals an erosion of the basin of attraction of the stable orbits that depends heavily on the amplitude and frequency of the AC excitation. Simulations show that the smoothness of the boundary of the basin of attraction can be lost to be replaced by fractal tongues, which increase the sensitivity of the microbeam response to initial conditions. As a result, the locations of the stable and unstable fixed points are likely to be disturbed.

T1602-3-1 Metal-Induced Lateral Crystallization Using Ni Ferritin Supramolecules to Increase Tensile Stress in Si Film for MEMS

2010 ◽  
Vol 2010.8 (0) ◽  
pp. 235-236
Author(s):  
Shinya KUMAGAI ◽  
Syusuke MIYACHI ◽  
Ichiro YAMASHITA ◽  
Yukiharu URAOKA ◽  
Minoru SASAKI
Keyword(s):  
Tensile Stress ◽  
Lateral Crystallization

Mesomechanical Strength Model of Nano-Fibers Composite Ceramics

2007 ◽  
Vol 121-123 ◽  
pp. 1157-1160 ◽  
Author(s):  
Xie Quan Liu ◽  
Xin Hua Ni ◽  
Yun Ting Liu ◽  
Bao Hong Han
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Volume Fraction ◽  
Slenderness Ratio ◽  
Eutectic Structure ◽  
Theoretical Expression ◽  
Strength Model ◽  
Composite Ceramics ◽  
Random Orientation ◽  
External Strain

Recent experiment showed that nano-fibers composite ceramics, fabricated through SHS process, can acquire high toughening and strengthening. Composite ceramics are mainly composed of fiber eutectic structures with random orientation, in which nanometer sized zirconia fibers are dispersed within the alumina matrix. First, it can be visualized that tensile force is transmitted from the matrix to the nano-fiber by means of shear stress that develop along the fiber- matrix interface. Then the mesomechanical strength model of the fiber eutectic structure is built. The longitudinal tensile stress of the fiber eutectic structure and shear stress on the surface of the fiber eutectic structure are obtained. They related to the volume fraction and slenderness ratio of the nano-fibers, and external strain of the fiber eutectic structure. Then considering random orientation of the fiber eutectic structure, as composite ceramics is subjected to tensile stress, external strain of the fiber eutectic structure can be determined. Finally, theoretical expression for the strength prediction of composite ceramics is gotten.

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