scholarly journals A Laterally Vibrating Lithium Niobate MEMS Resonator Array Operating at 500 °C in Air

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 149
Author(s):  
Savannah R. Eisner ◽  
Cailin A. Chapin ◽  
Ruochen Lu ◽  
Yansong Yang ◽  
Songbin Gong ◽  
...  

This paper reports the high-temperature characteristics of a laterally vibrating piezoelectric lithium niobate (LiNbO3; LN) MEMS resonator array up to 500 °C in air. After a high-temperature burn-in treatment, device quality factor (Q) was enhanced to 508 and the resonance shifted to a lower frequency and remained stable up to 500 °C. During subsequent in situ high-temperature testing, the resonant frequencies of two coupled shear horizontal (SH0) modes in the array were 87.36 MHz and 87.21 MHz at 25 °C and 84.56 MHz and 84.39 MHz at 500 °C, correspondingly, representing a −3% shift in frequency over the temperature range. Upon cooling to room temperature, the resonant frequency returned to 87.36 MHz, demonstrating the recoverability of device performance. The first- and second-order temperature coefficient of frequency (TCF) were found to be −95.27 ppm/°C and 57.5 ppb/°C2 for resonant mode A, and −95.43 ppm/°C and 55.8 ppb/°C2 for resonant mode B, respectively. The temperature-dependent quality factor and electromechanical coupling coefficient (kt2) were extracted and are reported. Device Q decreased to 334 and total kt2 increased to 12.40% after high-temperature exposure. This work supports the use of piezoelectric LN as a material platform for harsh environment radio-frequency (RF) resonant sensors (e.g., temperature and infrared) incorporated with high coupling acoustic readout.

2004 ◽  
Vol 14 (03) ◽  
pp. 837-846 ◽  
Author(s):  
GANG BU ◽  
DAUMANTAS CIPLYS ◽  
MICHAEL S. SHUR ◽  
LEO J. SCHOWALTER ◽  
SANDRA B. SCHUJMAN ◽  
...  

We report on the velocity V and the electromechanical coupling coefficient K2 of the first and the second leaky surface acoustic waves in various propagation directions in the a-plane AlN single-crystal. For c-propagation direction, the second leaky wave exhibited the velocity of 11016 m/s and K2 of 0.45%. For this direction, the temperature coefficient of frequency was found to be -30 ppm/°C. A near match of the velocities of the plane and leaky waves in the a-plane AlN allowed us to establish analytical relationships between the piezoelectric and elastic constants. A full set of elastic and piezoelectric constants of AlN has been evaluated by fitting the measured and calculated dependencies of velocities and electromechanical coupling coefficients on the propagation direction for both Rayleigh and leaky waves.


2010 ◽  
Vol 123-125 ◽  
pp. 161-164
Author(s):  
Dong Yu Xu ◽  
Shi Feng Huang ◽  
Chao Ju ◽  
Zong Zhen Zhang ◽  
Xin Cheng ◽  
...  

Periodic and non-periodic 1-3 type cement based piezoelectric composites were fabricated by cut and filling technique, using P(MN)ZT ceramic as functional material and cement as matrix. The influences of periodicity of piezoelectric ceramic rods in the composites on electrical properties of all the composites were discussed. The results show that the non-periodic composites have larger dielectric factor and piezoelectric strain constant than those of the periodic composite. The impedance-frequency spectra analysis indicates that the non-periodic arrangement of ceramic rods can effectively restrict the lateral structural mode of the composite, accordingly reduces the coupling resonant between the thickness resonant mode and lateral resonant mode. The thickness electromechanical coupling coefficient of non-periodic composites is larger than that of the periodic composite. With increasing the non-periodic level of P(MN)ZT ceramic in the composites, the mechanical quality factor of the composites increases gradually. Therefore, 1-3 type cement based piezoelectric composites with different special abilities can be obtained by varying the periodic arrangement of P(MN)ZT ceramic rods in the composites.


2021 ◽  
Vol 8 ◽  
Author(s):  
Rui Ma ◽  
Weiguo Liu ◽  
Xueping Sun ◽  
Shun Zhou

This paper studied the manufacturing process of Piezoelectric-on-Silicon (POS) substrate which integrates 128° Y–X Lithium niobate thin film and silicon wafer using Smart-Cut technology. The blistering and exfoliation processes of the He as-implanted LN crystal under different annealing temperatures are observed by the in-situ method. Unlike the conventional polishing process, the stripping mechanism of the Lithium niobate thin film is changed by controlling annealing temperature, which can improve the surface morphology of the peeling lithium niobate thin film. We prepared the 128° Y–X POS substrate with high single-crystal Lithium niobate thin film and surface roughness of 3.91 nm through Benzocyclobutene bonding. After simulating the surface acoustic wave (SAW) characteristics of the POS substrate, the results demonstrate that the Benzocyclobutene layer not only performs as a bonding layer but also can couple more vibrations into the LN thin film. The electromechanical coupling coefficient of the POS substrate is up to 7.59% in the Rayleigh mode when hLN/λ is 0.3 and hBCB/λ is 0.1. Therefore, as a high-performance substrate material, the POS substrate has proved to be an efficient method to miniaturize and integrate the SAW sensor.


2002 ◽  
Vol 720 ◽  
Author(s):  
Sun-Ki Kim ◽  
Min-Jung Park ◽  
Cheol-Yeong Jang ◽  
Hyun-Chul Choi ◽  
Jung-Hee Lee ◽  
...  

AbstractAlxGa1-xN sample with x=0.36 was epitaxially grown on sapphire by MOCVD. SAW velocity of 5420 m/s and TCF (temperature coefficient of frequency) of -51.20 ppm/°C were measured from the SAW devices fabricated on the AlxGa1-xN sample, when kh value was 0.078, at temperatures between –30 °C and 60 °C Electromechanical coupling coefficient was ranged from 1.26 % to 2.22 %. The fabricated SAW filter have shown a good device performance with insertion loss of -33.853 dB and side lobe attenuation of 20 dB.


2014 ◽  
Vol 15 (2) ◽  
Author(s):  
Aliza Aini Md Ralib ◽  
Anis Nurashikin Nordin

ABSTRACT: Continuous advancement in wireless technology and silicon microfabrication has fueled exciting growth in wireless products. The bulky size of discrete vibrating mechanical devices such as quartz crystals and surface acoustic wave resonators impedes the ultimate miniaturization of single-chip transceivers. Fabrication of acoustic wave resonators on silicon allows complete integration of a resonator with its accompanying circuitry.  Integration leads to enhanced performance, better functionality with reduced cost at large volume production. This paper compiles the state-of-the-art technology of silicon compatible acoustic resonators, which can be integrated with interface circuitry. Typical acoustic wave resonators are surface acoustic wave (SAW) and bulk acoustic wave (BAW) resonators.  Performance of the resonator is measured in terms of quality factor, resonance frequency and insertion loss. Selection of appropriate piezoelectric material is significant to ensure sufficient electromechanical coupling coefficient is produced to reduce the insertion loss. The insulating passive SiO2 layer acts as a low loss material and aims to increase the quality factor and temperature stability of the design. The integration technique also is influenced by the fabrication process and packaging.  Packageless structure using AlN as the additional isolation layer is proposed to protect the SAW device from the environment for high reliability. Advancement in miniaturization technology of silicon compatible acoustic wave resonators to realize a single chip transceiver system is still needed. ABSTRAK: Kemajuan yang berterusan dalam teknologi tanpa wayar dan silikon telah menguatkan pertumbuhan yang menarik dalam produk tanpa wayar. Saiz yang besar bagi peralatan mekanikal bergetar seperti kristal kuarza menghalang pengecilan untuk merealisasikan peranti cip. Silikon serasi  gelombang akustik resonator mempunyai potensi yang besar untuk menggantikan unsur-unsur diskret kerana keupayaan untuk mengintegrasikan dengan litar yang disertakan itu. Integrasi ini membawa kepada peningkatan prestasi, fungsi yang lebih baik dengan pengurangan kos pada pengeluaran jumlah yang besar. Oleh itu, Karya ini mengkaji silikon resonator akustik yang serasi, yang bersepadu dengan muka litar untuk membolehkan integrasi yang lengkap. Resonator gelombang akustik yang digunakan adalah gelombang permukaan akustik ( SAW ) dan gelombang akustik pukal ( BAW ) resonator . Kriteria penting untuk menilai prestasi resonator seperti faktor kualiti, frekuensi resonans dan kehilangan sisipan juga digariskan dalam setiap kerja sebelumnya. Pemilihan bahan piezoelektrik yang sesuai adalah penting untuk memastikan pekali gandingan elektromekanik yang mencukupi dihasilkan untuk mengurangkan kehilangan sisipan. Lapisan tambahan pasif SiO2   yang bertindak sebagai bahan rendah sisipan dipercayai meningkatkan faktor kualiti dan kestabilan suhu reka bentuk. Teknik integrasi juga dipengaruhi oleh proses fabrikasi dan pembungkusan. Struktur tanpa pembungkusan menggunakan AlN sebagai lapisan pengasingan tambahan itu dicadangkan untuk melindungi peranti SAW dari persekitaran untuk kebolehpercayaan yang tinggi. Banyak lagi kemajuan perlu dilakukan dalam pengecilan silikon serasi resonator gelombang akustik untuk merealisasikan sistem cip transceiver tunggal.KEYWORDS: RF-MEMS; piezoelectric; resonator; surface acoustic wave (SAW);bulk acoustic wave (BAW); FBAR


2013 ◽  
Vol 364 ◽  
pp. 794-798 ◽  
Author(s):  
Yi Chen ◽  
Jian Guo Zhu ◽  
Ding Quan Xiao

The gallium and indium double-modified bismuth scandate-lead titanate (1-x)Bi (In0.20Ga0.05Sc0.75)O3-xPbTiO3((1-x)BIGS-xPT,x=0.55-0.70) ceramics were prepared by using conventional ceramic technique. (1-x)BIGS-xPT ceramics for nearx=0.60 exhibits an evident enhancement in room temperature dielectric and piezoelectric properties, with dielectric constantε, piezoelectric constantd33, planar electromechanical coupling coefficientkpand Curie temperatureTCof 1100, 295 pC/N, 0.43 and 435 °C, respectively. TheTCof (1-x)BIGS-xPT is in the range of 425-530 °C for the compositions investigated. The combination of highTCand excellent piezoelectric activity suggest that the (1-x)BIGS-xPT ceramics are usable candidate materials for high temperature piezoelectric devices applications.


2003 ◽  
Vol 764 ◽  
Author(s):  
Sheng-Yuan Chu ◽  
Te-Yi Chen ◽  
Walter Water ◽  
Tung-Yi Huang

AbstractPoly-crystal ZnO films with c-axis (002) orientation have been successfully grown on the lead-based ceramic substrates by r.f. magnetron sputtering technique. The deposited films were characterized as a function of deposition time and argon-oxygen gas flow ratio. Crystalline structures of the films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Highly oriented films with c-axis normal to the substrates can be obtained by depositing under a total pressure of 10mTorr containing 50% argon and 50% oxygen and r.f. power of 70W for 3 hours. The phase velocity, electromechanical coupling coefficient and temperature coefficient of frequency of SAW device with ZnO/IDT/PT-ceramic structure were investigated. It shows that the preferred oriented ZnO film is beneficial for improving the electromechanical coupling coefficient of SAW device.


Author(s):  
J. H. Cho ◽  
J. C. Raupp ◽  
P. D. Hayenga ◽  
R. F. Richards ◽  
D. F. Bahr ◽  
...  

The efficiency of energy conversion by piezoelectric devices depends upon the quality factor Q, and electromechanical coupling coefficient k2. Efficiency, Q, and k2 were measured for a piezoelectric cantilever and piezoelectric stack, and compared to a model of the efficiency in terms of Q and k2. The model and experiment agree very well.


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