The effects of relative humidity and reducing gases on the temperature coefficient of resonant frequency of ZnO based film bulk acoustic wave resonator

2010 ◽  
Vol 57 (9) ◽  
pp. 1902-1905 ◽  
Author(s):  
Xiaotun Qiu ◽  
Ziyu Wang ◽  
Jie Zhu ◽  
J Oiler ◽  
Rui Tang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Acoustic Wave ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Bulk Acoustic Wave ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk ◽  
Reducing Gases

The Improvement of Temperature Coefficient of Frequency in Thin Film Bulk Acoustic Wave Resonator using Secondary Harmonics

2002 ◽  
Vol 741 ◽  
Author(s):  
Yukio Yoshino ◽  
Masaki Takeuchi ◽  
Hajime Yamada ◽  
Yoshihiko Goto ◽  
Tadashi Nomura ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Temperature Coefficient ◽  
Finite Element Method Simulation ◽  
Thickness Ratio ◽  
Bulk Acoustic Wave ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk ◽  
Temperature Coefficient Of Frequency

ABSTRACTWe have succeeded in making an 870MHz-range thin film bulk acoustic wave (BAW) resonator that has a small temperature coefficient of frequency (TCF) using secondary harmonics. The 870MHz-range BAW resonator has been requested to have nearly zero TCF, because it will be used in an oscillator for remote keyless entry systems. The BAW resonator has composite structure that consists of Al electrodes and ZnO/SiO2. We directed our attention to the fact that ZnO and Al have negative TCF, and SiO2 has a positive one. It is theoretically possible to make zero TCF BAW resonators by optimizing the thickness ratio of ZnO and SiO2. However, using fundamental resonance, TCF is so sensitive to the thickness ratio that it cannot be easily controlled by MEMS techniques. We founds in finite element method simulation and confirmed by experiment that the TCF of secondary harmonics has a local minimum when changing the ZnO/SiO2 thickness ratio. As the result, a nearly zero TCF resonator without strict control of ZnO/SiO2 thickness ratio has been realized by adopting Al/ZnO/SiO2/ZnO/Al/SiO2 structure and combining thermal oxidized Si and sputtered SiO2. The resonator has the TCF of -1.86ppm/degree in the range of −40 to 85 degrees centigrade.

Stress Adjustment and Characteristics Improvement in a 1.8GHz Range Film Bulk Acoustic Wave Resonator by Using Multi-layer Structure of ZnO/A12O3/SiO2

2002 ◽  
Vol 741 ◽  
Author(s):  
Masaki Takeuchi ◽  
Hajime Yamada ◽  
Hideki Kawamura ◽  
Yoshihiko Goto ◽  
Tadashi Nomura ◽  
...  
Keyword(s):  
Thin Films ◽  
Acoustic Wave ◽  
Temperature Coefficient ◽  
Layer Structure ◽  
Fem Simulation ◽  
Bulk Acoustic Wave ◽  
Positive Temperature ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk

ABSTRACTStress adjustment and improvement of electrical characteristics in film bulk acoustic wave resonator (BAW) have been successfully carried out in 1.8GHz range by using a multi-layer structure of ZnO / Al2O3 / SiO2. The BAW resonator, designed on secondary harmonics at about 1.8GHz, has Al / ZnO / Al / Al2O3 / SiO2 structure. ZnO and SiO2 thin films have a negative and a positive temperature coefficient of sound velocity, respectively. So temperature coefficient of frequency (TCF) of the BAW resonator can be controlled by the thickness ratio of ZnO and SiO2 thin films. Since both ZnO and SiO2 have compressive stress, and Al2O3 has tensile one, the stress of the membrane is reduced by combining these thin films so that the membrane can avoid deformation. The BAW resonator, with thickness of ZnO / Al2O3 / SiO2=1.2 /0.45/1.25 microns, was designed by finite element method (FEM) simulation and fabricated. The value of quality factor (Q factor) and the TCF of the BAW resonator were realized over 1000 and −20 ppm/degree C, respectively. The Q of ZnO / Al2O3 / SiO2 structure was higher than that of ZnO / SiO2 one with keeping small TCF.

Film Bulk Acoustic-Wave Resonator Based Relative Humidity Sensor Using ZnO Films

2010 ◽  
Vol 13 (5) ◽  
pp. J65 ◽  
Author(s):  
Xiaotun Qiu ◽  
Jon Oiler ◽  
Jie Zhu ◽  
Ziyu Wang ◽  
Rui Tang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Acoustic Wave ◽  
Humidity Sensor ◽  
Bulk Acoustic Wave ◽  
Zno Films ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk ◽  
Relative Humidity Sensor

scholarly journals The thin film bulk acoustic wave resonator based on single-crystalline 43○Y-cut lithium niobate thin films

AIP Advances ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 075002
Author(s):  
Xiaoyuan Bai ◽  
Yao Shuai ◽  
Lu Lv ◽  
Ying Xing ◽  
Jiaoling Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Lithium Niobate ◽  
Acoustic Wave ◽  
Bulk Acoustic Wave ◽  
Single Crystalline ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk

Simulation and fabrication of thin film bulk acoustic wave resonator

2016 ◽  
Vol 37 (7) ◽  
pp. 074009
Author(s):  
Xixi Han ◽  
Yi Ou ◽  
Zhigang Li ◽  
Wen Ou ◽  
Dapeng Chen ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Bulk Acoustic Wave ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk

Thin film bulk acoustic wave resonator (TFBAR) gas sensor

2005 ◽  
Author(s):  
M. Benetti ◽  
D. Cannat ◽  
A. D'Amico ◽  
F. Di Pietrantonio ◽  
V. Foglietti ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Gas Sensor ◽  
Bulk Acoustic Wave ◽  
Bulk Acoustic Wave Resonator ◽  
Wave Resonator ◽  
Film Bulk
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