1. A Laterally Vibrating Lithium Niobate MEMS Resonator Array Operating at 500 °C in Air.
- Author
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Eisner, Savannah R., Chapin, Cailin A., Lu, Ruochen, Yang, Yansong, Gong, Songbin, and Senesky, Debbie G.
- Subjects
MEMS resonators ,LITHIUM niobate ,QUALITY factor ,ACOUSTIC couplers ,PIEZOELECTRIC materials ,CRYSTAL resonators - Abstract
This paper reports the high-temperature characteristics of a laterally vibrating piezoelectric lithium niobate (LiNbO
3 ; 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 (kt 2 ) were extracted and are reported. Device Q decreased to 334 and total kt 2 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. [ABSTRACT FROM AUTHOR]- Published
- 2021
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