title: The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures.
abstract: We report in this paper on the study of surface acoustic wave (SAW) resonators based on an AlN/titanium alloy (TC4) structure. The AlN/TC4 structure with different thicknesses of AlN films was simulated, and the acoustic propagating modes were discussed. Based on the simulation results, interdigital transducers with a periodic length of 24 μm were patterned by lift-off photolithography techniques on the AlN films/TC4 structure, while the AlN film thickness was in the range 1.5-3.5 μm. The device performances in terms of quality factor (Q-factor) and electromechanical coupling coefficient (k²) were determined from the measure S11 parameters. The Q-factor and k² were strongly dependent not only on the normalized AlN film thickness but also on the full-width at half-maximum (FWHM) of AlN (002) peak. The dispersion curve of the SAW phase velocity was analyzed, and the experimental results showed a good agreement with simulations. The temperature behaviors of the devices were also presented and discussed. The prepared SAW resonators based on AlN/TC4 structure have potential applications in integrated micromechanical sensing systems.
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. s89s89s@126.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Shu
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. bpeng@uestc.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. uestc_lich@hotmail.com.
authors.forename: Chuan
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. 15196609270@163.com.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Gong
authors.affiliation: China Gas Turbine Establishment, Jiangyou 621703, China. zbyang668@163.com.
authors.forename: Zhengbing
authors.initials: Z
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. xzliu@uestc.edu.cn.
authors.forename: Xingzhao
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. wlzhang@uestc.edu.cn.
authors.forename: Wanli
authors.initials: W
authors.lastname: Zhang
keywords: AlN film; TC4; layered structure; simulation; surface acoustic wave