The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures

Lin Shu; Bin Peng; Chuan Li; Dongdong Gong; Zhengbing Yang; Xingzhao Liu; Wanli Zhang

doi:10.3390/s16040526

The Characterization of Surface Acoustic Wave Devices Based on AlN-Metal Structures

Sensors (Basel). 2016 Apr 12;16(4):526. doi: 10.3390/s16040526.

Authors

Lin Shu¹, Bin Peng², Chuan Li³, Dongdong Gong⁴, Zhengbing Yang⁵, Xingzhao Liu⁶, Wanli Zhang⁷

Affiliations

¹ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. s89s89s@126.com.
² 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.
³ 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.
⁴ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. 15196609270@163.com.
⁵ China Gas Turbine Establishment, Jiangyou 621703, China. zbyang668@163.com.
⁶ 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.
⁷ 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.

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.

Keywords: AlN film; TC4; layered structure; simulation; surface acoustic wave.

Publication types

Research Support, Non-U.S. Gov't