Shu Lin, Peng Bin, Li Chuan, Gong Dongdong, Yang Zhengbing, Liu Xingzhao, Zhang Wanli
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
China Gas Turbine Establishment, Jiangyou 621703, China.
Sensors (Basel). 2016 Apr 12;16(4):526. doi: 10.3390/s16040526.
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.
我们在本文中报告了基于氮化铝/钛合金（TC4）结构的表面声波（SAW）谐振器的研究。对具有不同厚度氮化铝薄膜的氮化铝/TC4结构进行了模拟，并讨论了声传播模式。基于模拟结果，在氮化铝薄膜/TC4结构上通过剥离光刻技术制作了周期长度为24μm的叉指换能器，此时氮化铝薄膜厚度在1.5 - 3.5μm范围内。根据测量的S11参数确定了器件在品质因数（Q因子）和机电耦合系数（k²）方面的性能。Q因子和k²不仅强烈依赖于归一化的氮化铝薄膜厚度，还依赖于氮化铝（002）峰的半高宽（FWHM）。分析了SAW相速度的色散曲线，实验结果与模拟结果吻合良好。还展示并讨论了器件的温度特性。所制备的基于氮化铝/TC4结构的SAW谐振器在集成微机械传感系统中具有潜在应用。
