光学 精密工程, 2016, 24 (6): 1328, 网络出版: 2016-08-18
柔性声表面波器件的波模式分析
Analysis on wave mode of flexible surface acoustic wave devices
声表面波器件 柔性衬底 聚酰亚胺衬底 压电薄膜 波模式 S0兰姆波 Surface Acoustic Wave(SAW) device flexible substrate polyimide substrate piezoelectric film wave mode Lamb wave
摘要
用反应磁控溅射法在柔性聚酰亚胺衬底上沉积了ZnO压电薄膜,并制备了基于ZnO压电薄膜的柔性声表面波(SAW)器件。制备的柔性SAW器件显示了良好的谐振性能,而且展现出两个波模式: 模式0和模式1。当波长为32 μm,ZnO厚度为4 μm时,SAW器件的模式0和模式1的谐振频率分别为34.4 MHz 和158.5 MHz,对应声速为1 100.8 m/s 和5 072 m/s。模式0为已知的瑞利波,模式1为新的高频模式。 沉积了不同厚度的ZnO薄膜制备柔性SAW器件,进一步分析了薄膜厚度对SAW器件和模式1的影响。分析认为该高频模式不是传统硬质衬底上SAW器件产生的Sezawa波,而是S0兰姆波,并且是有衬底情况下的S0兰姆波。文中还采用Comsol仿真分析了新的高频模式1的粒子振动位移,结果和S0兰姆波粒子振动位移一致,从而验证了其为广义兰姆波的正确性。
Abstract
ZnO piezoelectric films were deposited on polyimide substrates by reactive magnetron sputtering method, and flexible Surface Acoustic Wave( SAW) devices were prepared based on the ZnO piezoelectric films. The flexible SAW devices show excellent resonant characteristics and two wave modes, mode 0 and mode 1. The resonant frequencies of the SAW devices with a ZnO layer by thickness of 4 m are 34.4 MHz and 158.5 MHz for the mode 0 and mode 1, and corresponding acoustic phase velocities are 1 100.8 m/s and 5 072 m/s, respectively. The Mode 0 is Rayleigh wave, while the Mode 1 is a new high frequency mode. The ZnO piezoelectric films with different thicknesses were deposited for preparing the SAW devices, and the effects of ZnO film thicknesses on the SAW devices and the new mode were analyzed by Finite Element Method. The results show that the new high frequency mode is not the Sezawa wave produced on the traditional hard substrate but is a S0 Lamb wave with a substrate. Moreover, the Comsol was used to simulate and analyze the vibration and surface displacement of the Mode 1 with PI or without PI substrates and the results indicate that the vibration and surface displacement of the Mode 1 is in agreement with that of S0 Lamb wave, which validates that the new mode is S0 Lamb wave.
周剑, 吴学忠, 肖定邦, 何兴理, 金浩, 董树荣, 张伟策. 柔性声表面波器件的波模式分析[J]. 光学 精密工程, 2016, 24(6): 1328. ZHOU Jian, WU Xue-zhong, XIAO Ding-bang, HE Xing-li, JIN Hao, DONG Shu-rong, ZHANG Wei-ce. Analysis on wave mode of flexible surface acoustic wave devices[J]. Optics and Precision Engineering, 2016, 24(6): 1328.