柔性声表面波器件的波模式分析  

Analysis on wave mode of flexible surface acoustic wave devices

作　　者：周剑[1] 吴学忠[1] 肖定邦[1] 何兴理[2] 金浩[3] 董树荣[3] 张伟策 

机构地区：[1]国防科学技术大学机电工程与自动化学院,湖南长沙410073 [2]福建工程学院信息科学与工程学院,福建福州350108 [3]浙江大学信息与电子工程学院,浙江杭州310027 [4]南昌陆军学院,江西南昌330100

出　　处：《光学精密工程》2016年第6期1328-1334,共7页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.61204124);中央高校基本科研业务费专项基金资助项目(No.2014QNA5002)

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32μm,ZnO厚度为4μm时,SAW器件的模式0和模式1的谐振频率分别为34.4MHz和158.5MHz,对应声速为1 100.8m/s和5 072m/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S_0兰姆波,并且是有衬底情况下的S_0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S_0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。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 0and mode 1.The resonant frequencies of the SAW devices with a ZnO layer by thickness of 4 mare 34.4 MHz and 158.5 MHz for the mode 0 and mode 1,and corresponding acoustic phase velocities are 1 100.8m/s and 5 072m/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 S_0 Lamb wave with a substrate.Moreover,the Comsol was used to simulate and analyze the vibration and surface displacement of the Mode 1with PI or without PI substrates and the results indicate that the vibration and surface displacement of the Mode 1is in agreement with that of S_0 Lamb wave,which validates that the new mode is S_0 Lamb wave.

关 键 词：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 

分 类 号：TN65[电子电信—电路与系统]