摘要
基于薄膜体声波谐振器(FBAR)的力学传感器有很大的应用潜力,但其应力负载效应的敏感机理尚不明确。电极化效应可能是应力负载效应的敏感机理之一。为了研究电极化效应对谐振频率的影响,提出了电极化效应的解析模型。首先根据在理想FBAR中并联谐振频率与纵波声速的关系,推导出并联谐振频率关于压电层材料参数的表达式;然后根据直流电压主要对FBAR的弹性常数和厚度的影响,推导出并联谐振频率与直流电压的关系;最后利用压电效应,得到了力载荷与并联谐振频率的关系。代入数值计算得到并联谐振频率的相对偏移量为+1.003%@400V,对比测试结果,并联谐振频率的相对偏移量为+0.90%@400V,验证了模型的正确性。计算了力载荷为1mN时,电极化效应导致谐振频率的偏移量约为0.5kHz。对比实验测得的应力负载效应对谐振频率的偏移量最低约为262kHz,证明了在应力负载效应中,电极化效应对谐振频率偏移的影响可忽略。
The mechanical sensors based on the thin film acoustic resonator （FBAR） have great potential for application, but the sensitive mechanism of the stress-loading effect is not yet clear. The charge polarization effect may be one of the sensitive mechanisms of the stress-loading effect. An analytical model of the charge polarization effect is proposed to study the effect of the charge polarization effect on the resonant frequency shift. First, the expression of the anti-resonant frequency about the material parameters of the piezoelectric layer is derived according to the relationship between the anti-resonant frequency and the longitudinal wave acoustic velocity in the ideal FBAR. Then according to the influence of the DC voltage on the elastic constants and the thickness of FBAR, the relationship between the anti-resonant frequency and the DC voltage is deduced. Finally, the relationship between the loading force and the charge is obtained by the piezoelectric effect. The relative offset of parallel resonant frequency is ＋1.003% @400 V from the numerical calculation, and the correctness of model is verified by comparing this result with that of ＋0.90%@400 V from the experiment. The calculation shows that the offset of the resonant frequency caused by the charge polarization is 0.5 kHz at 1 mN of loading force. The minimum offset of the resonant frequency measured by the contrast experiment is about 262 kHz. It is proved that the effect of the charge polarization effect on the resonance frequency offset is negligible in the stress load effect.
作者
张大鹏
高杨
王宇航
文数文
ZHANG Dapeng;GAO Yang;WANG Yuhang;WEN Shuwen(School of Information Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Institute of Electronic Engineering,China Academy of Engineering Physics,Mianyang 621999,China;State Key Laboratory of Particle Detection and Electronics,Institute of High Energy Physics,CAS,Beijing 100049,China;National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology,Chongqing University,Chongqing 400044,China)
出处
《压电与声光》
CAS
CSCD
北大核心
2018年第3期366-369,共4页
Piezoelectrics & Acoustooptics
基金
国家自然科学基金资助项目(61574131)
核探测与核电子学国家重点实验室开放课题基金资助项目(2016KF-02)
特殊环境机器人技术四川省重点实验室(西南科技大学)开放基金资助项目(14ZXTK01)
关键词
微机电系统
力学传感器
薄膜体声波谐振器
应力负载效应
电极化效应
解析模型
MEMS
mechanical sensor
thin film bulk acoustic wave resonator
stress-loading effect
charge polarization effect
analytical model
