作者：高杨, 张大鹏, 刘婷婷

作者单位：西南科技大学信息工程学院, 四川 绵阳 621010

关键词：微加速度计;薄膜体声波谐振器;频率偏移;摄动;有限元

摘要：

薄膜体声波谐振器（FBAR）力学传感器有很大的应用潜力，但其敏感机理——应力负载效应尚不能被准确描述。为准确描述应力负载效应，预测FBAR力学传感器的频率灵敏度，提出一种摄动与有限元联合求解方法，并利用该方法计算FBAR微加速度计的频率-加速度灵敏度。首先，在COMSOL有限元软件中计算FBAR微加速度计在加速度下其压电层AlN的平均偏置应力；接着，在COMSOL中计算单个FBAR的谐振频率与相应的振型；最后，将有限元的计算数据和AlN的材料常数代入摄动积分公式中，得到FBAR微加速度计的频率-加速度灵敏度约为–98.879 kHz/g，与文献报道的实验结果–100 kHz/g相吻合，验证方法的可行性。

Perturbation analysis of frequency shifts in thin film bulk acoustic wave resonator under biasing fields
GAO Yang, ZHANG Dapeng, LIU Tingting
School of Information Engineering, Southwest University of Science and Technology, Mianyang 621010, China
Abstract: The mechanical sensor of thin film bulk acoustic resonator (FBAR) has great potential for application, but its sensitive mechanism, stress-loading effect, can not be accurately described. In order to accurately describe the stress loading effect and predict the sensitivity of FBAR mechanical sensor, a combined perturbation and finite element method is proposed. The frequency-acceleration sensitivity of FBAR accelerometer is calculated by this method. Firstly, the average biasing stress of piezoelectric layer AlN of FBAR accelerometer under acceleration is calculated in COMSOL finite element software. Then, the resonant frequency and corresponding mode shape of a single FBAR are calculated in COMSOL. Finally, the calculated data of finite element and the material constants of AlN are substituted into the perturbation integral formula, and the frequency-acceleration sensitivity of FBAR micro accelerometer is about -98.879 kHz/g. It is consistent with the reported experimental result of -100 kHz/g, and feasibility of this method is validated.
Keywords: micro accelerometer;thin film bulk acoustic wave resonator;frequency shift;perturbation;finite element
2019, 45(9):1-5  收稿日期: 2019-02-21;收到修改稿日期: 2019-04-25
基金项目: 国家自然科学基金（61574131）；四川省教育厅资助科研项目（17ZA0402）
作者简介: 高杨(1972-),男,四川绵阳市人,研究员,博士,研究方向为MEMS(微电子机械系统)
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