基于PZT的500MHz超声传感器设计和MEMS制作

Design of PZT-based 500 MHz ultrasonic sensor and MEMS fabrication

利用KLM等效电路模型设计了一种中心频率为478 MHz的超声传感器。采用溶胶—凝胶法在硅衬底上制备了厚度为4μm的锆钛酸铅(PZT)厚膜压电材料,对压电材料的晶体结构、表面剖面形貌、压电性进行了测试,材料均匀致密,具有较好的压电性。研究了超声传感器的制作工艺,制作出实际工作频率为459 MHz的高频超声传感器,搭建测试平台测试其电阻抗,实验值与理论值相匹配,电阻抗误差为1.8%,中心频率误差为3.9%。

An ultrasonic sensor with a center frequency of 478 MHz is designed using the KLM equivalent circuit model, and the PZT thick film piezoelectric material with thickness of 4μm is prepared on a silicon substrate by sol-gel method. The crystal structure, surface profile and piezoelectricity of the piezoelectric material are tested. The material is uniform and compact, and the piezoelectric properties are good. The fabrication process of ultrasonic sensor is studied, a high frequency ultrasonic sensor with a working frequency of 459 MHz is made. The test platform is set up to test its electrical impedance, experimental value is matched with theoretical value, the impedance error is 1.8 % , and the center frequency error is 3.9 %.