新型氮化铝MEMS声压传感器技术

MEMS sound pressure sensor technology based on a new type of AlN piezoelectric film

为了解决水下声学传感器技术领域中一直存在的提高低频响应灵敏度方面的迫切需求,本文利用氮化铝新型氮化铝敏感材料与声传感器设计技术相结合进行了声学传感器设计技术研究。开展了基于MEMS微结构的弯曲振动声敏感模式、力敏特性与压电敏感特性耦合、电荷信号提取电极设计等相关技术验证研究,完成了氮化铝MEMS声传感器测试芯片的工艺与版图设计及加工与制作。通过样品测试分析,在典型检测电极上分别得到了0.61、1.12、1.64μV/Pa的单电极声压灵敏度和平坦的低频频率响应曲线,验证了基于ALN薄膜、采用弯曲振动模式的MEMS声敏感芯片设计可以实现低频高灵敏度声传感器。

Improvement of the low-frequency response sensitivity of underwater acoustic sensor technology is an urgent undertaking.In this paper,a novel acoustic sensor is developed by combining an aluminum nitride(ALN)MEMS sensitive material with the current acoustic sensor design technology.The coupling of force and piezoelectric sensing characteristics,the design of a charge-signal extraction electrode,and other related technical verification research are carried out on the basis of the MEMS microstructure and bending vibration acoustic sensing mode.The layout design,processing,and fabrication of an ALN MEMS acoustic sensor test chip are then completed.The single-electrode pressure sensitivity and flat low-frequency response curves under the conditions of 0.61,1.12,and 1.64μV/Pa are obtained by testing the fabricated acoustic sensor chip on a typical detection electrode and analyzing the results.The design of MEMS acoustic sensor chips based on ALN films and bending vibration mode may be employed to achieve low-frequency,high-sensitivity acoustic sensors.