基于MEMS技术的集成压力-湿度传感器  

Integrated Humidity-Pressure Sensor Based on MEMS Technology

作　　者：陈果[1,2] 刘正波 王韬 张万里[1] CHEN Guo;LIU Zhengbo;WANG Tao;ZHANG Wanli(School of Integrated Circuit Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China;Guizhou Aerospace intelligent Agriculture Co.,Ltd.,Guiyang 550000,China)

机构地区：[1]电子科技大学集成电路科学与工程学院,成都611731 [2]贵州航天智慧农业有限公司,贵阳550000

出　　处：《电子科技大学学报》2024年第1期21-28,共8页Journal of University of Electronic Science and Technology of China

摘　　要：设计了一种高灵敏度的集成压力和湿度传感单元的芯片。压力传感单元基于SOI和蛇形电阻结构。室温下,传感器在载压范围为3~129 kPa内灵敏度为0.026 mV/kPa,与有限元仿真基本吻合。传感器在25~120℃范围内的热灵敏度漂移为0.004‰FS/℃,热零点漂移为0.25%FS/℃。湿度传感单元采用的叉指电极和电容式结构,引入含氟PI作湿度敏感膜。设计Mo电阻加热结构加快传感器降湿过程,缩短降湿时间近32%。在10%~90%RH的湿度范围,含氟PI湿度传感器的灵敏度为0.121 pF/%RH,略低于无氟PI器件。含氟基团的引入,使得传感器的湿滞较无氟PI降低16%。“电容-湿度”曲线呈指数分布,相关系数R^(2)=0.996。测试结果发现,湿度传感单元和压力传感单元拥有良好的独立工作性能。In this paper,a high-sensitivity integrated humidity and pressure sensor chip is designed.The pressure sensing unit is based on the silicon on insulator(SOI)and serpentine resistors structure.The sensitivity of the sensor at room temperature is 0.026 mV/kPa with the pressure of 3 kPa to 129 kPa,which is consistent with the finite element simulation.The thermal sensitivity shift reaches 0.004‰FS/℃and the thermal zero shift is 0.25%FS/℃.The humidity sensing unit adopts interdigital electrodes(IDT)and capacitive structure.The hydrophobic group introduced by fluorinated polyimide(PI)is used as the humidity sensitive film.The design of Mo resistance heating structure speeds up the dehumidification process of the sensor and shortens the dehumidification time by nearly 32%.In the humidity range of 10%RH to 90%RH,the sensitivity of the humidity sensor with fluorinated PI reaches 0.121 pF/%RH,slightly lower than the fluorine-free sensor.The humidity hysteresis of the sensor with fluorinated PI is reduced by 16%compared with the sensor without fluorinated PI.The capacitance-humidity curve is an exponential distribution,the correlation coefficient R^(2)=0.996.The test results show that the humidity sensing unit and the pressure sensing unit have good independent performance.

关 键 词：电容式湿度传感器 惠斯通电桥 MEMS工艺 聚酰亚胺(PI) 压力传感器 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]