基于全硅工艺的硅谐振压力传感器设计与制备

Design and Manufacture of Silicon Resonant Pressure Sensor Based on All Silicon Technology

硅谐振压力传感器制备工艺包括硅-玻璃工艺和全硅工艺,采用硅-玻璃工艺时,硅材料和玻璃材料热膨胀系数存在差异,会产生热应力。为解决硅材料和玻璃材料热膨胀系数不匹配而产生的热应力,设计一种基于全硅工艺的硅谐振压力传感器。该设计采用全硅工艺制备,其中电极层和敏感膜层集成于一体,密封层实现真空键合,在消除热应力的同时可减小黏接剂带来的应力干扰。采用全硅工艺制备的硅谐振压力传感器能够克服各种应力干扰,使传感器迟滞、重复性等指标得到改善,进而提升综合精度、长期稳定性等指标。全硅工艺还可改善传感器温度系数,可提升传感器温度跟随性指标。传感器最终测试结果显示,其综合精度优于±0.01%F.S.,其余指标如温度系数、迟滞、重复性等均优于基于硅-玻璃工艺的同类产品。

The manufacturing technology of silicon resonant pressure sensor contains silicon-glass process and all silicon process.The thermal expansion coefficient of silicon and glass materials is different when using silicon-glass technology, which will produce thermal stress.In order to solve the thermal stress caused by the mismatch of thermal expansion coefficient between silicon and glass, a silicon resonant pressure sensor based on all-silicon process is designed.The design adopts all-silicon manufacturing process, in which the electrode layer and sensitive film layer are integrated, and the sealing layer is vacuum bonded, which can eliminate the thermal stress and reduce the stress interference caused by the adhesive.The silicon resonant pressure sensor manufactured by the all-silicon process can overcome various stress disturbances, improve the sensor’s hysteresis and repeatability, and then improve the comprehensive accuracy, long-term stability and other indicators.The all-silicon process can also improve the temperature coefficient of the sensor, which can improve the temperature following index of the sensor.The final sensor test results show that its comprehensive accuracy is better than ±0.01%F.S..Other indexes such as temperature coefficient, hysteresis and repeatability are better than similar products based on silicon-glass process.