This paper presents a new fabrication process for the SOI-based novel miniature electric field sensor. This new process uses polyimide film to release the SiO_2 layer.Compared with the CO_2 critical point release method,it significantly improves the device surface cleanliness and shortens the process flow.The impurity on the base layer is analyzed.The problem of peak and butterfly-type contamination occurring on the base layer of the SOI wafer during the DRIE process is discussed and solved by thickening the photoresist layer and coating with polyimide film twice.This new process could fabricate MEMS sensors and actuators such as SOI-based electric field sensors,gyroscopes,and micro mirrors and can be an alternative fabrication process compared to commercial SOIMUMPS fabrication processes.
In this paper,the design and experimental results for a novel high-stability sounding electrostatic field micro sensor are presented.By means of hermetic chip sealing,digital weak signal demodulation unit,and probe sensor structure design,harsh environmental adaptation problems such as low temperature,high humidity,low air pressure,waterfall are solved.The sensor has a high resolution of 14 V/m,a wide measurement range of±100 kV/m,and is proved to have superior stability and performance in sounding electric field experiments than traditional sensors under different kinds of weather.