A new fabrication process for the SOI-based miniature electric field sensor

Abstract

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 SiO2 layer. Compared with the CO2 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.