A silicon-on-insulator based micro electric field sensor and a method for manufacturing the same

Abstract

This invention belongs to the field of electric field sensing technology, specifically disclosing a micro electric field sensor based on silicon-on-insulator (SOI) and its fabrication method. The sensor, from top to bottom, includes a piezoelectric block, a SOI structural layer, and a supporting substrate. The SOI structural layer comprises a substrate layer, an insulating layer, a device layer, and metal electrodes. The substrate layer has a hollow structure, and the four protrusions of the device layer form a peninsula beam membrane structure. The piezoresistive elements in the region of maximum strain form a Wheatstone bridge. After sensing an external electric field, the piezoelectric block drives the peninsula beam membrane to vibrate based on the inverse piezoelectric effect, and the Wheatstone bridge converts the mechanical strain into an electrical signal. The fabrication method uses an SOI wafer as the substrate and completes the process through photolithography, ion implantation, etching, and bonding. This invention improves stress concentration and sensing efficiency, while also possessing low power consumption and MEMS process compatibility. It exhibits excellent measurement accuracy and stability, making it suitable for scenarios such as power transmission and transformation equipment monitoring.

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