Piezoelectric MEMS hydrophone based on bionic cochlea structure and preparation method thereof

Abstract

The application provides a piezoelectric MEMS hydrophone based on a bionic cochlea structure and a preparation method thereof. The preparation method comprises the following steps: forming a blocking layer, a lower electrode layer, a piezoelectric layer and an upper electrode layer on a substrate, and forming a hard mask on the back of the substrate; performing photoetching on the upper electrode layer and then performing reactive ion beam etching to obtain a bionic cochlea structure pattern; performing photoetching and patterning on the piezoelectric layer to obtain a bionic cochlea structure pattern, and then etching to expose the lower electrode layer; forming a positive electrode and a negative electrode on the upper electrode layer; forming an etched hard mask; performing deep silicon etching steps on the back after photoetching and patterning to obtain a back bionic cochlea spiral cavity structure and in-situ arrayed cilia; etching and releasing the device; bonding the piezoelectric vector hydrophone with a PCB board, and wire-bonding the positive electrode and the negative electrode with the PCB board. The hydrophone has the characteristics of miniaturization, realizes wide-frequency underwater sound detection by using a bionic cochlea spiral diaphragm structure, and improves detection sensitivity by using in-situ integrated bionic cochlea cilia.

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