A MEMS microphone device and a manufacturing method thereof

By setting a cutoff ring on the substrate of the MEMS microphone device to block etching, the problem of the lower electrode plate falling off during wet etching is solved, achieving more stable device repeatability and diaphragm protection, and improving the performance and reliability of the device.

CN115696157BActive Publication Date: 2026-07-14SEMICON MFG ELECTRONICS (SHAOXING) CORP
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
SEMICON MFG ELECTRONICS (SHAOXING) CORP
Filing Date
2022-09-27
Publication Date
2026-07-14

AI Technical Summary

Technical Problem

In the prior art, it is difficult to control the uneven lateral etching during the wet etching process of MEMS microphone devices, which can lead to the detachment of the lower electrode plate, affecting the repeatability and performance stability of the device. In particular, when the lower electrode plate is used as a diaphragm, it is easy to cause diaphragm damage due to over-etching.

Method used

A stop ring is set on the substrate to block the lateral expansion of wet etching. The etching is controlled to stop inside the stop ring by forming a stop ring inside the via, thus avoiding over-etching. The stop ring made of silicon nitride material blocks the etching, ensuring stable support of the lower electrode and stress release of the diaphragm.

Benefits of technology

This effectively avoids the risk of the lower electrode plate detaching, improves the repeatability and performance stability of MEMS microphone devices, reduces the possibility of diaphragm damage, and improves the overall reliability of the device.

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Abstract

The present application relates to a kind of MEMS microphone device and its manufacturing method, wherein the MEMS microphone device includes: substrate with back cavity, first support part formed on the upper surface of substrate and with the through hole being communicated with back cavity, cut-off ring formed on the upper surface of substrate inside through hole, lower plate formed on the upper surface of first support part and cut-off ring, and upper plate;Cut-off ring is used to block the lateral etching of first support part when etching through hole;Lower plate includes lower plate main part and lower plate lead-out part connected with each other;Upper plate is formed above lower plate main part and forms cavity between lower plate main part.The present application stops wet release process in cut-off ring by using cut-off ring, avoids the risk of lower plate falling off caused by over-etching, and can also release the stress of diaphragm for diaphragm structure, to reduce the occurrence of diaphragm breakage.
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