MEMS microphone and micro-electromechanical structure

Abstract

The invention discloses an MEMS microphone and a micro electro mechanical system structure. The micro-electro-mechanical structure is applied to the front sound inlet MEMS microphone, and comprises asubstrate which is provided with a top surface, a bottom surface and a back cavity penetrating through the top surface and the bottom surface, wherein the top surface and the bottom surface are opposite; a back polar plate which is positioned on the top surface of the substrate and is provided with at least one through hole; a vibrating diaphragm, wherein the vibrating diaphragm and the back polarplate form a variable capacitor; and a protective layer which is located on the bottom surface of the substrate and used for preventing foreign matter from entering the gap between the back polar plate and the vibrating diaphragm through the back cavity and the through hole, and the vibrating diaphragm covers the back polar plate so as to prevent the foreign matter from entering the gap from thesurface, away from the back polar plate, of the vibrating diaphragm.

Description

technical field [0001] This application relates to the field of semiconductor device manufacturing, and more specifically, to MEMS microphones and micro-electromechanical structures. Background technique [0002] Devices manufactured based on Micro Electro Mechanical Systems (MEMS) are called MEMS devices. MEMS devices mainly include a vibrating membrane and a back plate, and there is a gap between the vibrating membrane and the back plate. The change of air pressure will cause the deformation of the vibrating membrane, and the capacitance value between the vibrating membrane and the electrode plate will change, which will be converted into an electrical signal output. [0003] In the traditional MEMS microphone structure, it is mainly composed of two parallel plate capacitor structures, the back plate and the vibrating membrane. Among them, the back plate is on the top, and the vibrating film is on the bottom. The sound hole is located on the substrate of the package struc...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the present invention provides an improved MEMS microphone and micro-electromechanical structure, by setting a protective layer in the micro-electromechanical structure, thereby preventing foreign matter from entering the gap between the back plate and the vibrating membrane through the through hole of the back plate , thus improving the short circuit between the back plate and the vibrating membrane in the MEMS structure caused by foreign matter

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