Micro-electromechanical system (MEMS) silicon microphone utilizing multi-hole signal operation instruction (SOI) silicon bonding and manufacturing method thereof

Abstract

The invention provides a micro-electromechanical system (MEMS) silicon microphone utilizing multi-hole signal operation instruction (SOI) silicon bonding and a manufacturing method thereof. The MEMS silicon microphone comprises a multi-hole back pole plate silicon substrate and a single crystal silicon vibrating diaphragm placed above the multi-hole back plate silicon substrate. The MEMS silicon microphone is characterized in that the multi-hole back plate silicon substrate and the single crystal silicon vibrating diaphragm serve as two pole plates of a microphone capacitor and are integrated in a bonding mode through a silicon bonding process. The multi-hole back pole plate silicon substrate is provided with a back pole plate metal electrode, a sound aperture and a back cavity, the single crystal silicon vibrating diaphragm is provided with a metal electrode and a small protruded column, and the vibrating diaphragm electrode and the back pole plate respectively serve as output signal leading-out ends of two pole plates of the microphone capacitor to be used for being in electric connection with a complementary metal oxide semiconductor (CMOS) signal amplifying circuit. The single crystal silicon vibrating diaphragm is supported by a silicon oxide layer to be suspended above the multi-hole back plate silicon substrate, and an air gap exists between the single crystal silicon vibrating diaphragm and the multi-hole back plate silicon substrate, and the multi-hole back plate silicon substrate, the single crystal silicon vibrating diaphragm and the air gap form a capacitance structure. The MEMS silicon microphone utilizing multi-hole SOI silicon bonding and the manufacturing method thereof are simple in process, high in product sensitivity, good in consistency and high in yield rate.

Description

technical field [0001] The invention relates to a capacitive silicon microphone and a preparation method thereof, in particular discloses a MEMS silicon microphone using porous SOI silicon-silicon bonding, which belongs to the technical field of silicon microphones. Background technique [0002] Microphones can convert human voice signals into corresponding electrical signals, and are widely used in mobile phones, computers, telephones, cameras and video cameras, etc. The traditional electret condenser microphone uses Teflon as the vibration film, which cannot withstand the high temperature of nearly 300 degrees in the reflow soldering process of the printed circuit board, so it can only be separated from the assembly of the integrated circuit and assembled by hand alone, which greatly increases the production cost . [0003] The development of MEMS (Microelectromechanical Systems) technology and process in the past three decades, especially the development of MEMS technolo...

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Problems solved by technology

However, the method of changing the structure of the vibrating film will complicate the preparation process, increase the cost and reduce the yield

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