mems device and its preparation method

Abstract

The invention provides a MEMS device and a manufacturing method thereof. A vibrating membrane is formed on the front of a base, a supporting part is formed between the vibrating membrane and the base, and the vibrating membrane vibrates relative to the supporting part. The projection on the membrane is symmetrical to the center, and a back cavity is formed on the back of the substrate, the back cavity exposes the vibrating membrane and faces away from the gap, and retains an area facing the support part in the back cavity The base of the support part is used as the support base of the support part, and the vibrating membrane vibrates at the middle position between the edge and the center of the vibrating membrane when vibrating, and compared with the prior art, the effective vibration area is increased, As a result, the sensitivity and signal-to-noise ratio of MEMS devices are improved, while the amplitude of vibration is reduced, and the fluctuation range of sensitivity and signal-to-noise ratio is reduced; at the same time, the force applied to the vibrating membrane in the mechanical reliability test is reduced, Therefore, the reliability of the MEMS device is increased.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a MEMS device and a preparation method thereof. Background technique [0002] MEMS (Micro-Electro-Mechanical System, Micro-Electro-Mechanical System) technology refers to a micro-system that can integrate mechanical components, drive components, optical systems, and electronic control systems into a whole. It uses microelectronics technology and micromachining technology ( Such as silicon body micromachining, silicon surface micromachining, wafer bonding, etc.) combined manufacturing process, to produce a variety of excellent performance, low price, miniaturized sensors (such as inertial sensors, pressure sensors, acceleration sensors, etc.), execution drives, drives and microsystems. [0003] Existing MEMS devices generally include a base, the base has a front and a back, and the base has a back cavity that runs through the front and the back, a vibrating membrane is for...

AI Technical Summary

Problems solved by technology

[0004] However, since the vibrating membrane is equivalent to a thin film in motion, a relatively large amplitude will be generated in a relatively small effective vibration area, and the large vibration amplitude will cause the sensitivity of the device and the fluctuation range of the signal-to-noise ratio to increase, and in some Mechanical reliability tests will exert relatively large force on the vibrating membrane, such as air pressure test or mechanical impact test, which may easily cause loss or damage of the vibrating membrane

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