MEMS structure

Abstract

The invention discloses an MEMS structure comprising a substrate which comprises an outer ring body and a first inner ring body which is arranged in the outer ring body and spaced from the outer ringbody, wherein cavities are formed between the outer ring body and the first inner ring body and in the inner side of the first inner ring body; and a piezoelectric composite vibration layer formed above the substrate, and comprising a fixed end connected with the first inner ring body and a free end suspended above the cavity. By arranging one or more inner ring bodies, the length of a cantileverbeam from the fixed end to the free end is shortened, so that the warping probability of the diaphragm of the piezoelectric composite vibration layer is reduced. The sensitivity of a plurality of cantilever beam structures in the piezoelectric composite vibration layer is effectively improved.

Description

technical field [0001] The present application relates to the field of semiconductor technology, and in particular, relates to a MEMS (short for MicroelectroMechanical Systems, microelectromechanical systems) structure. Background technique [0002] MEMS microphones (microphones) mainly include two types: capacitive and piezoelectric. MEMS piezoelectric microphone is a microphone prepared by microelectromechanical system technology and piezoelectric thin film technology. Due to the use of semiconductor planar technology and bulk silicon processing technology, it has small size, small volume and good consistency. At the same time, compared with condenser microphones, there are advantages such as no need for bias voltage, wide operating temperature range, dustproof, waterproof, etc., but its sensitivity is relatively low, which restricts the development of MEMS piezoelectric microphones. Moreover, when the diaphragm size of the MEMS piezoelectric microphone is large, it is ea...

AI Technical Summary

Problems solved by technology

At the same time, compared with condenser microphones, there are advantages such as no need for bias voltage, wide operating temperature range, dustproof, waterproof, etc., but its sensitivity is relatively low, which restricts the development of MEMS piezoelectric microphones.

Moreover, when the diaphragm size of the MEMS piezoelectric microphone is large, it is easy to cause the diaphragm to warp

[0003] For the problems of how to improve the low sensitivity of the piezoelectric MEMS structure and the easy warping of the diaphragm in related technologies, no effective solution has been proposed so far.

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