Structure and device of silicon-based cantilever beam type MEMS piezoelectric microphone

Abstract

The invention relates to a structure and device of a silicon-based cantilever beam type MEMS piezoelectric microphone, in particular to the field of microphone devices. The invention provides a structure of a silicon-based cantilever beam type MEMS piezoelectric microphone. The structure comprises a substrate, a first electrode layer, a piezoelectric material layer and a second electrode layer, the first electrode layer, the piezoelectric material layer and the second electrode layer are all of a T-shaped structure, and the short end of the first electrode layer of the T-shaped structure is connected with the edge of the opening position of the opening cavity structure, so that the first electrode layer, the piezoelectric material layer and the second electrode layer form a cantilever beam structure, the cantilever beam structure can vibrate under the action of sound vibration, so that charges on the piezoelectric material layer are transferred, the quantity of charges on the first electrode layer and the second electrode layer is changed, that is, the output of the microphone structure is changed, and by detecting an output electric signal, a more accurate sound signal can be obtained.

Description

technical field [0001] The present application relates to the field of microphone devices, in particular to the structure and device of a silicon-based cantilever beam MEMS piezoelectric microphone. Background technique [0002] A microphone is an energy conversion device that converts sound signals into electrical signals, also known as microphones and microphones. At present, it has been widely used in various electronic fields, military fields, medical fields, etc. In addition, sensitivity and lower resonant frequency will become necessary conditions. [0003] MEMS microphones are now widely used in consumer electronics. With the advancement of technology, piezoelectric silicon microphones have gradually begun to develop. However, compared with the capacitor microphone, the biggest disadvantage affecting the popularization and application of the piezoelectric microphone is that the sensitivity of the piezoelectric microphone is too low due to the high resonant frequenc...

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Problems solved by technology

[0004] The working frequency of the microphone is generally 20-20kHz. In order to improve the sensitivity of the piezoelectric microphone, most manufacturers use slots on the piezoelectric film, but the design of the slot makes the leakage of low-frequency signals and even intermediate-frequency signals extremely Seriously, making the microphones in the prior art less sensitive

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