Microphone, preparation method thereof and electronic equipment

Abstract

The invention provides a microphone, a preparation method thereof and electronic equipment. The preparation method comprises the steps: firstly forming a peripheral pattern of an upper back polar plate in advance, then carrying out the material deposition of a protection layer, and finally forming a through hole pattern needed by the sound transmission of the upper back polar plate. According to the method, a protective layer on the side wall of the upper back polar plate and an isolation material layer on the upper back polar plate are formed at the same time; therefore, an existing double-layer protection structure of a buffer layer and a barrier layer on the side wall of the upper back polar plate can be thinned into a one-layer structure with only the barrier layer; an existing three-layer upper back polar plate structure including a silicon nitride layer, a polycrystalline silicon layer and a silicon nitride layer is thinned into a double-layer structure including a silicon nitride layer and a polycrystalline silicon layer. Therefore, the process is simplified, the number of film layers of the microphone is reduced, the problem of wafer warping caused by overlarge film stacking stress and the problem of film peeling caused by mismatching of film stress are solved, and the performance of the microphone is ensured.

Description

technical field [0001] The invention relates to the technical field of microphone production, in particular to a microphone, a preparation method thereof, and electronic equipment. Background technique [0002] MEMS (Micro-Electro-Mechanical Systems) microphone is an acoustic-electric transducer manufactured by micro-machining technology, which has the characteristics of small size, good frequency response characteristics, and low noise. With the miniaturization and thinning of electronic devices, MEMS microphones are more and more widely used in these devices. The basic structure of a kind of double-back polar MEMS microphone comprises: a diaphragm positioned in the middle and two back polar plates separated on both sides of the diaphragm, i.e. an upper back polar plate (TBP, top back plate) and a lower back polar plate. plate (BBP, bottom back plate), wherein each of the back plates adopts a sandwich structure with a layer of polysilicon film sandwiched between two layers...

AI Technical Summary

Problems solved by technology

[0003] The preparation process of the existing dual-back pole MEMS microphone is complex, there are too many films, and the problem of film peeling is prone to occur due to the stress mismatch between the films

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