Miniature microphone manufacturing method based on Si-Si bonding process

Abstract

The invention relates to a miniature microphone manufacturing method based on an Si-Si bonding process, which comprises the following steps that: a. a connecting plate and a back plate are provided; b. the back plate and the connecting plate are bonded and fixed; c. the back plate is thinned; d. an insulating bonding layer is grown on the thinned back plate; e. a substrate is provided; f. an insulating supporting layer is grown on the substrate; g. a vibrating diaphragm is precipitated on the substrate; h. the vibrating diaphragm which is arranged in a groove is obtained; i. the back plate and the substrate are bonded and fixed; j. the connecting plate and an oxidization layer above the substrate are etched; k. a lower electrode hole is obtained on the back plate; l. an electrode layer is precipitated on the back plate; m. electrodes on the back plate and the vibrating diaphragm are obtained; n. a plurality of sound holes on the back plate are obtained; and o. the other end of the substrate which corresponds to the back plate is etched to obtain a vocal cavity below the vibrating diaphragm. The miniature microphone manufacturing method based on the Si-Si bonding process has the advantages of high sensitivity, low cost, wide frequency band, high finished product rate and simple manufacturing process.

Description

technical field [0001] The invention relates to a method for preparing a miniature microphone, in particular to a method for preparing a miniature microphone based on a silicon-silicon bonding process. Background technique [0002] MEMS (Micro-Electro-Mechanical Systems) technology is a high-tech that has developed rapidly in the past few years. Compared with traditional counterparts, MEMS devices have obvious advantages in terms of volume, power consumption, and weight. The advanced semiconductor manufacturing process can realize the batch manufacturing of MEMS devices, can control the production cost extremely well, and improve the consistency of the devices. For the current MEMS products, accelerometers, pressure sensors, gyroscopes, micromirrors, silicon microphones, etc. have all been mass-produced and have occupied a certain share in the corresponding market. [0003] Silicon microphones are characterized by high temperature resistance, low power consumption, and smal...

AI Technical Summary

Problems solved by technology

[0005] At present, there are usually two ways to improve the residual stress of the diaphragm. One is to use an additional process and annealing. This method requires extremely high process control and the repeatability is not very good; the other is through structural adjustment, such as manufacturing Free film or textured film structure, but the fabrication of this structure will increase the complexity of the process, and it may be necessary to add a multi-step process to control the diaphragm

Realizing a rigid back electrode is also a major difficulty in the microphone manufacturing process. At present, there are two main methods to solve it. One is to make a thick back electrode, but it is difficult to obtain the required thick back electrode through conventional deposition processes; One method is to improve the rigidity of the back plate through structural adjustment, but it also increases the complexity of the process

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