Method for reducing stickiness in manufacturing process of micro-electro-mechanic-system microphone

Abstract

The invention discloses a method for reducing stickiness in a manufacturing process of a micro-electro-mechanic-system microphone. The micro-electro-mechanic-system microphone includes a silicon substrate with an acoustic rear cavity, an oxide film on the silicon substrate, a first polycrystalline silicon layer on the oxide film, a silicon dioxide layer on the first polycrystalline silicon layer, and a second polycrystalline silicon layer which is on the silicon dioxide layer and provided with sound holes. The method includes the following steps: removing the silicon dioxide layer so as to form an acoustic front cavity; cleaning the micro-electro-mechanic-system microphone; immersing the micro-electro-mechanic-system microphone in a low-surface-tension liquid; and drying the micro-electro-mechanic-system microphone so as to enable the low-surface-tension liquid in the acoustic front cavity to volatilize and at the same time, and using sound wave vibration to enable a vibrating diaphragm of the micro-electro-mechanic-system microphone to vibrate so as to reduce generation of stickiness. During drying of the micro-electro-mechanic-system microphone, sound wave vibration is used so enable the vibrating diaphragm of the micro-electro-mechanic-system microphone to vibrate so that a probability that a stickiness phenomenon happens is reduced and the yield of the micro-electro-mechanic-system microphone is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing technology, in particular to the field of micro-electro-mechanical system microphone manufacturing technology, and in particular to a method for reducing stickiness generated during the manufacturing process of micro-electro-mechanical system microphones. Background technique [0002] In the micro-electro-mechanical system (Micro-Electro-Mechanic System, MEMS) process, for microphone products, it is necessary to release the medium between the diaphragm and the substrate. [0003] figure 1 A schematic cross-sectional view of the MEMS microphone before media release is shown. Such as figure 1 As shown, the MEMS microphone before dielectric release includes a silicon substrate 1 with an acoustic back cavity 6, an oxide film 2 on the silicon substrate, a first polysilicon layer (Poly1 ) 3. A silicon dioxide layer 4 on the first polysilicon layer, a second polysilicon layer (Poly2) 5 with ...

AI Technical Summary

Problems solved by technology

When drying in the prior art, due to the influence of the surface tension of the liquid, the diaphragm of the MEMS microphone will be driven to move toward the substrate, and finally the diaphragm and the substrate will stick together, resulting in stickiness, such as Figure 4 As shown, and this phenomenon is irreversible, that is to say, it is impossible to separate the diaphragm and substrate of the sticky microphone, which will affect the yield of the microphone product.

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