Etching method of micro-electromechanical system element

Abstract

The invention discloses an etching method of a micro-electromechanical system element. The method comprises the following steps: providing a substrate having a first surface and a second surface opposite to the first surface, wherein the first surface of the substrate is provided with a substrate structure, a sacrifice structure and at least one adhesion layer, the adhesion layer is arranged between the substrate structure and the sacrifice structure, and the substrate structure is arranged between the adhesion layer and the substrate; performing a surface grinding manufacturing process on the second surface of the substrate; performing a first plasma etching manufacturing process on the sacrifice structure with a first mixed gas containing oxygen and a first nitrogen-containing gas to remove the sacrifice structure; and performing a second plasma etching manufacturing process on the adhesion layer with a second mixed gas containing a second nitrogen-containing gas and a fluorine-containing gas to remove the adhesion layer.

Description

technical field [0001] The invention relates to an etching method of a microelectromechanical element, and in particular to a plasma etching method of a microelectromechanical element. Background technique [0002] Microphones are widely used in daily life. For example, any device that converts received sound into electrical signals can be seen, such as mobile phones, recording pens, telephones, walkie-talkies, earphones, etc. Compared with traditional microphones, microphones manufactured by semiconductor processing have the characteristics of miniaturization, power saving and multi-function. Moreover, currently there are generally products on the market that package a micro-microphone and an analog amplifier circuit into a single micro-electro-mechanical microphone (MEMS Microphone). [0003] There are about three common types of MEMS microphones, namely piezoelectric (Piezoelectric), piezoresistive (Piezoresistive) and capacitive (Capacitive). Generally, piezoelectric M...

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Problems solved by technology

[0005] However, in the traditional MEMS manufacturing process, it is not easy to completely remove the sacrificial layer originally located in the insulating air layer 130 to form a clean insulating air layer 130

However, if the residue of the sacrificial layer exists between the diaphragm 110 and the back plate 120, it may cause reliability problems and power consumption problems of the capacitive MEMS microphone.

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