Manufacturing method of micro-electromechanical device, micro-electromechanical device and micro-electromechanical device base structure

Abstract

The invention relates to a manufacturing method of a micro-electromechanical device, a micro-electromechanical device and a micro-electromechanical device base structure. The manufacturing method of the micro-electromechanical device comprises the following steps: S1: providing a micro-electromechanical device base structure, wherein the micro-electromechanical device base structure comprises a substrate provided with an upper surface and a lower surface, at least one stop layer arranged on the upper surface of the substrate, and a device layer arranged on the topmost stop layer, wherein the substrate and the stop layer most adjacent to the substrate are made from different materials; and S2: etching the substrate by a dry process, and etching the stop layer(s) by a wet process. In the dry-process substrate etching according to the manufacturing method, the etching firstly stops at the stop layer, and the stop layer is etched by the wet-process etching technique; and thus, in the dry-process etching, the stop layer is utilized to enhance the strength of the device layer so as to avoid the damage of the device layer, thereby enhancing the yield and satisfying the manufacturing of minisize devices.

Description

technical field [0001] The invention relates to a manufacturing method of a microelectromechanical device, a microelectromechanical device and a base structure of the microelectromechanical device. Background technique [0002] Silicon is widely used in IC manufacturing and MEMS manufacturing because of its superior mechanical and electrical properties. In order to meet the manufacturing requirements of various geometric shapes such as pits, holes, teeth, etc., it is mainly obtained by dry etching and wet etching. When etching the back cavity of the device, KOH solution or TMAH can be used as the etching solution. However, the etching rate of this method is slower than that of dry deep silicon etching (DRIE), and at the same time, the sidewall forms a 54.74-degree inclination angle with the silicon wafer surface, resulting in a larger chip area. DRIE uses the Bosch process of etching and sidewall protection alternately to protect the sidewall, which can achieve controllabl...

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Problems solved by technology

However, see figure 1 and figure 2 , when etching the silicon substrate 11, due to the weak strength of the thinner device layer 12, the thin film of the device layer 12 is prone to damage

The damaged device layer 12 will contaminate or even damage the machine, which will increase the manufacturing cost and even make mass production impossible

[0004] In addition, due to the possibility of etching deviation during dry etching of the substrate, in order to compensate for the deviation of dry etching, it is usually necessary to etch the bottom substrate by overetching, so it is easy to etch the bottom substrate. damage device layer 12 during etching

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