Manufacturing method of closed cavity of micro-electromechanical system (MEMS)

Abstract

The invention provides a manufacturing method of a closed cavity of a micro-electromechanical system (MEMS). The manufacturing method comprises the steps: forming a sacrificial oxidation layer on a semiconductor substrate, and etching the sacrificial oxidation layer to form a cavity boundary figure; depositing a stop layer of the cavity, and etching the cavity stop layer to form a cavity etching hole array; etching the sacrificial oxidation layer and the semiconductor substrate by the cavity etching hole array to form a cavity; filling the cavity etching hole array to form the closed cavity. The cavity stop layer is deposited on the semiconductor substrate, the sacrificial oxidation layer is formed on the semiconductor substrate, the sacrificial oxidation layer and the semiconductor substrate are etched by the cavity etching hole array formed on the cavity stop layer, so that the cavity is formed; and therefore, the minimum size of the cavity can greatly reduced to a certain extent, the minimum thickness of a top dielectric layer is reduced, a silicon wafer bonding process is omitted, the problems of interfaces holes and the like can be avoided, and the reliability of a device can be improved.

Description

technical field [0001] The invention relates to the technical field of micro-electromechanical systems, in particular to a method for manufacturing a MEMS closed cavity. Background technique [0002] At present, as a semiconductor substrate that can improve the performance of semiconductor devices, SOI (Silicon on Insulator, silicon on insulator) has been widely valued. SOI is a conventional single crystal silicon wafer embedded with a layer of insulating silicon dioxide. A new type of semiconductor silicon material formed from silicon, including a silicon substrate, an insulating layer and a top silicon layer. In the prior art, the methods for manufacturing SOI materials mainly include: [0003] Ion implantation technology: Using the principle of ion implantation of oxygen, oxygen ions are implanted under the surface of the silicon wafer, and a layer of buried oxide layer is formed through annealing treatment, so as to obtain a top silicon layer on the insulating silicon s...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a method for manufacturing a MEMS closed cavity, which does not need to use a silicon wafer bonding process, and solves the problems of high cost, long processing cycle and easy silicon-silicon bonding caused by CSOI production in the prior art. Interface holes and other issues

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