SOI structure and manufacturing method thereof, MEMS device and manufacturing method thereof

Abstract

The invention relates to an SOI structure and a manufacturing method, and also relates to an MEMSdevice manufactured by utilizing the SOI structure and a method for manufacturing the MEMS device. An insulating layer of the SOI structure is mainly designed to be of a silicon oxide-silicon nitride-silicon oxide multilayer structure, a protruding retaining wall structure is formed on a silicon nitride layer, when an MEMS device is manufactured, an upper silicon dioxide layer is used as a stop layer for deep silicon etching of an isolation groove, it is guaranteed that deep silicon etching has enough process windows, and the fatal problem of short circuit caused by insufficient etching of the isolation groove is avoided; and when a mask layer for etching a comb tooth electrode and an isolation groove is removed, a VHF gas phase etching technology in an existing technology is replaced by a wet etching technology, a silicon nitride layer is used as a stop layer of wet etching, silicon nitride retaining wall structures on the two sides of the bottom of the isolation groove can effectively prevent lateral corrosion to the insulating layer in the wet etching process, and the insulating effect of the isolation groove and the reliability of the device can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an SOI structure and a manufacturing method, and also to a MEMS device made with the SOI structure and a method for manufacturing the MEMS device. Background technique [0002] SOI (Silicon-On-Insulator) is silicon on insulating layer. This technology is a multi-layer structure formed by introducing a buried oxide layer between the top silicon and the back substrate silicon. Due to the unique advantages of the SOI structure, devices based on this structure will substantially reduce junction capacitance and leakage current, increase switching speed, reduce power consumption, and achieve high-speed, low-power operation. Its performance is significantly better than bulk silicon devices and circuit. At present, devices manufactured with SOI structures have been widely used in most fields of microelectronics, and are also applied in other fields such as optoelectr...

AI Technical Summary

Problems solved by technology

If the patent figure 1 The insulating layer structure shown is used to solve the problem of poor insulation of the isolation trench of MEMS devices, but it still cannot avoid the problem of lateral corrosion of the oxide layer at the bottom of both sides of the isolation trench during the etching process, and the reliability of the device cannot be effectively improved.

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