The invention provides an MEMS integrated device and a preparation method thereof. The device comprises a first rewiring layer, an MEMS layer and an application-specific
integrated circuit layer, the MEMS layer and the application-specific
integrated circuit layer are connected through
wafer-level low-temperature
silicon-
silicon bonding; the MEMS layer is provided with a first through hole and a second through hole which are filled with
copper, the first through hole penetrates through the MEMS layer, and the second through hole penetrates through the cover plate layer and is connected with the MEMS movable structure layer; the first
redistribution layer includes an internal wiring connecting the first via, the second via, and the external
electrode. The internal
electrode is electrically connected with the first through hole.
Wafer-level integration and packaging of the MEMS device and the application-specific
integrated circuit are completed through
wafer-level low-temperature
silicon-silicon bonding, the through holes filled with
copper are formed in the MEMS layer to achieve vertical
interconnection between multiple
chip layers, the situation that through holes used for internal and
external communication are additionally formed in the application-specific integrated circuit is avoided,
copper filling is compatible with the advanced
integrated circuit manufacturing process, and the manufacturing cost is reduced. The MEMS device can be directly integrated with an application-specific integrated circuit
wafer of less than 90 nanometers, so that the compatibility is improved, the packaging cost is reduced, and the packaging efficiency is improved.