All-silicon MEMS device structure and manufacture method thereof

Abstract

The invention relates to an all-silicon MEMS (Micro Electro-Mechanical Systems) device. The all-silicon MEMS device consists of a liner SOI silicon chip (17), a structural layer silicon chip (10) and a nut cap SOI silicon chip (16) which are subjected to direct silicon-silicon bonding, and is characterized in that a top silicon (6) of the structural layer silicon chip (10) and the nut cap SOI silicon chip are low-resistance silicon; the top silicon (6) of the nut cap SOI silicon chip is made into an electric interconnection wire and subjected to direct silicon-silicon bonding with the structural layer silicon through a bonding face (5); an electrical signal of the structural layer is led to a silicon electrode (9) in the nut cap SOI silicon chip through the electric interconnection wire and is electrically connected with a pressure welding point (3) on the silicon electrode (9); the silicon electrode (9) is subjected to direct silicon-silicon bonding with the structural layer silicon. The all-silicon MEMS device has the advantages that as the nut cap layer bulk silicon wires are adopted, the structural layer is prevented from pickling splash damage; as twice direct silicon-silicon bonding is adopted, residual stress is eliminated; the direct silicon-silicon bonding is good in airtightness; a getter does not need to be additionally added during vacuum packaging, so that the cost is effectively reduced.

Description

technical field [0001] The invention belongs to the field of micro-electromechanical technology, and in particular relates to a structure of an all-silicon MEMS device through a silicon lead of a cap body and a manufacturing method thereof. Background technique [0002] Micro Electro-Mechanical Systems (MEMS) is a new discipline developed on the basis of semiconductor integrated circuits. MEMS has attracted widespread attention due to its advantages of miniaturization, low power consumption, and mass production. It is widely used in automotive electronics, consumer electronics, biomedicine, aerospace, information technology and other fields. In recent years, the MEMS market has developed rapidly and has become a new economic growth point. [0003] MEMS processing technology is developed on the basis of semiconductor integrated circuits, and has formed processing methods represented by bulk silicon technology and surface sacrificial layer technology. Compared with semicondu...

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Problems solved by technology

The MEMS process method based on silicon-glass bonding is simple, but the residual stress after bonding the silicon wafer and glass affects the performance of the device; in the processing method based on the silicon-silicon bonding process, the silicon on the top layer of the substrate SOI silicon wafer is used as the interconnection line. The bottom surface needs to be covered by a silicon dioxide protective layer. After the suspension structure is etched through, etching ions bombard the silicon dioxide layer on the surface of the substrate, which will cause backsplash, which will easily cause backsplash damage to the back of the suspension structure. The method needs to add a getter during vacuum packaging, resulting in a significant increase in processing costs

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