Method for manufacturing monolithic polysilicon cantilever structure

Abstract

The invention relates to a method for manufacturing a monolithic polysilicon cantilever structure. In the invention, a processing step of the polysilicon cantilever structure is inserted in a conventional BiCMOS (Bipolar Complementary Metal Oxide Semiconductor) technical process, the deposition and the annealing of polysilicon are finished and an MEMS (Micro-Electro-Mechanical Systems) high-temperature process is prevented from influencing on the metalation process before the metalation process. In the release process of the polysilicon cantilever structure, a special etching solution is adopted, and a negative photoresist is used as a post of the polysilicon cantilever structure so as to effectively avoid the problem of substrate adhesion in the cantilever structure release process by using a wet method. The method provided by the invention solves the technical problems of compatibility between a manufacture process of the polysilicon cantilever structure and a processing process of a BiCMOS circuit, realizes the monolithic integration of the polysilicon cantilever structure and a BiCMOS signal processing circuit, and can be widely applied to the monolithic integration manufacture field of MEMS sensors, such as capacitive accelerometers, gyroscopes, and the like.

Description

technical field [0001] The present invention relates to a monolithic manufacturing method of a polysilicon cantilever structure, in particular to a monolithic integrated manufacturing method of a polysilicon cantilever structure and a BiCMOS signal processing circuit, which is directly applied to monolithic MEMS sensors such as capacitive accelerometers and gyroscopes integrated manufacturing field. Background technique [0002] MEMS sensors usually include two parts, MEMS microstructure and signal processing circuit. There are generally two methods to realize the electrical connection between the two. One is the hybrid integration method, that is, MEMS microstructure and signal processing circuit are produced separately, and then The finished two chips are hybrid-integrated on a PCB or a ceramic substrate, and packaged into a housing. The biggest advantage of this method is that it avoids the problem of process compatibility and greatly reduces the difficulty of process de...

AI Technical Summary

Problems solved by technology

For example, the high-temperature process steps involved in the manufacture of MEMS microstructures can be completed before the CMOS metallization process, that is, the MEMS high-temperature process is embedded into the standard CMOS process steps, so that the MEMS high-temperature process will not affect the CMOS metallization process process, but this method requires major modifications to the existing standard CMOS process steps, so the cost of this process method is relatively high

[0008] Regardless of the above methods, it is difficult to realize the integration of MEMS microstructure and signal processing circuit.

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