Monolithic integrated CMOS (Complementary Metal Oxide Semiconductor) MEMS (Micro-electromechanical Systems) multilayer metal three-axis capacitive accelerometer and manufacturing method thereof

Abstract

The invention provides a monolithic integrated three-axis accelerometer and a manufacturing method thereof so as to solve the defects in structure and manufacturing technology of the existing structural capacitive accelerometer. Three layers of metal Al thin films are deposited in the direction of an axis Z so as to form a comb pair sensitive electrode; four layers of metal Al/SiO2 thin films are deposited in the directions of an axis X and an axis Y so as to form comb pair sensitive electrodes, and the accelerations of the three axis directions are detected simultaneously by a single integrated structure. The accelerometer and the manufacturing method thereof have the following positive technical effects: the interconnection stray capacitance among accelerator devices in three axis directions is lowered remarkably, and high detection accuracy and lower noise performance are realized; since the accelerometer is provided with the multiple metal layers, compared with a microaccelerometer manufactured from the same material, namely polycrystalline silicon, the accelerometer is more flexible in wiring; a foldable beam is used in the structure of the accelerometer, so that the own stress of the accelerometer is released better, and therefore the influence of the stress on the system can be reduced effectively.

Description

technical field [0001] The invention relates to the technical field of micro sensor manufacturing, in particular to a single-chip integrated CMOS MEMS multi-layer metal triaxial capacitive acceleration sensor. Background technique [0002] MEMS microsensors are an important part of microelectromechanical systems, such as pressure sensors, chemical sensors, biosensors, accelerometers, etc. Among them, micromechanical accelerometers that integrate IC technology and MEMS technology are small in size, low in power consumption, and easy to use. The characteristics of integration, strong overload resistance and mass production are widely used in the core components of MIMU. With the development of MEMS design methods and process technology, micro-mechanical accelerometers have been widely used in various consumer fields such as missile guidance, household appliances, and automotive electronics. [0003] Capacitive accelerometers have become the most widely used type of micromachi...

AI Technical Summary

Problems solved by technology

Due to the use of three independent capacitive acceleration sensors, the overall volume of the three-axis capacitive acceleration sensor with this structure is bound to be too large, and additional wiring is required, which leads to the complicated process of the three-axis capacitive acceleration sensor with this structure. High cost and low authenticity rate

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