Integrated Fabry-Perot MEMS acceleration sensitive chip processing method

Abstract

The invention discloses a method for processing an integrated Fabry-Perot MEMS acceleration sensitive chip, which comprises the following steps of: firstly, manufacturing a cavity depth reference groove by wet etching, etching a cavity on a silicon wafer by taking the groove as a reference, and repeatedly and alternately depositing silicon oxide and silicon nitride films on the surface of the cavity to manufacture an optical reflection increasing film; repeatedly and alternately depositing silicon oxide and silicon nitride films on the surface of the glass wafer, and patterning to form an optical reflection increasing film; carrying out anodic bonding on the silicon and the glass wafer, and thinning the silicon wafer to a target thickness; and finally, releasing the spring mass structure by adopting a deep reactive ion etching technology. According to the invention, the problem that the sensitive chip is deformed or damaged due to residual stress caused by bonding after etching in the prior art can be avoided, and the method has the advantages of simple process and high yield; in addition, due to the cavity depth reference groove step, it can be guaranteed that the manufactured sensitive chip works in a high-sensitivity state.

Description

technical field [0001] The invention relates to the technical field of micro-electro-mechanical systems, in particular to an integrated Fabry-Perot MEMS acceleration-sensitive chip processing method. Background technique [0002] MEMS acceleration sensors are widely used in robotics, drones, smart cars, consumer electronics and other fields due to their advantages of high precision, small size, low power consumption, low cost, and ease of mass production. At present, common MEMS acceleration sensors can be divided into capacitive, resonant, piezoresistive, optical and other types according to their different detection methods. Among them, the MEMS acceleration sensor based on the principle of optical interference combines the ultra-high displacement resolution of optical detection with the characteristics of small size and low power consumption of MEMS technology, and has a wide range of application prospects. [0003] The processing technology of the sensitive chip of the ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide an integrated Fabry-Perot MEMS acceleration-sensitive chip processing method to overcome the problem of deformation or damage of the sensitive chip caused by the residual stress in the prior art after etching first and then bonding, and has the advantages of simple process and high yield. In addition, the present invention can ensure that the cavity length of the final Fabry-Perot cavity is consistent with the design value, thereby ensuring that the sensor is in a highly sensitive working state

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