MEMS resonant pressure sensor based on Si-Si-Si-glass wafer bonding technology and manufacturing process thereof

Abstract

The invention discloses a MEMS resonant pressure sensor based on Si-Si-Si-glass wafer bonding technology and a manufacturing process thereof. The order of the MEMS resonant pressure sensor from top tobottom is a Si pressure sensitive layer, a Si resonator layer, a Si pit substrate layer, a glass pit substrate layer, a Si pressure sensitive layer and a Si resonator layer. The Si resonator layer and the Si pit substrate layer are bonded by a Si-Si bonding process. The Si pit substrate layer and the glass pit substrate layer are bonded by a Si-glass anodic bonding process. A first SiO2 layer isarranged between the Si pressure sensitive layer and the Si resonator layer, and a second SiO2 layer is arranged between the Si resonator layer and the Si pit substrate layer. According to the MEMS resonant pressure sensor of the invention, the process difficulty of MEMS micro-nano processing and high vacuum packaging is reduced; residual stress and thermal stress are effectively reduced; reliability and vacuum and long-term maintenance of the vacuum reference cavity are improved; temperature compensation accuracy is improved; the overall accuracy and stability of the pressure sensor is improved.

Description

technical field [0001] The invention belongs to the field of sensitive chips of resonant pressure sensors, in particular to a high-precision and high-stability MEMS resonant pressure sensor based on Si-Si-Si-glass four-layer wafer bonding technology. Background technique [0002] High-precision, high-stability pressure sensors are used in new generation fighters, large transport aircraft and civil aviation airliners, space stations and deep space and extraterrestrial planet detection, submarines and deep-sea submersibles, aerospace and missile weapons, vacuum pipeline high-speed vehicles, meteorological observation, Consumer electronics and other fields have a wide range of application requirements. The resonant pressure sensor is the one with the highest comprehensive accuracy, the best temperature stability and long-term stability among all kinds of pressure sensors, and has been widely recognized by the academic research field and the industry. Micro-Electro-Mechanical S...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to overcome the shortcomings of the existing MEMS silicon resonant pressure sensor in terms of long-term stability, reliability, and manufacturing process difficulty, and provide a high-precision and high-precision sensor based on Si-Si-Si-glass four-layer wafer bonding technology. Stable MEMS resonant pressure sensor reduces the manufacturing process difficulty of high-vacuum wafer packaging and long-term vacuum maintenance, and the accuracy, stability and reliability of the sensor are significantly improved

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