Linkage membrane capacitive pressure sensitive chip and manufacturing method thereof

Abstract

The invention discloses a linkage membrane capacitive pressure sensitive chip and a manufacturing method thereof. The chip comprises a substrate silicon wafer (1), an upper polar plate (2) and a lowerpolar plate (3); and the upper part of the substrate silicon wafer (1) is provided with a groove, the lower polar plate (3) is disposed inside the groove, and the upper polar plate (2) covers an opening of the groove, so that the groove forms a sealed cavity. In the linkage membrane capacitive pressure sensitive chip and the manufacturing method thereof, the suspended movable lower polar plate isdesigned, so that the upper and lower polar plates become movable structures, thereby improving linearity, and a measuring range of a linear region is increased; a silicon thin film on an SOI substrate is utilized to manufacture the upper polar plate of monocrystalline silicon, so that the thickness of the upper polar plate is more easily controlled; silicon-silicon direct bonding technology is used to transfer a single crystal silicon film of the SOI substrate, and a manufacturing process of the upper polar plate is more easily realized; and by controlling the thickness of a deposited sacrificial layer, a suspended height of the lower polar plate is reasonably controlled, and the accuracy of the suspended height is improved.

Description

technical field [0001] The invention mainly relates to a linkage membrane capacitive pressure sensitive chip and a manufacturing method thereof. It belongs to the field of microelectromechanical systems (MEMS). Background technique [0002] With the rapid development of the microelectronics industry, the current MEMS pressure sensor is moving towards the direction of intelligence, miniaturization and integration. Compared with piezoresistive pressure sensors, capacitive pressure sensors have the advantages of high sensitivity, low power consumption, and small temperature drift, and have been widely used in automotive electronics, biomedicine, industrial environmental detection, and national defense and military industries. Especially in the context of increasing pressure measurement accuracy and reliability requirements in modern aerospace technology and modern defense equipment, MEMS capacitive pressure sensors have become a focus of intensive research at home and abroad. ...

AI Technical Summary

Problems solved by technology

Although this structure can alleviate the problem of poor linearity, its working range in the linear region is small and the relative change in capacitance is small, which limits the further improvement of sensor performance.

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