Silicon piezoresistive type pressure sensor chip with shielding layer

Abstract

A silicon piezoresistive type pressure sensor chip with a shielding layer comprises a silicon substrate, voltage dependent resistors, metal wires, a metal welding plate, a protective layer, a shielding layer cap and heavy doping silicon wires. A Wheatstone bridge composed of a plurality of voltage dependent resistors is arranged on the surface of the pressure diaphragm on the silicon substrate, the protective layer is arranged on the pressure diaphragm, and the plurality of voltage dependent resistors are connected with the metal welding plate on the protective layer through the heavy doping silicon wires and the metal wires. The silicon piezoresistive type pressure sensor chip with the shielding layer is characterized in that a shielding layer cap which is used for improving the performance of a sensor and undergoes a doping process is arranged between the pressure diaphragm and the protective layer, and the shielding layer cap isolates the protective layer and the voltage dependent resistors. The silicon piezoresistive type pressure sensor chip with the shielding layer has the advantages of arranging a shielding layer undergoing the doping process between the pressure diaphragm and the protective layer, and solving the problem of pressure sensor output drift.

Description

technical field [0001] The invention relates to a device for measuring pressure, in particular to a silicon piezoresistive pressure sensor chip with a shielding layer. Background technique [0002] Silicon piezoresistive pressure sensor is a sensor made by using the piezoresistive effect of single crystal silicon material and integrated circuit technology. After the monocrystalline silicon material is subjected to force, the resistivity changes, and the electrical signal output proportional to the force change can be obtained through the measurement circuit. Silicon piezoresistive pressure sensors have been widely used in the measurement and control of pressure, tension, pressure difference, and other physical quantities that can be converted into changes in force (such as liquid level, acceleration, weight, strain, flow, vacuum). [0003] Since the piezoresistor of the silicon piezoresistive pressure sensor has been doped, the carriers in the piezoresistor have the charact...

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Problems solved by technology

[0003] Since the piezoresistor of the silicon piezoresistive pressure sensor has been doped, the carriers in the piezoresistor have the characteristics of mobility, so the resistance of the piezoresistor changes with the change of the external electric field, resulting in the output of the pressure sensor drift

So far, there have been no reports about domestic sensor manufacturers making improvements to this phenomenon.

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