Silicon piezoresistive type pressure sensor chip

Abstract

The invention relates to a silicon piezoresistive type pressure sensor chip comprising a silicon piezoresistive type pressure sensor base body, an isolation layer, a stability enhancement layer, a metal layer, contact holes, and a silicon substrate heavily-doped region. The chip is characterized in that the silicon piezoresistive type pressure sensor is made of an SOI silicon wafer; and a silicon dioxide layer is buried below piezoresistors. The isolation layer covers the silicon piezoresistive type pressure sensor base body; the contact holes are etched in the isolation layer and are filled with metals; the metals and the silicon substrate heavily-doped region are in ohmic contact and the metals are also connected with the metal layer of the chip surface; the stability enhancement layer is arranged on the isolation layer; and the stability enhancement layer and the metals in the contact holes are electrically connected by the metal layer. A highest potential point of the chip is formed at the metal layer, thereby forming a power supply welding plate of the sensor. The chip has the following advantages: on the premise that the structure of the traditional silicon piezoresistive type pressure sensor chip is not changed substantially, the structure of the silicon piezoresistive type pressure sensor chip is changed slightly and a few process steps are added, so that the output stability is improved obviously.

Description

technical field [0001] The invention relates to a device for measuring pressure, in particular to a silicon piezoresistive pressure sensor chip. 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, differential pressure, and other physical quantities that can be converted into changes in force (such as liquid level, acceleration, weight, strain, flow, vacuum). [0003] At present, silicon piezoresistive pressure sensor chips produced and used in large quantities are made of P-type piezoresistors on N-type silicon substrates...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the phenomenon that the current silicon piezoresistive pressure sensor chip is unstable due to leakage and static charge. The present invention provides a silicon piezoresistive pressure sensor chip for improving the stability structure pressure sensor chip

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