Temperature-integrated high-performance pressure sensor chip and manufacturing method thereof

Abstract

The invention discloses a temperature-integrated high-performance pressure sensor chip and a manufacturing method of the chip. The manufacturing method comprises the steps that an SOI silicon wafer is subjected to thermal oxidation to form a thin oxide layer, and then low-stress silicon nitride is subjected to LPCVD; photoetching is conducted on the reverse side of the SOI silicon wafer, a pressure sensitive film is obtained through wet etching, and a cavity is formed in the area of the pressure sensitive film; the silicon nitride and silicon oxide on the SOI silicon wafer are removed; a monocrystalline silicon substrate silicon wafer is subjected to thermal oxidation, alignment marks are formed in the reverse side of the monocrystalline silicon substrate silicon wafer through photoetching and corrosion, and the oxide layer is removed; the SOI silicon wafer and a monocrystalline silicon substrate are subjected to silicon-silicon bonding so that the cavity in the SOI silicon wafer can form an airtight cavity; top-layer silicon of the SOI silicon wafer is subjected to ion injection, photoetching and etching to form eight bulk resistors doped with monocrystalline silicon; metal sputtering, photoetching and corrosion are conducted to form metal guide lines, and the metal guide lines are connected with all the bulk resistors to form a measuring circuit. The temperature-integrated high-performance pressure sensor chip achieves simultaneous measurement of pressure and temperature, and overcomes the defect that device performance deteriorates due to reverse leakage currents of a PN junction of a pressure sensor at a high temperature.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a temperature-integrated high-performance pressure sensor chip and a manufacturing method. Background technique [0002] High-performance pressure sensors are widely used in many fields such as aerospace, industrial automation control, automotive systems, navigation, environmental monitoring and measurement, and biomedical diagnosis. However, in many applications, while measuring pressure, it is also necessary to measure temperature. [0003] Compared with other types of pressure sensors, piezoresistive pressure sensors are characterized by simple processing and easy signal measurement. However, due to the temperature characteristics of the piezoresistor itself, the sensor has a large temperature drift, and the sensor working in a large temperature range must be temperature compensated. In addition, as the temperature increases, the leakage current of the PN junction increases, wh...

AI Technical Summary

Problems solved by technology

However, due to the temperature characteristics of the piezoresistor itself, the sensor has a large temperature drift, and the sensor working in a large temperature range must be temperature compensated

In addition, as the temperature increases, the leakage current of the PN junction increases, which makes the performance of the sensor more discrete and the stability worse.

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