Monolithic silicon based SOI high-temperature low-drift pressure sensor

Abstract

The invention relates to a single chip silicon SOI high temperature low drift pressure sensor in the field of sensitive sensing technology. Wherein the four voltage-sensitive resistances which form the Wheatstone bridge adopt SOI material; it adopts the interval compensation and the outer compensation technology of partial interval resistance of the SOI resistance network to make the zero point temperature drift below 1X10-6Vs / íµ; it adopts girder-film-island structure to improve the sensibility and linearity of the sensor; it adopts polysilicon with thick boron and the aluminum lead wire covered the lead wire surface to form the interval lead wire of the sensor; it adopts thick boron automatically end technology to make high sensibility high temperature low drift pressure sensor.

Description

technical field [0001] The invention belongs to the field of sensing technology, and in particular relates to a monolithic silicon-based SOI high-temperature and low-drift pressure sensor and a manufacturing method thereof. Background technique [0002] At present, the general monocrystalline silicon pressure sensor adopts P-N junction isolation, and there is P-N junction leakage, which leads to low yield, large output temperature drift, and cannot work above 250°C. The pressure sensor made of polysilicon or other SOI technology, due to the use of dielectric isolation, its operating temperature can reach more than 300 ° C, which can meet the requirements of the operating temperature, but the zero point drift is too large to meet the requirements of practical applications. [0003] Due to technical reasons, there is always a certain offset voltage in micromachined silicon pressure sensors. This offset voltage is typically between 50mV and 100mV. In principle, the offset vol...

AI Technical Summary

Problems solved by technology

But in fact it doesn't solve the problem

Parallel or series compensation can achieve zero adjustment at a certain temperature, but it will cause a large additional temperature drift, and the additional temperature drift caused by compensation can generally reach 1 to 2×10 -5 VS / °C, which is equivalent to the additional temperature drift caused by the change of operating temperature of 200°C is more than 50% of the full-scale output, which is not practical

However, the series-parallel compensation has strict requirements on the temperature coefficient of the resistance used for compensation, which cannot be practically applied.

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