Silicon micro-piezoresistive accelerometer capable of reducing temperature excursion

Abstract

The invention relates to a piezoresistive silicon-micro-accelerometer, in particular to the piezoresistive silicon-micro-accelerometer which can reduce temperature drift. The temperature property of the piezoresistive silicon-micro-accelerometer is improved, and the temperature drift is reduced. The accelerometer comprises a silicon basal framework, a socle beam, a mass block, a strain varistor arranged at the fixed end part of the socle beam, the mass block and the silicon basal framework, a reference varistor arranged on the silicon basal framework and a peripheral zero-regulating resistor arranged outside the silicon basal framework; the peripheral zero-regulating resistor, the strain varistors and the reference varistor are connected to form a wheatstone bridge, the peripheral zero-regulating resistor is independently taken as a bridge arm of the wheatstone bridge; and the peripheral zero-regulating resistor is a varistor which is produced on anther silicon substrate with the same property by adopting an ion injection technology, and the wheatstone bridge containing the varistor is zeroed by controlling the ion injection speed when the varistor is produced. The invention has the advantages of convenient zeroing, low temperature drift, small error output and large operation temperature range.

Description

technical field [0001] The invention relates to a silicon micro piezoresistive accelerometer, in particular to a silicon micro piezoresistive accelerometer capable of reducing temperature drift. Background technique [0002] The design idea of ​​the silicon micro piezoresistive accelerometer comes from the pressure sensor. As early as 1977, the silicon micro accelerometer produced by the Stanford University, the University of California, Berkley and the Draper laboratory using the micromachining process used the piezoresistive detection method. Cantilever beams and mass blocks are processed on the silicon base by using bulk silicon processing technology, and varistors are fabricated on the cantilever beams by ion implantation technology, which are connected to form a Wheatstone bridge. When there is an acceleration acting on the mass block, it will cause the strain of the cantilever beam to be proportional to the acceleration, and the resistance value of the piezoresistor em...

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Problems solved by technology

[0005] However, since the temperature characteristics of the peripheral variable resistance material are different from those of the piezoresistor formed by the ion implantation process on the cantilever beam, this leads to the fact that the output of the accelerometer Wheatstone bridge will change with temperature in the absence of acceleration. The change of the accelerometer changes, and with the increase of the deviation between the ambient temperature and the zero temperature, the output of the accelerometer Wheatstone bridge will be larger, which limits the temperature range of the accelerometer and increases the error of the accelerometer

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