Reduction of offset in pressure sensors with polysilicon piezoresistors by the pulse current annealing method

The effect of the pulse current annealing on conductivity of polysilicon piezoresistors was researched. This method allows to adjust the offset in pressure sensors. The polysilicon resistors with different doping concentration were researched. The first current pulses during annealing lead to the electrical forming of conductivity channels in the polysilicon film and the conductivity of resistor is increased. The further change of resistance depends on the relation between the current amplitude in pulse and the threshold current. If the current amplitude exceeds the threshold value, the resistance of polysilicon piezoresistors is reduced. Otherwise, the resistance is increased.