MAGNETIC FIELD SENSOR USING MAGNETORESISTANCE AND METHOD FOR MAKING SAME

摘要

The invention concerns magnetic field sensors wherein magnetoresistance is used as physical phenomenon for detecting and measuring the magnetic field. It consists in producing a stack comprising a first ferromagnetic layer (101), and insulating layer (103), a second ferromagnetic layer (102) and an antiferromagnetic layer (104). The two ferromagnetic layers have opposite magnetizing directions and they form with the insulating layer a tunnel junction. The anisotropy of the first layer is derived from the energy of the shape of the substrate whereon it rests and which is slightly disoriented relative to it. The anisotropy of the second layer is obtained by the action of the antiferromagnetic layer. The magnetic field to be measured, wherein is immersed the sensor, modifies the characteristics of the tunnel junction, and hence of the current which passes therein when the magnetic layers are powered by a voltage source, in proportions much greater than those obtained with other systems.