Magnetic field sensor using magnetoresistance and method for making same

Abstract

The invention relates to magnetic field sensors in which magnetoresistance is used as the physical phenomenon for detecting and measuring the magnetic field. It consists in producing a stack comprising a first ferromagnetic layer (101), an insulating layer (103), a second ferromagnetic layer (102) and an antiferromagnetic layer (104). The two ferromagnetic layers exhibit crossed magnetic anisotropies and form with the insulating layer a tunnel junction. The anisotropy of the first layer is obtained from the shape energy of the substrate on which this first layer rests and which is slightly misoriented with respect thereto. The anisotropy of the second layer is obtained by the action of the antiferromagnetic layer. The magnetic field to be measured, in which the sensor is immersed, modifies the characteristic of the tunnel junction, and therefore the current which flows through it when the magnetic layers are supplied by a voltage source, in very much greater proportion than those obtained with other systems.

Dependencies are inferred from the claim text.