Self-referenced MRAM element and device having improved magnetic field

摘要

Self-reference-based MRAM element including: first and second magnetic tunnel junctions, each having a magnetoresistance that can be varied; and a field line for passing a field current to vary the magnetoresistance of the first and second magnetic tunnel junctions. The field line includes a first branch and a second branch each branch including cladding. The first branch is arranged for passing a first portion of the field current to selectively vary the magnetoresistance of the first magnetic tunnel junction, and the second branch is electrically connected in parallel with the first branch and arranged for passing a second portion of the field current to selectively vary the magnetoresistance of the second magnetic tunnel junction. The self-referenced MRAM element and an MRAM device including corresponding MRAM elements can use a reduced field current.

主权项

1. Self-reference-based MRAM element comprising
a first magnetic tunnel junction and a second magnetic tunnel junction, each having a magnetoresistance that can be varied; and a single field line only for passing a field current destined to vary the magnetoresistance of the first and second magnetic tunnel junctions; the single field line comprising a first branch and a second branch, each branch comprising a cladding; the first branch being arranged for passing a first portion of the field current so as to generate a magnetic field which can exclusively selectively vary the magnetoresistance of the first magnetic tunnel junction, and the second branch being electrically connected in parallel with the first branch and arranged for passing a second portion of the field current so as to generate a magnetic field which can exclusively selectively vary the magnetoresistance of the second magnetic tunnel junction; wherein the cladding for the first and second branches is provided on their respective surfaces, and wherein a portion of the surface of the first branch which is closest to the first magnetic tunnel junction is free of cladding so that said portion of the surface is exposed, and a portion of the surface of the second branch which is closest to the second magnetic tunnel junction is free of cladding so that said portion of the surface is exposed, so that a first portion of magnetic field generated by passing the first portion of field current in the first branch can only vary the magnetization of the first magnetic tunnel junction and so that said first portion of magnetic field is concentrated on the first magnetic tunnel junction so that the first portion of magnetic field alone can vary the magnetization of the first magnetic tunnel junction, and a second portion of magnetic field generated by passing the second portion of field current in the second branch can only vary the magnetization of the second magnetic tunnel junction and so that said second portion of magnetic field is concentrated on the second magnetic tunnel junction so that the second portion of magnetic field alone can vary the magnetization of the second magnetic tunnel junction.