Thermally-assisted mram cells with improved reliability at writing
AssigneeCrocus Technology SA
InventorsSebastien Bandiera, Ioan Lucian Prejbeanu
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Abstract
MRAM cell including a magnetic tunnel junction including a reference layer, a storage layer having a storage magnetization, a tunnel barrier layer between the reference and the storage layers; and an antiferromagnetic layer exchange-coupling the storage layer such as to pin the storage magnetization at a low temperature threshold and free it at a high temperature threshold. The storage layer includes a first ferromagnetic layer in contact with the tunnel barrier layer, a second ferromagnetic layer in contact with the antiferromagnetic layer, and a low saturation magnetization storage layer including a ferromagnetic material and a non-magnetic material. The MRAM cell can be written with improved reliability.
Claims7
MRAM cell comprising a magnetic tunnel junction including a reference layer, a storage layer having a storage magnetization, a tunnel barrier layer comprised between the reference and the storage layers;
- and an antiferromagnetic layer exchange-coupling the storage layer such as to pin the storage magnetization at a low temperature threshold and free it at a high temperature threshold;
- wherein
- the storage layer comprises a first ferromagnetic layer in contact with the tunnel barrier layer, a second ferromagnetic layer in contact with the antiferromagnetic layer, and a low saturation magnetization storage layer between the first ferromagnetic layer and the second ferromagnetic layer, wherein the low saturation magnetization storage layer has a saturation magnetization which is lower than the saturation magnetization of the first ferromagnetic layer and lower than the saturation magnetization of the second ferromagnetic layer,
- the low saturation magnetization storage layer comprising a Co, Fe or Ni based alloy, wherein the Co, Fe or Ni based alloy comprises between 1 at. % and 40 at. % of a non-magnetic element selected from Ta, Ti, Cr, V, Nb, Hf, Mo, Zn and Zr or of an alloy of at least one of these non-magnetic elements.
(canceled)
MRAM device comprises a plurality of MRAM cells, each MRAM cell comprising a magnetic tunnel junction including a reference layer, a storage layer having a storage magnetization, a tunnel barrier layer, and an antiferromagnetic layer exchange-coupling the storage layer such as to pin the storage magnetization at a low temperature threshold and free it at a high temperature threshold;
- wherein the storage layer comprises a first ferromagnetic layer in contact with the tunnel barrier layer, a second ferromagnetic layer in contact with the antiferromagnetic layer, and a low saturation magnetization storage layer between the first ferromagnetic layer and the second ferromagnetic layer, wherein the low saturation magnetization storage layer has a saturation magnetization which is lower than the saturation magnetization of the first ferromagnetic layer and lower than the saturation magnetization of the second ferromagnetic layer;
- the low saturation magnetization storage layer comprising a Co, Fe or Ni based alloy, wherein the Co, Fe or Ni based alloy comprises between 1 at. % and 40 at. % of a non-magnetic element selected from Ta, Ti, Cr, V, Nb, Hf, Mo, Zn and Zr or of an alloy of at least one of these non-magnetic elements;
- the MRAM device further comprising a plurality of current lines being operatively coupled with the plurality of MRAM cells.
Dependencies are inferred from the claim text.