Crocus-technology Sa

Commissariat a L'energie Atomique

Centre National De La Recherche Scientifique

Commissariat À L'énergie Atomique Et Aux Énergies Alternatives

Crocus Technology Inc.

Clarisse Ducruet

Ioan Lucian Prejbeanu

Bernard Dieny

Ricardo Sousa

Lucien Lombard

Lucian Prejbeanu

Céline Portemont

Cécile Maunoury

The present disclosure concerns a method of fabricating a magnetic tunnel junction suitable for a magnetic random access memory (MRAM) cell and comprising a first ferromagnetic layer, a tunnel barrier layer, and a second ferromagnetic layer, comprising: forming the first ferromagnetic layer; forming the tunnel barrier layer; and forming the second ferromagnetic layer; wherein said forming the tunnel barrier layer comprises depositing a layer of metallic Mg; and oxidizing the deposited layer of metallic Mg such as to transform the metallic Mg into MgO; the step of forming the tunnel barrier layer being performed at least twice such that the tunnel barrier layer comprises at least two layers of MgO.

Magnetic tunnel junction with an improved tunnel barrier

The present disclosure concerns a magnetic random access memory (MRAM) cell suitable for performing a thermally assisted write operation or a spin torque transfer (STT) based write operation, comprising a magnetic tunnel junction comprising a top electrode; a tunnel barrier layer comprised between a first ferromagnetic layer having a first magnetization direction, and a second ferromagnetic layer having a second magnetization direction adjustable with respect to the first magnetization direction; a front-end layer; and a magnetic or metallic layer on which the second ferromagnetic layer is deposited; the second ferromagnetic layer being comprised between the front-end layer and the tunnel barrier layer and having a thickness comprised between about 0.5 nm and about 2 nm, such that magnetic tunnel junction has a magnetoresistance larger than about 100%. The MRAM cell disclosed herein has lower power consumption compared to conventional MRAM cells.

Low power magnetic random access memory cell

A thermally assisted switching MRAM element including a magnetic tunnel junction including a reference layer having a reference magnetization; a storage layer having a storage magnetization; a tunnel barrier layer included between the storage layer and the reference layer; and a storage antiferromagnetic layer exchange-coupling the storage layer such as to pin the storage magnetization at a low temperature threshold and to free it at a high temperature threshold. The antiferromagnetic layer includes: at least one first antiferromagnetic layer having a first storage blocking temperature, and at least one second antiferromagnetic layer having a second storage blocking temperature; wherein the first storage blocking temperature is below 200&#xb0; C. and the second storage blocking temperature is above 250&#xb0; C. The MRAM element combines better data retention compared with known MRAM elements with low writing mode operating temperature.

MRAM element having improved data retention and low writing temperature

A magnetic random access memory (MRAM) cell with a thermally assisted switching (TAS) writing procedure, comprising a magnetic tunnel junction formed from a ferromagnetic storage layer having a first magnetization adjustable at a high temperature threshold, a ferromagnetic reference layer having a fixed second magnetization direction, and an insulating layer, said insulating layer being disposed between the ferromagnetic storage and reference layers; a select transistor being electrically connected to said magnetic tunnel junction and controllable via a word line; a current line electrically connected to said magnetic tunnel junction; characterized in that the magnetocrystalline anisotropy of the ferromagnetic storage layer is essentially orthogonal with the magnetocrystalline anisotropy of the ferromagnetic reference layer. The TAS-MRAM cell of the invention can be written with a smaller magnetic field than the one used in conventional TAS-MRAM cells and has low power consumption.

Magnetic memory with a thermally assisted writing procedure and reduced writing field

A magnetic element with thermally-assisted writing using a field or spin transfer provided, including a magnetic reference layer referred to as the 'trapped layer,' the magnetization of which is in a fixed direction, and a magnetic storage layer called the 'free layer' having a variable magnetization direction and consisting of a layer made of a ferromagnetic material with magnetization in the plane of the layer and magnetically coupled to a magnetization-trapping layer made of an antiferromagnetic material. A semiconductor or an insulating layer with confined-current-paths is sandwiched between the reference layer and the storage layer. At least one bilayer, consisting respectively of an amorphous or quasi-amorphous material and a material having the same structure or the same crystal lattice as the antiferromagnetic layer, is provided in the storage layer between ferromagnetic layer, which is in contact with the semiconductor or insulating layer with confined-current-paths, and antiferromagnetic layer.

Growing community of inventors

Grenoble, France

Clarisse Ducruet