Crocus-technology Sa

Kenneth MacKay

Ioan Lucian Prejbeanu

Bertrand Francis Cambou

Bernard Dieny

Lucien Lombard

Jeffrey Childress

Jason S Reid

Quentin Stainer

Romain Foissac

Erwan Gapihan

A magnetic sensor cell including a magnetic tunnel junction including a reference layer having a reference magnetization oriented substantially parallel to the plane of the reference layer, a sense layer having a sense magnetization, and a tunnel barrier layer between the sense and reference layers. The sense layer includes an intrinsic anisotropy substantially perpendicular to the plane of the sense layer such that the sense magnetization is orientable between an initial direction perpendicular to the plane of the sense layer and a direction parallel to the plane of the sense layer; the intrinsic anisotropy having in anisotropy field being above 150 Oe.

Magnetic sensor cell for measuring one- and two-dimensional magnetic fields and method for measuring said magnetic fields using the magnetic sensor cell

A magnetic logic unit (MLU) cell includes a first magnetic tunnel junction and a second magnetic tunnel junction, each magnetic tunnel junction including a first magnetic layer having a first magnetization, a second magnetic layer having a second magnetization, and a tunnel barrier layer between the first and second layer. A field line for passing a field current such as to generate an external magnetic field is adapted to switch the first magnetization. The first magnetic layer is arranged such that the magnetic tunnel junction magnetization varies linearly with the generated external magnetic field. An MLU amplifier includes a plurality of the MLU cells. The MLU amplifier has large gains, extended cut off frequencies and improved linearity.

Magnetic logic unit (MLU) cell and amplifier having a linear magnetic signal

A magnetic logic unit (MLU) cell includes a first and second magnetic tunnel junction, each including a first magnetic layer having a first magnetization, a second magnetic layer having a second magnetization, and a barrier layer; and a field line for passing a field current such as to generate an external magnetic field adapted to adjust the first magnetization. The first and second magnetic layers and the barrier layer are arranged such that the first magnetization is magnetically coupled antiparallel with the second magnetization through the barrier layer. The MLU cell also includes a biasing device arranged for applying a static biasing magnetic field oriented substantially parallel to the external magnetic field such as to orient the first magnetization at about 90&#xb0; relative to the second magnetization, the first and second magnetizations being oriented symmetrically relative to the direction of the external magnetic field.

The present disclosure concerns a method for writing to a self-referenced MRAM cell comprising a magnetic tunnel junction comprising: a storage layer including a first ferromagnetic layer having a first storage magnetization, a second ferromagnetic layer having a second storage magnetization, and a non-magnetic coupling layer separating the first and second ferromagnetic layers; a sense layer having a free sense magnetization; and a tunnel barrier layer included between the sense and storage layers; the first and second ferromagnetic layers being arranged such that a dipolar coupling between the storage) and the sense layers is substantially null; the method comprising: switching the second ferromagnetic magnetization by passing a spin-polarized current in the magnetic tunnel junction; wherein the spin-polarized current is polarized when passing in the sense layer, in accordance with the direction of the sense magnetization. The MRAM cell can be written with low power consumption.

Self-referenced MRAM cell and method for writing the cell using a spin transfer torque write operation

The present disclosure concerns a self-referenced MRAM element, comprising a magnetic tunnel junction having a magnetoresistance, comprising: a storage layer having a storage magnetization that is pinned along a first direction when the magnetic tunnel junction is at a low temperature threshold; a sense layer having a sense magnetization; and a tunnel barrier layer included between the storage layer and the sense layer; and an aligning device arranged for providing the sense magnetization with a magnetic anisotropy along a second direction that is substantially perpendicular to the first direction such that the sense magnetization is adjusted about the second direction; the aligning device being further arranged such that, when a first read magnetic field is provided, a resistance variation range of the magnetic tunnel junction is at least about 20% of the magnetoresistance. The self-referenced MRAM cell can be read with an increased reliability and has reducing power consumption.

Self-referenced MRAM element with linear sensing signal

The present disclosure concerns a MRAM element comprising a magnetic tunnel junction comprising: a storage layer, a sense layer, and a tunnel barrier layer included between the storage layer and the sense layer; the storage layer comprising a first magnetic layer having a first storage magnetization; a second magnetic layer having a second storage magnetization; and a non-magnetic coupling layer separating the first and second magnetic layers such that the first storage magnetization is substantially antiparallel to the second storage magnetization; the first and second magnetic layers being arranged such that: at a read temperature the first storage magnetization is substantially equal to the second storage magnetization; and at a write temperature which is higher than the read temperature the second storage magnetization is larger than the first storage magnetization. The disclosed MRAM element generates a low stray field when the magnetic tunnel junction is cooled at a low temperature.

Self-referenced magnetic random access memory element comprising a synthetic storage layer

The present disclosure concerns a magnetic memory element suitable for a thermally-assisted switching write operation, comprising a current line in electrical communication with one end of a magnetic tunnel junction, the magnetic tunnel junction comprising: a first ferromagnetic layer having a fixed magnetization; a second ferromagnetic layer having a magnetization that can be freely aligned at a predetermined high temperature threshold; and a tunnel barrier provided between the first and second ferromagnetic layer; the current line being adapted to pass a heating current through the magnetic tunnel junction during the write operation; wherein said magnetic tunnel junction further comprises at least one heating element being adapted to generate heat when the heating current is passed through the magnetic tunnel junction; and a thermal barrier in series with said at least one heating element, said thermal barrier being adapted to confine the heat generated by said at least one heating element within the magnetic tunnel junction.

Thermally assisted magnetic random access memory element with improved endurance

The present disclosure concerns a magnetic element to be written using a thermally-assisted switching write operation comprising a magnetic tunnel junction formed from a tunnel barrier being disposed between first and second magnetic layers, said second magnetic layer having a second magnetization which direction can be adjusted during a write operation when the magnetic tunnel junction is heated at a high threshold temperature; an upper current line connected at the upper end of the magnetic tunnel junction; and a strap portion extending laterally and connected to the bottom end of the magnetic tunnel junction; the magnetic device further comprising a bottom thermal insulating layer extending substantially parallel to the strap portion and arranged such that the strap portion is between the magnetic tunnel junction and the bottom thermal insulating layer. The magnetic element allows for reducing heat losses during the write operation and has reduced power consumption.

Growing community of inventors

Le Sappey en Chartreuse, France

Kenneth MacKay