Imec Vzw

Katholieke Universiteit Leuven

Katholieke Universiteit Leuven, K.u. Leuven Research & Development

Kevin Garello

Manu Komalan Perumkunnil

Mohit Gupta

Johan Swerts

Gouri Sankar Kar

Sushil Sakhare

Davide Francesco Crotti

Siddharth Rao

According to an aspect there is provided a memory cell. The memory cell comprises: a first and a second electrode; a spin-orbit-torque, SOT, layer comprising a first and a second electrode contact portion arranged in contact with the first and the second electrode, respectively, and an intermediate portion between the first and second electrode contact portions; a first magnetic tunnel junction, MTJ, layer stack arranged in contact with the intermediate portion; and a second MTJ layer stack arranged in contact with the second electrode contact portion and directly above the second electrode. A memory device comprising such a memory cell and a method for writing to such a memory cell are also provided.

Memory cell including a spin-orbit-torque (SOT) layer and magnetic tunnel junction (MTJ) layer stacks and writing method therefor

According to an aspect, there is provided a method of forming a magnetic tunneling junction (MTJ) device, including: forming a layer stack including an MTJ layer structure and a spin-orbit torque (SOT) layer below the MTJ layer structure; forming a first etch mask over the layer stack, the first etch mask including a first mask line extending in a first horizontal direction; patterning the layer stack to form an MTJ line extending in the first horizontal direction, the patterning including etching while the first etch mask masks the layer stack, and stopping etching on or above the SOT-layer; forming sidewall spacers on one or both sides of the MTJ line; while the sidewall spacers mask the SOT-layer, etching the SOT-layer to form a patterned layer stack including the MTJ line and a first patterned SOT-layer; forming a second etch mask over the patterned layer stack, the second etch mask including a second mask line extending in a second horizontal direction across the MTJ line; and patterning the patterned layer stack to form a twice patterned SOT-layer, the twice patterned SOT-layer including an SOT-line extending in the second horizontal direction, and to form an MTJ pillar on the SOT-line, the patterning including etching while the second etch mask masks the patterned layer stack.

Method of forming a magnetic tunneling junction device

The disclosed technology relates generally to semiconductor devices and more particularly to magnetic tunnel junction devices. According to an aspect, an MTJ device comprises a spin-orbit-torque (SOT)-layer. The MTJ device additionally comprises a first free layer, a second free layer, a reference layer and a tunnel barrier layer arranged between the second free layer and the reference layer. The MTJ device further comprises a spacer layer arranged as an interfacial layer between the first free layer and the second free layer. The SOT-layer is adapted to switch a magnetization direction of the first free layer through SOT. The first free layer is adapted to generate a magnetic stray field acting on the second free layer such that a magnetization direction of the second free layer is responsive to a magnetization direction of the first free layer. According to another aspect, a circuit comprises the MTJ device.

Magnetic tunnel junction device

The disclosed technology generally relates to magnetic devices and more particularly to magnetic tunnel junction (MTJ) devices in which switching can be mediated by spin-orbit torque, and further relates to a method of fabricating such devices. In an aspect, a magnetic tunnel junction (MTJ) device includes a spin-orbit torque (SOT) mediating layer, a hard-mask layer used to define a shape of the SOT layer, a magnetic tunnel junction arranged between the SOT layer and the hard-mask layer. The MTJ includes at least a free layer and a reference layer separated by a non-magnetic barrier layer. The device further includes at least two electrical accesses arranged to contact the SOT layer to pass a write current therethrough. To provide field-free switching of the free layer, the device further includes a ferromagnetic element as at least one of a ferromagnetic sublayer of the hard-mask and a material in the electrical accesses.

Spin-orbit torque magnetic tunnel junction device and method of fabricating same

The disclosed technology relates generally to magnetic random access memory, and more particularly to spin-orbit-torque (SOT) magnetoresistive random access memory (MRAM). According to an aspect, a MRAM device comprises a first transistor, a second transistor, and a resistive memory element. The resistive memory element comprises a magnetic tunnel junction (MTJ) pillar arranged between a top electrode and bottom electrode having a first terminal and a second terminal. According to another aspect, a method of using the MRAM device is disclosed.

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Leuven, Belgium

Kevin Garello