The disclosure is directed to spin-orbit torque MRAM structures and methods. A SOT channel of the SOT-MRAM includes multiple heavy metal layers and one or more dielectric dusting layers each sandwiched between two adjacent heavy metal layers. The dielectric dusting layers each include discrete molecules or discrete molecule clusters of a dielectric material scattered in or adjacent to an interface between two adjacent heavy metal layers.

Disclosed are examples of multiple bit magnetoresistive random access memory (MRAM) cells. A multiple bit MRAM cell may comprise a fixed layer, alternately stacked N tunnel barriers and N free layers, and a tunnel cap. N, which may represent number of bits of the MRAM cell, may be greater than or equal to two. Magnetic moment of the fixed layer may be fixed in one perpendicular direction. Magnetic moments of the free layers may be switchable from one to other perpendicular directions upon application of switch currents. The switch currents may be different for different layers. The magnetic moments of the free layers may be switched separately or otherwise independently of other free layers when the switch currents are applied separately.

A resistive memory device includes a magnetic tunnel junction structure. The magnetic tunnel junction structure includes a free magnetic layer. The free magnetic layer includes a magnetic material configurable to host topological spin textures to tune a conductance state of the resistive memory device.

A perpendicular magnetoresistive element comprises (counting from the element bottom): a reference layer having magnetic anisotropy in a direction perpendicular to a film surface and having an invariable magnetization direction; a tunnel barrier layer; a crystalline recording layer having magnetic anisotropy in a direction perpendicular to a film surface and having a variable magnetization direction; an oxide buffer layer; and a cap layer, wherein the crystalline recording layer consists of a CoFe alloy that is substantially free of boron and has BCC (body-centered cubic) CoFe grains having epitaxial growth with (100) plane parallel to a film surface.

A spin-current magnetization rotational element includes: a ferromagnetic metal layer; and a spin-orbit torque wiring that extends in a first direction intersecting a stacking direction of the ferromagnetic metal layer and is bonded to the ferromagnetic metal layer. A direction of a spin injected into the ferromagnetic metal layer from the spin-orbit torque wiring intersects a magnetization direction of the ferromagnetic metal layer. The ferromagnetic metal layer has shape anisotropy and has a demagnetizing field distribution caused by the shape anisotropy. The demagnetizing field distribution generates an easy magnetization rotational direction in which the magnetization of the ferromagnetic metal layer is most easily reversed. The easy magnetization rotational direction intersects the first direction in a plan view seen from the stacking direction.

A dual magnetic tunnel junction (DMTJ) is disclosed with a PL1/TB1/free layer/TB2/PL2 configuration wherein a first tunnel barrier (TB1) has a substantially lower resistance×area (RA.sub.1) product than RA.sub.2 for an overlying second tunnel barrier (TB2) to provide an acceptable magnetoresistive ratio (DRR). Moreover, first and second pinned layers, PL1 and PL2, respectively, have magnetizations that are aligned antiparallel to enable a lower critical switching current that when in a parallel alignment. The condition RA1<RA2 is achieved with one or more of a smaller thickness and a lower oxidation state for TB1 compared with TB2, with conductive (metal) pathways formed in a metal oxide or metal oxynitride matrix for TB1, or with a TB1 containing a dopant to create conducting states in the TB1 band gap. Alternatively, TB1 may be replaced with a metallic spacer to improve conductivity between PL1 and the FL.

A magnetoresistance effect element according to an embodiment includes: a spin orbit torque wiring extending in a first direction; a laminated body laminated on the spin orbit torque wiring and having a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer between the first ferromagnetic layer and the second ferromagnetic layer; a conductive layer in contact with a side of the laminated body opposite to the spin orbit torque wiring; and a heat dissipation layer separated from the laminated body in the first direction and connected to the spin orbit torque wiring and the conductive layer.

A tunneling magnetoresistance (TMR) sensor device is disclosed that includes four or more TMR resistors. The TMR sensor device comprises a first TMR resistor comprising a first TMR film, a second TMR resistor comprising a second TMR film different than the first TMR film, a third TMR resistor comprising the second TMR film, and a fourth TMR resistor comprising the first TMR film. The first, second, third, and fourth TMR resistors are disposed in the same plane. The first TMR film comprises a synthetic anti-ferromagnetic pinned layer having a magnetization direction of the reference layer orthogonal to a free layer. The second TMR film comprises a double synthetic anti-ferromagnetic pinned layer having a magnetization direction of the reference layer orthogonal to the magnetization of a free layer, but opposite to the magnetization direction of the reference layer of the first TMR film.

According to one embodiment, a magnetoresistive memory device includes: a first ferromagnetic layer; a stoichiometric first layer; a first insulator between the first ferromagnetic layer and the first layer; a second ferromagnetic layer between the first insulator and the first layer; and a non-stoichiometric second layer between the second ferromagnetic layer and the first layer. The second layer is in contact with the second ferromagnetic layer and the first layer.

A magnetic tunnel junction (MTJ) device includes a bottom electrode, a reference layer, a tunnel barrier layer, a free layer and a top electrode. The bottom electrode and the top electrode are facing each other. The reference layer, the tunnel barrier layer and the free layer are stacked from the bottom electrode to the top electrode, wherein the free layer includes a first ferromagnetic layer, a spacer and a second ferromagnetic layer, wherein the spacer is sandwiched by the first ferromagnetic layer and the second ferromagnetic layer, wherein the spacer includes oxidized spacer sidewall parts, the first ferromagnetic layer includes first oxidized sidewall parts, and the second ferromagnetic layer includes second oxidized sidewall parts. The present invention also provides a method of manufacturing a magnetic tunnel junction (MTJ) device.