The disclosure is directed to spin-orbit torque (“SOT”) magnetoresistive random-access memory (“MRAM”) (“SOT-MRAM”) structures and methods. A new structure of the SOT channel has one or more magnetic insertion layers superposed or stacked with one or more heavy metal layer(s). Through proximity to a magnetic insertion layer, a surface portion of a heavy metal layer is magnetized to include a magnetization. The magnetization within the heavy metal layer enhances spin-dependent scattering, which leads to increased transverse spin imbalance.

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 semiconductor structure forms two or more tightly pitched memory devices using a dielectric material for a gap fill material. The approach includes providing two adjacent bottom electrodes in a layer of an insulating material and above a metal layer. Two adjacent pillars are each above one of the two adjacent bottom electrodes where each pillar of the two adjacent pillars is composed of a stack of materials for a memory device. A spacer is around the vertical sides each of the two adjacent pillars. The dielectric material is on the spacer around the vertical sides each of the two adjacent pillars, on the layer of the insulating material between the two adjacent bottom electrodes. The dielectric material fills at least a first portion of a gap between the two adjacent pillars. A low k material covers the dielectric material and exposed portions of the layer of the insulating material.

A method includes forming a magnetic tunnel junction (MTJ) stack over a substrate. The MTJ stack including a top magnetic layer, a barrier layer, and a bottom magnetic layer. The method also includes patterning the top magnetic layer in a first etch process, after the patterning of the top magnetic layer depositing a spacer on sidewalls of the patterned top magnetic layer, and patterning the bottom magnetic layer in a second etch process.

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 semiconductor device includes a plurality of magnetic tunnel junction (MTJ) structures in an interlayer insulating layer on a substrate. A blocking layer is on the interlayer insulating layer and the plurality of MTJ structures. An upper insulating layer is on the blocking layer. An upper interconnection is on the upper insulating layer. An upper plug is connected to the upper interconnection and a corresponding one of the plurality of MTJ structures and extends into the upper insulating layer and the blocking layer. The blocking layer includes a material having a higher absorbance constant than the upper insulating layer.