In an embodiment, a device includes: a magnetoresistive random access memory cell including: a bottom electrode; a reference layer over the bottom electrode; a tunnel barrier layer over the reference layer, the tunnel barrier layer including a first composition of magnesium and oxygen; a free layer over the tunnel barrier layer, the free layer having a lesser coercivity than the reference layer; a cap layer over the free layer, the cap layer including a second composition of magnesium and oxygen, the second composition of magnesium and oxygen having a greater atomic concentration of oxygen and a lesser atomic concentration of magnesium than the first composition of magnesium and oxygen; and a top electrode over the cap layer.

Embodiments of magnetic tunnel junction (MTJ) structures discussed herein employ seed layers of one or more layer of chromium (Cr), NiCr, NiFeCr, RuCr, IrCr, or CoCr, or combinations thereof. These seed layers are used in combination with one or more pinning layers, a first pinning layer in contact with the seed layer can contain a single layer of cobalt, or can contain cobalt in combination with bilayers of cobalt and platinum (Pt), iridium (Ir), nickel (Ni), or palladium (Pd), The second pinning layer can be the same composition and configuration as the first, or can be of a different composition or configuration. The MTJ stacks discussed herein maintain desirable magnetic properties subsequent to high temperature annealing.

A high-temperature three-dimensional Hall sensor with a real-time working temperature monitoring function includes a buffer layer, an epitaxial layer, and a barrier layer sequentially grown on a substrate. A high-density two-dimensional electron gas is induced by polarization charges in a potential well at an interface of heterojunctions of the epitaxial layer. A lower surface of the substrate includes a vertical Hall sensor for sensing a magnetic field parallel to a surface of a device. An upper surface of the barrier layer includes a “cross” horizontal Hall sensor for sensing a magnetic field perpendicular to the surface of the device.

A magnetic domain wall movement type magnetic recording element according to an embodiment includes: a first ferromagnetic layer which includes a ferromagnetic body; a non-magnetic layer which faces the first ferromagnetic layer; and a magnetic recording layer which faces a surface of the non-magnetic layer on a side opposite to the first ferromagnetic layer and extends in a first direction. A first surface of the magnetic recording layer which faces the non-magnetic layer has a smaller arithmetic mean roughness than a second surface opposite to the first surface.

One illustrative MRAM cell disclosed herein includes a bottom electrode, a top electrode positioned above the bottom electrode and an MTJ (Magnetic Tunnel Junction) element positioned above the bottom electrode and below the top electrode. In this example, the MTJ element includes a bottom insulation layer positioned above the bottom electrode, a top insulation layer positioned above the bottom electrode; and a first ferromagnetic material layer positioned between the bottom insulation layer and the top insulation layer.

A method for forming a semiconductor memory structure is provided. The method includes following operations. An interlayer is formed over a first ferromagnetic layer, wherein forming the interlayer includes following operations. A first metal film is formed by sputtering a first target material. A first oxygen treatment is conducted to the first metal film to form a first metal oxide film. A second metal oxide film is formed over the first metal oxide film by sputtering a second target material different from the first target material. A second metal film is formed by sputtering a third target material. A second oxygen treatment is conducted to the second metal film to form a third metal oxide film.

A magnetic domain wall movement element includes a magnetoresistance effect part, a first electrode, a second electrode, a third electrode, a first magnetization fixed layer, and a second magnetization fixed layer. The magnetoresistance effect part includes a reference layer, a magnetic domain wall movement layer, and a non-magnetic layer. The magnetic domain wall movement layer has a first region and second region in which a magnetization direction is fixed, and a third region in which a magnetization direction is variable. The reference layer overlaps at least part of the first region and the second region in a plan view in a first direction, and at least part of the first region and the second region is shorter than the third region in a third direction orthogonal to the first direction and the second direction.

An ultra-fast magnetic random access memory (MRAM) comprises a three terminal composite SOT magnetic tunneling junction (CSOT-MTJ) element including a magnetic flux guide (MFG) having a very high magnetic permeability, a spin Hall channel (SHC) having a large positive spin Hall angle, an in-plane magnetic memory (MM) layer, a tunnel barrier (TB) layer, and a magnetic pinning stack (MPS) having a synthetic antiparallel coupling pinned by an antiferromagnetic material. The magnetic writing is significantly boosted by a combined effort of enhanced spin orbit torque (SOT) and Lorentz force generated by current-flowing wire (CFW) in the SHC layer and spin transfer torque (STT) by a current flowing through the MTJ stack, and further enhanced by a magnetic close loop formed at the cross section of MFG/SHC/MM tri-layer.

A SOT-MRAM cell, comprising at least one magnetic tunnel junction (MTJ) comprising a tunnel barrier layer between a pinned ferromagnetic layer and a free ferromagnetic layer; a SOT line, extending substantially parallel to the plane of the layers and contacting a first end of said at least one MTJ; at least a first source line connected to one end of the SOT line; at least a first bit line and a second bit line, wherein the SOT-MRAM cell comprises one MTJ, each bit line being connected to the other end of the MTJ; or wherein the SOT-MRAM cell comprises two MTJs, each MTJ being connected to one of the first bit line and second bit line.

The present disclosure provides a domain wall magnetic tunnel junction device. Integration of input spikes pushes a domain wall within a ferromagnetic track toward a magnetic tunnel junction (MTJ). An energy gradient within the track pushes the domain wall away from the MTJ by leaking accumulated energy from the input spikes. If the integrated input spikes exceed the energy leak of the gradient within a specified time period, the domain wall reaches the MTJ and reverses its resistance, producing an output spike. The leaking energy gradient can be created by a magnetic field, a trapezoidal shape of the ferromagnetic track, or nonuniform material properties in the ferromagnetic track.