15 results about "Perpendicular anisotropy" patented technology

The invention provides a synthetic antiferromagnetic memory cell driven by spin orbit moment without magnetic field assistance, and belongs to the technical field of magnetic memory, the synthetic antiferromagnetic memory cell comprises a magnetic tunnel junction of a multilayer film structure, the magnetic tunnel junction comprises a heavy metal layer and a synthetic antiferromagnetic free layer located on the heavy metal layer; the tunneling insulating layer is located on the synthetic antiferromagnetic free layer, the reference layer is located on the tunneling insulating layer, and the metal electrode layer is located on the reference layer; wherein the synthetic antiferromagnetic free layer comprises an inclined vertical magnetic layer, a non-magnetic metal layer and a coupling magnetic layer which are stacked in sequence, and the inclined vertical magnetic layer and the coupling magnetic layer are subjected to antiferromagnetic coupling through the middle non-magnetic metal layer; the inclined perpendicular magnetic layer has inclined perpendicular anisotropy. According to the invention, deterministic magnetization flipping driven by spin orbit moment and resistance state control of the magnetic tunnel junction memory cell without the assistance of an external magnetic field are realized.

The invention relates to a perpendicular anisotropic magnetic memory based on rare earth doped antiferromagnetic, which comprises a thin film structure, and the thin film structure sequentially comprises a buffer layer, a heavy metal layer, a perpendicular magnetic anisotropic layer, a rare earth doped antiferromagnetic layer and a protective layer from bottom to top, according to the invention, the magnetic texture is changed by doping rare earth elements into the collinear antiferromagnetic to break the symmetry of the system, and the spin-orbit torque is utilized to drive the magnetic state of the memory device with perpendicular magnetic anisotropy to overturn only by means of current under the condition of no external field assistance. The method provides a new implementation path for a low-power-consumption and high-density spin storage technology, has a good application prospect, and is expected to promote actual development and application of novel magnetic storage devices in the future.

This invention discloses a SOT-MRAM device, belonging to the field of magnetic random access memory technology. The SOT-MRAM device includes, from bottom to top, a bottom electrode, a spin orbital layer, a magnetic tunnel junction, an antiferromagnetic coupling layer, and a top electrode. The current propagation direction in the spin orbital layer is the same as its own long axis direction. The magnetic moment of the magnetic tunnel junction is perpendicular to its own film surface direction. The magnetic tunnel junction includes a free layer with bulk vertical anisotropy. An inclined sidewall is formed on one side of the free layer using an etching process, creating a continuous thickness gradient along the short axis of the spin orbital layer. This invention introduces structural asymmetry through the thickness gradient of the free layer, breaking the symmetry and replacing the effect of the traditional external magnetic field to achieve zero-magnetic-field flipping.

The present invention discloses a spin-orbit torque magnetic memory and a preparation method thereof, relating to the field of electronics. The spin-orbit torque magnetic memory includes: a heavy metal layer and a composite magnetic tunnel junction disposed on the heavy metal layer. Among them, the composite magnetic tunnel junction includes: a composite free layer, a non-magnetic barrier layer, and a fixed layer. The composite free layer and the fixed layer are respectively disposed on both sides of the non-magnetic barrier layer. The composite free layer includes a free layer and an induction layer. The induction layer is disposed between the free layer and the tunneling resistance layer. In response to a first signal, the induction layer and the free layer are flipped, and the flipping actions of the two are consistent to achieve the flipping of the composite free layer. The induction layer is used to reduce the demagnetization energy of the free layer to reduce the critical current. It can be seen that by disposing an induction layer in the magnetic tunnel junction to generate perpendicular magnetic anisotropy energy, the effective demagnetization energy of the free layer is reduced, thereby reducing the magnitude of the flipping current and reducing the loss during the operation of the device.

The application provides a magnetic tunnel junction device, comprising: a reference layer, a barrier layer, a free layer and a cap layer which are sequentially stacked, the reference layer has a fixed magnetization which is substantially perpendicular to the plane of the reference layer, the free layer comprises: a first ferromagnetic layer, a second ferromagnetic layer and an antiferromagnetic coupling layer between the first ferromagnetic layer and the second ferromagnetic layer, the first ferromagnetic layer is adjacent to the barrier layer, the first ferromagnetic layer has a magnetization which is perpendicular to the film surface and can be reversed, and the second ferromagnetic layer has a magnetization which is opposite to the magnetization direction of the first ferromagnetic layer. And a spacer layer is arranged between the two ferromagnetic layers of the free layer and the antiferromagnetic coupling layer or between the two ferromagnetic layers, so as to improve the saturation magnetization of the free layer. The magnetic tunnel junction device of the application has high perpendicular anisotropy and low switching current.

A non-volatile magnetoresistive random-access memory device is provided. The device comprises a three-terminal spin-orbit torque magnetic tunnel junction (MTJ) with perpendicular anisotropy. The MTJ comprises a fixed ferromagnetic layer, a free ferromagnetic layer, a tunnel barrier between the fixed and free ferromagnetic layers, and a heavy metal layer under the free ferromagnetic layer. A read access transistor is connected to a first terminal of the fixed magnetic layer. A write access transistor is connected to a second terminal of the heavy metal layer. A ground voltage is connected to a third terminal of the heavy metal layer. A read bit line is connected to the read access transistor, and a read word line is connected to the gate of the read access transistor. A write bit line is connected to the write access transistor, and a write word line is connected to the gate of the write access transistor.

The present disclosure provides a hard magnetic material with strong perpendicular magnetic anisotropy and preparation and application thereof, a general formula of the hard magnetic material with strong perpendicular magnetic anisotropy is R x A 1‑x BO 2.5 , wherein the R is a lanthanide element; the value of x is within 0.01 to 0.50; the A is selected from the group of group IIA main group elements, and the B is selected from the group of 3d transition metal elements; the atomic structure of the material is an alternately stacked structure of one layer of B-O tetrahedron and one layer of B-O octahedron, observed along the c-axis direction of the crystal structure. The hard magnetic material has strong magnetic anisotropy, and the strong magnetic anisotropy and saturation magnetization of the material can be controllably modulated.

The invention provides a method for preparing a magnetic flux collector in the vertical direction of a chip and a corresponding magnetic flux collector, and the method comprises the steps: preparing a preparation region with a trumpet-shaped or trapezoidal front view and a truncated cone-shaped three-dimensional structure at the bottom of a silicon substrate through the photoetching and etching technology, the bottom of the preparation region is wider than the top of the preparation region, and the preparation region does not penetrate through the silicon substrate; the bottom of the silicon substrate is arranged on the chip plane; depositing a magnetic flux concentrator material in the flared region to form a first magnetic flux concentrating unit; preparing a magnetic sensitive unit at the top of the silicon substrate by micro-nano processing, wherein the magnetic sensitive unit is positioned right above the first magnetic flux gathering unit; and preparing a second magnetic flux gathering unit symmetrical to the first magnetic flux gathering unit at the top of the magnetic sensitive unit. The magnetic flux collector is integrated in the z-axis direction of the chip to gather the magnetic flux, and the sensitivity of the magnetic sensitive unit with perpendicular anisotropy and the sensitivity of the sensor with the in-plane magnetic sensitive unit can be enhanced through the design.

The invention relates to a magnetic tunnel junction without an external magnetic field, an SOT-MRAM structure, a full-electric-control write-in device and a manufacturing method, belongs to the technical field of semiconductor devices, and solves the problems that the existing MRAM with a PMA needs an additional magnetic field to realize deterministic SOT magnetic field overturning, so that tunnel junctions are difficult to be arranged tightly in a limited space, and the reliability of the device is poor. And the storage capacity of the device is low. The magnetic tunnel junction comprises a bottom electrode layer, a free layer, a tunneling layer and a reference layer which are sequentially arranged from bottom to top, the bottom electrode layer comprises a first electrode layer and a second electrode layer, and the first electrode layer is located between the second electrode layer and the free layer; wherein the material of the first electrode layer comprises metal capable of enabling the free layer to generate magnetic perpendicular anisotropy; and the material of the second electrode layer comprises metal capable of enabling the free layer to generate tensile stress.

The invention discloses a Fe2O3 buffer layer-based magnetic random access memory capable of realizing directional overturning of a magnetization layer without an external magnetic field and driven by a vertical magnetic layer current, and belongs to the field of spintronics. The structure of the device sequentially comprises an antiferromagnetic layer Fe2O3, a spin current generation layer Pt, a magnetic layer Co with vertical anisotropy and a protective layer TaOx for preventing a thin film from being oxidized from bottom to top. Due to the addition of the antiferromagnetic layer Fe2O3, magnetization overturning can be induced to be free of external field. According to the invention, the insulated Fe2O3 is used as the buffer layer to be inserted into the Pt / Co system, so that not only can zero field flip be realized, but also the problem of increase of critical flip current of the device caused by a shunting effect due to introduction of the functional layer can be avoided. The invention provides a structure and a preparation process of a current-driven magnetization turnover device based on an insulating antiferromagnetic layer.

A non-volatile magnetoresistive random-access memory device is provided. The device comprises a three-terminal spin-orbit torque magnetic tunnel junction (MTJ) with perpendicular anisotropy. The MTJ comprises a fixed ferromagnetic layer, a free ferromagnetic layer, a tunnel barrier between the fixed and free ferromagnetic layers, and a heavy metal layer under the free ferromagnetic layer. A read access transistor is connected to a first terminal of the fixed magnetic layer. A write access transistor is connected to a second terminal of the heavy metal layer. A ground voltage is connected to a third terminal of the heavy metal layer. A read bit line is connected to the read access transistor, and a read word line is connected to the gate of the read access transistor. A write bit line is connected to the write access transistor, and a write word line is connected to the gate of the write access transistor.

A method for generating and erasing magnetic skyrmions using photoinduced strain induction includes the following steps: S1: preparing a magnetic multi-period film with a critical anisotropy between perpendicular and horizontal anisotropy on an azobenzene liquid crystal film by magnetron sputtering; S2: fabricating a magnetic nanodot array on the magnetic multi-period film prepared in step S1 using micro-nanofabrication technology; S3: generating skyrmions using photoinduced strain by applying a 355-375 nm light pulse; S4: erasing skyrmions using photoinduced strain by applying a 510-530 nm light pulse to destabilize the skyrmion state and restore it to a ferromagnetic state. The present invention also provides a device for writing and erasing magnetic skyrmions, comprising a magnetic multi-period film, a photoinduced strain substrate, and a photoinduced unit. The method and device of the present invention consume low energy to generate and erase skyrmions, enhance device stability, and facilitate device miniaturization.

The invention discloses a field-free flip spin memory based on a double-wedge-shaped structure. Comprising a cross Hall rod structure and four electrodes. The cross Hall rod structure sequentially comprises a substrate layer, a buffer layer, a thin film layer and a protective layer from bottom to top. The thin film layer comprises a lower Pt layer, a Co layer and an upper Pt layer from bottom to top, and the lower Pt layer is of a double-wedge-shaped splicing structure and comprises two attached wedge-shaped Pt layers. On one hand, the double-wedge-shaped Pt structure provides spin current for the Co layer, and on the other hand, the double-wedge-shaped Pt structure has the characteristic of interface symmetry breaking and can generate an in-plane equivalent magnetic field. The upper layer Pt further enhances the perpendicular anisotropy of the thin film layer. Pulse current is introduced along the direction perpendicular to the wedge-shaped tangent plane, and the resistance values of the device are detected at the other two ends. The problem that the thickness of a thin film layer of a single wedge-shaped device is not uniform is solved, and the stability of the device is improved while magnetic-field-free overturning is achieved.

This invention discloses a magnetic tunnel junction with low power consumption and high storage density, comprising a free layer and a barrier layer, with an interface formed between the free layer and the barrier layer. A ring-shaped defect structure is formed at the edge of the interface by etching. This structure has a ring-shaped defect structure at the interface between the free layer and the barrier layer. The interface-induced vertical anisotropy of the ring-shaped defect structure is low, thereby reducing the overall vertical anisotropy of the free layer. Simultaneously, an in-plane magnetization direction is formed at the edge of the magnetic tunnel junction, which helps to reduce the critical switching current and improve the magnetic switching speed, storage density, and operating speed, while reducing power consumption.

The invention provides an auxiliary device and a preparation method of a perpendicular anisotropic inclined magnetic layer, and belongs to the technical field of magnetic storage. The auxiliary device comprises a shielding unit, a first sputtering target gun, a second sputtering target gun, a movable sliding rail, a fixing clamp, a substrate tray, a stepping motor and a controller; the shielding unit comprises a shielding plate, a connecting rod and a fixing buckle; the shielding unit is fixed on a gun barrel of the first sputtering target gun through a fixing buckle, the fixing buckle is connected with one end of a connecting rod, and the other end of the connecting rod is connected with a shielding plate; the shielding plate is located between a gun barrel of the first sputtering target gun and the substrate tray, a hollowed-out slit is formed in the shielding plate face in the substrate direction, and the hollowed-out slit is used for limiting the emitting angle and the sputtering area of sputtering particles from a first target after penetrating through the hollowed-out slit; the stepping motor and the controller are connected with the movable sliding rail. The preparation method can be used for preparing a large-area uniform perpendicular anisotropic inclined magnetic layer.