22 results about "Spin transfer" patented technology

A neuromorphic computing array includes horizontal lines and vertical lines that intersect the horizontal lines at cell locations. Magnetic tunnel junction cells are located at the cell locations. Each cell is electrically connected to a corresponding one of the horizontal lines and to a corresponding one of the vertical lines. Each cell includes a substrate, a seed layer overlying the substrate, and a nitride layer, overlying the seed layer, and optionally having a thickness greater than 5 Angstroms. Each cell further includes a templating layer, outward of the nitride layer, including a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms. Each cell still further includes a magnetic layer overlying the templating layer, a tunnel barrier outward of the magnetic layer; and a magnetic layer outward of the tunnel barrier. The magnetic layer includes a Heusler compound and exhibits perpendicular magnetic anisotropy (PMA).

A neuromorphic computing array includes horizontal lines and vertical lines that intersect the horizontal lines at cell locations. Magnetic tunnel junction cells are located at the cell locations. Each cell is electrically connected to a corresponding one of the horizontal lines and to a corresponding one of the vertical lines. Each cell includes a substrate (1401), a seed layer (1403) overlying the substrate, and a nitride layer (1403A) overlying the seed layer, and optionally having a thickness greater than 5 Angstroms. Each cell further includes a templating layer (1403B) outward of the nitride layer, including a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms. Each cell still further includes a first magnetic layer (1405) overlying the templating layer, a tunnel barrier (1409) outward of the first magnetic layer; and a second magnetic layer (1411) outward of the tunnel barrier. The first magnetic layer (1405) includes a Heusler compound and exhibits perpendicular magnetic anisotropy, PMA.

A memory device includes a spin-orbit-transfer (SOT) bottom electrode, an SOT ferromagnetic free layer, a first tunnel barrier layer, a spin-transfer-torque (STT) ferromagnetic free layer, a second tunnel barrier layer and a reference layer. The SOT ferromagnetic free layer is over the SOT bottom electrode. The SOT ferromagnetic free layer has a magnetic orientation switchable by the SOT bottom electrode using a spin Hall effect or Rashba effect. The first tunnel barrier layer is over the SOT ferromagnetic free layer. The STT ferromagnetic free layer is over the first tunnel barrier layer and has a magnetic orientation switchable using an STT effect. The second tunnel barrier layer is over the STT ferromagnetic free layer. The second tunnel barrier layer has a thickness different from a thickness of the first tunnel barrier layer. The reference layer is over the second tunnel barrier layer and has a fixed magnetic orientation.

A non-volatile static random-access memory (NVSRAM) device includes at least one array of NVSRAM cells. Each NVSRAM cell includes an SRAM unit and an MRAM unit. The SRAM unit includes at least six transistors, and the MRAM unit includes at least two-transistors and two magnetic tunnel junction (MTJ) structures. The SRAM units are accessed during normal read / write operations to allows for fast access to the NVSRAM cells with unlimited endurance and without read / write error rate issues. Hidden MRAM write operations in NVSRAM cells that are not accessed for normal read / write operations may be activated manually or automatically to back up the data stored in the corresponding SRAM units. When the NVSRAM device loses power, data stored in the SRAM units are lost, while the data backed-up in corresponding MRAM units are retained. When power is restored, an automatic data restore write cycle is started, during which the SRAM units recover their data from their corresponding MRAM units.

Spin-Hall (SH) material (135) is provided near free regions (110) of magnetoresistive devices that include magnetic tunnel junctions (110, 115, 120). Current flowing through such SH material injects spin current into the free regions such that spin torque is applied to the free regions. The spin torque generated from SH material can be used to switch the free region or to act as an assist to spin-transfer torque generated by current flowing vertically through the magnetic tunnel junction, in order to improve the reliability, endurance, or both of the magnetoresistive device. Further, one or more additional regions or manufacturing steps may improve the switching efficiency and the thermal stability of magnetoresistive devices.

The present specification relates to a writing and reading apparatus and method for spin-transfer torque magnetic RAM (STT-MRAM). An STT-MRAM writing apparatus using a dual reference and step-wise current increases, according to one embodiment, comprises: an array including a plurality of STT-MRAM cells; a reference voltage generation unit for generating reference data to be compared with data to be determined for STT-MRAM cells of a selected address from among the plurality of STT-MRAM cells; and a control unit that transmits a designation signal for obtaining the data to be determined for the STT-MRAM cells of the selected address, wherein the control unit can obtain, from the reference voltage generation unit, a first reference voltage, which is the largest value from among voltage values generated on the basis of a current flowing through an Rp resistor in a low state, and a second reference voltage, which is the smallest value from among voltage values generated on the basis of a current flowing through an Rap resistor in a high state, and generate, on the basis of the first reference voltage and the second reference voltage, a first write current from Rp to Rap, which is to be applied to designated STT-MRAM, or the first write current from Rap to Rp, which is to be applied to the designated STT-MRAM.

A magnetic sensor element is disclosed, comprising a magnetic tunnel junction (MTJ) comprising a reference layer, a tunnel barrier layer, a sense layer having a sense magnetization freely orientable in the presence of the external magnetic field. The reference layer has a reference magnetization and comprises a reference SAF structure and an in-plane sensitivity axis. A SOT electrode configured to pass a SOT current adapted to switch the first reference magnetization in two opposed directions along the sensitivity axis by a spin orbit torque interaction. Also disclosed is a sensing device comprising at least one sensing branch including at least one magnetic sensor element and a sensing operation using the sensing device for sensing an external magnetic field. The magnetic sensor element allows for sensing the external magnetic field with low 1 / f noise.

A magnetic sensor element is disclosed, comprising a magnetic tunnel junction (MTJ) comprising a reference layer, a tunnel barrier layer, a sense layer having a sense magnetization freely orientable in the presence of the external magnetic field. The reference layer has a reference magnetization and comprises a reference SAF structure and an in-plane sensitivity axis. A SOT electrode configured to pass a SOT current adapted to switch the first reference magnetization in two opposed directions along the sensitivity axis by a spin orbit torque interaction. Also disclosed is a sensing device comprising at least one sensing branch including at least one magnetic sensor element and a sensing operation using the sensing device for sensing an external magnetic field. The magnetic sensor element allows for sensing the external magnetic field with low 1 / f noise.

The present invention discloses a multifunctional racetrack design experimental method based on ferromagnetic skyrmions, comprising the following steps: first, constructing a racetrack using photolithography technology; second, setting a magnetic tunnel junction; third, performing logical operations of an AND gate and an OR gate; fourth, performing logical operations of a NOT gate; and fifth, performing operations on a unidirectional transmission function of a diode. The test racetrack of the present invention integrates the operational functions of an AND gate, an OR gate, a NOT gate, and a diode, thereby being multifunctional and having a wider scope of application. Furthermore, the racetrack of the present invention has low energy consumption, a small structural space, and is easy to integrate into a high-density spintronic device. Furthermore, the racetrack has high accuracy and strong non-volatility, and is driven by spin transfer torque, thus being highly subjectively controllable and suitable for promotion.

This invention belongs to the field of magnetic tunnel junction technology, and particularly relates to a free layer of a magnetic tunnel junction, a magnetic tunnel junction, and a spin-transfer torque magnetic random access memory (STM). The free layer provided by this invention comprises a first ferromagnetic layer, a spacer layer, and a second ferromagnetic layer in sequential contact; the thicknesses of both the first and second ferromagnetic layers are ≤1 nm, and the thickness of the second ferromagnetic layer is less than the thickness of the first ferromagnetic layer; the spacer layer comprises at least two non-magnetic elements. By controlling the thickness of the first and second ferromagnetic layers in the free layer structure to less than 1 nm, this invention effectively improves STT efficiency and reduces write current; simultaneously, the spacer layer in this free layer structure is composed of at least two different non-magnetic elements with strong binding energy, ensuring the stability of the spacer layer structure, suppressing element diffusion caused by the thinning of the magnetic layer, and improving erasure and write resistance.

The invention relates to the technical field of memories, in particular to a storage / random function fused MRAM (Magnetic Random Access Memory) unit and an implementation method thereof. The MRAM storage unit comprises a heavy metal layer, a free layer, a barrier layer, a reference layer, a pinning layer and a top metal electrode which are sequentially stacked from bottom to top, the pinning layer is of an artificial antiferromagnetic structure with perpendicular magnetic anisotropy. According to the storage / random function fused MRAM storage unit, under the synergistic effect of the unipolar spin transfer current and the unipolar spin orbit current, the same storage unit can be switched between the storage function and the true random number generation function.

The present embodiments relate to write heads implementing microwave-assisted magnetic recording utilizing multiple spin torque oscillators (STOs). Each STO can include a field-generation layer (FGL) that can oscillate in a same frequency and out of phase with one another. The layers in each STO can enable mutual spin transfer torques between adjacent layers, which can drive the FGLs into a large angle oscillation. The oscillation between the FGLs can cause a magnetic field to be generated that can assist in writing to a magnetic recording medium.

Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures on a substrate in for spin-transfer-torque magnetoresistive random access memory (STT-MRAM) applications. In one example, a film stack utilized to form a magnetic tunnel junction structure on a substrate includes a pinned layer disposed on a substrate, wherein the pinned layer comprises multiple layers including at least one or more of a Co containing layer, Pt containing layer, Ta containing layer, an Ru containing layer, an optional structure decoupling layer disposed on the pinned magnetic layer, a magnetic reference layer disposed on the optional structure decoupling layer, a tunneling barrier layer disposed on the magnetic reference layer, a magnetic storage layer disposed on the tunneling barrier layer, and a capping layer disposed on the magnetic storage layer.

An interconnected spin majority gate device based on a magnetic tunnel junction comprises, from the surface to the substrate, a top electrode layer, a magnetic pinning layer, an insulating tunneling layer, a first magnetic magnetization free layer FL1, an isolation coupling layer, a second magnetic magnetization free layer FL2, a heavy metal layer, and a bottom electrode layer. The magnetic pinning layer consists of a magnetic layer and a coupled antiferromagnetic layer. An isolation coupling layer is provided between the first and second magnetic magnetization free layers to separate them. The magnetic pinning layer, the insulating tunneling layer, and the magnetic magnetization free layers constitute a magnetic tunnel junction. The magnetization direction of the magnetic magnetization free layers is controlled by the spin-transfer torque effect generated by the current, and logic is implemented by the exchange coupling effect of the interconnected magnetic magnetization free layers. The device includes four dual-magnetization free layer magnetic tunnel junctions sharing a common magnetic magnetization free layer, denoted as the first, second, and third inputs MTJ and the output, respectively. The device has a cross shape with four branches, three of which are input branches and the fourth branch is the output branch.

A multilayered magnetic free layer structure is provided that includes a first magnetic free layer and a second magnetic free layer separated by a non-magnetic layer in which the second magnetic free layer has a lower perpendicular magnetic anisotropy field, Hk, as compared with the first magnetic free layer. The multilayered magnetic free layer structure of the present application substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers. The lower Hk value of the second magnetic free layer as compared to the first magnetic free layer improves the switching speed of the second magnetic free layer and thus reduces, and even eliminates, write errors.

A method for forming structures with desired crystallinity used in MRAM applications is disclosed. Embodiments of the disclosure provide methods and apparatus for fabricating magnetic tunnel junction (MTJ) structures used in spin transfer torque magnetoresistive random access memory (STT-MRAM) applications on a substrate. In one embodiment, the method includes patterning a film stack disposed on a substrate having a tunneling barrier disposed between a magnetic reference layer and a magnetic storage layer to remove a portion of the film stack from the substrate until an upper surface of the substrate is exposed; forming a sidewall passivation layer on sidewalls of the patterned film stack; and subsequently performing a thermal anneal process on the film stack.

The present application discloses a magnetic pulse neuron device and its application. The device comprises: a magnetic tunnel junction for emitting a spike pulse electrical signal in response to a driving electrical signal. The magnetic tunnel junction comprises a capping layer, a magnetic free layer, a barrier layer, a pinning layer, and an antiferromagnetic layer stacked in sequence, with the magnetization direction of the magnetic free layer being in-plane oriented; a first electrode layer; a second electrode layer; and a high thermal resistance interface formed between the capping layer and the magnetic free layer. The high thermal resistance interface is configured to generate a thermally driven spin transfer torque and thermal noise under the action of the driving electrical signal. The magnetization direction of the magnetic free layer continuously flips under the action of the thermally driven spin transfer torque and the electrically driven spin transfer torque generated by the driving electrical signal. The magnetic pulse neuron device of the present application can generate a modulated spike pulse signal under the excitation of an external DC voltage or a pulse voltage, significantly saving area and reducing power consumption.

A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a metal oxide (Mox) layer and a tunnel barrier layer to produce interfacial perpendicular magnetic anisotropy (PMA). The Mox layer has a non-stoichiometric oxidation state to minimize parasitic resistance, and comprises a dopant to fill vacant lattice sites thereby blocking oxygen diffusion through the Mox layer to preserve interfacial PMA and high thermal stability at process temperatures up to 400° C. Various methods of forming the doped Mox layer include deposition of the M layer in a reactive environment of 02 and dopant species in gas form, exposing a metal oxide layer to dopant species in gas form, and ion implanting the dopant. In another embodiment, where the dopant is N, a metal nitride layer is formed on a metal oxide layer, and then an anneal step drives nitrogen into vacant sites in the metal oxide lattice.

The present disclosure is applicable to the technical field of spintronics. Provided is a spin transfer torque-based spin micro system. The system comprises a spin sensor device, which is configured to sense an external magnetic field and an external microwave signal, convert the external magnetic field and the external microwave signal into an electrical signal, and output same to a spin storage device; a spin logic device, which is configured to generate a first spin current to perform logic operation on the electric signal to obtain magnetic field information about the external magnetic field and microwave information about the external microwave signal, and output the magnetic field information and the microwave information to the spin storage device; a spin storage device, which is configured to receive the electric signal, the magnetic field information and the microwave information, generate a second spin current to output the electric signal to the spin logic device, and output the magnetic field information and the microwave information to a spin oscillator device; and a spin oscillator device, which is configured to receive the magnetic field information and the microwave information and generate a third spin current to convert the magnetic field information and the microwave information into an output microwave signal.

Embodiments of the present application provide a nano-oscillator array based on spin-transfer torque and a manufacturing method therefor, an oscillator network, and a computing device. The nano-oscillator array comprises a seed crystal layer, and a nanopillar shared layer and a nanopillar array that are sequentially formed in a direction away from the seed crystal layer; the nanopillar shared layer comprises at least a first magnetic thin film layer; the nanopillar array comprises a plurality of nanopillars arranged in an array, and each nanopillar correspondingly generates a spin nano-oscillator; and each nanopillar comprises a second magnetic thin film layer and a cap layer that are sequentially arranged in the direction away from the seed crystal layer. The present application can improve in-plane current shunting, and significantly improve the effective current density and the coupling strength of nano-oscillators.

The present embodiments relate to write heads implementing microwave-assisted magnetic recording utilizing multiple spin torque oscillators (STOs). Each STO can include a field-generation layer (FGL) that can oscillate in a same frequency and out of phase with one another. The layers in each STO can enable mutual spin transfer torques between adjacent layers, which can drive the FGLs into a large angle oscillation. The oscillation between the FGLs can cause a magnetic field to be generated that can assist in writing to a magnetic recording medium.

An approach for providing a semiconductor structure for a stacked magnetoresistive random-access memory (MRAM) device that includes a first magnetic tunnel junction on a bottom electrode and at least one second magnetic tunnel junction above the first magnetic tunnel junction. The semiconductor structure includes the first magnetic tunnel junction is a voltage-controlled magnetic anisotropy (VCMA) magnetic tunnel junction of a voltage-controlled magnetic anisotropy (VCMA) MRAM device. The VCMA-MRAM device is composed of a first reference layer, a first tunnel barrier layer, and a first free layer. The semiconductor structure includes the second magnetic tunnel junction that is a spin-transfer torque (STT) magnetic tunnel junction of a STT-MRAM device. The STT-MRAM device is composed of a second reference layer, a second tunnel barrier layer, and a second free layer where the STT magnetic tunnel junction has a smaller cross-sectional area than the VCMA magnetic tunnel junction (MTJ).