Magnetic random storage unit, writing method and storage system

Abstract

The invention provides a magnetic random storage unit, a writing method and a storage system, and the magnetic random storage unit comprises a bottom electrode layer which is arranged on a substrate; the at least one magnetic tunnel junction is arranged on the bottom electrode layer and comprises a free layer, an insulating layer arranged on the free layer and a reference layer arranged on the insulating layer; a write-in current is input through a write-in channel, the write-in channel extends from one end of the bottom electrode layer to the top end of the magnetic tunnel junction through the magnetic tunnel junction, and the magnetic moment direction of a free layer of the magnetic tunnel junction is subjected to deterministic overturning based on a track flow effect formed when the write-in current is introduced into the bottom electrode layer. The process difficulty, the device power consumption and the device area can be reduced, and reliable writing of data is realized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a magnetic random access memory cell, a writing method, and a storage system. Background Technology

[0002] As semiconductor process dimensions continue to shrink and Moore's Law slows down, increased leakage current and interconnect delays have become bottlenecks for traditional CMOS memories. Finding solutions for next-generation memory technologies has become a key focus of integrated circuit research, with magnetic random access memory (MRAM) receiving widespread attention. Compared to traditional devices, MRAM offers advantages such as unlimited erase / write cycles, non-volatility, fast read / write speeds, and radiation resistance, making it a promising candidate for general-purpose memory and an ideal device for building next-generation non-volatile memories and in-memory computing.

[0003] Currently, utilizing spin-orbit torques (SOTs) to alter the magnetic moment state of ferromagnetic layers has become a research hotspot. The core structure is typically a two-layer structure of a ferromagnetic layer and a spin-orbit torque layer. The spin-orbit torque can originate from the spin Hall effect (SHE) and the Rashba (spin-orbit coupling) effect. Based on the mechanism, the SOT can be divided into two parts: a field-like moment and a damping-like moment. When current flows through the spin-orbit torque layer, the presence of spin-orbit coupling generates a spin current. This spin current acts on the adjacent ferromagnetic layer, producing the SOT and thus altering the magnetic moment state of the ferromagnetic layer.

[0004] However, SOT-MRAM currently suffers from the following problems: 1. SOT-MRAM typically uses thin (usually a few nanometers) heavy metal materials with strong spin-orbit coupling as the bottom electrode, which is often expensive. Furthermore, the etching process requires precise stopping on this bottom electrode layer, and a stop window of only a few nanometers poses a significant challenge to the etching process. The thinner bottom electrode also leads to higher resistance and makes compatibility with existing transistors more difficult. 2. SOT-MRAM is a three-port device, while most mainstream memory devices are two-port devices. The introduction of this additional input port increases the complexity of circuit design and transistor area overhead. 3. Current mainstream SOT-MRAM uses a vertically anisotropic design, requiring an external magnetic field for data writing. A reliable writing method without external magnetic field assistance is needed. Summary of the Invention

[0005] One object of the present invention is to provide a magnetic random access memory (RAM) cell that reduces manufacturing complexity and device area while enabling reliable data writing. Another object of the present invention is to provide a method for writing to a magnetic RAM cell. A further object of the present invention is to provide a magnetic random access memory (RAM) system.

[0006] To achieve the above objectives, the present invention discloses a magnetic random access memory unit, comprising:

[0007] The bottom electrode layer is disposed on the substrate;

[0008] At least one magnetic tunnel junction is disposed on the bottom electrode layer, including a free layer, an insulating layer disposed on the free layer, and a reference layer disposed on the insulating layer;

[0009] The write current is input via a write channel that extends from one end of the bottom electrode layer through the magnetic tunnel junction to the top of the magnetic tunnel junction. The magnetic moment direction of the free layer of the magnetic tunnel junction is deterministically reversed based on the orbital current generated when the write current is applied to the bottom electrode layer.

[0010] Optionally, the bottom electrode layer forms an orbital flow due to the orbital Hall effect, the bottom electrode layer is formed by an orbital Hall layer or an orbital Hall layer and a conversion layer, and the free layer is composed of a ferromagnetic material or a composite layer of antiferromagnetic material and ferromagnetic material.

[0011] Optionally, the orbital Hall layer is formed of a light metal material or a heavy metal material with a strong orbital Hall effect. The light metal material includes at least titanium (Ti), chromium (Cr), vanadium (V), niobium (Nb), and copper (Cu) and their oxides or alloys. The heavy metal material includes at least tantalum (Ta), ruthenium (Ru) and their oxides or alloys.

[0012] The conversion layer is formed of a metallic material with strong spin-orbit coupling and is disposed between the free layer and the orbital Hall layer. It is used to convert the orbital flow formed by the orbital Hall layer based on the orbital Hall effect into a spin flow, so that the free layer magnetic moment of the magnetic tunnel junction undergoes a deterministic reversal under the action of the converted spin flow.

[0013] The ferromagnetic material is formed of a material with a strong orbital magnetic moment or a strong spin magnetic moment, including at least samarium nitride (SmN), cobalt iron boron (CoFeB), or nickel (Ni), and the antiferromagnetic material includes at least cobalt oxide (CoO) or nickel oxide (NiO).

[0014] Optionally, the magnetic moment direction of the free layer is flipped based on the effect of the orbital flow in the orbital Hall layer, or by the effect of the orbital flow being converted into a spin flow through the conversion layer.

[0015] Optionally, the metallic material with strong spin-orbit coupling includes at least one of platinum (Pt), tungsten (W), gadolinium (Gd), samarium (Sm), and terbium (Tb) and their alloys.

[0016] The present invention also discloses a method for writing to a magnetic random access memory cell as described above, comprising:

[0017] Write current is input to the bottom electrode layer on the substrate through the write channel;

[0018] The magnetic moment direction of the free layer of at least one magnetic tunnel junction on the bottom electrode layer is deterministically reversed based on the orbital current formed when the write current is input to the bottom electrode layer. The magnetic tunnel junction includes a free layer, an insulating layer disposed on the free layer, and a reference layer disposed on the insulating layer. The write channel extends from one end of the bottom electrode layer through the magnetic tunnel junction to the top end of the magnetic tunnel junction.

[0019] The present invention also discloses a magnetic random access memory system, including a magnetic random access memory unit and a write module as described above;

[0020] The writing module is used to input writing current into the writing channel.

[0021] Optionally, the write module includes a first switching element disposed on the write channel and electrically connected to one end of the bottom electrode layer that receives the write current, and a second switching element electrically connected to the top end of the magnetic tunnel junction.

[0022] The magnetic random access memory (RAM) cell of this invention includes a bottom electrode layer and a magnetic tunnel junction (MTJ) disposed on a substrate. A write current is input via a write channel extending from one end of the bottom electrode layer through the MTJ to the top of the MTJ. The magnetic moment direction of the free layer of the MTJ undergoes a deterministic reversal based on the orbital current generated by the Orbital Hall effect (OHE) when the write current is input to the bottom electrode layer. Therefore, the bottom electrode of this invention generates an orbital current based on the Orbital Hall effect, eliminating the need for thin heavy metal materials, thus reducing manufacturing complexity. Furthermore, reliable data writing to the MTJ can be achieved without the aid of an external magnetic field. Since the write channel extends from one end of the bottom electrode layer through the MTJ to the top of the MTJ, only two switching elements such as transistors are needed at one end of the bottom electrode layer and the top of the MTJ, eliminating the need for three transistors to form a three-port device, reducing circuit design complexity and device area. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This diagram shows one of the structural diagrams of a specific embodiment of the magnetic random access memory cell of the present invention;

[0025] Figure 2 This diagram illustrates a specific embodiment of the magnetic random access memory cell of the present invention, which incorporates multiple magnetic tunnel junctions.

[0026] Figure 3 A schematic diagram of the write channel of a specific embodiment of the magnetic random access memory cell of the present invention is shown;

[0027] Figure 4 This diagram illustrates data erasure in a specific embodiment of the magnetic random access memory (RAM) of the present invention.

[0028] Figure 5 This diagram illustrates a specific embodiment of the magnetic random access memory cell of the present invention, including a conversion layer.

[0029] Figure 6 A schematic diagram of the structure of a computer device according to an embodiment of the present invention is shown. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] According to one aspect of the present invention, this embodiment discloses a magnetic random access memory (RAM) unit. For example... Figure 1 As shown, in this embodiment, the magnetic random access memory cell includes a bottom electrode layer disposed on the substrate and at least one magnetic tunnel junction (MTJ).

[0032] In some optional implementations, such as Figure 2 As shown, a magnetic random access memory cell can have multiple magnetic tunnel junctions 1 on the bottom electrode layer, with multiple magnetic tunnel junctions 1 sharing a single bottom electrode layer, in order to achieve the design of a high data density magnetic device.

[0033] The at least one magnetic tunnel junction 1 is disposed on the bottom electrode layer, and the magnetic tunnel junction 1 includes a free layer 12, an insulating layer disposed on the free layer 12, and a reference layer 14 disposed on the insulating layer.

[0034] like Figure 3 As shown, the write current is input via a write channel that extends from one end of the bottom electrode layer through the magnetic tunnel junction 1 to the top of the magnetic tunnel junction 1. The magnetic moment direction of the free layer 12 of the magnetic tunnel junction 1 is deterministically reversed based on the orbital flow formed when the write current is applied to the bottom electrode layer.

[0035] The magnetic random access memory (RAM) cell of this invention includes a bottom electrode layer and a magnetic tunnel junction (MTJ) disposed on a substrate. A write current is input via a write channel extending from one end of the bottom electrode layer through the MTJ to its top. The magnetic moment direction of the free layer of the MTJ undergoes a deterministic reversal based on the orbital current generated by the Orbital Hall effect (OHE) when the write current is input to the bottom electrode layer. Therefore, the bottom electrode of this invention generates an orbital current based on the Orbital Hall effect, eliminating the need for thin, heavy metal materials, thus reducing manufacturing complexity. Furthermore, reliable data writing via the MTJ can be achieved without the aid of an external magnetic field. The write channel extends from one end of the bottom electrode layer through the MTJ to its top. Only two switching elements, such as transistors, are needed at one end of the bottom electrode layer and the top of the MTJ, eliminating the need for three transistors to form a three-port device, reducing circuit design complexity and device area.

[0036] The magnetic memory includes a reference layer 14, an insulating layer 13, and a free layer 12 arranged sequentially from top to bottom. The bottom surface of the free layer 12 is fixedly disposed to the top surface of the bottom electrode layer.

[0037] It is understandable that the resistance of magnetic tunnel junction 1 depends on the magnetization directions of reference layer 14 and free layer 12, which are determined by the magnetic moment directions. Specifically, when the magnetic moment directions of reference layer 14 and free layer 12 are the same, magnetic tunnel junction 1 is in a low-resistance state; when the magnetic moment directions of reference layer 14 and free layer 12 are opposite, magnetic tunnel junction 1 is in a high-resistance state. The high-resistance and low-resistance states of magnetic tunnel junction 1 can be pre-assigned to different data. For example, if the high-resistance state is pre-set to correspond to data "1" and the low-resistance state to data "0", then by inputting current or voltage into magnetic tunnel junction 1 through a reading circuit, the resistance state of magnetic tunnel junction 1 (high-resistance or low-resistance) can be determined based on the change in current or voltage. Based on the resistance state of magnetic tunnel junction 1, the data stored in magnetic tunnel junction 1 can be determined as "1" or "0". Determining the range of high resistance and low resistance states is a common technique in this field. Those skilled in the art can determine the resistance range of the magnetic tunnel junction 1 in the high resistance and low resistance states based on common knowledge. This invention will not elaborate further here.

[0038] The inventors discovered that the orbital Hall effect can generate strong orbital currents in some metals with low resistivity or high thickness, and these orbital currents can also complete data writing to the device. This strong OHE material not only improves upon thickness, resistivity, and price, but also has high writing efficiency.

[0039] Accordingly, in an optional embodiment, the bottom electrode layer is formed of an orbital Hall layer 11, in which an orbital flow is formed by the orbital Hall effect.

[0040] In existing technologies, to achieve SOT writing, a spin-orbit moment layer is typically formed using a heavy metal material with strong spin-orbit coupling. This results in a thin spin-orbit moment layer, leading to high costs in fabricating magnetic cells. When multiple magnetic tunnel junctions 1 are arranged on the spin-orbit moment layer, the high magnetoresistivity caused by the thin spin-orbit moment layer also requires special design for the writing operation. In this preferred embodiment, the bottom electrode layer includes an orbital Hall layer 11, which is formed of a light metal material. The bottom electrode formed of light metal can be thicker, reducing the difficulty of fabrication and facilitating the integration of multiple magnetic tunnel junctions 1.

[0041] The write current is input from one end of the orbit Hall layer 11, forming an orbital current based on the orbit Hall effect. The orbital current flows through the write channel to the top of the magnetic tunnel junction, forming a longitudinal orbital current. Under the combined action of the orbital current formed by the orbital Hall effect in the orbit Hall layer 11 and the longitudinal orbital moment formed by the orbital current flowing through the magnetic tunnel junction, the magnetic moment direction of the free layer 12 of the magnetic tunnel junction 1 undergoes a deterministic reversal. The longitudinal orbital moment increases the write efficiency, enabling the vertically anisotropic magnetic tunnel junction 1 to achieve deterministic data writing even without an external auxiliary magnetic field.

[0042] Furthermore, the write channel of the magnetic random access memory cell of the present invention extends from one end of the track Hall layer 11 through the free layer 12 to the top of the magnetic tunnel junction 1. Data writing can be achieved by setting only two switching elements at one end of the track Hall layer 11 and the top of the magnetic tunnel junction 1, which eliminates the need for three switching elements as required by the three-terminal device in the prior art, thus saving the number of devices and reducing the area of ​​the magnetic device.

[0043] In alternative implementations, such as Figure 4 As shown, when the magnetic random access memory cell erases the data stored in the magnetic tunnel junction 1, it can pass an erasure current to the orbital Hall layer 11, causing the magnetic moment of the free layer 12 to rotate under the action of the orbital current generated by the current, restoring it to the default initial state.

[0044] In an optional embodiment, the orbital Hall layer 11 is formed of a light or heavy metal material with a strong orbital Hall effect. The light metal material includes at least titanium (Ti), chromium (Cr), vanadium (V), niobium (Nb), and copper (Cu) and their oxides or alloys, and the heavy metal material includes at least tantalum (Ta), ruthenium (Ru), and their oxides or alloys. Of course, in practical applications, other feasible light metal materials can be used to form the orbital Hall layer 11, and the present invention does not limit this.

[0045] In an optional embodiment, the free layer 12 is composed of a ferromagnetic material or a composite layer of an antiferromagnetic material and a ferromagnetic material. The ferromagnetic material is a material with a strong orbital magnetic moment or a strong spin magnetic moment, including at least samarium nitride (SmN), cobalt iron boron (CoFeB), or nickel (Ni). The antiferromagnetic material includes at least cobalt oxide (CoO) or nickel oxide (NiO). Of course, in practical applications, other feasible materials can be used for the free layer 12, and this invention does not limit this. The reference layer 14 has the same material type as the free layer 12.

[0046] In an optional embodiment, when the free layer 12 is composed of a ferromagnetic material or a composite layer of antiferromagnetic and ferromagnetic materials, the thickness of the free layer 12 is less than 5 nanometers.

[0047] In another alternative implementation, such as Figure 5As shown, in this embodiment, the bottom electrode layer is formed by an orbital Hall layer 11 and a conversion layer 15. The conversion layer 15 is disposed between the free layer 12 and the orbital Hall layer 11, and is used to convert the orbital flow formed by the orbital Hall layer 11 based on the orbital Hall effect into a spin flow on the free layer 12, so that the magnetic moment of the free layer 12 of the magnetic tunnel junction 1 undergoes a deterministic reversal under the action of the converted spin flow.

[0048] Specifically, it is understandable that existing magnetic random access memory (MRM) cells typically employ a SOT+STT method to achieve deterministic data writing. However, in these existing schemes, writing via SOT+STT requires switching elements (e.g., transistors) at both ends of the spin-orbit moment layer of the magnetic tunnel junction 1 to input the SOT current, while STT writing requires a switching element at the top of the magnetic tunnel junction 1 to input the STT current. Existing technologies typically employ a magnetic tunnel junction 1 with in-plane anisotropy, utilizing the characteristics of in-plane magnetic anisotropy to achieve deterministic data writing of the magnetic tunnel junction 1 without an external auxiliary magnetic field.

[0049] In this embodiment, the conversion layer 15 converts the orbital flow formed by the orbital Hall layer 11 into a longitudinal spin flow of the magnetic tunnel junction 1, so that the magnetic moment of the free layer 12 of the magnetic tunnel junction 1 undergoes a deterministic reversal under the combined action of the orbital flow and the spin flow. The reversal of the magnetic moment of the free layer 12 can be achieved without the need for an external auxiliary magnetic field, which reduces the complexity of the device structure and the size of the device.

[0050] In an optional embodiment, the orbital Hall layer 11 is formed of a light metal material or a heavy metal material with a strong orbital Hall effect; the conversion layer 15 is formed of a metal material with strong spin-orbit coupling; and the free layer 12 is composed of a ferromagnetic material or a composite layer of antiferromagnetic and ferromagnetic materials.

[0051] Optionally, the light metal material includes at least titanium (Ti), chromium (Cr), vanadium (V), niobium (Nb), and copper (Cu) and their oxides or alloys, and the heavy metal material includes at least tantalum (Ta), ruthenium (Ru), and their oxides or alloys. Of course, in practical applications, other feasible heavy metal materials can be used to form the orbital Hall layer 11, and this invention does not limit this to any particular material.

[0052] Optionally, the metallic material with strong spin-orbit coupling includes at least one of platinum (Pt), tungsten (W), gadolinium (Gd), samarium (Sm), and terbium (Tb) and their alloys. That is, the metallic material with strong spin-orbit coupling forming the conversion layer 15 can be at least one of platinum (Pt), tungsten (W), gadolinium (Gd), samarium (Sm), and terbium (Tb), or an alloy formed from at least one of these materials. Of course, in practical applications, other feasible metallic materials can also be used, and this invention does not limit this.

[0053] It should be noted that in this optional embodiment, the other technical features of the magnetic random access memory cell when the bottom electrode layer is formed by the orbital Hall layer 11 and the conversion layer 15 are similar to the technical features of the magnetic random access memory cell when the bottom electrode layer is formed by the orbital Hall layer 11. Please refer to the description of the above embodiment, and it will not be repeated here.

[0054] In optional embodiments, the magnetic tunnel junction 1 may further include at least one of the following layered structures: an insertion layer, a pinning layer, a seed layer, and a capping layer. The arrangement of each layered structure can be one or more layers depending on actual needs, and those skilled in the art can determine the top-to-bottom arrangement order of the layers in the magnetic tunnel junction 1 according to requirements; this invention does not limit this.

[0055] Optionally, the shape of the magnetic tunnel junction 1 on the orbital Hall layer 11 can be any of the shapes such as cube, cylinder, cubic, or elliptical cylinder. The bottom surface shape of at least one magnetic tunnel junction 1 disposed on the orbital Hall layer 11, i.e., the lower surface of the free layer 12, is coupled to the orbital Hall layer 11.

[0056] Preferably, the orbital Hall layer 11 can be rectangular, such that the top surface area of ​​the orbital Hall layer 11 is larger than the area occupied by at least one magnetic tunnel junction 1 disposed on the orbital Hall layer 11, even if at least one magnetic tunnel junction 1 can be disposed on the orbital Hall layer 11, and the outer edge of at least one magnetic tunnel junction 1 is located inside the outer edge of the orbital Hall layer 11.

[0057] In a preferred embodiment, when the magnetic random access memory (RAM) inputs current to the track Hall layer 11 and the magnetic tunnel junction 1, it can be done by setting electrodes on the track Hall layer 11 and the magnetic tunnel junction 1. For example, a top electrode can be set on the top of the magnetic tunnel junction 1, and input electrodes and output electrodes can be set on opposite sides of the track Hall layer 11, respectively. Preferably, the electrode material can be any one of tantalum (Ta), aluminum (Al), gold (Au), or copper (Cu).

[0058] Preferably, the insulating layer 13 can be made of an oxide. If the magnetic tunnel junction 1 has perpendicular magnetic anisotropy, it means that the magnetization directions of the free layer 12 and the fixed layer forming the magnetic tunnel junction 1 are along the perpendicular direction. If the magnetic tunnel junction 1 has planar magnetic anisotropy, it means that the magnetization directions of the free layer 12 and the fixed layer forming the magnetic tunnel junction 1 are along a plane parallel to the orbital Hall layer 11. The oxide can be one of magnesium oxide (MgO) or aluminum oxide (Al2O3), used to generate the tunneling magnetoresistance effect. In practical applications, other feasible materials can also be used as oxides, and this invention does not limit this.

[0059] The free layer 12 of the magnetic tunnel junction 1 is fixed in contact with the orbital Hall layer 11. The layers of the magnetic tunnel junction 1 and the orbital Hall layer 11 can be deposited on the substrate in a bottom-to-top order by traditional methods such as ion beam epitaxy, atomic layer deposition or magnetron sputtering. Then, the magnetic tunnel junction 1 is formed by traditional nano-device processing technology such as photolithography and etching.

[0060] In this embodiment, the magnetic tunnel junction 1 includes a top fixed layer, a free layer 12 in contact with the orbital Hall layer 11, and an insulating layer 13 disposed between the fixed layer and the free layer 12. The magnetic tunnel junction 1 has a three-layer structure, including only one free layer 12. In other embodiments, there may be multiple free layers 12, i.e., two or more free layers 12. Then the magnetic tunnel junction 1 includes a top fixed layer, multiple free layers 12, and an insulating layer 13 disposed between each adjacent pair of layers, with the bottom free layer 12 in contact with the orbital Hall layer 11. For example, in a specific example, when two free layers 12 are included, the magnetic storage cell structure may include an orbital Hall layer 11, a second free layer 12 disposed sequentially on the orbital Hall layer 11, an insulating layer 13, a first free layer 12, an insulating layer 13, and a fixed layer.

[0061] This invention proposes a complete third-generation SOT-MRAM design scheme, from the material structure design of magnetic devices and the device writing method to the final device array structure, which can solve the three difficulties listed above. Utilizing the Orbital Hall effect (OHE) of light metals, and employing a thicker light metal bottom electrode film design, it effectively solves the problems of bottom electrode thickness, resistance, and price in traditional SOT-MRAM designs. Simultaneously, the use of the STT+SOT writing method and the NAND-SPIN array design solves the problems of three-port design and the need for external magnetic field-assisted writing. In summary, the thicker Orbital Hall layer 11 forming the bottom electrode of this invention reduces the difficulty of process fabrication and improves the yield. The lower resistance bottom electrode allows for the integration of multiple magnetic tunnel junction 1 devices on a single bottom electrode, increasing the device integration density. The two-end writing method of the magnetic tunnel junction 1 in the magnetic unit, combined with the device integration design, can reduce the number of transistors and reduce the area overhead of the magnetic memory chip. In summary, this invention provides a low-power and high-integration-density solution for existing SOT-MRAM, which optimizes the bottom electrode structure and device integration method compared to current structural designs.

[0062] Based on the same principle, this embodiment also discloses a method for writing to a magnetic random access memory cell as described in this embodiment. The method includes:

[0063] S100: Input write current to the bottom electrode layer on the substrate through the write channel.

[0064] S200: The magnetic moment direction of the free layer 12 of at least one magnetic tunnel junction 1 on the bottom electrode layer is deterministically reversed based on the orbital current formed when the write current is input to the bottom electrode layer, wherein the magnetic tunnel junction 1 includes a free layer 12, an insulating layer disposed on the free layer 12, and a reference layer 14 disposed on the insulating layer, and the write channel extends from one end of the bottom electrode layer through the magnetic tunnel junction 1 to the top end of the magnetic tunnel junction 1.

[0065] Based on the same principle, this embodiment also discloses a magnetic random access memory system. The magnetic random access memory system includes a magnetic random access memory unit and a write module as described in this embodiment, wherein the write module is used to input a write current into the write channel.

[0066] The writing module includes a first switching element disposed on the writing channel and electrically connected to one end of the bottom electrode layer that receives the writing current, and a second switching element electrically connected to the top end of the magnetic tunnel junction 1.

[0067] Therefore, the first and second switching elements of this invention can be turned on under the control of the writing module's control command. The first and second switching elements are turned on to open the input channel, thereby enabling deterministic writing of data into the magnetic tunnel junction 1 by inputting a writing current through the input channel. This invention requires only two switching elements for data writing, fewer than existing three-terminal devices, thus saving on the area overhead of the magnetic unit and the device.

[0068] It should be noted that the specific structure and implementation of the writing module of the present invention can be set by those skilled in the art according to actual needs in practical applications, and are conventional technical means in the field, and will not be described in detail here.

[0069] The magnetic unit and system described in the above embodiments can be specifically installed in a product device with a certain function. A typical implementation device is a computer device, specifically, such as a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0070] In a typical example, a computer device specifically includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor and / or the memory includes radiation-resistant magnetic storage units as described in this embodiment.

[0071] The following is for reference. Figure 6 It shows a schematic diagram of the structure of a computer device 600 suitable for implementing embodiments of the present invention.

[0072] like Figure 6 As shown, the computer device 600 includes a central processing unit (CPU) 601, which can perform various appropriate tasks and processes based on programs stored in read-only memory (ROM) 602 or programs loaded from storage section 608 into random access memory (RAM) 603. The RAM 603 also stores various programs and data required for the operation of the computer device 600. The CPU 601, ROM 602, and RAM 603 are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0073] The following components are connected to I / O interface 605: an input section 606 including a keyboard, mouse, etc.; an output section 607 including a cathode ray tube (CRT), liquid crystal feedback (LCD), etc., and speakers, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN card, modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to I / O interface 605 as needed. A removable medium 611, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 610 as needed so that computer programs read from it can be installed in storage section 608 as needed.

[0074] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0075] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0076] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0077] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0078] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can be applied to computer program products implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0079] This invention can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This invention can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0080] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0081] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A magnetic random access memory unit, characterized in that, include: The bottom electrode layer is disposed on the substrate; At least one magnetic tunnel junction is disposed on the bottom electrode layer, including a free layer, an insulating layer disposed on the free layer, and a reference layer disposed on the insulating layer; The write current is input via a write channel that extends from one end of the bottom electrode layer through the magnetic tunnel junction to the top of the magnetic tunnel junction. The magnetic moment direction of the free layer of the magnetic tunnel junction is deterministically reversed based on the orbital current generated when the write current is applied to the bottom electrode layer.

2. The magnetic random access memory unit according to claim 1, characterized in that, The bottom electrode layer is formed by the orbital Hall effect to create an orbital flow. The bottom electrode layer is formed by an orbital Hall layer or an orbital Hall layer and a conversion layer. The free layer is composed of a ferromagnetic material or a composite layer of antiferromagnetic material and ferromagnetic material.

3. The magnetic random access memory unit according to claim 2, characterized in that, The orbital Hall layer is formed of a light metal material or a heavy metal material with a strong orbital Hall effect. The light metal material includes at least titanium (Ti), chromium (Cr), vanadium (V), niobium (Nb), and copper (Cu) and their oxides or alloys. The heavy metal material includes at least tantalum (Ta), ruthenium (Ru) and their oxides or alloys. The conversion layer is formed of a metallic material with strong spin-orbit coupling and is disposed between the free layer and the orbital Hall layer. It is used to convert the orbital flow formed by the orbital Hall layer based on the orbital Hall effect into a spin flow, so that the free layer magnetic moment of the magnetic tunnel junction undergoes a deterministic reversal under the action of the converted spin flow. The ferromagnetic material is a material with a strong orbital magnetic moment or a strong spin magnetic moment, including at least samarium nitride (SmN), cobalt iron boron (CoFeB), or nickel (Ni), and the antiferromagnetic material includes at least cobalt oxide (CoO) or nickel oxide (NiO).

4. The magnetic random access memory unit according to claim 2, characterized in that, The magnetic moment direction of the free layer is flipped based on the effect of the orbital flow in the orbital Hall layer, or by the effect of the orbital flow being converted into a spin flow through the conversion layer.

5. The magnetic random access memory unit according to claim 3, characterized in that, Metallic materials with strong spin-orbit coupling include at least one of platinum (Pt), tungsten (W), gadolinium (Gd), samarium (Sm), and terbium (Tb) and their alloys.

6. A method for writing to a magnetic random access memory cell as described in any one of claims 1-5, characterized in that, include: Write current is input to the bottom electrode layer on the substrate through the write channel; The magnetic moment direction of the free layer of at least one magnetic tunnel junction on the bottom electrode layer is deterministically reversed based on the orbital current formed when the write current is input to the bottom electrode layer. The magnetic tunnel junction includes a free layer, an insulating layer disposed on the free layer, and a reference layer disposed on the insulating layer. The write channel extends from one end of the bottom electrode layer through the magnetic tunnel junction to the top end of the magnetic tunnel junction.

7. A magnetic random access memory system, characterized in that, Includes the magnetic random access memory unit and write module as described in any one of claims 1-5; The write module is used to input write current into the write channel.

8. The magnetic random access memory system according to claim 7, characterized in that, The writing module includes a first switching element disposed on the writing channel and electrically connected to one end of the bottom electrode layer that receives the writing current, and a second switching element electrically connected to the top end of the magnetic tunnel junction.

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