Spinning electronic device and in-memory computing device

Abstract

The embodiment of the invention provides a spinning electronic device and an in-memory computing device. The spinning electronic device comprises a substrate; the complex oxide layer and the magnetic tunnel junction structure are sequentially formed on the substrate from bottom to top, a two-dimensional electron gas area is arranged on an interface of the complex oxide layer, and under the condition that read-write voltage is applied to the spin electron device, spin current generated by the magnetic tunnel junction structure enters the two-dimensional electron gas area of the interface of the complex oxide layer in a tunneling mode. And the density of the two-dimensional electron gas is changed, so that the magnetic tunnel junction structure completes data reading or writing. Therefore, the reading reliability of the device is improved.

Description

Technical Field

[0001] The present application relates to the field of synaptic technology, and in particular to a spin electronic device and an in-memory computing device. Background Art

[0002] Spintronic devices are a new type of devices that use electron spin as an information carrier. They exhibit unique advantages in information storage, processing and transmission, such as non-volatility, high speed and low power consumption.

[0003] However, spintronic devices are limited by their small switching ratio, which makes external circuit design complex. Spintronic devices also have the disadvantage of relatively low magnetoresistance, which is not conducive to improving reading reliability. Summary of the invention

[0004] The embodiments of the present application provide a spin electronic device and an in-memory computing device, which are used to improve the high-resistance and low-resistance state magnetoresistance ratio of the spin electronic device and improve the reliability of device reading.

[0005] In a first aspect, an embodiment of the present application provides a spin electronic device, comprising:

[0006] A substrate; and a complex oxide layer and a magnetic tunnel junction structure formed sequentially from bottom to top on the substrate, wherein a two-dimensional electron gas region is present at the interface of the complex oxide layer, and when a read / write voltage is applied to the spin electronic device, a spin current generated by the magnetic tunnel junction structure tunnels into the two-dimensional electron gas region at the interface of the complex oxide layer, thereby changing the density of the two-dimensional electron gas and enabling the magnetic tunnel junction structure to complete data reading or writing.

[0007] In a possible implementation manner, a heavy metal layer is further included between the complex oxide layer and the magnetic tunnel junction structure.

[0008] In a possible implementation, the heavy metal layer includes one or more heavy metals selected from the group consisting of W, Pt, Ta, and Ir.

[0009] In a possible implementation, the magnetic tunnel junction structure includes, from bottom to top, a magnetic domain free layer, a barrier layer, a reference layer, a pinned layer, and a top electrode.

[0010] In one possible implementation, when a write voltage is applied to the spin electronic device, the magnetic domains of the magnetic tunnel junction structure move or shrink under the stimulation of an electric field or a magnetic field pulse, causing the relative magnetization ratio of the magnetic domain free layer and the reference layer to change, thereby modulating the resistance of the magnetic tunnel junction.

[0011] In a possible implementation, when a read voltage is applied to the spin electronic device, the spin current generated by the magnetic tunnel junction structure is converted into a charge current in the two-dimensional electron gas region under the action of spin-charge conversion, and an electric charge current is formed under the action of a fixed electric field, thereby changing the density of the two-dimensional electron gas.

[0012] In one possible implementation, the difference in charge flow generated by different polarization directions of the spin current is fed back to the electric field applied by the spin electronic device, and the information of the spin electronic device forms a positive feedback relationship with the electric field, so that the density of the two-dimensional electron gas changes, and the change in charge density is fed back to the size of the back gate voltage, thereby enhancing the change in the density of the two-dimensional electron gas.

[0013] In a possible implementation manner, the complex oxide layer and the magnetic domain free layer are both rectangular parallelepiped structures, and the barrier layer, the reference layer, the pinned layer and the top electrode are all cylindrical structures.

[0014] In a possible implementation, the complex oxide layer includes one or more complex oxides.

[0015] In a possible implementation, the complex oxide layer includes one or more complex oxides.

[0016] In a second aspect, an embodiment of the present application provides a spin electronic device, and the above-mentioned spin electronic device is the above-mentioned spin electronic device.

[0017] In a possible implementation, when calculating weight modulation in memory, the spin-orbit moment current of the magnetic storage layer drives the magnetic domain to move, the proportion of the spin direction of the magnetic storage layer changes, and different weights are linearly set;

[0018] During the in-memory computing data reading process, different spin directions account for a proportion between the maximum charge and the minimum charge, exhibiting different conductivity values. When the read voltage is applied, in-memory multiplication and addition operations are realized.

[0019] The spin electronic device and the in-memory computing device provided by the embodiment of the present application are through a substrate; and a complex oxide layer and a magnetic tunnel junction structure formed sequentially from bottom to top on the substrate, wherein there is a two-dimensional electron gas region at the interface of the complex oxide layer. When a read-write voltage is applied to the spin electronic device, the spin current generated by the magnetic tunnel junction structure tunnels into the two-dimensional electron gas region at the interface of the complex oxide layer, changes the density of the two-dimensional electron gas, and enables the magnetic tunnel junction structure to complete the reading or writing of data. Therefore, in the scheme of the present application, the spin synapse device generates a two-dimensional electron gas at the interface through a complex oxide layer, and changes the density of the two-dimensional electron gas under the action of spin-charge conversion through spin current injection. When writing information, different spin polarization directions bring different changes in the density of the two-dimensional electron gas. In the reading stage, when reading the spin polarization, the density of the two-dimensional electron gas changes. Through the feedback of the back gate, the high-low resistance state magnetoresistance ratio of the spin electronic device is improved, and the reliability of the device reading is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0021] Figure 1 The basic structure of the spin electronic device provided in this application;

[0022] Figure 2 Another basic structure of the spin electronic device provided by the present application;

[0023] Figure 3 The working principle of the spintronic device provided for this application;

[0024] Figure 4 A process for increasing the magnetoresistance ratio of the spin electronic device provided in the present application;

[0025] Figure 5 The electric field driven multi-resistance state information writing and reading of the spin electronic device provided in this application;

[0026] Figure 6 Magnetic domain generation for the spintronic device provided in the present application;

[0027] Figure 7 The expansion of magnetic domains generated by the spintronic device provided in the present application under the drive of a magnetic field;

[0028] Figure 8 The preparation process of the spin electronic device provided in this application;

[0029] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0030] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0031] Figure 1 The schematic diagram of the structure of the spin electronic device provided in this application is as follows: Figure 1 As shown, the device includes:

[0032] A substrate; and a complex oxide layer and a magnetic tunnel junction structure formed sequentially from bottom to top on the substrate, wherein a two-dimensional electron gas region is present at the interface of the complex oxide layer, and when a read / write voltage is applied to the spin electronic device, a spin current generated by the magnetic tunnel junction structure tunnels into the two-dimensional electron gas region at the interface of the complex oxide layer, thereby changing the density of the two-dimensional electron gas and enabling the magnetic tunnel junction structure to complete data reading or writing.

[0033] In this embodiment, a two-dimensional electron gas (2DEG) is an electronic system formed in a semiconductor heterojunction in which electrons are confined to move in two dimensions. This electron gas is usually formed at the interface of the heterojunction, and due to band discontinuity and quantum confinement, the electrons are confined to a two-dimensional region perpendicular to the interface. In this region, electrons can move freely along the interface plane, exhibiting quantized electronic properties. The two-dimensional electron gas density (the electron concentration of the two-dimensional electron gas) refers to the number of electrons per unit area in a two-dimensional electron gas system. A two-dimensional electron gas is a quantum state of electrons in which the movement of electrons is restricted in one direction, while they can move freely in the other two directions.

[0034] Exemplarily, the complex oxide layer is composed of one or more complex oxides, which may include but are not limited to La 1-x Sr x CoO 3-δ , SrTiO3, LaAlO3 / SrTiO3, BiFeO3 / SrTiO3 or metal oxide / SrTiO3 systems, etc., can form a two-dimensional electron gas at the interface.

[0035] In this embodiment, a two-dimensional electron gas is generated at the interface, so that the magnetic tunnel junction structure is injected with spin current, and the density of the two-dimensional electron gas is changed under the action of spin-charge conversion. When writing information, different spin polarization directions bring different changes in the density of the two-dimensional electron gas. In the reading stage, when reading the spin polarization, the density of the two-dimensional electron gas changes, and through the feedback of the back gate, the high-to-low resistance state magnetoresistance ratio of the spin electronic device is improved, and the reliability of the device reading is improved.

[0036] In one example, a heavy metal layer is further included between the complex oxide layer and the magnetic tunnel junction structure.

[0037] It can be understood that the magnetic tunnel junction structure includes a heavy metal interlayer between the two-dimensional electron gas layer to achieve the purpose of generating periodic magnetic domains or magnetic bubbles, while generating spin currents of different polarizations. Magnetic domains are spontaneously formed regions inside magnetic materials, and the magnetization direction of each region is roughly the same. At the macroscopic level, due to the interaction of magnetic domains, magnetic materials can exhibit zero net magnetization. The boundary of a magnetic domain is called a domain wall, which is where the magnetization direction inside the material changes suddenly. The formation of magnetic domains helps to reduce the magnetic energy of the material because the magnetization directions of adjacent magnetic domains are opposite, which can partially offset the influence of the external magnetic field.

[0038] In one example, the heavy metal layer includes one or more heavy metals such as W, Pt, Ta, and Ir.

[0039] In one example, the magnetic tunnel junction structure includes, from bottom to top, a magnetic domain free layer, a barrier layer, a reference layer, a pinned layer, and a top electrode.

[0040] Among them, the magnetic domain free layer of the tunnel junction includes: traditional ferromagnetic materials, such as one or more of NiFe, CoFeB, Co and CoPt; two-dimensional ferromagnetic materials, such as one or more of CrBr3, CrTe, FeTe, CrSe, 1T-VSe2, Cr2Ge2Te6, Fe3GeTe2 and Fe5GeTe2.

[0041] A magnetic tunnel junction (MTJ) is a nanostructure consisting of two ferromagnetic layers and a non-magnetic insulating layer. In an MTJ, the magnetization direction of one of the two ferromagnetic layers (the reference layer) is fixed, while the magnetization direction of the other (the free layer) can be flipped by external stimulation (such as a magnetic field or a spin-polarized current). The resistance of an MTJ depends on whether the magnetization directions of the two ferromagnetic layers are parallel or antiparallel. This dependence is the basis of the magnetoresistance effect of a magnetic tunnel junction and is widely used in spintronic devices such as magnetic random access memory (MRAM).

[0042] It is understandable that the heterostructure device based on the tunnel junction structure stores information and uses the two-dimensional electron gas structure in the same device to increase the magnetoresistance ratio. Figure 2 As shown in Figure 2, due to the spin-orbit coupling, the heavy metal layer generates a longitudinal spin current. At this time, the spin current J injected by the ferromagnet is S The conversion generates a charge current J C , injected into the two-dimensional electron gas region at the interface between the oxide layer and the metal.

[0043] Compared with the high-low magnetoresistance ratio of about 150% of the conventional magnetic tunnel junction, the working principle of the device of the present invention is as follows Figure 3 As shown, by changing the ratio of the spin magnetization of the free layer and the reference layer of the magnetic domain, the resistance feedback of the two-dimensional electron gas is changed, and the resistance change of the two-dimensional electron gas is used to feed back to the back gate voltage V BG This further changes the charge density in the two-dimensional electrons and amplifies the magnetoresistance ratio of the magnetic domains.

[0044] In one example, when a write voltage is applied to a spin electronic device, the magnetic domains of the magnetic tunnel junction structure move or shrink under the stimulation of an electric field or a magnetic field pulse, causing the relative magnetization ratio of the magnetic domain free layer and the reference layer to change, thereby modulating the resistance of the magnetic tunnel junction.

[0045] It can be understood that the magnetization ratio between the free layer and the reference layer changes, and the magnetic tunnel junction resistance is modulated by the magnetization ratio. Due to the dipole interaction and antisymmetric interaction between the heavy metal layer and the free layer, the magnetic domains are generated as follows Figure 6 The periodic magnetic domain structure shown on the left has different partitions representing different magnetization directions, and the magnetic domains transition through the magnetic domain walls pointing inward along the plane. The reference layer in the magnetic tunnel junction is magnetized in a fixed direction, such as upward. At this time, the proportion of the magnetization in the junction area in the magnetic free layer that is in the same direction as the reference layer can reflect the magnitude of the magnetic resistance. If they are exactly the same, it is low resistance, and if they are completely opposite, it is high resistance. After the electric pulse is driven, the magnetic domain wall is driven along the direction of the current and gradually changes to a vertical direction, such as Figure 6 As shown on the right, Figure 7 It shows that under the drive of magnetic field, the expansion of magnetic domains occurs, and the above magnetic domain change process produces magnetoresistance change. However, the magnetoresistance ratio obtained by traditional anisotropic magnetoresistance test is at the order of 1%, and the magnetoresistance ratio measured by tunnel junction can reach about 150%. The change of two-dimensional electron gas obtained by feedback of the inverse Edelstein effect is conducive to further increasing the high-low resistance ratio through resistance change.

[0046] In one example, when a read voltage is applied to a spin electronic device, the spin current generated by the magnetic tunnel junction structure is converted into a charge flow in the two-dimensional electron gas region under the action of spin-charge conversion, and an electric charge flow is formed under the action of a fixed electric field, causing the density of the two-dimensional electron gas to change.

[0047] It is understandable that during the reading process, due to the spin-charge conversion effect, spin currents with different polarizations are injected into the two-dimensional electron gas, which will generate charge flows of different polarities and change the charge density of the two-dimensional electron gas. The amount of change is positively correlated with the tunnel junction. The change in charge density is fed back to the back gate voltage, enhancing the change in the density of the two-dimensional electron gas. This increases the high-to-low resistance ratio of the device's lateral resistance. Under the action of spin-charge conversion, spin polarization is converted into charge flow in the two-dimensional electron gas region, forming a charge flow under the action of a fixed electric field, resulting in a change in the density of the two-dimensional electron gas.

[0048] It is understandable that if Figure 5 During the device reading process, a reading voltage is applied to the top electrode, and the spin current tunnels through the magnetic layer into the two-dimensional electron gas region. At this time, the spin current J injected by the ferromagnet is injected by the auxiliary voltage of the top electrode and the inverse Edelstein effect. S The conversion generates a charge current J C .J C The sign of changes with the change of the ferroelectric polarization direction. Under the action of spin-charge conversion, spin polarization is converted into charge flow in the two-dimensional electron gas region, resulting in a change in the density of the two-dimensional electron gas. At the same time, the difference in charge flow generated by different polarizations is fed back to the applied back gate electric field V BG When the magnetic resistance is low, it has a large electric field V BG , and when the magnetic resistance is high, it has a smaller electric field V BG This forms a positive feedback relationship, further changing the density of the two-dimensional electron gas. As a result, a resistance value difference far higher than the magnetoresistance ratio of the spin device itself is generated, which serves the purpose of improving the high-low resistance ratio of the device, expanding the margin of device reading, and improving device reliability.

[0049] In one example, the difference in charge flow caused by different polarization directions of the spin current is fed back to the electric field applied by the spin electronic device. The information of the spin electronic device and the electric field form a positive feedback relationship, causing the density of the two-dimensional electron gas to change. The change in charge density is fed back to the size of the back gate voltage, thereby enhancing the change in the density of the two-dimensional electron gas.

[0050] It can be understood that the difference in charge flow caused by different polarizations is fed back to the electric field applied by the device. When the device information is "0", it has a smaller electric field E1, and when the device information is "1", it has a larger electric field E2, forming a positive feedback relationship, which further changes the density of the two-dimensional electron gas. The difference in resistance value that is much higher than the magnetoresistance ratio of the spin device itself is generated, which serves the purpose of improving the high-low resistance ratio of the device. Therefore, during the reading process, the magnetization information "0" and the magnetization information "1" lead to a decrease or increase in the resistance of the two-dimensional electron gas region.

[0051] In one example, the preparation process of the spin electronic device of the present application is as follows: Figure 8 As shown, the preparation process includes:

[0052] By laser pulse deposition method, a bottom electrode and a complex oxide layer are grown on a silicon, silicon oxide or SrTiO3 substrate to form a basic structure of a two-dimensional electron gas;

[0053] The junction region is etched out by ion beam etching technology, and the bottom electrode and the upper two-dimensional electron gas are isolated by SiO2;

[0054] A heavy metal layer, a magnetic domain free layer, a barrier layer, a reference layer, a pinning layer and a top electrode are grown on the upper layer of the material by magnetron sputtering;

[0055] Patterning is performed using photolithography and ion beam etching techniques to etch out a cylindrical magnetic tunnel junction (MTJ) structure;

[0056] Etch the heavy metal layer and the top electrode pattern area to prepare a complete device.

[0057] The present application provides an in-memory computing device, which includes the above-mentioned spin electronic device.

[0058] In-Memory Computing (IMC) is a computing paradigm that closely integrates data processing and storage, aiming to solve the "memory wall" problem in the traditional von Neumann architecture. In the traditional architecture, the processor and memory are separated, and data needs to be transferred back and forth between the two, which leads to a significant performance bottleneck. In-Memory Computing reduces the number of data movements by performing calculations directly in the storage device, thereby reducing energy consumption and latency, and improving the efficiency and responsiveness of the system. In-Memory Computing technology usually utilizes specific storage devices that can not only store data, but also perform simple computing operations such as addition, multiplication, or comparison.

[0059] The spin electronic device can refer to the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0060] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0061] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (Non-volatile Memory, NVM), such as at least one disk memory.

[0062] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0063] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0064] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0065] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0066] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0067] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0068] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0069] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0070] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. According to this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0071] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0072] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A spin electronic device, characterized in that: include: substrate; And, a complex oxide layer and a magnetic tunnel junction structure are formed in sequence from bottom to top on the substrate, wherein there is a two-dimensional electron gas region at the interface of the complex oxide layer, and when a read-write voltage is applied to the spin electronic device, the spin current generated by the magnetic tunnel junction structure tunnels into the two-dimensional electron gas region at the interface of the complex oxide layer, changing the density of the two-dimensional electron gas, so that the magnetic tunnel junction structure completes data reading or writing.

2. The spintronic device according to claim 1, characterized in that A heavy metal layer is further included between the complex oxide layer and the magnetic tunnel junction structure.

3. The spintronic device according to claim 1, wherein: The heavy metal layer includes one or more heavy metals selected from the group consisting of W, Pt, Ta, and Ir.

4. The spintronic device according to claim 1, wherein: The magnetic tunnel junction structure comprises, from bottom to top, a magnetic domain free layer, a barrier layer, a reference layer, a pinning layer and a top electrode.

5. The spintronic device according to claim 4, characterized in that When a write voltage is applied to the spin electronic device, the magnetic domains of the magnetic tunnel junction structure move or shrink under the stimulation of an electric field or a magnetic field pulse, causing the relative magnetization ratio of the magnetic domain free layer and the reference layer to change, thereby modulating the magnetic tunnel junction resistance.

6. The spintronic device according to claim 4, characterized in that When a read voltage is applied to the spin electronic device, the spin current generated by the magnetic tunnel junction structure is converted into a charge flow in the two-dimensional electron gas region under the action of spin-charge conversion, and an electric charge flow is formed under the action of a fixed electric field, thereby changing the density of the two-dimensional electron gas.

7. The spintronic device according to claim 6, characterized in that The difference in charge flow generated by different polarization directions of the spin current is fed back to the electric field applied by the spin electronic device. The information of the spin electronic device and the electric field form a positive feedback relationship, so that the density of the two-dimensional electron gas changes. The change in charge density is fed back to the size of the back gate voltage, thereby enhancing the change in the density of the two-dimensional electron gas.

8. The spintronic device according to claim 4, characterized in that The complex oxide layer and the magnetic domain free layer are both rectangular parallelepiped structures, and the barrier layer, the reference layer, the pinned layer and the top electrode are all cylindrical structures.

9. The spintronic device according to claim 1, wherein: The complex oxide layer includes one or more complex oxides.

10. An in-memory computing device, characterized in that: A spin electronic device comprising any one of claims 1 to 9.

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