Ion regulation based sot device, sot cross array, device gating method and memory chip

Abstract

The application discloses an ion regulation-based SOT device, an SOT cross array, a device gating method and a storage chip, and relates to the field of magnetic random memories. The ion regulation-based SOT device comprises a source-drain electrode, a voltage access end and a substrate, a perpendicular magnetic anisotropy magnetic layer, a low-symmetry crystal material layer, a gate oxide layer and a top electrode which are sequentially stacked from bottom to top. The source-drain electrode is used for applying an in-plane writing current. The voltage access end receives a regulation voltage, an electric field is formed between the top electrode and the low-symmetry crystal material layer, and a potential relationship is changed, so as to drive oxygen ion migration, thereby regulating the out-of-plane spin polarization ability of the low-symmetry crystal material layer, and regulating the deterministic perpendicular magnetic anisotropy magnetic moment flip of the SOT device under the condition of no external magnetic field. The application can regulate the spin-orbit torque to drive the magnetic moment flip.

Description

Technical Field

[0001] This application relates to the field of magnetic random access memory, and in particular to an ion-controlled SOT device, an SOT cross array, a device gating method, and a memory chip. Background Technology

[0002] Magnetic random access memory (MRAM) exhibits broad application prospects due to its low power consumption and high-speed read / write capabilities. The performance of magnetic storage technology largely depends on the efficiency of writing and reading information from the storage cells. In recent years, spin-orbit torque technology, developed based on the fundamental physical mechanism of spin-orbit coupling, has attracted widespread research interest in the interdisciplinary field of condensed matter physics and electronic information due to its ability to efficiently control the magnetic state of magnetic cells. Research on using the spin-orbit torque effect in non-magnetic layers to drive magnetic moment reversal in ferromagnetic layers has received considerable attention, as effective control of magnetic moments is a key element for information storage or computation in the field of spintronics. Materials used to generate spin-orbit torque (SOT) are mainly divided into two categories based on their magnetic moment reversal characteristics. One category requires the application of an in-plane magnetic field to achieve deterministic perpendicular magnetic anisotropy (PMA) magnetic moment reversal; the other category can achieve deterministic perpendicular anisotropy magnetic moment reversal without the application of an external magnetic field (i.e., no external field, zero magnetic field, or zero field), and these are typically low-symmetry crystalline materials. Low-symmetry crystal materials exhibit a non-traditional spin-orbit torque effect driven by current, enabling deterministic vertical anisotropic magnetic moment reversal at room temperature without an external magnetic field.

[0003] However, when constructing large-scale SOT-MRAM arrays, especially cross-arrays using shared write lines (such as word lines or bit lines), SOT devices based on low-symmetry crystal materials face a significant challenge: when a write operation is performed on a target cell in the array, other non-target cells (i.e., "half-select cells") located in the same row or column are inevitably exposed to the write current. Because these low-symmetry materials inherently possess the ability to "flip without external field," these half-select cells are highly susceptible to having their magnetic states erroneously flipped by the write current, leading to severe "crosstalk" or "mis-write" problems.

[0004] Traditional solutions, such as integrating gating transistors under each cell (e.g., STT-MRAM), significantly increase device size, manufacturing cost, and power consumption; or using an external magnetic field to assist SOT switching, which increases device complexity and energy consumption and limits miniaturization integration. Therefore, effectively solving the crosstalk problem of low-symmetry crystal material SOT cross arrays without increasing device complexity, without relying on external magnetic fields, and while achieving high integration has become a key technological bottleneck that urgently needs to be overcome in the current SOT-MRAM field. Summary of the Invention

[0005] The purpose of this application is to provide an ion-controlled SOT device, an SOT cross array, a device gating method, and a memory chip that can regulate spin-orbit torque to drive magnetic moment reversal.

[0006] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides an ion-controlled SOT device, comprising: source and drain electrodes, a voltage access terminal, and a substrate, a vertical magnetic anisotropic magnetic layer, a low-symmetry crystal material layer, a gate oxide layer, and a top electrode stacked sequentially from bottom to top. The voltage access terminal is electrically connected to the top electrode and the low-symmetry crystal material layer, respectively; The low-symmetry crystal material layer, the gate oxide layer, the top electrode, and the voltage access terminal form a closed loop; an electric field is formed between the top electrode and the low-symmetry crystal material layer, spanning the gate oxide layer; The gate oxide layer is a non-stoichiometric oxygen-rich metal oxide layer, and the oxygen vacancy concentration is spatially non-uniformly distributed. The source and drain electrodes are electrically connected to the low-symmetry crystal material layer; the source and drain electrodes are used to apply in-plane write current. When a control voltage is applied to the voltage access terminal, the voltage access terminal receives the control voltage, forming an electric field between the top electrode and the low-symmetry crystal material layer and changing the potential relationship to drive the migration of oxygen ions in the gate oxide layer, thereby controlling the out-of-plane spin polarization capability of the low-symmetry crystal material layer to control the deterministic vertical magnetic anisotropy magnetic moment reversal of the SOT device under the condition of no external magnetic field. When oxygen ions migrate into the low-symmetry crystal material layer, the low-symmetry crystal material layer is oxidized and its out-of-plane spin polarization capability is reduced; when oxygen ions migrate from the low-symmetry crystal material layer back to the gate oxide layer, the low-symmetry crystal material layer is reduced and its out-of-plane spin polarization capability is enhanced or restored.

[0007] In one embodiment, the low-symmetry crystal material in the low-symmetry crystal material layer has a crystal structure with inversion symmetry broken, and in the unoxidized state, the out-of-plane spin polarization component S is generated. z ; Low-symmetry crystalline materials include monolayer, few-layer structures, or thin film morphologies that break centrosymmetry through interface / lattice distortion; Due to lattice symmetry breaking or interface symmetry breaking, the low-symmetry crystal material layer can generate a non-zero out-of-plane spin polarization component S under in-plane writing current. z .

[0008] In one embodiment, the low-symmetry crystal material is selected as WTe2.

[0009] Secondly, this application provides an ion-controlled SOT cross array, comprising several ion-controlled SOT devices distributed in a row and column matrix. The ion-controlled SOT device is the ion-controlled SOT device described above. The ion-controlled SOT cross array is a row or column shared write line SOT cross array.

[0010] Thirdly, this application provides a device gating method for an SOT cross array, applied to the aforementioned ion-controlled SOT cross array; the SOT cross array has a shared write line; The device gating method for the SOT cross-array includes: In the SOT cross array, the SOT device to be written is identified as the target SOT device, and other SOT devices on the same shared write line as the target SOT device are non-target SOT devices. A reverse modulation voltage is applied to the voltage input terminal of the non-target SOT device to drive oxygen ions to migrate into the low-symmetry crystal material layer of the non-target SOT device, thereby suppressing the out-of-plane spin polarization capability. A control voltage is applied to the voltage access terminal of the target SOT device so that the potential of the top electrode in the target SOT device is higher than the potential of the low symmetry crystal material layer. Under the action of the electric field, oxygen ions in the low symmetry crystal material layer are driven to migrate back to the gate oxide layer and undergo a reduction reaction, thereby enhancing or restoring its out-of-plane spin polarization capability. When an in-plane write current is applied to the shared write line, the target SOT device undergoes a deterministic vertical magnetic anisotropy magnetic moment reversal under the drive of the in-plane write current in the absence of an external magnetic field. Meanwhile, the non-target SOT device maintains its original magnetic moment state reversal due to the suppression of its out-of-plane spin polarization capability, thereby reducing the risk of write crosstalk in the cross array.

[0011] In one embodiment, when the positive and negative terminals of the voltage access terminal of the target SOT device are connected to the top electrode and the low-symmetry crystal material layer, respectively, the control voltage is a positive voltage. When the positive and negative terminals of the voltage input terminal of the target SOT device are connected to the low-symmetry crystal material layer and the top electrode, respectively, the control voltage is a negative voltage.

[0012] Thirdly, this application provides a memory chip that integrates the aforementioned ion-controlled SOT cross array.

[0013] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides an ion-controlled SOT device, an SOT cross-array, a device gating method, and a memory chip. The SOT device's deterministic perpendicular magnetic anisotropy (PMA) magnetic moment reversal capability under no external magnetic field can be controlled by applying a control voltage. This allows for the regulation of spin-orbit torque to drive magnetic moment reversal. Furthermore, when applied to a cross-array with a shared write line, even if each SOT device on a shared write line can receive in-plane write current, applying a potential to the SOT devices that do not require writing, such that the potential of their top electrodes is lower than that of the low-symmetry crystal material layer, can significantly suppress magnetic moment reversal in these magnetic memory devices under the influence of the shared write line current. Therefore, the aforementioned SOT device reduces the crosstalk risk in magnetic memory device cross-arrays and increases its application ceiling in cross-arrays. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of an ion-controlled SOT device according to an embodiment of this application; Figure 2 This is a schematic diagram of the architecture of an ion-controlled SOT device according to one embodiment of this application; Figure 3 This is a schematic diagram of the architecture of a cross-array of an ion-controlled SOT device according to one embodiment of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] First, we will introduce the basic definitions of some terms that may be involved in the embodiments of this application.

[0019] Spin Hall effect: When a current is applied to a material exhibiting the spin Hall effect, a spin current is generated in the direction perpendicular to the current. The spin polarization direction of the spin current is perpendicular to both the current direction and the spin current direction.

[0020] Spin-orbit coupling: In quantum mechanics, the interaction between a particle's spin and its orbital motion is called spin-orbit interaction, also known as spin-orbit effect or spin-orbit coupling. When an electron moves through the electric field of an atomic nucleus, it experiences an electromagnetic interaction. The coupling between the electron's spin and its orbital motion forms the spin-orbit interaction.

[0021] Spin-orbit torque (SOT): Spin-orbit torque is the effect exerted by a spin current on the magnetic moment of a material. It originates from spin-orbit coupling effects such as the spin Hall effect and the Rashba effect. Compared to the traditional spin-transfer torque (STT), spin-orbit torque (SOT) exhibits superior performance in terms of speed and device lifetime. Spin-orbit torque technology can be used to develop magnetic random access memories, spin nano-oscillators, microwave analyzers, true random number generators, spin logic, and unique data processing chips based on spin-orbit torque.

[0022] Magnetic Moment and Magnetic Anisotropy: In its simplest case, an object's magnetic moment has no preferred direction. It responds to an applied magnetic field in the same way regardless of the direction in which the field is applied; this is known as magnetic isotropy. Whether a magnetically anisotropic material is easier or harder to magnetize depends on the object's orientation. For most magnetically anisotropic materials, there are two directions that are most easily magnetized, rotated 180° apart. The straight lines parallel to these directions are called easy axes. In other words, easy axes are favorable directions for spontaneous magnetization. Because magnetization is generally equally easy along the two opposite directions of the easy axes, the actual direction of magnetization can be easily fixed in either direction. The binary information "0" and "1" can be defined along the two directions of the easy axes, respectively.

[0023] like Figure 1 and Figure 2 As shown, the ion-controlled SOT device includes source and drain electrodes, voltage access terminals, and a substrate, a vertical magnetic anisotropic magnetic layer (magnetic layer), a low-symmetry crystal material layer, a gate oxide layer, and a top electrode stacked sequentially from bottom to top.

[0024] For example, the substrate is a SiO2 or Si substrate.

[0025] The voltage input terminal is electrically connected to both the top electrode and the low-symmetry crystal material layer; the low-symmetry crystal material layer, the gate oxide layer, the top electrode, and the voltage input terminal form a closed loop. An electric field is formed between the top electrode and the low-symmetry crystal material layer, spanning the gate oxide layer.

[0026] The gate oxide layer is a non-stoichiometric oxygen-rich metal oxide layer, and the oxygen vacancy concentration is spatially non-uniformly distributed.

[0027] The source and drain electrodes are electrically connected to the low-symmetry crystal material layer; the source and drain electrodes are used to apply in-plane write current.

[0028] When a regulating voltage is applied to the voltage access terminal, the voltage access terminal receives the regulating voltage, forming an electric field between the top electrode and the low-symmetry crystal material layer and changing the potential relationship to drive the migration of oxygen ions in the gate oxide layer, thereby regulating the out-of-plane spin polarization capability of the low-symmetry crystal material layer to regulate the deterministic vertical magnetic anisotropy magnetic moment reversal of the SOT device under the condition of no external magnetic field.

[0029] When oxygen ions migrate into the low-symmetry crystal material layer, the low-symmetry crystal material layer is oxidized and its out-of-plane spin polarization capability is reduced; when oxygen ions migrate back from the low-symmetry crystal material layer to the gate oxide layer, the low-symmetry crystal material layer is reduced and its out-of-plane spin polarization capability is enhanced or restored.

[0030] When a voltage (regulation voltage) is applied to the voltage input terminal, the potential relationship between the top electrode and the low-symmetry crystal material layer can be changed.

[0031] In short, when the potential of the top electrode is lower than the potential of the low-symmetry crystal material layer, oxygen ions in the gate oxide layer migrate to the low-symmetry crystal material layer, thereby oxidizing the low-symmetry crystal material and suppressing or weakening the deterministic vertical anisotropy (PMA) magnetic moment reversal capability under conditions without an external magnetic field.

[0032] When the potential of the top electrode is higher than that of the low-symmetry crystal material layer, oxygen ions in the oxidized low-symmetry crystal material layer migrate to the gate oxide layer, thereby reducing the low-symmetry crystal material and enhancing or restoring the deterministic vertical magnetic anisotropy (PMA) magnetic moment reversal capability under conditions without an external magnetic field.

[0033] The oxidized or reduced state formed by the control voltage has non-volatile characteristics; after the control voltage is removed, the low-symmetry crystal material layer can still maintain the suppressed or restored spin orbital moment driving capability, thereby realizing the non-volatile configuration of the write enable state of the magnetic storage device (e.g., for in-memory computing chips or hardware security switches).

[0034] The essential difference between the aforementioned SOT device and a traditional SOT device lies in the fact that the top electrode and the low-symmetry crystal material are electrically connected to the voltage access terminal, forming a closed loop consisting of the low-symmetry crystal material layer, the gate oxide layer, the top electrode, and the voltage access terminal. This design allows for the control of the charge-spin-transfer efficiency of the low-symmetry crystal material layer, thereby affecting its deterministic vertical magnetic anisotropy (PMA) moment reversal capability under conditions without an external magnetic field.

[0035] Specifically, the potential relationship between the top electrode and the low-symmetry crystal material layer can be controlled by applying a voltage (regulation voltage) to the voltage input terminal. When the potential of the top electrode is lower than that of the low-symmetry crystal material layer, oxygen ions in the gate oxide migrate towards the low-symmetry crystal material. When these oxygen ions are driven to the surface of the low-symmetry crystal material layer, partial oxidation occurs, thereby suppressing or weakening the deterministic vertical magnetic anisotropy (PMA) moment reversal capability under conditions without an external magnetic field. When the potential of the top electrode is higher than that of the low-symmetry crystal material layer, oxygen ions in the oxidized low-symmetry crystal material layer migrate towards the gate oxide, reducing the low-symmetry crystal material layer and thus enhancing or restoring the deterministic vertical magnetic anisotropy (PMA) moment reversal capability under conditions without an external magnetic field. In a SOT cross-array, for SOT devices that do not require writing, a voltage can be applied such that the potential of the top electrode is lower than the potential of the low-symmetry crystal material layer. This suppresses the vertical magnetic anisotropy (PMA) moment reversal under the shared write line current. For SOT devices that require writing, a voltage can be applied such that the potential of the top electrode is higher than the potential of the low-symmetry crystal material layer. This allows them to normally undergo PMA moment reversal under the influence of the write current. This enables the magnetic memory devices that require writing to undergo corresponding PMA moment reversals and suppresses erroneous reversals in non-target magnetic memory devices.

[0036] Therefore, the above SOT device can regulate its deterministic perpendicular magnetic anisotropy (PMA) magnetic moment switching capability without an external magnetic field by applying a voltage. When it is applied to a SOT crossbar array with shared write lines, even though each SOT device on a shared write line can receive the write current, by applying a voltage to the SOT devices that do not need to be written that makes the potential of the top electrode lower than the potential of the low-symmetry crystalline material layer, the risk of erroneous switching of these SOT devices under the action of the shared write line current can be reduced. Therefore, the above SOT device will not cause the crosstalk problem of the SOT crossbar array, and improves the upper limit of its application in the SOT crossbar array.

[0037] The low-symmetry crystalline material in the low-symmetry crystalline material layer has an inversion symmetry-breaking crystal structure, and in an unoxidized state, the generated out-of-plane spin polarization component S z is non-zero. The low-symmetry crystalline material includes a single-layer, few-layer structure, or a thin film form that breaks central symmetry through interface / lattice distortion. WTe₂ is selected as the low-symmetry crystalline material.

[0038] Alternatively, the low-symmetry crystalline material layer has a non-centrosymmetric structure, and the low-symmetry crystalline material is selected from at least one of transition metal chalcogenides, topological insulators, or metal heterojunctions with interface symmetry breaking.

[0039] In one embodiment, the low-symmetry crystalline material comprises: WTe₂, Bi 1-x Sb x , Bi 1-x Se x , (BiSb) x Te 1-x , Bi 1-x Te x , Sb 1-x Te x , Mo 1-x Te x , SnTe, PtTe x , PtSe x , PdTe x , W 1-x Mo x Te₂, WSe x , MoSe x one of. Wherein, the variable x in the chemical formula of the above material satisfies 0<x<1 (or a specific numerical range such as 0<x<3).

[0040] Due to lattice symmetry breaking or interface symmetry breaking, the low-symmetry crystalline material layer can generate a non-zero out-of-plane spin polarization component S under the drive of in-plane current zThe migration of oxygen ions effectively modulates the intensity of out-of-plane spin polarization, enabling controllable vertical magnetic anisotropic magnetic moment reversal without an external magnetic field.

[0041] WTe2, exhibiting broken inversion symmetry in its crystal structure, possesses a non-traditional spin-orbit torque effect. This non-traditional spin-orbit torque effect, driven by current, enables deterministic perpendicular magnetic anisotropy (PMA) reversal at room temperature without an external magnetic field. Furthermore, this material exhibits high electrical conductivity. Therefore, WTe2 with broken inversion symmetry is a very promising material for constructing WTe2 / Ti / Co structures. 20 Fe 60 B 20 Heterojunctions such as MgO, Pt / Co / Pt / WTe2 are used to realize vertical magnetic anisotropy (PMA) devices for SOT research, with applications in low-power spintronic devices and chips. However, SOT devices using WTe2 are more prone to crosstalk problems in SOT cross-arrays. This problem can be solved by the oxygen ion migration modulation described above. By driving oxygen ions to reversibly insert and extract from WTe2, the charge spin-transformation properties of WTe2 are modulated, changing its z-polarization generation efficiency. This enables dynamic control of deterministic vertical magnetic anisotropy (PMA) switching without an external magnetic field, achieving reversible and non-volatile property control. This allows for deterministic PMA switching of desired cells in large-scale device arrays without affecting other memory cells, significantly reducing the switching power consumption of spintronic devices and promoting the development of novel device architectures.

[0042] Based on the ion-controlled SOT devices provided above, this application also provides an ion-controlled SOT cross array, comprising a plurality of ion-controlled SOT devices arranged in a row-column matrix. The SOT cross array is a SOT cross array with shared write lines in either rows or columns.

[0043] To achieve precise writing of the ion-controlled SOT cross array provided in the above embodiments, this application also provides a device gating method for the SOT cross array, applied to the ion-controlled SOT cross array.

[0044] Reference Figure 3 Specifically, the device selection methods for SOT cross-arrays include: In the SOT cross array, the SOT device to be written is identified as the target SOT device, and other SOT devices on the same shared write line as the target SOT device are non-target SOT devices.

[0045] Applying a reverse modulation voltage to the voltage input terminal of a non-target SOT device drives oxygen ions to migrate into the low-symmetry crystal material layer of the non-target SOT device, thereby suppressing out-of-plane spin polarization.

[0046] A control voltage is applied to the voltage access terminal of the target SOT device to make the potential of the top electrode in the target SOT device higher than the potential of the low symmetry crystal material layer. Under the action of the electric field, oxygen ions in the low symmetry crystal material layer are driven to migrate back to the gate oxide layer and undergo a reduction reaction, thereby enhancing or restoring its out-of-plane spin polarization capability.

[0047] By applying an in-plane write current to the shared write line, the target SOT device undergoes a deterministic vertical magnetic anisotropy magnetic moment reversal under the drive of the in-plane write current, without the application of an external magnetic field. Meanwhile, the non-target SOT device maintains its original magnetic moment state reversal due to the suppression of its out-of-plane spin polarization capability, thereby reducing the risk of write crosstalk in the cross array.

[0048] For example, when the positive and negative terminals of the voltage access terminal of the target SOT device are connected to the top electrode and the low-symmetry crystal material layer, respectively, the control voltage is a positive voltage.

[0049] When the positive and negative terminals of the target SOT device's voltage input are connected to the low-symmetry crystal material layer and the top electrode, respectively, the control voltage is negative.

[0050] In the process of using a SOT cross-array, the SOT device to be written to is first identified, defined as the target SOT device, and the other SOT devices are non-target SOT devices. Then, a control voltage is applied to the voltage access terminal of the non-target SOT device to make the potential of the top electrode in the non-target SOT device lower than the potential of the low-symmetry crystal material, driving oxygen ions in the gate oxide to migrate to the low-symmetry crystal material. Conversely, a control voltage is applied to the voltage access terminal of the target SOT device to make the potential of the top electrode in the target SOT device higher than the potential of the low-symmetry crystal material, driving oxygen ions in the low-symmetry crystal material to migrate to the gate oxide. At this point, in the non-target SOT device, the surface of the low-symmetry crystal material has oxygen ions oxidized, suppressing or weakening the deterministic perpendicular magnetic anisotropy (PMA) moment reversal capability under conditions without an external magnetic field. Applying current to this device greatly suppresses the PMA moment reversal of the non-target magnetic memory device. In the target SOT device, oxygen ions are released from the surface of the low-symmetry crystal material, which is close to an unoxidized state. When a current is applied to it, the target SOT device will generate a vertical magnetic anisotropy (PMA) magnetic moment reversal.

[0051] In an example where the low-symmetry crystal material is WTe2 and the positive and negative terminals of the voltage input in the SOT device are connected to the top electrode and WTe2, respectively: The regulation voltage V applied to the voltage access terminal G controls the migration of oxygen ions. When a negative voltage (V G < 0) is applied, oxygen ions migrate to the WTe2 layer, and WTe2 is oxidized into WO x (2 < x < 3) and TeO2, the in-plane and out-of-plane charge-spin conversion efficiencies decrease, and the out-of-plane spin polarization capability weakens, thereby suppressing the deterministic perpendicular magnetic anisotropy (PMA) switching under the condition of no external magnetic field; when a positive voltage (V G > 0) is applied, WO x (2 < x < 3) and TeO2 lose oxygen ions and revert back to WTe2, and both the in-plane and out-of-plane charge-spin conversion efficiencies are enhanced, which can enhance or restore the deterministic perpendicular magnetic anisotropy (PMA) switching capability under the condition of no external magnetic field. By controlling the migration of oxygen ions, selective switching of target SOT devices in the array can be achieved, and the influence on other memory cells can be reduced.

[0052] Correspondingly, in a SOT cross array, the word line and bit line of the target SOT device are activated simultaneously, and a voltage V G > 0 is applied to the target SOT device, which drives oxygen ions to detach from WTe2, enables WTe2 to normally generate z-direction polarization, allows the current on the word line and the bit line to flow through the SOT channel of the target SOT device, and generates perpendicular magnetic anisotropy (PMA) switching. The voltage V of the half-selected cell (selected only by the word line or only by the bit line) G is in the state where V G < 0, at this time, oxygen ions are embedded into WTe2 to form oxide WO x (2 < x < 3) and TeO2, which significantly reduces both the in-plane and out-of-plane charge-spin conversion efficiencies of WTe2 and suppresses the out-of-plane spin polarization capability, thereby significantly suppressing its magnetic moment switching under the condition of no external magnetic field and reducing the risk of erroneous writing.

[0053] It should be noted that once oxygen ions migrate to a new position driven by an electric field, they will be "locked" at this position due to the energy barrier after the electric field is removed. This state of ion distribution is stable unless a reverse electric field is applied, which meets the requirements of non-volatile memory.

[0054] Furthermore, the regulation is mainly achieved through the regulation voltage, which requires a small current and is beneficial to reducing the power consumption of the device. The current required for oxygen ion migration is very small (mainly displacement current and weak ion migration current), which is much lower than the critical current density required for spin transfer torque.

[0055] Moreover, the write and read paths for oxygen ion modulation are separate. Writing (ion migration) occurs at the magnetic layer / oxide interface, while reading still measures the tunneling magnetoresistance of the magnetic tunnel junction (MTJ).

[0056] This means that the writing process does not damage the critical tunnel barrier layer, thus enabling extremely high read / write endurance.

[0057] This application also provides a memory chip that integrates the ion-controlled SOT cross array provided in the above embodiments.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A SOT device based on ion modulation, characterized in that, include: The source and drain electrodes, voltage access terminals, and a substrate, a vertical magnetic anisotropic magnetic layer, a low-symmetry crystal material layer, a gate oxide layer, and a top electrode are stacked sequentially from bottom to top. The voltage access terminal is electrically connected to the top electrode and the low-symmetry crystal material layer, respectively; The low-symmetry crystal material layer, the gate oxide layer, the top electrode, and the voltage access terminal form a closed loop; an electric field is formed between the top electrode and the low-symmetry crystal material layer, spanning the gate oxide layer; The gate oxide layer is a non-stoichiometric oxygen-rich metal oxide layer, and the oxygen vacancy concentration is spatially non-uniformly distributed. The source and drain electrodes are electrically connected to the low-symmetry crystal material layer; The source and drain electrodes are used to apply in-plane write current; When a control voltage is applied to the voltage access terminal, the voltage access terminal receives the control voltage, forming an electric field between the top electrode and the low-symmetry crystal material layer and changing the potential relationship to drive the migration of oxygen ions in the gate oxide layer, thereby controlling the out-of-plane spin polarization capability of the low-symmetry crystal material layer to control the deterministic vertical magnetic anisotropy magnetic moment reversal of the SOT device under the condition of no external magnetic field. When oxygen ions migrate into the low-symmetry crystal material layer, the low-symmetry crystal material layer is oxidized and its out-of-plane spin polarization capability is reduced; when oxygen ions migrate from the low-symmetry crystal material layer back to the gate oxide layer, the low-symmetry crystal material layer is reduced and its out-of-plane spin polarization capability is enhanced or restored.

2. The SOT device based on ion control according to claim 1, characterized in that, The low-symmetry crystal material in the low-symmetry crystal material layer has a crystal structure with broken inversion symmetry, and in the unoxidized state, it generates an out-of-plane spin polarization component S. z Non-zero; Low-symmetry crystalline materials include monolayer, few-layer structures, or thin film morphologies that break centrosymmetry through interface / lattice distortion; Due to lattice symmetry breaking or interface symmetry breaking, the low-symmetry crystal material layer can generate a non-zero out-of-plane spin polarization component S under in-plane writing current. z .

3. The SOT device based on ion modulation according to claim 2, characterized in that, The low-symmetry crystal material is selected as WTe2.

4. A SOT cross-array based on ion regulation, characterized in that, This includes several ion-controlled SOT devices with a row and column matrix distribution; The ion-controlled SOT device is the ion-controlled SOT device according to any one of claims 1-3; The ion-controlled SOT cross array is a row or column shared write line SOT cross array.

5. A device selection method for an SOT cross-array, characterized in that, Applied to the ion-controlled SOT cross array as described in claim 4; the SOT cross array has a shared write line; The device gating method for the SOT cross-array includes: In the SOT cross array, the SOT device to be written is identified as the target SOT device, and other SOT devices on the same shared write line as the target SOT device are non-target SOT devices. A reverse modulation voltage is applied to the voltage input terminal of the non-target SOT device to drive oxygen ions to migrate into the low-symmetry crystal material layer of the non-target SOT device, thereby suppressing the out-of-plane spin polarization capability. A control voltage is applied to the voltage access terminal of the target SOT device so that the potential of the top electrode in the target SOT device is higher than the potential of the low symmetry crystal material layer. Under the action of the electric field, oxygen ions in the low symmetry crystal material layer are driven to migrate back to the gate oxide layer and undergo a reduction reaction, thereby enhancing or restoring its out-of-plane spin polarization capability. When an in-plane write current is applied to the shared write line, the target SOT device undergoes a deterministic vertical magnetic anisotropy magnetic moment reversal under the drive of the in-plane write current in the absence of an external magnetic field. Meanwhile, the non-target SOT device maintains its original magnetic moment state reversal due to the suppression of its out-of-plane spin polarization capability, thereby reducing the risk of write crosstalk in the cross array.

6. The device selection method for an SOT cross-array according to claim 5, characterized in that, When the positive and negative terminals of the voltage input terminal of the target SOT device are connected to the top electrode and the low-symmetry crystal material layer, respectively, the control voltage is a positive voltage. When the positive and negative terminals of the voltage input terminal of the target SOT device are connected to the low-symmetry crystal material layer and the top electrode, respectively, the control voltage is a negative voltage.

7. A memory chip, characterized in that, It integrates the ion-controlled SOT cross array as described in claim 4.

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