Magnetoresistance effect device and magnetic memory

Abstract

To provide a magnetoresistance effect device and a magnetic memory which are easy to manufacture and capable of stable operation.SOLUTION: A magnetoresistive effect device includes a magnetoresistive effect element, a capacitor, and a selector. The magnetoresistive effect element includes a spin-orbit torque wiring and a laminate in contact with the spin-orbit torque wiring. The laminate includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic layer. The capacitor is connected to a first end of the spin-orbit torque wiring. The selector is connected to a second end of the spin-orbit torque wiring. A write pulse can be applied to the spin-orbit torque wiring in either direction, from the first end toward the second end or from the second end toward the first end. A read pulse can be applied between the second ferromagnetic layer and the selector.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to magnetoresistive devices and magnetic memories. [Background technology]

[0002] Giant magnetoresistance (GMR) elements, which consist of a multilayer film of ferromagnetic and non-magnetic layers, and tunnel magnetoresistance (TMR) elements, which use an insulating layer (tunnel barrier layer or barrier layer) as the non-magnetic layer, are known as magnetoresistance effect elements. Magnetoresistance effect elements can be applied to magnetic sensors, high-frequency components, magnetic heads, and non-volatile random access memories (MRAM).

[0003] MRAM is a memory device that integrates magnetoresistive elements. MRAM reads and writes data by utilizing the property that the resistance of a magnetoresistive element changes when the magnetization directions of the two ferromagnetic layers sandwiching a nonmagnetic layer in the magnetoresistive element change. The magnetization direction of the ferromagnetic layer is controlled, for example, by using a magnetic field generated by an electric current. Alternatively, the magnetization direction of the ferromagnetic layer can be controlled by using spin transfer torque (STT) generated by passing an electric current in the stacking direction of the magnetoresistive element.

[0004] When using STT to rewrite the magnetization direction of a ferromagnetic layer, a current is passed through the magnetoresistive element in the stacking direction, and the write current causes deterioration of the magnetoresistive element's characteristics.

[0005] In recent years, attention has been focused on methods that do not require current to flow in the stacking direction of a magnetoresistive element during writing (for example, Patent Document 1). One such method is a writing method that utilizes spin-orbit torque (SOT). SOT is induced by spin current generated by spin-orbit interaction or the Rashba effect at the interface of different materials. The current used to induce SOT in a magnetoresistive element flows in a direction that intersects with the stacking direction of the magnetoresistive element. In other words, magnetization rotation using SOT does not require current to flow in the stacking direction of the magnetoresistive element, and is expected to extend the life of the magnetoresistive element. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-216286 Summary of the Invention [Problem to be solved by the invention]

[0007] In magnetoresistive elements using SOT, the write current for inducing SOT flows along the spin orbit torque wiring. To reduce the write current while maintaining the write current density necessary for magnetization reversal, the spin orbit torque wiring is often made thin. Connecting via wiring to a thin spin orbit torque wiring narrows the tolerance for deviation during manufacturing, resulting in low product yields.

[0008] The present disclosure has been made in view of the above circumstances, and has an object to provide a magnetoresistive device and a magnetic memory that are easy to manufacture and capable of stable operation. [Means for solving the problem]

[0009] To solve the above problems, the present disclosure provides the following means.

[0010] A magnetoresistive device according to a first aspect includes a magnetoresistive element, a capacitor, and a selector. The magnetoresistive element includes a spin orbit torque wiring and a stacked body in contact with the spin orbit torque wiring. The stacked body includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer. The capacitor is connected to a first end of the spin orbit torque wiring. The selector is connected to a second end of the spin orbit torque wiring. A write pulse is configured to be applied to the spin orbit torque wiring in either a direction from the first end to the second end or a direction from the second end to the first end. A read pulse is configured to be applied between the second ferromagnetic layer and the selector. [Effects of the Invention]

[0011] The magnetoresistive device and magnetic memory according to the present disclosure are easy to manufacture and can operate stably. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a circuit diagram of a magnetic memory according to a first embodiment. [Figure 2] 1 is a cross-sectional view of a magnetoresistive effect device according to a first embodiment. [Figure 3] 1 is a cross-sectional view of a characteristic portion of a magnetoresistive device according to a first embodiment. [Figure 4] FIG. 1 is a plan view of a characteristic portion of a magnetoresistive device according to a first embodiment. [Figure 5] FIG. 10 is a cross-sectional view of the vicinity of a magnetoresistive effect element according to a first modified example. [Figure 6] FIG. 2 is a diagram illustrating a write operation of the magnetic memory according to the first embodiment. [Figure 7] FIG. 3 is a diagram illustrating a read operation of the magnetic memory according to the first embodiment. [Figure 8] 3A and 3B are schematic diagrams illustrating an example of a write pulse and a read pulse of the magnetic memory according to the first embodiment. [Figure 9] FIG. 10 is a cross-sectional view of the vicinity of a magnetoresistive effect element according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of the vicinity of a magnetoresistive effect element according to a third embodiment. [Figure 11] FIG. 10 is a circuit diagram of a magnetoresistive device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present embodiment will be described in detail below with reference to the drawings as appropriate. The drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate changes can be made within the scope of the effects of the present invention.

[0014] First, directions are defined. One direction on one surface of the substrate Sub (see FIG. 2), which will be described later, is defined as the x-direction, and the direction perpendicular to the x-direction is defined as the y-direction. The x-direction is, for example, the longitudinal direction of the spin orbit torque wiring 6. The z-direction is a direction perpendicular to the x-direction and the y-direction. The z-direction is an example of the stacking direction in which each layer is stacked. The z-direction is an example of the thickness direction. Hereinafter, the +z direction may be expressed as "up" and the -z direction as "down". Up and down do not necessarily coincide with the direction in which gravity is applied.

[0015] In this specification, "extending in the x-direction" means, for example, that the dimension in the x-direction is larger than the smallest dimension among the dimensions in the x-direction, y-direction, and z-direction. The same applies to extending in other directions. Furthermore, in this specification, "connection" is not limited to physical connection. For example, "connection" is not limited to when two layers are physically in contact with each other, but also includes when two layers are connected with another layer sandwiched between them. Furthermore, in this specification, "connection" also includes electrical connection.

[0016] "First embodiment" Fig. 1 is a configuration diagram of a magnetic memory 200 according to a first embodiment. The magnetic memory 200 shown in Fig. 1 includes a plurality of magnetoresistive effect devices 100, write wiring WL1, WL2, common wiring CL1, CL2, read wiring RL1, RL2, gate wiring GL1, GL2, GL3, a write circuit 40, and a read circuit 50. In the magnetic memory 200, for example, the magnetoresistive effect devices 100 are arranged in a matrix. Although Fig. 1 shows an example in which the magnetoresistive effect devices 100 are arranged in three rows and two columns, the number of rows and columns is not particularly limited.

[0017] Each of the magnetoresistive devices 100 includes a magnetoresistive element 10, a capacitor 20, and a selector 30. The specific configuration of the magnetoresistive device 100 will be described later.

[0018] The write wirings WL1 and WL2 each electrically connect the write circuit 40 to one or more magnetoresistive devices 100. For example, the write wirings WL1 and WL2 are each connected to a plurality of magnetoresistive devices 100 that belong to the same column. The write wirings WL1 and WL2 are each connected to the capacitors 20 of the magnetoresistive devices 100 that belong to the same column. The write wirings WL1 and WL2 each connect the capacitors 20 to the write circuit 40.

[0019] The common wirings CL1 and CL2 electrically connect the write circuit 40 and the read circuit 50 to one or more magnetoresistive devices 100, respectively. For example, the common wirings CL1 and CL2 are each connected to a plurality of magnetoresistive devices 100 that belong to the same column. The common wirings CL1 and CL2 are each connected to the selectors 30 of the magnetoresistive devices 100 that belong to the same column. The common wirings CL1 and CL2 connect the selectors 30 to the write circuit 40 and the read circuit 50, respectively.

[0020] The readout wirings RL1 and RL2 each electrically connect the readout circuit 50 to one or more magnetoresistive devices 100. For example, the readout wirings RL1 and RL2 are each connected to a plurality of magnetoresistive devices 100 that belong to the same column. The readout wirings RL1 and RL2 are each connected to the magnetoresistive elements 10 of the magnetoresistive devices 100 that belong to the same column. The readout wirings RL1 and RL2 each connect the magnetoresistive elements 10 to the readout circuit 50.

[0021] The gate lines GL1, GL2, and GL3 each control the ON / OFF of the selector 30. The gate lines GL1, GL2, and GL3 are each connected to the selectors 30 of the magnetoresistive devices 100 that belong to the same row, for example.

[0022] The write circuit 40 controls writing of data to the magnetoresistive element 10. The write circuit 40 includes, for example, a power supply, a processor, and a memory. The processor is, for example, a CPU (Central Processing Unit). The processor operates based on an operating program stored in the memory. The write circuit 40 is connected to write lines WL1 and WL2 and common lines CL1 and CL2. The write circuit 40 is connected to the capacitor 20 via the write lines WL1 and WL2, and to the selector 30 via the common lines CL1 and CL2.

[0023] The read circuit 50 controls the reading of data from the magnetoresistive element 10. The read circuit 50 includes, for example, a power supply, a processor, and a memory. The read circuit 50 is connected to read lines RL1 and RL2 and common lines CL1 and CL2. The read circuit 50 is connected to the second ferromagnetic layer of the magnetoresistive element 10 via the read lines RL1 and RL2, and is connected to the selector 30 via the common lines CL1 and CL2.

[0024] Fig. 2 is a cross-sectional view of the magnetoresistive device 100 according to the first embodiment. Fig. 2 is a cross-section of the magnetoresistive device 100 taken along the xz plane passing through the center of the width of the spin orbit torque wiring in the y direction.

[0025] The magnetoresistive device 100 includes, for example, a substrate Sub, a magnetoresistive element 10, a capacitor 20, a selector 30, via wirings V1, V2, V3, V4, and V5, and an insulating layer 90.

[0026] The substrate Sub is, for example, a semiconductor substrate. The magnetoresistive element 10, the capacitor 20, the selector 30, the via wirings V1, V2, V3, V4, and V5, and the insulating layer 90 are formed on the substrate Sub.

[0027] The magnetoresistive element 10 is an element that records and stores data. The magnetoresistive element 10 is a magnetic element that utilizes spin orbit torque (SOT), and may be called a spin orbit torque type magnetoresistive element, a spin injection type magnetoresistive element, or a spin current magnetoresistive element. The magnetoresistive element 10 is connected to a readout wiring RL1 through a via wiring V3.

[0028] The capacitor 20 is connected to a first end of the spin orbit torque wiring of the magnetoresistive element 10. The capacitor 20 is connected to the write wiring WL1 through a via wiring V1.

[0029] The selector 30 is an element that controls the flow of current. The selector 30 is, for example, an element that uses a phase change of a crystal layer such as a transistor or an Ovonic Threshold Switch (OTS), an element that uses a change in band structure such as a metal-insulator transition (MIT) switch, an element that uses a breakdown voltage such as a Zener diode or an avalanche diode, or an element whose conductivity changes with a change in atomic position.

[0030] 2 shows an example in which the selector 30 is a transistor. The transistor has a gate electrode G, a gate insulating film GI, a source S, and a drain D. The source S and the drain D are determined by the direction of current flow, and the positional relationship between the source S and the drain D may be reversed.

[0031] The selector 30 is connected to the magnetoresistive element 10 through a via wiring V2. The selector 30 is connected to a second end of the spin orbit torque wiring of the magnetoresistive element 10. The second end is an end different from the first end to which the capacitor 20 is connected.

[0032] The gate electrode G of the selector 30 is connected to the gate line GL1 through a via line V4, and the drain D of the selector 30 is connected to the common line CL1 through a via line V5.

[0033] The insulating layer 90 covers the periphery of the magnetoresistive element 10, the capacitor 20, and the selector 30. The insulating layer 90 is an insulating layer that insulates between the wires in the multilayer wiring and between the elements. The insulating layer 90 is made of, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO x ), magnesium oxide (MgO), aluminum nitride (AlN), etc. The via wirings V1, V2, V3, V4, and V5 are made of a conductor that fills vias formed in the insulating layer 90. The via wirings V1, V2, V3, V4, and V5 extend in the z direction.

[0034] Fig. 3 is a cross-sectional view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 100. Fig. 3 is a cross-section of the magnetoresistive element 10 taken along the xz plane passing through the center of the width in the y direction of the spin orbit torque wiring 6. Fig. 4 is a plan view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 100 as viewed from the z direction.

[0035] The magnetoresistive element 10 includes, for example, a stacked body 5 and a spin orbit torque wire 6. The stacked body 5 is in contact with the spin orbit torque wire 6. The stacked body 5 may be located below or above the spin orbit torque wire 6. Other layers may be located between the stacked body 5 and the spin orbit torque wire 6.

[0036] The stack 5 has a first ferromagnetic layer 1, a second ferromagnetic layer 2, and a non-magnetic layer 3. The non-magnetic layer 3 is sandwiched between the first ferromagnetic layer 1 and the second ferromagnetic layer 2 in the z direction. The resistance value of the stack 5 in the z direction changes when spins are injected into the stack 5 (first ferromagnetic layer 1) from the spin orbit torque wiring 6. The resistance value of the stack 5 changes depending on the difference in the relative angle between the magnetizations of the first ferromagnetic layer 1 and the second ferromagnetic layer 2, which sandwich the non-magnetic layer 3.

[0037] The stack 5 is sandwiched in the z direction between the spin orbit torque wire 6 and the via wire V3. The stack 5 is a columnar body. The shape of the stack 5 in plan view in the z direction is, for example, circular, elliptical, or rectangular.

[0038] The first ferromagnetic layer 1 is in contact with, for example, the spin orbit torque wiring 6. Spins are injected into the first ferromagnetic layer 1 from the spin orbit torque wiring 6. The magnetization of the first ferromagnetic layer 1 is subjected to a spin orbit torque (SOT) by the injected spins, and the orientation direction of the magnetization changes.

[0039] The first ferromagnetic layer 1 and the second ferromagnetic layer 2 each have a magnetization. The magnetization of the second ferromagnetic layer 2 is less likely to change orientation than the magnetization of the first ferromagnetic layer 1 when a predetermined external force is applied. The first ferromagnetic layer 1 is sometimes called a magnetization free layer, and the second ferromagnetic layer 2 is sometimes called a magnetization fixed layer or a magnetization reference layer. The stack 5 shown in FIG. 3 has the magnetization fixed layer on the side closer to the substrate Sub, and is called a bottom-pinned structure.

[0040] The first ferromagnetic layer 1 and the second ferromagnetic layer 2 include a ferromagnetic material, such as a metal selected from the group consisting of Cr, Mn, Co, Fe, and Ni, an alloy containing one or more of these metals, or an alloy containing one or more of these metals and at least one of B, C, and N. Examples of the ferromagnetic material include Co—Fe, Co—Fe—B, Ni—Fe, a Co—Ho alloy, a Sm—Fe alloy, a Fe—Pt alloy, a Co—Pt alloy, and a CoCrPt alloy.

[0041] The first ferromagnetic layer 1 and the second ferromagnetic layer 2 may include a Heusler alloy. The Heusler alloy includes an intermetallic compound having a chemical composition of XYZ or X2YZ. X is a transition metal element or a noble metal element of the Co, Fe, Ni, or Cu group on the periodic table, Y is a transition metal element or an element species of X of the Mn, V, Cr, or Ti group, and Z is a typical element of groups III to V. Examples of Heusler alloys include Co2FeSi, Co2FeGe, Co2FeGa, Co2MnSi, and Co2Mn 1-a Fe a Al b Si 1-b , Co2FeGe 1-c Ga c etc. Heusler alloys have high spin polarization.

[0042] The non-magnetic layer 3 includes a non-magnetic material. When the non-magnetic layer 3 is an insulator (when it is a tunnel barrier layer), its material can be, for example, Al2O3, SiO2, MgO, or MgAl2O4. In addition to these, materials in which part of Al, Si, or Mg is replaced with Zn, Be, or the like can also be used for the non-magnetic layer 3. Among these, MgO and MgAl2O4 are materials that can realize coherent tunneling. When the non-magnetic layer 3 is a metal, its material can be Cu, Au, Ag, or the like. Furthermore, when the non-magnetic layer 3 is a semiconductor, its material can be Si, Ge, CuInSe2, CuGaSe2, Cu(In,Ga)Se2, or the like.

[0043] The stack 5 may include layers other than the first ferromagnetic layer 1, the second ferromagnetic layer 2, and the non-magnetic layer 3. For example, an underlayer may be provided between the spin-orbit torque wiring 6 and the first ferromagnetic layer 1. The underlayer improves the crystallinity of each layer constituting the stack 5. Furthermore, for example, the stack 5 may include a cap layer on its uppermost surface.

[0044] The stack 5 may also include a ferromagnetic layer on the surface of the second ferromagnetic layer 2 opposite the nonmagnetic layer 3, with a spacer layer interposed between them. The second ferromagnetic layer 2, spacer layer, and ferromagnetic layer form a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure is composed of two magnetic layers sandwiching a nonmagnetic layer. Antiferromagnetic coupling between the second ferromagnetic layer 2 and the ferromagnetic layer increases the coercive force of the second ferromagnetic layer 2 compared to a case without a ferromagnetic layer. The ferromagnetic layer may be, for example, IrMn or PtMn. The spacer layer may include, for example, at least one selected from the group consisting of Ru, Ir, and Rh.

[0045] The spin orbit torque wire 6 extends in the x direction, for example, with its length in the x direction longer than in the y direction when viewed from the z direction. A write pulse flows along the spin orbit torque wire 6. The write pulse can be applied in either the direction from the first end to the second end of the spin orbit torque wire 6 or from the second end to the first end.

[0046] The spin-orbit torque wiring 6 induces a spin current by the spin-orbit interaction and the interfacial Rashba effect, and injects spin into the first ferromagnetic layer 1. The spin-orbit torque wiring 6 applies a spin-orbit torque (SOT) to the magnetization of the first ferromagnetic layer 1 that is sufficient to reverse the magnetization of the first ferromagnetic layer 1, for example.

[0047] The spin Hall effect is a phenomenon in which, when an electric current is passed through it, a spin current is induced in a direction perpendicular to the direction of the electric current due to the spin-orbit interaction. The spin Hall effect is similar to the standard Hall effect in that the direction of movement of moving charges (electrons) is bent. In the standard Hall effect, the direction of movement of charged particles moving in a magnetic field is bent by the Lorentz force. In contrast, in the spin Hall effect, the direction of spin movement can be bent simply by moving electrons (current flow) even in the absence of a magnetic field.

[0048] For example, when a current flows through the spin-orbit torque wiring 6, the first spin polarized in one direction and the second spin polarized in the opposite direction to the first spin are bent by the spin Hall effect in a direction perpendicular to the direction of the current flow. For example, the first spin polarized in the -y direction is bent from the x direction, which is the direction of travel, to the +z direction, and the second spin polarized in the +y direction is bent from the x direction, which is the direction of travel, to the -z direction.

[0049] In non-magnetic materials (materials that are not ferromagnetic), the number of electrons with the first spin, which is generated by the spin Hall effect, is equal to the number of electrons with the second spin. In other words, the number of electrons with the first spin in the +z direction is equal to the number of electrons with the second spin in the -z direction. The first and second spins flow in a direction that eliminates the spin imbalance. When the first and second spins move in the z direction, the flow of charge cancels each other out, so the amount of current is zero. Spin current that does not involve current is specifically called pure spin current.

[0050] The flow of electrons with the first spin is called J ↑ , the flow of electrons of the second spin is J ↓ , the spin current is J S Then, J S =J ↑ -J ↓ is defined as the spin current J S is generated in the z direction. The first spin is injected into the first ferromagnetic layer 1 from the spin orbit torque wiring 6.

[0051] The spin orbit torque wiring 6 includes any of a metal, alloy, intermetallic compound, metal boride, metal carbide, metal silicide, metal phosphide, and metal nitride that has the function of generating a spin current.

[0052] The spin-orbit torque wiring 6 includes, for example, any material selected from the group consisting of heavy metals with atomic numbers of 39 or more, metal oxides, metal nitrides, metal oxynitrides, and topological insulators. The spin-orbit torque wiring 6 may also include a magnetic material.

[0053] The spin orbit torque wiring 6 contains, for example, a non-magnetic heavy metal as a main component. Heavy metal means a metal with a specific gravity equal to or greater than that of yttrium (Y). A non-magnetic heavy metal is, for example, a non-magnetic metal with a large atomic number equal to or greater than 39, which has d electrons or f electrons in its outermost shell. A stronger spin-orbit interaction occurs in non-magnetic heavy metals than in other metals. The spin Hall effect occurs due to the spin orbit interaction, and spins tend to be unevenly distributed in the spin orbit torque wiring 6, causing a spin current J. S is more likely to occur.

[0054] The capacitor 20 is located at a first end of the spin orbit torque wiring 6. The capacitor 20 includes, for example, a dielectric layer 21 and a first conductive layer 22. The spin orbit torque wiring 6, the dielectric layer 21, and the first conductive layer 22 function as the capacitor 20.

[0055] The dielectric layer 21 is sandwiched between the spin orbit torque wiring 6 and the first conductive layer 22. The dielectric layer 21 may be made of any material as long as it has insulating properties, and may be made of, for example, SiO2, HfO2, ZrO2, Ta2O5, Al2O3, Mg2SiO4, CaZrO3, SrTiO3, BaTiO3, CaTiO3, SrBi2Ta2O9, Pb(Zr,Ti)O3, Ba(Mg 1 / 3 Nb 2 / 3 )O3, Ba3Nd 9.3 Ti 18 O 54 The dielectric layer 21 may also be a composite containing these or a laminated film containing these. The thickness of the dielectric layer 21 is, for example, 20 nm or less.

[0056] The first conductive layer 22 is made of a conductive material. As in the magnetoresistive device 101 shown in Fig. 5, the first conductive layer 22A may be integrated with the via wiring V1 shown in Fig. 3. The capacitor 20A shown in Fig. 5 is made of the spin-orbit torque wiring 6, the dielectric layer 21, and the first conductive layer 22A.

[0057] Next, a method for manufacturing the magnetoresistive device 100 will be described. The magnetoresistive device 100 is formed by a process of stacking each layer and a process of processing a portion of each layer into a predetermined shape. The magnetoresistive device 100 can be manufactured using a general semiconductor process. The layers can be stacked using methods such as sputtering, chemical vapor deposition (CVD), electron beam evaporation (EB evaporation), and atomic laser deposition. The layers can be processed using photolithography or the like.

[0058] Next, the operation of writing data to the magnetic memory 200 and the operation of reading data from the magnetic memory 200 will be described.

[0059] 6 is a diagram for explaining how data is written to a predetermined magnetoresistive effect device 100 in the magnetic memory 200. A magnetoresistive effect device 100 to which data is to be written is selected from the plurality of magnetoresistive effect devices 100. This device selection is performed by the processor of the write circuit 40.

[0060] The selector 30 of the magnetoresistive effect device 100 into which data is to be written is turned ON, and the selectors 30 of the other magnetoresistive effect devices 100 are turned OFF. In Fig. 6, to write data to the upper left magnetoresistive effect device 100, the selector 30 of the upper left magnetoresistive effect device 100 is turned ON, and the selectors 30 of the other magnetoresistive effect devices 100 are turned OFF.

[0061] The write circuit 40 outputs a write pulse to a predetermined magnetoresistive device 100. The write pulse flows along a current path I1. In the current path I1, the write pulse flows in the order of the capacitor 20, the spin orbit torque wiring 6 of the magnetoresistive element 10, and the selector 30. The write pulse may be a square wave, a spike wave, or any other waveform.

[0062] The capacitor 20 blocks the DC component of the write pulse, whereas the AC component of the write pulse can pass through the capacitor 20. If the write pulse contains a large AC component, the write pulse can be applied to the magnetoresistive element 10 efficiently.

[0063] The write pulse that has passed through the capacitor 20 flows along the spin orbit torque wire 6. When a write current flows through the spin orbit torque wire 6, spins are injected from the spin orbit torque wire 6 into the first ferromagnetic layer 1, and the magnetization of the first ferromagnetic layer 1 is reversed.

[0064] The magnetoresistive element 10 records data as the resistance value in the z direction of the stack 5. The resistance value in the z direction of the stack 5 changes depending on the relative angle between the magnetizations of the first ferromagnetic layer 1 and the second ferromagnetic layer 2. When the magnetization of the first ferromagnetic layer 1 is reversed, the resistance in the z direction of the stack 5 changes, and data is written to the magnetoresistive element 10. For example, when a write pulse is applied along the current path I1, the data stored in the magnetoresistive element 10 is rewritten from "0" to "1."

[0065] To change the data stored in the magnetoresistive element 10 back from "1" to "0," a write pulse is applied in the opposite direction to the current path I1. The write circuit 40 is configured to be able to apply a write pulse in either direction, from the first end to the second end of the spin-orbit torque wiring 6, or from the second end to the first end.

[0066] Here, current path I2 is also considered as a path through which the write pulse flows. Current path I2 can cause erroneous writing because current flows through the magnetoresistive device 100 when the selector 30 is not turned on. To avoid current path I2, it is preferable to make the electrical resistance between the second ferromagnetic layer 2 and the second end of the spin orbit torque wiring 6 greater than the electrical resistance between the first and second ends of the spin orbit torque wiring 6. If this configuration is met, almost no current flows from the spin orbit torque wiring 6 to the stack 5, and current path I2 does not occur. The resistance of the stack 5 can be freely designed by changing the shape, size, thickness of each layer, material of each layer, etc.

[0067] 7 is a diagram for explaining the operation of reading data from a predetermined magnetoresistive effect device 100 of the magnetic memory 200. A magnetoresistive effect device 100 from which data is to be read is selected from among the plurality of magnetoresistive effect devices 100. This device selection is performed by the processor of the read circuit 40.

[0068] The selector 30 of the magnetoresistive effect device 100 from which data is to be read is turned ON, and the selectors 30 of the other magnetoresistive effect devices 100 are turned OFF. In Fig. 7, to read data from the magnetoresistive effect device 100 at the bottom left, the selector 30 of the magnetoresistive effect device 100 at the bottom left is turned ON, and the selectors 30 of the other magnetoresistive effect devices 100 are turned OFF.

[0069] The read circuit 40 outputs a read pulse to a predetermined magnetoresistive device 100. The read pulse flows, for example, along a current path I3. The read pulse may also flow, for example, in the opposite direction to the current path I3. In the current path I3, the read pulse flows in the order of the stack 5 of the magnetoresistive element 10, the spin orbit torque wiring 6 of the magnetoresistive element 10, and the selector 30. The read pulse may be a square wave, a spike wave, or a wave of another waveform. The read pulse is configured to be applied between the second ferromagnetic layer of the magnetoresistive element 10 and the selector 30.

[0070] The capacitor 20 blocks the DC component of the read pulse. On the other hand, the AC component of the read pulse can pass through the capacitor 20. If the read pulse contains a large DC component, the current path I4 via the capacitor 20 is less likely to occur. The current path I4 allows current to flow through the magnetoresistive device 100 when the selector 30 is not turned on, which can cause erroneous reading.

[0071] FIG. 8 shows the write pulse P of the magnetic memory 200 according to the first embodiment. W and read pulse P R 8 is a schematic diagram of an example of a voltage, and the horizontal axis of FIG.

[0072] Write pulse P W Voltage V W is the read pulse P R Voltage V R Write pulse P W must have a current density that can reverse the magnetization of the first ferromagnetic layer 1, and the read pulse P R The applied voltage is larger.

[0073] Read pulse P R The rise time t R is the write pulse P W The rise time t W The longer the rise time t R , t W is the write pulse P R , P W Each of these is the time it takes to reach the maximum voltage. If the rise time is short, the potential changes rapidly, making the pulse behavior similar to AC. On the other hand, if the rise time is long, the potential changes slowly, making the pulse behavior similar to DC.

[0074] Write pulse P W It is preferable that the read pulse P contains a large amount of AC components because it passes through the capacitor 20. RIt is preferable that the read pulse P contains a large DC component so as not to pass through the capacitor 20. R The rise time t R is the write pulse P W The rise time t W If it is longer, the read pulse P R contains a large amount of DC components, and the write pulse P W In other words, if this configuration is satisfied, the current paths I2 and I4 are unlikely to occur.

[0075] The magnetoresistive device 100 according to this embodiment includes the dielectric layer 21 that constitutes the capacitor 20, allowing for a wide tolerance for variations in the via wiring V1 during formation. If the dielectric layer 21 is not present between the via wiring V1 and the spin orbit torque line 6, an opening for the via wiring V1 is formed toward the spin orbit torque line 6. Because the spin orbit torque line 6 is thin, even slight variations in manufacturing may cause the opening to penetrate the spin orbit torque line 6. If the opening penetrates the spin orbit torque line 6, the electrical contact between the via wiring V1 and the spin orbit torque line 6 is limited to the annular region along the opening formed in the spin orbit torque line 6. In this case, sufficient electrical connection between the via wiring V1 and the spin orbit torque line 6 cannot be ensured, resulting in a malfunction of the magnetoresistive element 10. In contrast, the magnetoresistive device 100 according to this embodiment allows for variations during manufacturing by the thickness of the dielectric layer 21 and the spin orbit torque line 6, making it easier to manufacture.

[0076] Furthermore, the magnetoresistive device 100 according to this embodiment can be controlled by one selector 30. The number of selectors 30 in an integration region where the magnetoresistive devices 100 are integrated is directly related to the degree of integration of the magnetoresistive devices 100 in the integration region. The magnetoresistive device 100 according to this embodiment has only one selector 30 arranged in each magnetoresistive device 100, which allows for an increased degree of integration in the integration region.

[0077] "Second embodiment" 9 is a cross-sectional view of a magnetoresistive effect device 102 according to the second embodiment. The magnetoresistive effect device 102 according to the second embodiment can be substituted for the magnetoresistive effect device 100 according to the first embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

[0078] The magnetoresistive device 102 differs from the magnetoresistive device 100 shown in FIG. 3 in the configuration of the capacitor 20B. The capacitor 20B includes, for example, a dielectric layer 21B and a first conductive layer 22. The spin orbit torque wiring 6, the dielectric layer 21B, and the first conductive layer 22 function as the capacitor 20B. As in the first modification shown in FIG. 5, the first conductive layer 22 may be integrated with the via wiring V1.

[0079] The dielectric layer 21B covers the entire upper surface of the spin orbit torque wire 6. When viewed from the z direction, the area of the dielectric layer 21B is larger than the area of the overlapping portion between the first conductive layer 22 and the spin orbit torque wire 6. When the dielectric layer 21B extends over a wide area, it becomes easier to align the via wire V1 when it is formed.

[0080] The magnetoresistive device 102 according to the second embodiment has the capacitor 20B at the first end of the spin orbit torque wiring 6, and therefore provides the same effects as the magnetoresistive device 100 according to the first embodiment.

[0081] "Third embodiment" 10 is a cross-sectional view of a magnetoresistive effect device 103 according to the third embodiment. The magnetoresistive effect device 103 according to the third embodiment can be substituted for the magnetoresistive effect device 100 according to the first embodiment. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

[0082] The magnetoresistive device 103 differs from the magnetoresistive device 100 shown in Fig. 3 in the configuration of the capacitor 20C. The capacitor 20C includes, for example, a dielectric layer 21, a first conductive layer 22, and a second conductive layer 23. The dielectric layer 21, the first conductive layer 22, and the second conductive layer 23 function as the capacitor 20C.

[0083] The dielectric layer 21 is sandwiched between the first conductive layer 22 and the second conductive layer 23 in the z direction. The second conductive layer 23 is connected to a first end of the spin orbit torque wire 6. The second conductive layer 23 is a conductor. The second conductive layer 23 only serves as an electrical connection and is not limited in size compared to the spin orbit torque wire 6. If the second conductive layer 23 serves as one of the pole plates of the capacitor 20C instead of the spin orbit torque wire 6, the area of the capacitor 20C can be increased. That is, the magnetoresistive device 103 can increase the capacitance of the capacitor 20C. A large capacitance of the capacitor 20C makes it easier to pass a large current and stabilizes the write operation.

[0084] The magnetoresistive device 103 according to the third embodiment has the capacitor 20C at the first end of the spin orbit torque wiring 6, and therefore provides the same effects as the magnetoresistive device 100 according to the first embodiment.

[0085] "Fourth embodiment" 11 is a configuration diagram of a magnetoresistive effect device 104 according to the fourth embodiment. The magnetoresistive effect device 110 according to the fourth embodiment differs from the first embodiment in that it does not have multiple magnetoresistive effect elements 10. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

[0086] In the first embodiment, the magnetoresistive device 100 is used as one element of the magnetic memory, but as shown in FIG. 11, the magnetoresistive device 100 can also be used independently.

[0087] Although preferred aspects of the present disclosure have been described above using several exemplary embodiments, the present disclosure is not limited to these embodiments. For example, the characteristic configurations of each embodiment and modification may be applied to other embodiments and modifications. [Explanation of symbols]

[0088] 1 First ferromagnetic layer 2 Second ferromagnetic layer 3 Non-magnetic layer 5. Laminate 6 Spin-orbit torque wiring 10 Magnetoresistive element 20, 20A, 20B, 20C capacitors 21, 21B Dielectric layer 22, 22A First conductive layer 23 Second conductive layer 30 Selectors 40 Write circuit 50 Readout circuit 90 Insulating layer 100, 101, 102, 103, 104, 110 Magnetoresistive effect devices 200 Magnetic Memory CL1, CL2 common wiring GL1, GL2, GL3 gate wiring I1, I2, I3, I4 current paths RL1, RL2 readout wiring t R , t W Rise time V1, V2, V3, V4, V5 via routing WL1, WL2 write wiring

Claims

1. a magnetoresistive element, a capacitor, and a selector; the magnetoresistive element comprises a spin orbit torque wiring and a stacked body in contact with the spin orbit torque wiring, the stacked body includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, the capacitor is connected to a first end of the spin-orbit torque wiring; the selector is connected to a second end of the spin-orbit torque wiring; a write pulse can be applied to the spin-orbit torque wiring in either a direction from the first end to the second end or a direction from the second end to the first end; The magnetoresistive device is configured so that a read pulse can be applied between the second ferromagnetic layer and the selector.

2. further comprising a write circuit and a read circuit; the write circuit is connected to the capacitor and the selector; 2. The magnetoresistive device according to claim 1, wherein the read circuit is connected to the second ferromagnetic layer and the selector.

3. the capacitor comprises a first conductive layer and a dielectric layer; The magnetoresistive device according to claim 1 , wherein the dielectric layer is sandwiched between the spin orbit torque wiring and the first conductive layer.

4. 4. The magnetoresistive device according to claim 3, wherein the area of the dielectric layer is larger than the area of an overlapping portion of the first conductive layer and the spin orbit torque wiring when viewed from the stacking direction.

5. the capacitor comprises a first conductive layer, a dielectric layer, and a second conductive layer; the dielectric layer is sandwiched between the first conductive layer and the second conductive layer, The magnetoresistive device according to claim 1 , wherein the second conductive layer is connected to the spin orbit torque wiring.

6. 6. The magnetoresistive device according to claim 3, wherein the dielectric layer has a thickness of 20 nm or less.

7. 2. The magnetoresistive device of claim 1, wherein the rise time of the read pulse is longer than the rise time of the write pulse.

8. 2. The magnetoresistive device according to claim 1, wherein an electrical resistance between the second ferromagnetic layer and the second end of the spin orbit torque wiring is greater than an electrical resistance between the first end and the second end of the spin orbit torque wiring.

9. a plurality of magnetoresistive devices; A magnetic memory, wherein each of the plurality of magnetoresistive effect devices is the magnetoresistive effect device according to claim 1 .

10. further comprising a write wiring, a read wiring, a common wiring, a write circuit, and a read circuit; the write wiring is connected to the capacitor of each of the plurality of magnetoresistive devices; the readout wiring is connected to the second ferromagnetic layer of each of the plurality of magnetoresistive devices; the common wiring is connected to the selector of each of the plurality of magnetoresistive devices; the write circuit is connected to the write wiring and the common wiring; 10. The magnetic memory according to claim 9, wherein the read circuit is connected to the read wiring and the common wiring.

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