Magnetized rotating element and magnetic array

Abstract

To provide a magnetized rotating element and a magnetic array, capable of lowering a current density required for magnetization reversal.SOLUTION: A magnetized rotating element includes a wiring layer, a laminate, a first conductive layer, and a second conductive layer. The laminate is in contact with the wiring layer. The laminate includes at least a first ferromagnetic layer. The first conductive layer is connected to the wiring layer. The second conductive layer is connected to the wiring layer at a different position from that of the first conductive layer. At least a portion of the first conductive layer and a portion of the second conductive layer overlap the laminate as viewed from a lamination direction. As viewed from the lamination direction, a portion, of the outer periphery of the laminate, overlapping the first conductive layer in the lamination direction has a first curved line. As viewed from the lamination direction, a first portion, of the outer periphery of the first conductive layer, facing the second conductive layer has a second curved line. The first curved line and the second curved line are curved in the same direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to magnetized rotating elements and magnetic arrays. [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] International Publication No. 2020 / 157912 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 improve the write efficiency, it is necessary to reduce the write current density of the write current flowing through the spin-orbit torque wiring.

[0008] The present disclosure has been made in view of the above circumstances, and has an object to provide a magnetization rotation element and a magnetic array that can reduce the current density required for magnetization reversal. [Means for solving the problem]

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

[0010] A magnetization rotating element according to a first aspect includes a wiring layer, a laminate, a first conductive layer, and a second conductive layer. The laminate is in contact with the wiring layer. The laminate has at least a first ferromagnetic layer. The first conductive layer is connected to the wiring layer. The second conductive layer is connected to the wiring layer at a position different from the first conductive layer. At least a portion of the first conductive layer and the second conductive layer overlap the laminate when viewed from the stacking direction. When viewed from the stacking direction, a portion of the outer periphery of the laminate that overlaps with the first conductive layer in the stacking direction has a curved first curved line. When viewed from the stacking direction, a first portion of the outer periphery of the first conductive layer that faces the second conductive layer has a curved second curved line. The first curved line and the second curved line are curved in the same direction. [Effects of the Invention]

[0011] The magnetization rotating element and magnetic array according to the present disclosure can reduce the current density required for magnetization reversal. [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] FIG. 1 is a cross-sectional view of a magnetic memory according to a first embodiment. [Figure 3] FIG. 1 is a cross-sectional view of a magnetoresistive effect element according to a first embodiment. [Figure 4] FIG. 1 is a plan view of a magnetoresistive effect element according to a first embodiment. [Figure 5] FIG. 10 is a plan view of a magnetoresistive element according to a comparative example. [Figure 6] FIG. 10 is a cross-sectional view of a magnetoresistive element according to a comparative example. [Figure 7] FIG. 10 is a plan view of a magnetoresistive effect element according to a second embodiment. [Figure 8] FIG. 10 is a plan view of a magnetoresistive effect element according to a third embodiment. [Figure 9] FIG. 10 is a plan view of a magnetoresistive element according to a fourth embodiment. [Figure 10] FIG. 10 is a plan view of a magnetoresistive element according to a fifth embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a magnetoresistive effect element according to a sixth embodiment. [Figure 12] FIG. 13 is a cross-sectional view of a magnetization rotating element according to a seventh embodiment. [Figure 13] FIG. 13 is a plan view of a magnetization rotating element according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present embodiment will be described in detail below with reference to the accompanying drawings. The drawings used in the following description may show characteristic portions enlarged for ease of understanding, 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 disclosure is not limited thereto. Appropriate modifications can be made within the scope of the present disclosure.

[0014] First, let us define directions. One direction on one surface of the substrate Sub (see Figure 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 direction from the first conductive layer to the second conductive layer within the same xy plane. The x direction is an example of a first direction. The y direction is an example of a second direction. The z direction is a direction perpendicular to the x and y directions. The z direction is an example of a stacking direction in which each layer is stacked. 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" 1 is a configuration diagram of a magnetic memory 200 according to the first embodiment. The magnetic memory 200 includes a plurality of magnetoresistive effect elements 100, a plurality of write wirings WL, a plurality of common wirings CL, a plurality of read wirings RL, a plurality of first switch elements Sw1, a plurality of second switch elements Sw2, and a plurality of third switch elements Sw3. In the magnetic memory 200, for example, the magnetoresistive effect elements 100 are arranged in a matrix. The magnetic memory 200 is one aspect of a magnetic array.

[0017] Each write wiring WL electrically connects a power supply to one or more magnetoresistive effect elements 100. Each common wiring CL is a wiring used both when writing and reading data. Each common wiring CL electrically connects a reference potential to one or more magnetoresistive effect elements 100. The reference potential is, for example, ground. The common wiring CL may be provided for each of the multiple magnetoresistive effect elements 100, or may be provided across the multiple magnetoresistive effect elements 100. Each read wiring RL electrically connects a power supply to one or more magnetoresistive effect elements 100. The power supply is connected to the magnetic memory 200 during use.

[0018] Each magnetoresistive element 100 is connected to a first switch element Sw1, a second switch element Sw2, and a third switch element Sw3, respectively. The first switch element Sw1 is connected between the magnetoresistive element 100 and a write wiring WL. The second switch element Sw2 is connected between the magnetoresistive element 100 and a common wiring CL. The third switch element Sw3 is connected to a read wiring RL that spans the multiple magnetoresistive elements 100.

[0019] When predetermined first switch element Sw1 and second switch element Sw2 are turned ON, a write current flows between the write wiring WL and the common wiring CL connected to the predetermined magnetoresistive effect element 100. The flow of the write current writes data to the predetermined magnetoresistive effect element 100. When predetermined second switch element Sw2 and third switch element Sw3 are turned ON, a read current flows between the common wiring CL and the read wiring RL connected to the predetermined magnetoresistive effect element 100. The flow of the read current reads data from the predetermined magnetoresistive effect element 100.

[0020] The first switch element Sw1, the second switch element Sw2, and the third switch element Sw3 are elements that control the flow of current. The first switch element Sw1, the second switch element Sw2, and the third switch element Sw3 are, for example, elements that utilize a phase change of a crystal layer such as a transistor or an Ovonic Threshold Switch (OTS), elements that utilize a change in band structure such as a Metal-Insulator Transition (MIT) switch, elements that utilize a breakdown voltage such as a Zener diode or an avalanche diode, or elements whose conductivity changes with a change in atomic position.

[0021] 1 is shared by the magnetoresistive effect elements 100 connected to the same read wiring RL. The third switch element Sw3 may be provided in each magnetoresistive effect element 100. Alternatively, the third switch element Sw3 may be provided in each magnetoresistive effect element 100, and the first switch element Sw1 or the second switch element Sw2 may be shared by the magnetoresistive effect elements 100 connected to the same wiring.

[0022] 2 is a cross-sectional view of a characteristic portion of the magnetic memory 200 according to the first embodiment. Fig. 2 is a cross-section of the magnetoresistive element 100 taken along the xz plane passing through the center of the width in the y direction of the spin orbit torque wiring 20, which will be described later.

[0023] The first switch element Sw1 and the second switch element Sw2 shown in Fig. 2 are transistors Tr. The third switch element Sw3 is electrically connected to the readout wiring RL and is located at a different position in the y direction in Fig. 2, for example. The transistor Tr is, for example, a field-effect transistor, and 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. The substrate Sub is, for example, a semiconductor substrate.

[0024] The transistor Tr and the magnetoresistive effect element 100 are electrically connected through a via wiring V. The transistor Tr and the write wiring WL or the common wiring CL are also connected by the via wiring V. The via wiring V extends, for example, in the z direction. The read wiring RL is connected to the stack 10. The via wiring V includes a conductive material.

[0025] The magnetoresistive element 100 and the transistor Tr are covered with an insulating layer 90. The insulating layer 90 is an insulating layer that provides insulation 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.

[0026] 3 is a cross-sectional view of the magnetoresistive element 100. FIG. 3 is a cross-section of the magnetoresistive element 100 taken along the xz plane passing through the center of the width of the spin orbit torque wiring 20 in the y direction.

[0027] The magnetoresistive element 100 includes, for example, a stacked body 10, a spin orbit torque wiring 20, a first conductive layer 30, and a second conductive layer 40. The spin orbit torque wiring 20 is an example of a wiring layer. The magnetoresistive element 100 is surrounded by an insulating layer 90.

[0028] The magnetoresistive element 100 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.

[0029] The magnetoresistive element 100 is an element that records and stores data. The magnetoresistive element 100 records data as the resistance value in the z direction of the stack 10. The resistance value in the z direction of the stack 10 is determined by a write current I WThe resistance of the stack 10 in the z direction is changed by applying a read current I R It can be read by applying

[0030] The stack 10 is in contact with the spin orbit torque wiring 20. The stack 10 is stacked on the spin orbit torque wiring 20, for example.

[0031] The resistance value in the z direction of the stack 10 changes when spins are injected from the spin orbit torque wiring 20 into the stack 10 (first ferromagnetic layer 1).

[0032] The stack 10 is sandwiched in the z direction between the spin-orbit torque wiring 20 and the readout wiring RL. The stack 10 is a columnar body. The shape of the stack 10 when viewed from the z direction is, for example, a circle or an ellipse.

[0033] The stack 10 has at least a first ferromagnetic layer 1. The stack 10 has, for example, the first ferromagnetic layer 1, a second ferromagnetic layer 2, and a non-magnetic layer 3. The resistance value of the stack 10 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.

[0034] The first ferromagnetic layer 1 is, for example, in contact with the spin orbit torque line 20 and is stacked on the spin orbit torque line 20. The first ferromagnetic layer 1 is closer to the spin orbit torque line 20 than the second ferromagnetic layer 2. Spins are injected into the first ferromagnetic layer 1 from the spin orbit torque line 20. 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.

[0035] The second ferromagnetic layer 2 is located farther from the spin orbit torque wiring 20 than the first ferromagnetic layer 1. 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 second ferromagnetic layer 2 is sometimes referred to as a magnetization fixed layer or a magnetization reference layer, and the first ferromagnetic layer 1 is sometimes referred to as a magnetization free layer.

[0036] 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.

[0037] 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.

[0038] The nonmagnetic layer 3 is sandwiched between the first ferromagnetic layer 1 and the second ferromagnetic layer 2 in the z direction.

[0039] 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.

[0040] The stack 10 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 20 and the second ferromagnetic layer 2. The underlayer improves the crystallinity of each layer constituting the stack 10. Furthermore, for example, the stack 10 may include a cap layer on the top surface thereof. Furthermore, the stack 10 may include an antiferromagnetic layer in contact with the second ferromagnetic layer 2.

[0041] The spin-orbit torque wiring 20 contacts the stack 10. The write current I W flows in the x-direction along the spin orbit torque wiring 20 between the first conductive layer 30 and the second conductive layer 40. The spin orbit torque wiring 20 is connected to each of the first conductive layer 30 and the second conductive layer 40.

[0042] The spin-orbit torque wiring 20 generates a spin current by the spin Hall effect when a current flows, and injects spin into the first ferromagnetic layer 1. The spin-orbit torque wiring 20 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.

[0043] 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.

[0044] For example, when a current flows through the spin-orbit torque wiring 20, 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.

[0045] 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.

[0046] 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 20.

[0047] The thickness of the spin orbit torque wire 20 is, for example, 2 nm or more. The thickness of the spin orbit torque wire 20 may be, for example, 20 nm or less.

[0048] The spin-orbit torque wiring 20 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.

[0049] The spin-orbit torque wiring 20 includes, for example, any material selected from the group consisting of heavy metals with atomic numbers of 39 or greater, metal oxides, metal nitrides, metal oxynitrides, and topological insulators. The spin-orbit torque wiring 20 may also include a magnetic material.

[0050] The spin orbit torque wiring 20 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 20, causing a spin current J. S is more likely to occur.

[0051] The first conductive layer 30 is connected to the spin orbit torque wiring 20. The second conductive layer 40 is connected to the spin orbit torque wiring 20 at a position different from that of the first conductive layer 30. The first conductive layer 30 and the second conductive layer 40 are made of a material having electrical conductivity.

[0052] 4 is a plan view of the magnetoresistive element 100 as viewed from the z direction. The read wiring RL and the insulating layer 90 are omitted in FIG.

[0053] The laminate 10 has, for example, a curved line C1 and a curved line C3. The curved line C1 is a portion of the outer periphery of the laminate 10 that overlaps with the first conductive layer 30 in the z direction when the laminate 10 is viewed from the z direction. The curved line C3 is a portion of the outer periphery of the laminate 10 that overlaps with the second conductive layer 40 in the z direction when the laminate 10 is viewed from the z direction. The curved line C1 is an example of a first curved line, and the curved line C3 is an example of a third curved line.

[0054] The shape of the laminate 10 when viewed from above in the z direction is, for example, a circle or an ellipse. The laminate 10 shown in Fig. 4 is an ellipse with its major axis in the y direction and its minor axis in the x direction. The minor axis of the ellipse shown in Fig. 4 coincides with the x direction.

[0055] The spin orbit torque line 20 has almost the same shape as the stack 10, and is a similar shape to the stack 10. The shape of the spin orbit torque line 20 when viewed in a plan view from the z direction is, for example, a circle or an ellipse. The length of the spin orbit torque line 20 shown in FIG. 4 is longer in the y direction than in the x direction.

[0056] At least a portion of the first conductive layer 30 and the second conductive layer 40 overlaps with the stacked body 10 when viewed from the z direction.

[0057] The first conductive layer 30 has, for example, a curved line C2. The curved line C2 is an example of a second curved line. The curved line C2 is located in a first portion 30A of the outer periphery of the first conductive layer 30 when viewed from the z direction, which is opposite the second conductive layer 40. The first portion 30A shown in FIG. 4 consists of the curved line C2. The curved line C2 is curved in the same direction as the curved line C1. The curved lines C1 and C2 are curved in a direction such that the centers of the curved lines C1 and C2 in the y direction move away from the y axis. The y axis is an axis that passes through the center of the laminate 10 and extends in the y direction.

[0058] The second conductive layer 40 has, for example, a curved line C4. The curved line C4 is an example of a fourth curved line. The curved line C4 is located in a second portion 40A of the outer periphery of the second conductive layer 40, facing the first conductive layer 30, when viewed from the z direction. The second portion 40A shown in FIG. 4 consists of the curved line C4. The curved line C4 is curved in the same direction as the curved line C3. The curved lines C3 and C4 are curved such that the centers of the curved lines C3 and C4 in the y direction move away from the y axis. The curved lines C3 and C4 are curved in the opposite direction to the curved lines C1 and C2, respectively.

[0059] The difference between the ellipticity of the first ellipse including the curved line C1 and the ellipticity of the second ellipse including the curved line C2 is preferably 0.5 or less. Here, the first ellipse corresponds to, for example, the planar shape of the laminate 10. The second ellipse is a virtual ellipse that can be drawn along the curved line C2 so that the curved line C2 is included as part of the ellipse.

[0060] Furthermore, the difference between the ellipticity of the third ellipse including the curved line C3 and the ellipticity of the fourth ellipse including the curved line C4 is preferably 0.5 or less. Here, the third ellipse corresponds to the shape of the laminate 10 in a plan view, for example, and may coincide with the first ellipse. The fourth ellipse is a virtual ellipse that can be drawn along the curved line C4 so that the curved line C4 is included as part of the ellipse. The fourth ellipse may coincide with the second ellipse.

[0061] Furthermore, the distance L1 between the first point p1 of the first portion 30A and the second point p2 of the second portion 40A is longer than the distance L2 between the third point p3 of the first portion 30A and the fourth point p4 of the second portion 40A. The first point p1 is the center of the first portion 30A in the y direction. The second point p2 is the center of the second portion 40A in the y direction. The third point p3 is the first end of the first portion 30A in the y direction. The fourth point p4 is the first end of the second portion 40A in the y direction. The third point p3 and the fourth point p4 are on the same side of the line connecting the first point p1 and the second point p2.

[0062] Furthermore, the distance L3 between the first point p1 of the first portion 30A and the fifth point p5 of the spin orbit torque wiring 20 is shorter than the distance L4 between the fifth point p5 and the sixth point p6. The fifth point p5 is one of two points where the x-axis and the outer periphery of the spin orbit torque wiring 20 intersect, and is closer to the first conductive layer 30. The x-axis is an axis that passes through the center of the stack 10 in the y direction and extends in the x-direction. The sixth point p6 is a point where the x-axis intersects with a perpendicular line drawn from the third point p3 to the x-axis. The distance L3 may be approximately equal to the distance L4 between the third point p3 of the first portion 30A and the ninth point p9 of the spin orbit torque wiring 20. The ninth point p9 is a point where the outer periphery of the spin orbit torque wiring 20 and the outer periphery of the first conductive layer 30 intersect when viewed from the z-direction.

[0063] Furthermore, the distance L5 between the second point p2 of the second portion 40A and the seventh point p7 of the spin orbit torque wiring 20 is shorter than the distance L6 between the seventh point p7 and the eighth point p8. The seventh point p7 is one of two points where the x-axis and the outer periphery of the spin orbit torque wiring 20 intersect, and is closer to the second conductive layer 40. The eighth point p8 is the point where the perpendicular line drawn from the fourth point p4 to the x-axis intersects with the x-axis. The distance L5 may be approximately equal to the distance L8 between the fourth point p4 of the second portion 40A and the tenth point p10 of the spin orbit torque wiring 20. The tenth point p10 is the point where the outer periphery of the spin orbit torque wiring 20 and the outer periphery of the second conductive layer 40 intersect when viewed from the z-direction.

[0064] The magnetoresistive element 100 can be fabricated by repeating a process of stacking each layer and a process of processing a portion of each layer into a predetermined shape. For example, the magnetoresistive element 100 can be fabricated using a general semiconductor process. The layers can be stacked using a sputtering method, a chemical vapor deposition (CVD) method, an electron beam evaporation method (EB evaporation method), an atomic laser deposition method, or the like. The layers can be processed using photolithography, or the like.

[0065] The first conductive layer 30 and the second conductive layer 40 can be fabricated by forming openings at predetermined positions in the insulating layer 90 and filling the openings with a conductor. By using a mask with a predetermined shape when forming the openings, the first conductive layer 30 and the second conductive layer 40 can be formed into the predetermined shape in a plan view. Alternatively, the first conductive layer 30 and the second conductive layer 40 can be formed into the predetermined shape in a plan view by filling the openings with a conductor and then etching a portion of the conductor through a mask with a predetermined shape. In this case, the mask used during etching is also formed into the predetermined shape.

[0066] In the magnetoresistive element 100 according to this embodiment, the curved line C2 is curved in the same direction as the curved line C1, so that the write current density during writing can be reduced.

[0067] As shown in Figure 3, the write current I WThe current flows from the interface between the first conductive layer 30 and the spin orbit torque wire 20 to the spin orbit torque wire 20, flows through the spin orbit torque wire 20 in the x direction, and then flows from the interface between the second conductive layer 40 and the spin orbit torque wire 20 towards the second conductive layer 40. While the current flows in the z direction in the first conductive layer 30 and the second conductive layer 40, the current flows in the x direction in the spin orbit torque wire 20. Therefore, near the interface between the first conductive layer 30 and the spin orbit torque wire 20 and near the interface between the second conductive layer 40 and the spin orbit torque wire 20, the current flows in a direction tilted with respect to the x and z directions.

[0068] The spin current is the write current I W In order to efficiently inject spins into the first ferromagnetic layer 1, the write current I W It is desirable to increase the proportion of the flow along the x direction.

[0069] 5 is a plan view of a magnetoresistive effect element 101 according to a comparative example. The magnetoresistive effect element 101 according to the comparative example differs from the magnetoresistive effect element 100 according to the first embodiment in the planar shapes of the first conductive layer 31 and the second conductive layer 41. The other configurations are similar, so similar reference numerals are used and descriptions thereof will be omitted.

[0070] The first conductive layer 31 is similar to the first conductive layer 30 except for its shape when viewed from the z direction. The second conductive layer 41 is similar to the second conductive layer 40 except for its shape when viewed from the z direction. A first portion 31A of the first conductive layer 31 differs from the first portion 30A in that it is not curved. A second portion 41A of the second conductive layer 41 differs from the second portion 40A in that it is not curved. The first portion 31A and the second portion 41A are not curved.

[0071] The distance L1' between the first point p1' of the first portion 31A and the second point p2' of the second portion 41A is equal to the distance L2' between the third point p3' of the first portion 31A and the fourth point p4' of the second portion 41A. The first point p1' is the center of the first portion 31A in the y direction. The second point p2' is the center of the second portion 41A in the y direction. The third point p3' is the first end of the first portion 31A in the y direction. The fourth point p4' is the first end of the second portion 41A in the y direction. The third point p3' and the fourth point p4' are on the same side of the line connecting the first point p1 and the second point p2.

[0072] The distance L1' is shorter than the distance L1 in the magnetoresistive element 100 according to the first embodiment. The portion where the spin-orbit torque wiring 20 is not in contact with either the first conductive layer or the second conductive layer is W In other words, if the distance L1 is longer than the distance L1', the write current I W The proportion of the flow that flows along the x direction increases.

[0073] Furthermore, the distance L3' between the first point p1' of the first portion 31A and the fifth point p5 of the spin orbit torque wiring 20 is longer than the distance L7' between the third point p3' of the first portion 31A and the ninth point p9 of the spin orbit torque wiring 20. The distance L3' corresponds to the distance L4 in the magnetoresistive element 100 according to the first embodiment. The distance L3' is longer than the distance L3 in the magnetoresistive element 100 according to the first embodiment. In the portions corresponding to the distances L3 and L3', the write current I W The write current I tends to flow in a direction inclined with respect to the x and z directions. That is, the distance L3 is shorter than the distance L3', so that the write current I W The proportion of the part that does not flow along the x direction can be reduced.

[0074] Furthermore, the distance L5' between the second point p2' of the second portion 41A and the seventh point p7 of the spin orbit torque wiring 20 is longer than the distance L8' between the fourth point p4' of the second portion 41A and the tenth point p10 of the spin orbit torque wiring 20. The distance L5' corresponds to the distance L6 in the magnetoresistive element 100 according to the first embodiment. The distance L5' is longer than the distance L5 in the magnetoresistive element 100 according to the first embodiment. In the portions corresponding to the distances L5 and L5', the write current I W The write current I tends to flow in a direction inclined with respect to the x and z directions. That is, since the distance L5 is shorter than the distance L5', the write current I W The proportion of the part that does not flow along the x direction can be reduced.

[0075] 6 is a cross-sectional view of a magnetoresistive element 101 according to a comparative example. For example, when the write current I W reaches the spin orbit torque line 20 from the interface between the first conductive layer 31 and the spin orbit torque line 20, flows in the spin orbit torque line 20 in the x direction, and then flows from the interface between the second conductive layer 41 and the spin orbit torque line 20 toward the second conductive layer 41. The magnetoresistive effect element 101 according to the comparative example has a write current I W In contrast, the magnetoresistive element 100 according to the first embodiment shown in FIG. W The proportion of the flow that flows along the x-direction is large.

[0076] The spin current is the write current I W Since the write current I W As a result, the efficiency of spin injection into the first ferromagnetic layer 1 increases. W Even if the current density is small, a torque sufficient to reverse the magnetization of the first ferromagnetic layer 1 can be generated.

[0077] "Second embodiment" 7 is a plan view of a magnetoresistive effect element 102 according to the second embodiment. The magnetoresistive effect element 102 according to the second embodiment can be substituted for the magnetoresistive effect element 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 element 102 differs from the magnetoresistive element 100 in the planar shapes of the stack 11 and the spin orbit torque wire 21. The planar shapes of the stack 11 and the spin orbit torque wire 21 are ellipses with the major axis in the x direction and the minor axis in the y direction. The major axis of the ellipse shown in FIG. 7 coincides with the x direction. The length of the spin orbit torque wire 21 in the x direction is longer than its length in the y direction.

[0079] Except for the shape in a plan view, the laminate 11 is similar to the laminate 10. The laminate 11 has, for example, a curved line C1 and a curved line C3.

[0080] The first conductive layer 32 is similar to the first conductive layer 30 except for its shape in a plan view. The second conductive layer 42 is similar to the second conductive layer 40 except for its shape in a plan view. At least a portion of the first conductive layer 32 and the second conductive layer 42 overlaps with the laminate 11 when viewed in the z direction. The first conductive layer 32 has, for example, a curved line C2 in the first portion 32A. The curved line C2 is curved in the same direction as the curved line C1. The second conductive layer 42 is similar to the second conductive layer 40 except for its shape in a plan view. The second conductive layer 42 has, for example, a curved line C4 in the second portion 42A. The curved line C4 is curved in the same direction as the curved line C3.

[0081] The magnetoresistive element 102 according to the second embodiment has the same effects as the magnetoresistive element 100 according to the first embodiment.

[0082] "Third embodiment" 8 is a plan view of a magnetoresistive effect element 103 according to the third embodiment. The magnetoresistive effect element 103 according to the third embodiment can be substituted for the magnetoresistive effect element 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 description thereof will be omitted.

[0083] The magnetoresistive element 103 differs from the magnetoresistive element 100 in the planar shapes of the stack 12 and the spin orbit torque wiring 22. The planar shapes of the stack 12 and the spin orbit torque wiring 22 are elliptical, with the major and minor axes of the ellipse tilted relative to the x and y directions.

[0084] Except for the shape in a plan view, the laminate 12 is similar to the laminate 10. The laminate 12 has, for example, a curved line C1 and a curved line C3.

[0085] The first conductive layer 33 is similar to the first conductive layer 30 except for its shape in a plan view. The second conductive layer 43 is similar to the second conductive layer 40 except for its shape in a plan view. At least a portion of the first conductive layer 33 and the second conductive layer 43 overlaps with the laminate 12 when viewed from the z direction. The first conductive layer 33 has, for example, a curved line C2 in the first portion 33A. The curved line C2 is curved in the same direction as the curved line C1. The second conductive layer 43 is similar to the second conductive layer 40 except for its shape in a plan view. The second conductive layer 43 has, for example, a curved line C4 in the second portion 43A. The curved line C4 is curved in the same direction as the curved line C3.

[0086] The magnetoresistive element 103 according to the third embodiment has the same effects as the magnetoresistive element 100 according to the first embodiment.

[0087] "Fourth embodiment" 9 is a plan view of a magnetoresistive effect element 104 according to the fourth embodiment. The magnetoresistive effect element 104 according to the fourth embodiment can be substituted for the magnetoresistive effect element 100 according to the first embodiment. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0088] The magnetoresistive element 104 differs from the magnetoresistive element 100 in the shapes of the first conductive layer 34 and the second conductive layer 44 in a plan view.

[0089] The first conductive layer 34 is similar to the first conductive layer 30 except for its shape in a plan view. The first conductive layer 34 has a curved line C2 in the first portion 34A. The first portion 34A is a portion of the outer periphery of the first conductive layer 34 that faces the second conductive layer 44. The first portion 34A has the curved line C2, a first straight line S1, and a second straight line S2. Depending on the processing conditions, straight line portions such as the first straight line S1 and the second straight line S2 may remain in the first portion 34A.

[0090] The second conductive layer 44 is similar to the second conductive layer 40 except for its shape in a plan view. The second conductive layer 44 has a curved line C4 in the second portion 44A. The second portion 44A is a portion of the outer periphery of the second conductive layer 44 that faces the first conductive layer 34. The second portion 44A has the curved line C4, a first straight line S3, and a second straight line S4. Depending on the processing conditions, straight line portions such as the first straight line S3 and the second straight line S4 may remain in the second portion 44A.

[0091] The magnetoresistive element 103 according to the fourth embodiment has the same effects as the magnetoresistive element 100 according to the first embodiment.

[0092] Furthermore, when the first portion 34A and the second portion 44A have straight portions, the write current I W A part of the spin-orbit torque wiring 20 extends in the y direction. The write current I W When the current flows more easily, the area of the portion of the first ferromagnetic layer 1 into which spins are injected increases, and the magnetization of the first ferromagnetic layer 1 becomes more likely to be reversed.

[0093] "Fifth embodiment" 10 is a plan view of a magnetoresistive effect element 105 according to the fifth embodiment. The magnetoresistive effect element 105 according to the fifth embodiment can be substituted for the magnetoresistive effect element 100 according to the first embodiment. In the fifth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

[0094] The magnetoresistive element 105 differs from the magnetoresistive element 100 in the shapes of the first conductive layer 35 and the second conductive layer 45 in a plan view.

[0095] The first conductive layer 35 is similar to the first conductive layer 30 except for its shape in a plan view. The first conductive layer 35 has a curved line C2 in the first portion 35A. The first portion 35A is a portion of the outer periphery of the first conductive layer 35 that faces the second conductive layer 45. The first portion 35A has curved line C2, curved line C5, and curved line C6. The curved line C5 and curved line C6 are curved in the opposite direction to the curved line C2. The curved line C5 is an example of a fifth curved line. Depending on the processing conditions, the curved line C5 and curved line C6 may be formed in the first portion 35A.

[0096] The second conductive layer 45 is similar to the second conductive layer 40 except for its shape in a plan view. The second conductive layer 45 has a curved line C4 in the second portion 45A. The second portion 45A is a portion of the outer periphery of the second conductive layer 45 that faces the first conductive layer 35. The second portion 45A has curved lines C4, C7, and C8. The curved lines C7 and C8 are curved in the opposite direction to the curved line C4. Depending on the processing conditions, the curved lines C7 and C8 may be formed in the second portion 45A.

[0097] The magnetoresistive element 105 according to the fifth embodiment has the same effects as the magnetoresistive element 100 according to the first embodiment.

[0098] Furthermore, if the first portion 35A has portions (curved lines C5 and C6) that curve in the opposite direction to the curved line C2, as shown in FIG. 10, the write current I W A part of the spin-orbit torque wiring 20 extends in the y direction. The write current I W When the current flows more easily, the area of the portion of the first ferromagnetic layer 1 into which spins are injected increases, and the magnetization of the first ferromagnetic layer 1 becomes more likely to be reversed.

[0099] "Sixth embodiment" 11 is a cross-sectional view of a magnetoresistive effect element 106 according to the sixth embodiment. The magnetoresistive effect element 106 according to the sixth embodiment can be substituted for the magnetoresistive effect element 100 according to the first embodiment. In the sixth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

[0100] The magnetoresistive effect element 106 differs from the magnetoresistive effect element 100 in the layer configuration of the stack 13. The stack 13 has a first ferromagnetic layer 1, a second ferromagnetic layer 2, and a non-magnetic layer 3. The second ferromagnetic layer 2 in the stack 13 has a first magnetization fixed layer 2A, a second magnetization fixed layer 2B, and an intermediate layer 2C. The first magnetization fixed layer 2A and the second magnetization fixed layer 2B are antiferromagnetically coupled. The intermediate layer 2C is made of, for example, Ru, Rh, or the like.

[0101] The magnetoresistive effect element 106 according to the sixth embodiment has the same effects as the magnetoresistive effect element 100 according to the first embodiment. Furthermore, since the first magnetization fixed layer 2A and the second magnetization fixed layer 2B are magnetically coupled, the magnetization stability of the entire second ferromagnetic layer 2 is high. The magnetoresistive effect element 106 retains data by utilizing a change in resistance that accompanies a change in the relative angle between the magnetizations of the first ferromagnetic layer 1 and the second ferromagnetic layer 2. When the magnetization stability of the second ferromagnetic layer 2, which serves as a reference, is high, the reliability of data recorded in the magnetoresistive effect element 106 is improved.

[0102] Seventh Embodiment Fig. 12 is a cross-sectional view of the magnetization rotation element 110 according to the seventh embodiment. Fig. 13 is a plan view of the magnetization rotation element 110 according to the seventh embodiment. The magnetization rotation element 110 can be substituted for the magnetoresistive effect element 100 according to the first embodiment.

[0103] The magnetization rotation element 110, for example, irradiates light onto the first ferromagnetic layer 1 and evaluates the light reflected by the first ferromagnetic layer 1. When the orientation direction of magnetization changes due to the magnetic Kerr effect, the polarization state of the reflected light changes. The magnetization rotation element 110 can be used, for example, as an optical element for an image display device or the like that utilizes the difference in the polarization state of light.

[0104] In addition, the magnetization rotating element 110 can be used alone as an anisotropic magnetic sensor, an optical element using the magnetic Faraday effect, or the like.

[0105] In the magnetization rotation element 110, the first portion 30A of the first conductive layer 30 has a curved line C2. The magnetization rotation element 110 according to the seventh embodiment is the magnetoresistive element 100 except that the non-magnetic layer 3 and the second ferromagnetic layer 2 are removed, and the same effects as those of the magnetoresistive element 100 according to the first embodiment can be obtained.

[0106] 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]

[0107] 1 First ferromagnetic layer 2 Second ferromagnetic layer 2A 1st magnetization fixed layer 2B Second magnetization fixed layer 2C middle layer 3 Non-magnetic layer 10, 11, 12, 13 Laminate 20, 21, 22 Spin-orbit torque wiring 30, 31, 32, 33, 34, 35 First conductive layer 30A, 31A, 32A, 33A, 34A, 35A 1st part 40, 41, 42, 43, 44, 45 Second conductive layer 40A, 41A, 42A, 43A, 44A, 45A 2nd part 90 Insulating layer 100, 101, 102, 103, 104, 105, 106 Magnetoresistive effect element 110 Magnetized Rotating Element 200 Magnetic Memory C1, C2, C3, C4, C5, C6, C7, C8 curved line S1, S3 1st straight line S2, S4 2nd straight line

Claims

1. a wiring layer, a laminate, a first conductive layer, and a second conductive layer; the laminate is in contact with the wiring layer, the stack includes at least a first ferromagnetic layer; the first conductive layer is connected to the wiring layer; the second conductive layer is connected to the wiring layer at a position different from that of the first conductive layer; At least a portion of the first conductive layer and the second conductive layer overlaps with the stacked body when viewed from the stacking direction, When viewed from the stacking direction, a portion of the outer periphery of the stacked body that overlaps with the first conductive layer in the stacking direction has a curved first curved line, When viewed from the stacking direction, a first portion of the outer periphery of the first conductive layer facing the second conductive layer has a curved second curved line, The magnetized rotating element, wherein the first curved line and the second curved line are curved in the same direction.

2. When viewed from the stacking direction, a portion of the outer periphery of the stacked body that overlaps with the second conductive layer in the stacking direction has a curved third curved line, a second portion of the outer periphery of the second conductive layer facing the first conductive layer when viewed from the stacking direction has a curved fourth curved line; The magnetization rotating element according to claim 1 , wherein the third curved line and the fourth curved line are curved in the same direction.

3. The shape of the laminate when viewed in a plane from the stacking direction is elliptical, The magnetization rotating element according to claim 1 , wherein a first direction from the first conductive layer toward the second conductive layer coincides with a major axis or a minor axis of the ellipse.

4. The shape of the laminate when viewed in a plane from the stacking direction is elliptical, The magnetization rotating element according to claim 1 , wherein a first direction from the first conductive layer toward the second conductive layer coincides with a minor axis of the ellipse.

5. The magnetized rotating element of claim 1 , wherein the first portion further comprises a straight portion.

6. The magnetized rotating element according to claim 1 , wherein the first portion further comprises a fifth curved line that curves in an opposite direction to the second curved line.

7. 2. The magnetization rotating element according to claim 1, wherein a difference between the ellipticity of the first ellipse including the first curved line and the ellipticity of the second ellipse including the second curved line is 0.5 or less.

8. 2. The magnetization rotating element according to claim 1, wherein, when viewed from the stacking direction, the length of the wiring layer in a first direction from the first conductive layer to the second conductive layer is longer than the length of the wiring layer in a second direction perpendicular to the first direction.

9. the stack further includes a nonmagnetic layer and a second ferromagnetic layer; The magnetization rotating element according to claim 1 , wherein the nonmagnetic layer is located between the first ferromagnetic layer and the second ferromagnetic layer in the stacking direction.

10. the second ferromagnetic layer includes a first magnetization fixed layer, an intermediate layer, and a second magnetization fixed layer; The magnetization rotating element according to claim 9 , wherein the first magnetization pinned layer and the second magnetization pinned layer are antiferromagnetically coupled.

11. a plurality of magnetized rotating elements; A magnetic array, wherein at least one of the plurality of magnetization rotating elements is the magnetization rotating element of claim 1 .

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