Magnetic array and neuromorphic device

Abstract

A magnetic array comprises a plurality of magnetic domain wall motion elements, a plurality of write wirings, and a write circuit. Each of the plurality of magnetic domain wall movement elements is provided with a magnetic domain wall movement layer that extends in a first direction, a first magnetization fixed layer that is connected to the magnetic domain wall movement layer, and a first electrode that is connected to the magnetic domain wall movement layer via the first magnetization fixed layer. Each of the plurality of magnetic domain wall movement elements has a first portion in which the first electrode and the magnetic domain wall movement layer face each other without the first magnetization fixed layer interposed therebetween. The plurality of magnetic domain wall movement elements are provided with a first magnetic domain wall movement element and a second magnetic domain wall movement element. A first length of write wiring between the write circuit and the first magnetic domain wall movement element is less than a second length of write wiring between the write circuit and the second magnetic domain wall movement element. The area of the first portion of the second magnetic domain wall movement element is less than the area of the first portion of the first magnetic domain wall movement element.

Description

Magnetic arrays and neuromorphic devices

[0001] This disclosure relates to magnetic arrays and neuromorphic devices.

[0002] A magnetoresistive element that utilizes a change in resistance (magnetoresistance change) based on a change in the relative angle of magnetization between two ferromagnetic layers is known. For example, the domain wall-moving type magnetoresistive element described in Patent Document 1 (hereinafter referred to as the domain wall-moving element) is an example of a magnetoresistive element. In the domain wall-moving element, the resistance value in the stacking direction changes depending on the position of the domain wall, and data can be recorded in multi-level or analog format. The domain wall-moving element has high linearity and symmetry of resistance change, excellent rewrite endurance, and enables high-speed operation.

[0003] Magnetic domain wall moving elements are often used in an integrated manner. If there is variation in the performance of each integrated magnetic domain wall moving element, the controllability of the entire integrated device will decrease. For example, if there is variation in the writing characteristics of each integrated magnetic domain wall moving element, the reliability of writing to the magnetic domain wall moving element will decrease. Patent Document 1 describes changing the element structure depending on the positional relationship with the substrate in order to suppress variations in the performance of magnetic domain wall moving elements.

[0004] Patent No. 7520673

[0005] When magnetic domain wall moving elements are arranged in a matrix, elements belonging to the same row are connected to the same writing circuit. We found that the length of the writing wiring connecting the writing circuit and the magnetic domain wall moving elements is one of the causes of variations in the writing performance of the magnetic domain wall moving elements.

[0006] This disclosure has been made in view of the above-mentioned problems and aims to provide a magnetic array and a neuromorphic device in which the writing performance of each magnetic domain wall moving element is small.

[0007] A magnetic array according to the first embodiment comprises a plurality of domain wall moving elements, a plurality of writing lines, and a writing circuit. The plurality of domain wall moving elements are arranged in a matrix. Each of the plurality of writing lines connects each of the domain wall moving elements belonging to the same row among the plurality of domain wall moving elements to the writing circuit. Each of the plurality of domain wall moving elements comprises a domain wall moving layer extending in a first direction, a first magnetization fixed layer connected to the domain wall moving layer, and a first electrode connected to the domain wall moving layer via the first magnetization fixed layer. Each of the plurality of domain wall moving elements has a first portion in which the first electrode and the domain wall moving layer face each other without the first magnetization fixed layer in between. The plurality of domain wall moving elements comprises a first domain wall moving element and a second domain wall moving element. The first length of the writing line between the writing circuit and the first domain wall moving element is shorter than the second length of the writing line between the writing circuit and the second domain wall moving element. The area of ​​the first portion of the second magnetic domain wall moving element is smaller than the area of ​​the first portion of the first magnetic domain wall moving element.

[0008] This is a block diagram of a magnetic array according to the first embodiment. This is a circuit diagram of the integration region of a magnetic array according to the first embodiment. This is a cross-sectional view of the vicinity of a magnetic wall moving element of a magnetic array according to the first embodiment. This is a plan view of the first magnetic wall moving element according to the first embodiment. This is a cross-sectional view of the first magnetic wall moving element according to the first embodiment. This is a plan view of the second magnetic wall moving element according to the first embodiment. This is a cross-sectional view of the second magnetic wall moving element according to the first embodiment. This is a plan view of the third magnetic wall moving element according to the first embodiment. This is a cross-sectional view of the third magnetic wall moving element according to the first embodiment. This is a conceptual diagram of a neural network. This is a block diagram of a system including a neuromorphic device according to the first embodiment. This is a plan view of the first magnetic wall moving element according to the second embodiment. This is a cross-sectional view of the first magnetic wall moving element according to the second embodiment. This is a plan view of the second magnetic wall moving element according to the second embodiment. This is a cross-sectional view of the second magnetic wall moving element according to the second embodiment. This is a circuit diagram of the integration region of a magnetic array according to the third embodiment. This is a cross-sectional view of the vicinity of the first magnetic wall moving element of a magnetic array according to the fourth embodiment. This is a cross-sectional view of the vicinity of the second magnetic wall moving element of a magnetic array according to the fourth embodiment. This is a circuit diagram of the integration region of a magnetic array according to the fifth embodiment. This is a circuit diagram of the integration region of a magnetic array according to the sixth embodiment. This is a cross-sectional view of the first magnetic domain wall moving element according to the seventh embodiment. This is a cross-sectional view of the second magnetic domain wall moving element according to the seventh embodiment.

[0009] The following description will detail this embodiment, with appropriate reference to the drawings. The drawings used in the following description may be enlarged for convenience to clearly illustrate the features of this embodiment, and the dimensional ratios of each component may differ from those of the actual components. The materials, dimensions, etc., exemplified in the following description are examples only, and this embodiment is not limited to them. It is possible to modify and implement this embodiment as appropriate, within the scope of achieving its intended effects.

[0010] First, the directions are defined. The x-direction and the y-direction are directions substantially parallel to one surface of a substrate Sub (see FIG. 3) described later. The x-direction is the direction in which a magnetic wall movement layer described later extends. The x-direction is an example of the first direction. The y-direction is a direction orthogonal to the x-direction in the xy-plane. The y-direction is an example of the second direction. The z-direction is the direction from the substrate described later toward the magnetic wall movement element. The z-direction is an example of the stacking direction. In this specification, the +z direction may be expressed as "up" and the -z direction may be expressed as "down", but these expressions are for convenience and do not define the direction of gravity. Also, in this specification, "extending in the x-direction" means that, for example, 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 the case of extending in other directions.

[0011] [First Embodiment] FIG. 1 is a block diagram of a magnetic array MA according to the first embodiment. The magnetic array MA has an integrated area I and a peripheral area 2. The magnetic array MA can be used, for example, in a magnetic memory, a multiplier-accumulator, a neuromorphic device, a spin memory transistor, and a magneto-optical element.

[0012] The integrated area I is an area in which a plurality of magnetic wall movement elements are integrated. When the magnetic array MA is used as a memory, data is stored in the integrated area I. When the magnetic array MA is used as a neuromorphic device, learning and inference are performed in the integrated area I.

[0013] The peripheral area 2 is an area in which a control element for controlling the operation of the magnetic wall movement elements in the integrated area I is mounted. The peripheral area 2 has, for example, a control device 3, a resistance detection device 4, and an output unit 5. The peripheral area 2 is not limited to an example outside the integrated area I. For example, the peripheral area 2 may be at a position overlapping the integrated area I and at a position different from the integrated area I in the z-direction.

[0014] The control device 3 is configured to be able to apply a pulse to at least one of the plurality of magnetic wall movement elements in the integrated area I. The control device 3 has, for example, a power supply 6 and a writing circuit 7.

[0015] The power supply 6 is a power supply for applying a writing voltage to the magnetic domain wall movement element. The writing circuit 7 has, for example, a processor and a memory. The processor is, for example, a CPU (Central Processing Unit). The processor operates based on an operation program stored in the memory. The writing circuit 7 controls, for example, the address of the magnetic domain wall movement element to which a pulse is applied, the magnitude (voltage, pulse length) of the pulse applied to a predetermined magnetic domain wall movement element, and the like. The writing circuit 7 may also have a clock, a counter, a random number generator, and the like. The clock serves as an indicator of the timing for applying a pulse, and the counter counts the number of times a pulse has been applied, etc. The writing circuit 7 applies a pulse toward the magnetic domain wall movement element.

[0016] The resistance detection device 4 is configured to be able to detect the resistance value of the magnetic domain wall movement element in the integration region 1. The resistance detection device 4 may detect the resistance of each magnetic domain wall movement element in the integration region 1, or may detect, for example, the sum of the resistances of the magnetic domain wall movement elements belonging to the same column. The resistance detection device 4 may have, for example, a comparator that compares the magnitudes of the detected resistance values. The comparator may compare, for example, the detected resistance values with each other, or may compare a preset reference resistance value with the detected resistance value.

[0017] The output unit 5 is connected to the resistance detection device 4. The output unit 5 has, for example, a processor, an output capacitor, an amplifier, a converter, and the like. When the magnetic array MA is used as a neuromorphic device, the output unit 5 may perform an operation of substituting the detection result of the resistance detection device 4 into an activation function. The operation is performed, for example, by a processor. The output unit 5 outputs the operation result to the outside. When the magnetic array MA is used as a neuromorphic device, for example, operations such as outputting the operation result as an input signal to another magnetic array or outputting it to the outside as an identification rate may be performed. The output unit 5 may also feedback the operation result to the control device 3.

[0018] Figure 2 is a circuit diagram of the integrated region 1 according to the first embodiment. Figure 2 also shows a writing circuit 7 connected to the integrated region 1. The integrated region 1 comprises a plurality of magnetic domain wall moving elements 100, a plurality of writing lines WL, a plurality of common lines CL, a plurality of reading lines RL, a plurality of first switches SW1, and a plurality of second switches SW2. The third switch SW3 may belong to, for example, the control device 3 of the peripheral region 2.

[0019] Multiple magnetic domain wall moving elements 100 are arranged in a matrix. The multiple magnetic domain wall moving elements 100 are not limited to actual elements arranged in a matrix, but may also be arranged in a matrix in a circuit diagram. Hereinafter, the magnetic domain wall moving element 100 belonging to the nth column of the matrix-arranged magnetic domain wall moving elements 100 will be referred to as the first magnetic domain wall moving element 101, the magnetic domain wall moving element 100 belonging to the mth column will be referred to as the second magnetic domain wall moving element 102, and the magnetic domain wall moving element 100 belonging to the l column will be referred to as the third magnetic domain wall moving element 103. When the first magnetic domain wall moving element 101, the second magnetic domain wall moving element 102, and the third magnetic domain wall moving element 103 are not distinguished, they will be referred to as magnetic domain wall moving elements 100. n, m, and l are positive integers satisfying the relationship n < m < l. In the example shown in Figure 2, the nth, mth, and lth columns are adjacent columns, but these columns do not have to be adjacent.

[0020] Each of the write wiring lines WL is used when writing data. Each write wiring line WL connects the magnetic wall moving element 100 belonging to the same row to the write circuit 7.

[0021] The distance between the writing circuit 7 and the magnetic wall moving element 100 (the length of the writing wiring WL) differs for each row of magnetic wall moving elements 100 arranged in a matrix.

[0022] For example, the first length L1 of the writing wiring WL between the writing circuit 7 and the first magnetic wall moving element 101 is shorter than the second length L2 of the writing wiring WL between the writing circuit 7 and the second magnetic wall moving element 102. The parasitic capacitance occurring in the writing wiring WL of the first length L1 is smaller than the parasitic capacitance occurring in the writing wiring WL of the second length L2.

[0023] The second length L2 of the writing wiring WL between the writing circuit 7 and the second magnetic domain wall moving element 102 is shorter than the third length L3 of the writing wiring WL between the writing circuit 7 and the third magnetic domain wall moving element 103. The parasitic capacitance occurring in the writing wiring WL of the second length L2 is smaller than the parasitic capacitance occurring in the writing wiring WL of the third length L3.

[0024] Each common wiring CL is used both when writing and reading data. Each common wiring CL is connected, for example, to a resistance detection device 4. The common wiring CL may be provided for each of the multiple magnetic domain wall moving elements 100, or it may be provided across the multiple magnetic domain wall moving elements 100.

[0025] Each of the read wirings RL is used when reading data. Each read wiring RL is electrically connected to, for example, a magnetic wall moving element 100 belonging to the same row as the control device 3. Each read wiring RL may also be electrically connected to, for example, a magnetic wall moving element 100 belonging to the same column as the control device 3.

[0026] The first switch SW1, the second switch SW2, and the third switch SW3 are elements that control the flow of current. The first switch SW1, the second switch SW2, and the third switch SW3 are, for example, elements that utilize phase changes in the crystal layer, such as transistors and ovonic threshold switches (OTS), elements that utilize changes in band structure, such as metal-insulator transition (MIT) switches, elements that utilize breakdown voltage, such as Zener diodes and avalanche diodes, and elements whose conductivity changes with changes in atomic position.

[0027] The first switch SW1 and the second switch SW2 are connected, for example, to each magnetic domain wall moving element 100. The first switch SW1 is connected, for example, between the magnetic domain wall moving element 100 and the write wiring WL. The second switch SW2 is connected, for example, between the magnetic domain wall moving element 100 and the common wiring CL. The third switch SW3 is connected, for example, across multiple magnetic domain wall moving elements 100. The third switch SW3 is connected, for example, to the read wiring RL.

[0028] The positional relationship between the first switch SW1, the second switch SW2, and the third switch SW3 is not limited to the case shown in Figure 2. For example, the first switch SW1 may be connected across multiple magnetic domain wall moving elements 100 and located upstream of the writing wiring WL. Also, for example, the second switch SW2 may be connected across multiple magnetic domain wall moving elements 100 and located upstream of the common wiring CL. Also, for example, the third switch SW3 may be connected to each of the magnetic domain wall moving elements 100.

[0029] Figure 3 is a cross-sectional view of the vicinity of the magnetic wall moving element 100 in the integrated region 1 according to the first embodiment. Figure 3 is a cross-section of one magnetic wall moving element 100 in Figure 2, cut by the xz plane passing through the center of the width in the y direction of the magnetic wall moving layer 10.

[0030] The magnetic domain wall moving element 100 comprises, for example, a magnetic domain wall moving layer 10, a non-magnetic layer 20, a reference layer 30, a first magnetization fixed layer 40, a second magnetization fixed layer 50, a first electrode 60, a second electrode 70, and a third electrode 80.

[0031] The first switch SW1 and the second switch SW2 shown in Figure 3 are transistors Tr. A transistor Tr has a gate electrode G, a gate insulating film GI, and a source S and a drain D formed on a substrate Sub. The source S and drain D are determined by the direction of current flow and are both active regions of the semiconductor. Figure 3 is just an example, and the positional relationship between the source S and drain D may be reversed. The substrate Sub is, for example, a semiconductor substrate. The third switch SW3 is electrically connected to the readout wiring RL and is located, for example, in a position shifted in the y direction in Figure 3.

[0032] The transistor Tr, the write wiring WL, the common wiring CL, the read wiring RL, and the magnetic domain wall moving element 100 are connected by via wiring V extending in the z direction or in-plane wiring IP extending in either the xy plane. The via wiring V and in-plane wiring IP contain conductive material. An insulating layer 90 is formed between different layers in the z direction, except for the via wiring V.

[0033] The insulating layer 90 is an insulating layer that insulates the spaces between wirings and elements in multilayer wiring. The magnetic domain wall moving element 100 and the transistor Tr are electrically isolated by the insulating layer 90, except for the via wiring V. The insulating layer 90 is made of, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon carbide (SiC), chromium nitride (CrN), silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al ２ O ３ ), zirconium oxide (ZrO ｘ ) etc.

[0034] Figure 4 is a plan view of the first magnetic domain wall moving element 101 as seen from the z direction. Figure 5 is a cross-section of the first magnetic domain wall moving element 101 cut by the xz plane passing through the center of the width in the y direction of the magnetic domain wall moving layer 11. The arrows shown in the figures are examples of the orientation direction of magnetization of the ferromagnetic material.

[0035] The first magnetic domain wall moving element 101 comprises, for example, a magnetic domain wall moving layer 11, a non-magnetic layer 21, a reference layer 31, a first magnetization fixed layer 41, a second magnetization fixed layer 51, a first electrode 61, a second electrode 71, and a third electrode 81.

[0036] The magnetic domain wall moving layer 11 is an example of the magnetic domain wall moving layer 10 in Figure 3. The non-magnetic layer 21 is an example of the non-magnetic layer 20 in Figure 3. The reference layer 31 is an example of the reference layer 30 in Figure 3. The first magnetization fixed layer 41 is an example of the first magnetization fixed layer 40 in Figure 3. The second magnetization fixed layer 51 is an example of the second magnetization fixed layer 50 in Figure 3. The first electrode 61 is an example of the first electrode 60 in Figure 3. The second electrode 71 is an example of the second electrode 70 in Figure 3. The third electrode 81 is an example of the third electrode 80 in Figure 3.

[0037] The magnetic domain wall moving layer 11 extends in the x-direction. When viewed from the z-direction, the length of the magnetic domain wall moving layer 11 in the x-direction is longer than its length in the y-direction. The magnetic domain wall moving layer 11 has two magnetic domains inside, and a magnetic domain wall DW at the boundary between the two magnetic domains. The magnetic domain wall moving layer 11 is a layer on which information can be magnetically recorded, for example, by a change in its magnetic state. The magnetic domain wall moving layer 11 is also called the analog layer or magnetic recording layer.

[0038] The magnetic wall movement layer 11 has a first magnetization region A1, a second magnetization region A2, and a third magnetization region A3.

[0039] The first magnetization region A1 is a region where the orientation direction of the magnetization M Ａ１ is fixed in one direction. That the magnetization is fixed means that the magnetization does not reverse in the normal operation of the magnetic wall movement element 100 (when no external force exceeding the assumption is applied). The first magnetization region A1 is, for example, a region of the magnetic wall movement layer that overlaps with the first magnetization fixing layer when viewed from the z direction. The magnetization M Ａ１ of the first magnetization region A1 is fixed, for example, by the magnetization M ４１ of the first magnetization fixing layer 41.

[0040] The second magnetization region A2 is a region where the orientation direction of the magnetization M Ａ２ is fixed in one direction. The orientation direction of the magnetization M Ａ２ of the second magnetization region A2 is different from the orientation direction of the magnetization M Ａ１ of the first magnetization region A1. The orientation direction of the magnetization M Ａ２ of the second magnetization region A2 is, for example, opposite to the orientation direction of the magnetization M Ａ１ of the first magnetization region A1. The second magnetization region A2 is, for example, a region of the magnetic wall movement layer that overlaps with the second magnetization fixing layer when viewed from the z direction. The magnetization M Ａ２ of the second magnetization region A2 is fixed, for example, by the magnetization M ５１ of the second magnetization fixing layer 51.

[0041] The third magnetization region A3 is a region other than the first magnetization region A1 and the second magnetization region A2 of the magnetic wall movement layer 11. The third magnetization region A3 is, for example, a region sandwiched between the first magnetization region A1 and the second magnetization region A2 in the x direction.

[0042] The third magnetization region A3 is a region where the direction of the magnetization changes and the magnetic wall DW can move. The third magnetization region A3 is referred to as a magnetic wall movable region. The third magnetization region A3 has a first magnetic domain A31 and a second magnetic domain A32. The orientation directions of the magnetization of the first magnetic domain A31 and the second magnetic domain A32 are opposite. The boundary between the first magnetic domain A31 and the second magnetic domain A32 is the magnetic wall DW. The magnetization M Ａ３１ [[ID=​It is oriented in the same direction. Magnetization M of the second magnetic domain A32 Ａ３２ For example, the magnetization M of the adjacent second magnetization region A2. Ａ２ It is oriented in the same direction. In principle, the magnetic domain wall DW moves within the third magnetization region A3 and does not penetrate the first magnetization region A1 and the second magnetization region A2.

[0043] When the ratio of the volumes of the first magnetic domain A31 and the second magnetic domain A32 within the third magnetization region A3 changes, the magnetic domain wall DW moves. The magnetic domain wall DW moves when a writing current is passed in the x direction of the third magnetization region A3. For example, when a writing current (e.g., a current pulse) is applied to the third magnetization region A3 in the +x direction, electrons flow in the opposite direction to the current, -x, so the magnetic domain wall DW moves in the -x direction. When a current flows from the first magnetic domain A31 to the second magnetic domain A32, the electrons that have been spin-polarized in the second magnetic domain A32 move to the magnetization M of the first magnetic domain A31. Ａ３１ The magnetization is reversed. Magnetization M of the first magnetic domain A31 Ａ３１ As it reverses, the magnetic domain wall DW moves in the -x direction.

[0044] The magnetic domain wall movement layer 11 is composed of a magnetic material. The magnetic domain wall movement layer 11 may be a ferromagnetic material, a ferrimagnetic material, or a combination of these with an antiferromagnetic material whose magnetic state can be changed by an electric current. Preferably, the magnetic domain wall movement layer 11 has at least one element selected from the group consisting of Co, Ni, Fe, Pt, Pd, Gd, Tb, Mn, Ge, and Ga.

[0045] Materials used for the magnetic domain wall migration layer 11 include, for example, a Co and Ni laminated film, a Co and Pt laminated film, a Co and Pd laminated film, and Co ｘ Fe １－ｘ Examples include a laminated film of B (0 ≤ x ≤ 1) and a material similar to the non-magnetic layer 20 described later, MnGa-based materials, GdCo-based materials, and TbCo-based materials. Ferrimagnetic materials such as MnGa-based materials, GdCo-based materials, and TbCo-based materials have low saturation magnetization, resulting in a small threshold current required to move the magnetic domain wall DW. Also, laminated films of Co and Ni, Co and Pt, and Co and Pd have high coercivity, resulting in a slow movement speed of the magnetic domain wall DW. Antiferromagnetic materials include, for example, Mn ３ X (where X is Sn, Ge, Ga, Pt, Ir, etc.), CuMnAs, Mn２ This includes materials such as Au. The magnetic domain wall moving layer 11 can also be made of the same material as the reference layer 31, which will be described later. Two or more types of laminated films or materials can also be applied.

[0046] The non-magnetic layer 21 is sandwiched between the domain wall movement layer 11 and the reference layer 31. The non-magnetic layer 21 inhibits the magnetic coupling between the domain wall movement layer 11 and the reference layer 31. The non-magnetic layer 21 is laminated on one surface of the reference layer 31.

[0047] The non-magnetic layer 21 is made of, for example, a non-magnetic insulator, semiconductor, or metal. Preferably, the non-magnetic layer 21 is a non-magnetic insulator. A non-magnetic insulator is, for example, Al ２ O ３ SiO ２ MgO, MgAl ２ O ４ These are materials in which some of the Al, Si, and Mg are replaced with Zn, Be, Ga, Ti, etc. These materials have a large band gap and excellent insulating properties. Non-magnetic insulators are, for example, oxides containing Mg or Al. When the non-magnetic layer 21 is made of a non-magnetic insulator, the non-magnetic layer 21 is a tunnel barrier layer. Non-magnetic metals are, for example, Cu, Au, Ag, etc. Non-magnetic semiconductors are, for example, Si, Ge, CuInSe ２ CuGaSe ２ , Cu(In,Ga)Se ２ And so on.

[0048] The thickness of the non-magnetic layer 21 is, for example, 20 Å or more, and may also be 25 Å or more.

[0049] The reference layer 31, together with the magnetic domain wall movement layer 11, sandwiches the non-magnetic layer 21. At least a portion of the reference layer 31 is located in a position that overlaps with the third magnetization region A3 in the z direction. The reference layer 31 is, for example, closer to the substrate Sub than the magnetic domain wall movement layer 11.

[0050] Magnetization M of the reference layer 31 ３１ The magnetization of the third magnetization region A3 of the magnetic domain wall moving layer 11 is less likely to reverse. ３１ The third magnetization region A3 remains fixed and does not change direction when an external force sufficient to reverse the magnetization is applied. The reference layer 31 is sometimes referred to as the fixed layer.

[0051] The reference layer 31 includes a ferromagnetic material. The reference layer 31 includes, for example, a material that readily produces a coherent tunneling effect with respect to the magnetic domain wall movement layer 11. The reference layer 31 includes, for example, a metal selected from the group consisting of Cr, Mn, Co, Fe, and Ni, an alloy containing one or more of these metals, an alloy containing these metals and at least one of the elements B, C, and N, etc. Examples of the reference layer 31 include Co-Fe, Co-Fe-B, and Ni-Fe. In addition, a multilayer film of Co and Ni, a multilayer film of Co and Pt, or a multilayer film of Co and Pd may be used as part of the reference layer 31.

[0052] The reference layer 31 may be, for example, a Heusler alloy. Heusler alloys are half-metallic and have a high spin polarizability. Heusler alloys are XYZ or X ２ It is an intermetallic compound with the chemical composition YZ, where X is a transition metal or noble metal element of group Co, Fe, Ni, or Cu on the periodic table, Y is a transition metal or element species of group Mn, V, Cr, or Ti, and Z is a typical element of group III to V. For example, a Heusler alloy is Co ２ FeSi, Co ２ FeGe, Co ２ FeGa, Co ２ MnSi, Co ２ Mn １－ａ Fe ａ Al ｂ Si １－ｂ Co ２ FeGe １－ｃ Ga ｃ These are some examples.

[0053] The reference layer 31 has multiple layers and may be a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure consists of two magnetic layers sandwiched between a non-magnetic spacer layer. The magnetic layers may include, for example, a ferromagnetic material and an antiferromagnetic material such as IrMn or PtMn. The spacer layer may include, for example, at least one selected from the group consisting of Ru, Ir, and Rh.

[0054] Each of the reference layer 31 and the non-magnetic layer 21 is, for example, longer than the third magnetization region A3 in the x-direction. The portion where the reference layer 31 and the third magnetization region A3 face each other with the non-magnetic layer 21 in between is responsible for the resistance change of the first magnetic domain wall moving element 101. In the bottom pin structure, the x-direction lengths of the reference layer 31 and the non-magnetic layer 21 are longer than the x-direction lengths of the third region, and the resistance change range is determined by the third region A3.

[0055] The reference layer 31 is, for example, longer than the magnetic domain wall moving layer 11 in the x-direction. When viewed from the z-direction, the reference layer 31 overlaps the entire magnetic domain wall moving layer 11, improving the heat dissipation of the magnetic domain wall moving layer 11. As a result, the stability of the magnetization in the first magnetization region A1 and the second magnetization region A2 is increased, and the reliability of the data from the first magnetic domain wall moving element 101 is improved.

[0056] The first magnetization fixed layer 41 is connected to the magnetic domain wall moving layer 11. The first magnetization fixed layer 41 is connected to the first magnetization region A1 of the magnetic domain wall moving layer 11. The magnetization M of the first magnetization fixed layer 41 ４１ This fixes the magnetization of the first magnetization region A1.

[0057] The first magnetization fixed layer 41 is, for example, a ferromagnetic material. The first magnetization fixed layer 41 can be made of, for example, the same material as the magnetic domain wall moving layer 11 or the reference layer 31. The first magnetization fixed layer 41 may have multiple layers. For example, the first magnetization fixed layer 41 may have a laminated structure of multiple layers and may include a mask layer, cap layer, etc., used during manufacturing.

[0058] The first magnetization fixed layer 41 has multiple layers and may be a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure consists of two magnetic layers sandwiched between a non-magnetic spacer layer. The magnetic layers may include, for example, a ferromagnetic material and an antiferromagnetic material such as IrMn or PtMn. The spacer layer may include, for example, at least one selected from the group consisting of Ru, Ir, and Rh.

[0059] Furthermore, the first magnetization-fixing layer 41 is not limited to a ferromagnetic material. If the first magnetization-fixing layer 41 is not a ferromagnetic material, the current density of the current flowing through the magnetic domain wall movement layer 11 changes rapidly in the region overlapping with the first magnetization-fixing layer 41, thereby restricting the movement of the magnetic domain wall DW and fixing the magnetization of the first magnetization region A1.

[0060] The second magnetization fixed layer 51 is connected to the magnetic domain wall moving layer 11 at a position spaced apart from the first magnetization fixed layer 41 in the x-direction. The second magnetization fixed layer 51 is connected to the second magnetization region A2 of the magnetic domain wall moving layer 11. The magnetization M of the second magnetization fixed layer 51 ５１ This fixes the magnetization of the second magnetization region A2.

[0061] The second magnetization fixed layer 51 can be made of the same material as the first magnetization fixed layer 41. The second magnetization fixed layer 51 may also be a synthetic antiferromagnetic structure (SAF structure). The second magnetization fixed layer 51 may have multiple layers. For example, the second magnetization fixed layer 51 may be a laminated structure of multiple layers, and may include a mask layer, cap layer, etc., used during manufacturing.

[0062] The film thickness of the first magnetization fixed layer 41 and the film thickness of the second magnetization fixed layer 51 may be the same or different. For example, the film thickness of the first magnetization fixed layer 41 may be thinner than the film thickness of the second magnetization fixed layer 51. For example, the film thickness of the first magnetization fixed layer 41 may be thicker than the film thickness of the second magnetization fixed layer 51. If the film thickness of the first magnetization fixed layer 41 and the film thickness of the second magnetization fixed layer 51 are different, a difference in coercivity is likely to occur between the first magnetization fixed layer 41 and the second magnetization fixed layer 51. If there is a difference in coercivity between the first magnetization fixed layer 41 and the second magnetization fixed layer 51, the magnetization M of the first magnetization fixed layer 41 will be affected at the time of manufacture. ４１ The orientation direction and the magnetization M of the second magnetization fixed layer 51 ５１ This makes it easier to set the orientation direction to a different direction from the orientation direction.

[0063] Here, the positional relationship between the first magnetization fixed layer 41 and the second magnetization fixed layer 51 is not limited to the example shown in Figure 5. The positional relationship between the first magnetization fixed layer 41 and the second magnetization fixed layer 51 may be reversed, and the first magnetization fixed layer 41 may be located in the +x direction relative to the second magnetization fixed layer 51.

[0064] The first electrode 61 is connected to the first magnetization fixed layer 41. The first electrode 61 may be in direct contact with the first magnetization fixed layer 41, or it may be indirectly connected across the layer. The first electrode 61 is, for example, a writing electrode used when applying a writing current to the first magnetic domain wall moving element 101. The writing current flows between the first electrode 61 and the second electrode 71. The first electrode 61 contains a conductive material.

[0065] Between the first electrode 61 and the magnetic domain wall moving layer 11, there is a first portion P1A in which the first electrode 61 and the magnetic domain wall moving layer 11 face each other without the first magnetization fixed layer 41 in between. The first portion P1A is the part in which the first electrode 61 and the magnetic domain wall moving layer 11 overlap without the first magnetization fixed layer 41 when viewed from the z direction. In the first portion P1A, charge accumulates between the first electrode 61 and the magnetic domain wall moving layer 11, and parasitic capacitance is generated.

[0066] The second electrode 71 is connected to the second magnetization fixed layer 51. The second electrode 71 may be in direct contact with the second magnetization fixed layer 51, or it may be indirectly connected across the layer. The second electrode 71 is a common electrode used when applying a write current to the first magnetic domain wall moving element 101 and when applying a read current to the first magnetic domain wall moving element 101. The second electrode 71 contains a conductive material.

[0067] There may be a second portion P2A between the second electrode 71 and the magnetic domain wall moving layer 11 in which the second electrode 71 and the magnetic domain wall moving layer 11 face each other without the second magnetization fixed layer 51 in between. The second portion P2A is the portion in which the second electrode 71 and the magnetic domain wall moving layer 11 overlap without the second magnetization fixed layer 51 when viewed from the z direction. In the second portion P2A, charge accumulates between the second electrode 71 and the magnetic domain wall moving layer 11, and parasitic capacitance is generated.

[0068] The third electrode 81 is connected to the reference layer 31. The third electrode 81 may be in direct contact with the reference layer 31, or it may be indirectly connected across the layer. The third electrode 81 is a readout electrode used when applying a readout current to the first magnetic domain wall moving element 101. The third electrode 81 contains a conductive material.

[0069] Figure 6 is a plan view of the second magnetic domain wall moving element 102 as seen from the z direction. Figure 7 is a cross-section of the second magnetic domain wall moving element 102 obtained by cutting it through the xz plane passing through the center of the width in the y direction of the magnetic domain wall moving layer 12. The arrows shown in the figures are examples of the orientation direction of magnetization of the ferromagnetic material.

[0070] The second magnetic domain wall moving element 102 comprises, for example, a magnetic domain wall moving layer 12, a non-magnetic layer 22, a reference layer 32, a first magnetization fixed layer 42, a second magnetization fixed layer 52, a first electrode 62, a second electrode 72, and a third electrode 82. The second magnetic domain wall moving element 102 has the same configuration as the first magnetic domain wall moving element 101, except for the shape of each layer.

[0071] The magnetic domain wall moving layer 12 corresponds to the magnetic domain wall moving layer 11. The non-magnetic layer 22 corresponds to the non-magnetic layer 21. The reference layer 32 corresponds to the reference layer 31. The first magnetization fixed layer 42 corresponds to the first magnetization fixed layer 41. The second magnetization fixed layer 52 corresponds to the second magnetization fixed layer 51. The first electrode 62 corresponds to the first electrode 61. The second electrode 72 corresponds to the second electrode 71. The third electrode 82 corresponds to the third electrode 81. The second magnetic domain wall moving element 102 replaces these components with the corresponding components of the first magnetic domain wall moving element 101.

[0072] Between the first electrode 62 and the magnetic domain wall moving layer 12, there is a first portion P1B in which the first electrode 62 and the magnetic domain wall moving layer 12 face each other without the first magnetization fixed layer 42 in between. The first portion P1B is the portion in which the first electrode 62 and the magnetic domain wall moving layer 12 overlap without the first magnetization fixed layer 42 when viewed from the z direction. In the first portion P1B, charge accumulates between the first electrode 62 and the magnetic domain wall moving layer 12, and parasitic capacitance is generated.

[0073] There may be a second portion P2B between the second electrode 72 and the magnetic domain wall moving layer 12 in which the second electrode 72 and the magnetic domain wall moving layer 12 face each other without the second magnetization fixed layer 52 in between. The second portion P2B is the portion in which the second electrode 72 and the magnetic domain wall moving layer 12 overlap without the second magnetization fixed layer 52 when viewed from the z direction. In the second portion P2B, charge accumulates between the second electrode 72 and the magnetic domain wall moving layer 12, and parasitic capacitance is generated.

[0074] When viewed from the z-direction in a plan view, the area of ​​the first portion P1B of the second magnetic domain wall moving element 102 is smaller than the area of ​​the first portion P1A of the first magnetic domain wall moving element 101. The parasitic capacitance generated in the first portion P1B of the second magnetic domain wall moving element 102 is smaller than the parasitic capacitance generated in the first portion P1A of the first magnetic domain wall moving element 101. The difference between the parasitic capacitance of the first portion P1A and the parasitic capacitance of the first portion P1B compensates for the difference between the parasitic capacitance of the writing wiring WL of first length L1 and the parasitic capacitance of the writing wiring WL of second length L2.

[0075] For example, the waveform of the write signal differs slightly between the moment it outputs from the write circuit 7 and the moment it reaches each of the magnetic domain wall moving elements 100. By the time it reaches the magnetic domain wall moving layer 10, the edges of the waveform are blurred, and the waveform becomes slightly rounded. This is due to the resistance and parasitic capacitance from the write circuit 7 to the magnetic domain wall moving layer 10. If the difference between the parasitic capacitance from the write circuit 7 to the magnetic domain wall moving layer 11 of the first magnetic domain wall moving element 101 and the parasitic capacitance from the write circuit 7 to the magnetic domain wall moving layer 12 of the second magnetic domain wall moving element 102 is small, the waveforms of the write signals in the magnetic domain wall moving layer 11 and the magnetic domain wall moving layer 12 will be similar, and the variation in the write characteristics of the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 will be reduced.

[0076] Furthermore, when viewed from the z-direction in a plan view, the area of ​​the second portion P2B of the second magnetic domain wall moving element 102 is smaller than the area of ​​the second portion P2A of the first magnetic domain wall moving element 101. The area of ​​the second portion P2B may be the same as the area of ​​the second portion P2A, or it may be larger. The size of the second portions P2A and P2B is irrelevant because the waveform generated by the writing circuit 7 passes through the magnetic domain wall DW.

[0077] For example, when viewed from a planar perspective from the z direction, the width W12 in the y direction of the magnetic wall moving layer 12 of the second magnetic wall moving element 102 is narrower than the width W11 in the y direction of the magnetic wall moving layer 11 of the first magnetic wall moving element 101. By making the width W12 of the magnetic wall moving layer 12 narrower than the width W11 of the magnetic wall moving layer 11, the area of ​​the first portion P1B can be easily made smaller than the area of ​​the first portion P1A.

[0078] On the other hand, if the width W11 of the magnetic wall moving layer 11 and the width W12 of the magnetic wall moving layer 12 are different, a difference in read resistance may occur between the first magnetic wall moving element 101 and the second magnetic wall moving element 102. Read resistance is the reciprocal of the ease with which the read current flows. In the first magnetic wall moving element 101, the read current flows between the second electrode 71 and the third electrode 81, and in the second magnetic wall moving element 102, the read current flows between the second electrode 72 and the third electrode 82. The magnetic wall moving layers 11 and 12 are paths for the read current, and the wider they are, the smaller the read resistance.

[0079] When viewed from a plan view in the z direction, the element length L102 of the second magnetic domain wall moving element 102 in the x direction may be longer than, for example, the element length L101 of the first magnetic domain wall moving element 101 in the x direction. The element length is the length of the magnetoresistive effect portion where the magnetic domain wall moving layer 10, the non-magnetic layer 20, and the reference layer 30 overlap in the z direction. The read current flows through the inside of the magnetic domain wall moving element 100 in the z direction. The larger the cross-sectional area when the magnetic domain wall moving element 100 is cut by an xy plane perpendicular to the z direction, the smaller the read resistance of the magnetic domain wall moving element 100. If the element length L102 of the second magnetic domain wall moving element 102 is longer than the element length L101 of the first magnetic domain wall moving element 101, the difference in read resistance caused by the difference in widths W11 and W12 can be mitigated.

[0080] When viewed from the z-direction in a plan view, the area of ​​the second magnetization fixed layer 52 of the second magnetic domain wall moving element 102 may be larger than the area of ​​the second magnetization fixed layer 51 of the first magnetic domain wall moving element 101. The larger the area of ​​the second magnetization fixed layer 50 when viewed from the z-direction in a plan view, the smaller the read resistance of the magnetic domain wall moving element 100 becomes. If the area of ​​the second magnetization fixed layer 51 is larger than the area of ​​the second magnetization fixed layer 52, the difference in read resistance caused by the difference in widths W11 and W12 can be mitigated.

[0081] Furthermore, the thickness t22 of the non-magnetic layer 22 of the second magnetic wall moving element 102 is thinner than the thickness t21 of the non-magnetic layer 21 of the first magnetic wall moving element 101. The thicker the non-magnetic layer 20, the greater the read resistance of the magnetic wall moving element 100. The resistance value of the non-magnetic layer 22 is smaller than the resistance value of the non-magnetic layer 21. If the thickness t22 of the non-magnetic layer 22 is thinner than the thickness t21 of the non-magnetic layer 21, the difference in read resistance caused by the difference in widths W11 and W12 can be mitigated.

[0082] Here, we have shown an example of mitigating the difference in read resistance caused by the difference in widths W11 and W12 by combining element length, the area of ​​the second magnetization fixed layer, and the thickness of the non-magnetic layer, but it is not necessary to combine all of the components.

[0083] For example, the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 may have the same element length and the same area of ​​the second magnetization fixed layer, but different thicknesses of the non-magnetic layer. For example, the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 may have the same element length and the same thickness of the non-magnetic layer, but different areas of the second magnetization fixed layer. For example, the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 may have the same area of ​​the second magnetization fixed layer and the same thickness of the non-magnetic layer, but different element lengths.

[0084] For example, the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 may have the same element length, but differ in the area of ​​the second magnetization fixed layer and the thickness of the non-magnetic layer. For example, the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 may have the same area of ​​the second magnetization fixed layer, but differ in element length and the thickness of the non-magnetic layer. For example, the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 may have the same thickness of the non-magnetic layer, but differ in element length and the area of ​​the second magnetization fixed layer.

[0085] Figure 8 is a plan view of the third magnetic domain wall moving element 103 as seen from the z direction. Figure 9 is a cross-section of the third magnetic domain wall moving element 103 obtained by cutting it through the xz plane passing through the center of the width in the y direction of the magnetic domain wall moving layer 13. The arrows shown in the figures are examples of the orientation direction of magnetization of the ferromagnetic material.

[0086] The third magnetic domain wall moving element 103 comprises, for example, a magnetic domain wall moving layer 13, a non-magnetic layer 23, a reference layer 33, a first magnetization fixed layer 43, a second magnetization fixed layer 53, a first electrode 63, a second electrode 73, and a third electrode 83. The third magnetic domain wall moving element 103 has the same configuration as the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102, except for the shape of each layer.

[0087] The magnetic domain wall moving layer 13 corresponds to the magnetic domain wall moving layer 11. The non-magnetic layer 23 corresponds to the non-magnetic layer 21. The reference layer 33 corresponds to the reference layer 31. The first magnetization fixed layer 43 corresponds to the first magnetization fixed layer 41. The second magnetization fixed layer 53 corresponds to the second magnetization fixed layer 51. The first electrode 63 corresponds to the first electrode 61. The second electrode 73 corresponds to the second electrode 71. The third electrode 83 corresponds to the third electrode 81. The third magnetic domain wall moving element 103 replaces these components with the corresponding components of the first magnetic domain wall moving element 101.

[0088] Between the first electrode 63 and the magnetic domain wall moving layer 13, there is a first portion P1C in which the first electrode 63 and the magnetic domain wall moving layer 13 face each other without the first magnetization fixed layer 43 in between. The first portion P1C is the part in which the first electrode 63 and the magnetic domain wall moving layer 13 overlap without the first magnetization fixed layer 43 when viewed from the z direction. In the first portion P1C, charge accumulates between the first electrode 63 and the magnetic domain wall moving layer 13, and parasitic capacitance is generated.

[0089] There may be a second portion P2C between the second electrode 73 and the magnetic domain wall moving layer 13 in which the second electrode 73 and the magnetic domain wall moving layer 13 face each other without the second magnetization fixed layer 53 in between. The second portion P2C is the portion in which the second electrode 73 and the magnetic domain wall moving layer 13 overlap without the second magnetization fixed layer 53 when viewed from the z direction.

[0090] When viewed from the z-direction in a plan view, the area of ​​the first portion P1C of the third magnetic domain wall moving element 103 is smaller than the area of ​​the first portion P1A of the first magnetic domain wall moving element 101 and the first portion P1B of the second magnetic domain wall moving element 102. The third length L3 of the writing wiring WL1 between the third magnetic domain wall moving element 103 and the writing circuit 7 is longer than the first length L1 and the second length L2. Because the area of ​​the first portion P1C is smaller than the areas of the first portions P1A and P1B, the difference in parasitic capacitance caused by the difference in the length of the writing wiring WL can be compensated for. As a result, the variation in the writing characteristics of the first magnetic domain wall moving element 101, the second magnetic domain wall moving element 102, and the third magnetic domain wall moving element 103 is reduced.

[0091] For example, when viewed from a planar perspective from the z direction, the width W13 in the y direction of the magnetic wall moving layer 13 of the third magnetic wall moving element 103 is narrower than the width W11 of the magnetic wall moving layer 11 of the first magnetic wall moving element 101 and the width W12 of the magnetic wall moving layer 12 of the second magnetic wall moving element 102.

[0092] Furthermore, when viewed from a planar perspective in the z direction, the element length L103 of the third magnetic domain wall moving element 103 in the x direction is longer than, for example, the element length L101 of the first magnetic domain wall moving element 101 and the element length L102 of the second magnetic domain wall moving element 102 in the x direction. By changing these element lengths L101, L102, and L103, the difference in read resistance of each magnetic domain wall moving element 100 is reduced.

[0093] When viewed from the z-direction in a plan view, the second magnetization fixed layer 53 of the third magnetic domain wall moving element 103 has a larger area than the second magnetization fixed layer 51 of the first magnetic domain wall moving element 101 and the second magnetization fixed layer 52 of the second magnetic domain wall moving element 102. By changing the area of ​​these second magnetization fixed layers 50, the difference in read resistance of each magnetic domain wall moving element 100 is reduced.

[0094] Furthermore, the thickness t23 of the non-magnetic layer 23 of the third magnetic wall moving element 103 is thinner than the thickness t21 of the non-magnetic layer 21 of the first magnetic wall moving element 101 and the thickness t22 of the non-magnetic layer 22 of the second magnetic wall moving element 102. By changing the thickness of these non-magnetic layers 20, the difference in read resistance of each magnetic wall moving element 100 is reduced.

[0095] Here, we have shown an example of reducing the difference in read resistance caused by the differences in widths W11, W12, and W13 by combining element length, the area of ​​the second magnetization fixed layer, and the thickness of the non-magnetic layer. However, as mentioned above, it is not necessary to combine all the components.

[0096] Up to this point, we have shown these relationships using three magnetic domain wall moving elements 100 (first magnetic domain wall moving element 101, second magnetic domain wall moving element 102, and third magnetic domain wall moving element 103) belonging to different columns as an example, but these relationships are not limited to the relationships between three magnetic domain wall moving elements 100.

[0097] For example, the area of ​​the first portion of the magnetic domain wall moving element 100 with the shortest length of the write wiring WL between it and the write circuit 7 may be larger than the area of ​​the first portions of the other magnetic domain wall moving elements 100. Also, the area of ​​the first portion of the magnetic domain wall moving element 100 with the longest length of the write wiring WL between it and the write circuit 7 may be smaller than the area of ​​the first portions of the other magnetic domain wall moving elements 100. By satisfying this relationship, the difference in parasitic capacitance caused by the difference in the length of the write wiring WL can be mitigated by the difference in parasitic capacitance occurring in the first portion.

[0098] For example, the area of ​​the first portion of each of the multiple magnetic domain wall moving elements 100 may be smaller as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements 100 increases. In other words, the area of ​​the first portion of a magnetic domain wall moving element 100 belonging to a row that is closer to the writing circuit 7 may be larger.

[0099] For example, the width of the magnetic domain wall movement layer 10 in each of the multiple magnetic domain wall movement elements 100 may be narrower as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall movement elements 100 increases. In other words, the width of the magnetic domain wall movement layer 10 may be wider for magnetic domain wall movement elements 100 belonging to rows that are closer to the writing circuit 7.

[0100] For example, the length of each of the multiple magnetic domain wall moving elements 100 may be longer as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements 100 increases. In other words, the magnetic domain wall moving elements 100 belonging to rows closer to the writing circuit 7 may have shorter element lengths.

[0101] For example, the area of ​​the second magnetization fixed layer 50 in each of the multiple magnetic domain wall moving elements 100 may be wider as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements 100 increases. In other words, the area of ​​the second magnetization fixed layer 50 may be smaller for magnetic domain wall moving elements 100 belonging to rows that are closer to the writing circuit 7.

[0102] For example, the thickness of the non-magnetic layer 20 in each of the multiple magnetic domain wall moving elements 100 may be thinner as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements 100 increases. In other words, the thickness of the non-magnetic layer 20 may be thicker for magnetic domain wall moving elements 100 belonging to rows that are closer to the writing circuit 7.

[0103] The magnetic domain wall moving element 100 may have layers other than those described above. For example, a magnetic layer may be provided on the side of the reference layer 30 opposite to the non-magnetic layer 20, via a spacer layer. The reference layer 30, spacer layer, and magnetic layer form a synthetic antiferromagnetic structure (SAF structure). Alternatively, a base layer may be provided on the side of the magnetic layer opposite to the spacer layer.

[0104] The direction of magnetization in each layer of the magnetic domain wall moving element 100 can be confirmed, for example, by measuring the magnetization curve. The magnetization curve can be measured, for example, using MOKE (Magneto-Optical Kerr Effect). MOKE measurement is a measurement method that uses the magneto-optical effect (magnetic Kerr effect), which occurs when linearly polarized light is incident on the object to be measured and the direction of polarization is rotated.

[0105] The magnetic domain wall moving element 100 is formed by a lamination process for each layer and a processing process for processing a portion of each layer into a predetermined shape. Lamination of each layer can be performed using sputtering, chemical vapor deposition (CVD), electron beam deposition (EB deposition), atomic laser deposition, etc. Processing of the laminate can be performed using photolithography and etching (e.g., Ar etching).

[0106] Next, we will explain the operation of writing signals to the magnetic array MA and the operation of reading signals from the magnetic array MA.

[0107] First, let's explain the signal writing operation to the magnetic array MA. The writing operation is performed, for example, by the processor executing an operation program stored in the writing circuit 7.

[0108] First, the control device 3 selects the domain wall moving element 100 to which a pulse is applied according to the operating program. When the magnetic array MA is used as a magnetic memory, the domain wall moving element 100 to which a pulse is applied is the element that stores data. When the magnetic array MA is used as a neural network, the domain wall moving element 100 to which a pulse is applied is the element whose weight changes according to learning.

[0109] The programming circuit 7 controls which of the multiple magnetic domain wall moving elements 100 to which a pulse is applied. The programming circuit 7 turns on the first switch SW1 and the second switch SW2 connected to the magnetic domain wall moving element 100 to which a pulse is applied, and turns off the third switch SW3. It also turns off at least one of the first switch SW1 and the second switch SW2 connected to the magnetic domain wall moving element 100 to which a pulse is not applied.

[0110] The control device 3 then outputs a write pulse toward the magnetic domain wall moving element 100 according to the operating program. The write pulse is applied between the first electrode 60 and the second electrode 70 along the magnetic domain wall moving layer 10 of the magnetic domain wall moving element 100. The write pulse may be a square wave, a spike wave, or any other waveform. By changing the number and magnitude of the write pulses, the position of the magnetic domain wall DW changes, and a signal is written to a specific magnetic domain wall moving element 100.

[0111] When the write pulse reaches the magnetic domain wall moving layer 10, the edges of the waveform become blurred, and the waveform becomes slightly rounded. The degree of change in the waveform of the write pulse when it reaches each magnetic domain wall moving element 100 is made equivalent by adjusting the length of the write wiring WL and the area of ​​the first portion. When a signal of the same intensity is output from the write circuit 7, the waveforms of the write pulses input to each magnetic domain wall moving element 100 are similar. Therefore, even when a write pulse is applied to any of the multiple magnetic domain wall moving elements 100, the variation in the write characteristics of each magnetic domain wall moving element 100 is small.

[0112] Next, the operation of reading signals from the magnetic array MA will be described. The reading operation is performed, for example, by the processor executing an operation program stored in the control device 3.

[0113] First, the control device 3 selects the domain wall moving element 100 to which a read pulse is applied, according to the operation program. When the magnetic array MA is used as a magnetic memory, the domain wall moving element 100 to which the read pulse is applied is the element that reads the data. When the magnetic array MA is used as a neural network, the application of a read pulse to a predetermined domain wall moving element 100 corresponds to the product operation between the input and the weight. In other words, when the magnetic array MA is used as a neural network, the read operation is the identification operation of the neural network.

[0114] The control device 3 controls which of the multiple magnetic wall moving elements 100 to which a pulse is applied. The control device 3 turns on the third switch SW3 and the second switch SW2 connected to the magnetic wall moving element 100 to which a pulse is applied, and turns off the first switch SW1. It also turns off at least one of the third switch SW3 and the second switch SW2 connected to the magnetic wall moving element 100 to which a pulse is not applied.

[0115] Next, the control device 3 applies a readout pulse to a predetermined magnetic domain wall moving element 100 according to the operation program. The readout pulse is applied, for example, between the third electrode 80 and the second electrode 70. The voltage of the readout pulse is such that a current density less than the critical current density required to move the magnetic domain wall DW of the magnetic domain wall moving layer 10 is obtained. In other words, the readout pulse does not move the magnetic domain wall DW.

[0116] The resistance detection device 4 detects the resistance value of the magnetic domain wall moving element 100 to which a read pulse has been applied. The output unit 5 outputs the calculation result to the outside, for example. In this procedure, a signal can be read from a specific magnetic domain wall moving element 100. Furthermore, by reducing the difference in read resistance of each magnetic domain wall moving element 100, the difference in read characteristics of each magnetic domain wall moving element 100 can be reduced.

[0117] As described above, the magnetic array according to this embodiment has small variations in the writing characteristics of each magnetic wall moving element 100 by adjusting the length of the writing wiring WL and the area of ​​the first portion. Since the writing current is larger than the reading current, variations in writing characteristics have a significant impact on the reliability of the magnetic array MA. Reducing variations in writing characteristics improves the reliability of the magnetic array MA.

[0118] Furthermore, the magnetic array according to this embodiment can also reduce the difference in read characteristics of each magnetic wall moving element 100 by reducing the difference in read resistance of each magnetic wall moving element 100. By reducing the variation in read characteristics in addition to write characteristics, the reliability of the magnetic array MA can be further improved.

[0119] In the first embodiment, the area of ​​the first portion is changed by changing the area of ​​the magnetic domain wall moving layer 10, the first magnetization fixed layer 40, and the first electrode 60 in each magnetic domain wall moving element 100. The means for changing the area of ​​the first portion in each magnetic domain wall moving element 100 are not limited to this example. For example, the area of ​​the first portion may be changed by changing the area of ​​one or more of the magnetic domain wall moving layer 10, the first magnetization fixed layer 40, and the first electrode 60.

[0120] The magnetic array MA according to the first embodiment can be used, for example, in magnetic memory and neuromorphic devices.

[0121] In the case of magnetic memory, each of the magnetic domain wall moving elements 100 functions as an element for storing data. At the position of the magnetic domain wall DW of the magnetic domain wall moving element 100, the resistance of the magnetic domain wall moving element 100 changes, and this resistance value is stored as data.

[0122] In the case of a neuromorphic device, each of the magnetic domain wall moving elements 100 functions as an multiplication element. The resistance of the magnetic domain wall moving element 100 changes at the position of the magnetic domain wall DW, and this resistance value represents the weight.

[0123] Neuromorphic devices are devices that artificially mimic the relationship between neurons and synapses in the human brain. Neuromorphic devices can perform neural network calculations.

[0124] Figure 10 is a schematic diagram of a neural network (NN). A neural network (NN) has an input layer L ｉｎ and the middle layer L ｍ and output layer L ｏｕｔ It has the intermediate layer L in Figure 10. ｍ The example shows three layers, but the intermediate layer L ｍ The number is irrelevant. Input layer L ｉｎ and the middle layer L ｍ and output layer L ｏｕｔ Each of these has multiple chips C, and each chip C corresponds to a neuron in the brain. Input layer L ｉｎ and the middle layer L ｍ and output layer L ｏｕｔ Each of these is connected by a transmission mechanism. The transmission mechanism corresponds to a synapse in the brain. The number of chips C and transmission mechanisms shown in Figure 10 is just one example.

[0125] A neural network (NN) improves its accuracy in answering problems by having its transmission mechanisms (synapses) learn. Learning is the process of finding potentially useful knowledge from information. A neural network (NN) learns by operating while changing the weights of its transmission mechanisms. The transmission mechanisms perform a multiplication operation by multiplying the input signal by its weight, and a sum operation by adding the results of the multiplication operation. In other words, the transmission mechanisms perform a sum-of-products operation. The magnetic domain wall moving element 100 in this embodiment is responsible for this multiplication operation.

[0126] Figure 11 is a block diagram showing a system 300 including a neuromorphic device 200 according to the first embodiment. The system 300 has a plurality of sensors 201, a neuromorphic device 200, and a communication unit 202.

[0127] Each of the multiple sensors 201 can be any sensor as needed for its application. For example, temperature sensors, humidity sensors, speed sensors, pressure sensors, acceleration sensors, etc., can be used as multiple sensors 201. The signals from these sensors are used, for example, in the input layer L of a neural network NN. ｉｎ It corresponds to the signal input to it.

[0128] The neuromorphic device 200 has, for example, multiple integration regions 1. Each integration region 1 performs a sum-of-accumulate operation. Each integration region 1 performs operations from each layer of the neural network NN to the next layer. Each integration region 1 may have a separate control device 3, or they may share a control device 3.

[0129] The conductance (or resistance) of the magnetic domain wall moving element 100 changes depending on the position of the magnetic domain wall DW. The conductance (or resistance) of the magnetic domain wall moving element 100 corresponds to the weight of the transmission means in a neural network NN. The conductance (or resistance) of the magnetic domain wall moving element 100 changes linearly with respect to the input. For example, if the information from a particular sensor 201 (e.g., temperature) is important among multiple sensors 201, the conductance (weight) of the magnetic domain wall moving element 100, which is responsible for propagating the signal from that sensor 201, is increased when the neuromorphic device 200 learns.

[0130] Each magnetic domain wall moving element 100 functions as an multiplication element because it outputs a signal that is the product of the input voltage and the conductance (or resistance) of the magnetic domain wall moving element 100 itself. The magnetic array MA functions as a multiply-accumulate unit because it combines the outputs from multiple magnetic domain wall moving elements 100. The multiply-accumulate operation by the multiple magnetic domain wall moving elements 100 is controlled by the control device 3.

[0131] The neuromorphic device 200 performs learning and inference. The conductance of the magnetic domain wall moving element 100 (corresponding to the weight of the transmission means) is adjusted during learning. Inference is performed using the set conductance of the magnetic domain wall moving element 100 (corresponding to the weight of the transmission means).

[0132] The neuromorphic device 200 used in system 300 may be capable of both learning and inference, or it may only perform inference. If it only performs inference, it is pre-trained to match the task, and weights appropriate for that task are installed in the domain wall moving elements 100 of the neuromorphic device 200. For example, the conductance of each domain wall moving element 100 is adjusted to correspond to the weights of the transmission means obtained in pre-training. If the neuromorphic device 200 only performs inference, the computational load on the edge device can be reduced.

[0133] The communication unit 202 outputs the calculation results from the neuromorphic device 200 to the outside. For example, the inference result for a predetermined task obtained by the neuromorphic device 200 is input to the communication unit 202, and the communication unit 202 outputs that information to the outside. The communication unit 202 may be wired or wireless.

[0134] Because the magnetic wall moving element 100 according to this embodiment exhibits small variations in writing characteristics, the reliability of the system 300 is high.

[0135] [Second Embodiment] The magnetic array according to the second embodiment differs from the magnetic array MA according to the first embodiment in the relationship between the magnetic domain wall moving elements in each row. In the second embodiment, the same configuration as in the first embodiment will not be described, and the main differences will be explained.

[0136] Figure 12 is a plan view of the first magnetic domain wall moving element 111 according to the second embodiment, as seen from the z direction. Figure 13 is a cross-section of the first magnetic domain wall moving element 111 according to the second embodiment, cut by the xz plane passing through the center of the width of the magnetic domain wall moving layer 11 in the y direction. The arrows shown in the figures are examples of the orientation direction of the magnetization of the ferromagnetic material. The first magnetic domain wall moving element 111 according to the second embodiment is the same as the first magnetic domain wall moving element 101 according to the first embodiment.

[0137] Figure 14 is a plan view of the second magnetic domain wall moving element 112 according to the second embodiment, as seen from the z direction. Figure 15 is a cross-section of the second magnetic domain wall moving element 112 according to the second embodiment, cut by the xz plane passing through the center of the width of the magnetic domain wall moving layer 11 in the y direction. The arrows shown in the figures are examples of the orientation direction of the magnetization of the ferromagnetic material.

[0138] In the magnetic array according to the second embodiment, when viewed from the z direction in a plan view, the area of ​​the first portion P1B of the second magnetic domain wall moving element 112 is smaller than the area of ​​the first portion P1A of the first magnetic domain wall moving element 111.

[0139] When viewed from the z-direction in a plan view, the width W12 in the y-direction of the magnetic wall moving layer 12 of the second magnetic wall moving element 112 is wider than the width W11 in the y-direction of the magnetic wall moving layer 11 of the first magnetic wall moving element 111. This relationship differs from the relationship between the first magnetic wall moving element 101 and the second magnetic wall moving element 102 in the first embodiment.

[0140] By making the width W12 of the magnetic domain wall moving layer 12 wider than the width W11 of the magnetic domain wall moving layer 11, the parasitic resistance in the second magnetic domain wall moving element 112 becomes smaller than the parasitic resistance in the first magnetic domain wall moving element 111.

[0141] The second length L2 of the writing wiring WL between the writing circuit 7 and the second magnetic domain wall moving element 112 is longer than the first length L1 of the writing wiring WL between the writing circuit 7 and the first magnetic domain wall moving element 111. The parasitic resistance of the writing wiring WL with the second length L2 is greater than the parasitic resistance of the writing wiring WL with the first length L1.

[0142] By making the width W12 of the magnetic domain wall moving layer 12 wider than the width W11 of the magnetic domain wall moving layer 11, the difference in parasitic resistance in the writing wiring WL can be mitigated by the difference in parasitic resistance within the magnetic domain wall moving elements. In the magnetic array according to the second embodiment, the difference in parasitic capacitance and parasitic resistance between each magnetic domain wall moving element is small, resulting in less variation in writing characteristics.

[0143] On the other hand, if the width W11 of the magnetic domain wall moving layer 11 and the width W12 of the magnetic domain wall moving layer 12 are different, a difference in read resistance may occur between the first magnetic domain wall moving element 111 and the second magnetic domain wall moving element 112. The magnetic domain wall moving layers 11 and 12 are paths for the read current, and the wider they are, the lower the read resistance.

[0144] When viewed from a plan view in the z direction, the element length L112 of the second magnetic domain wall moving element 112 in the x direction may be shorter than, for example, the element length L111 of the first magnetic domain wall moving element 111 in the x direction. If the element length L112 of the second magnetic domain wall moving element 112 is longer than the element length L111 of the first magnetic domain wall moving element 111, the difference in read resistance that occurs between the first magnetic domain wall moving element 111 and the second magnetic domain wall moving element 112 due to the difference in widths W11 and W12 can be mitigated.

[0145] When viewed from the z-direction in a plan view, the area of ​​the second magnetization fixed layer 52 of the second magnetic domain wall moving element 112 may be smaller than the area of ​​the second magnetization fixed layer 51 of the first magnetic domain wall moving element 111. If the area of ​​the second magnetization fixed layer 51 is smaller than the area of ​​the second magnetization fixed layer 52, the difference in read resistance that occurs between the first magnetic domain wall moving element 111 and the second magnetic domain wall moving element 112 due to the difference in widths W11 and W12 can be mitigated.

[0146] Furthermore, the thickness t22 of the non-magnetic layer 22 of the second magnetic domain wall moving element 112 may be thicker than the thickness t21 of the non-magnetic layer 21 of the first magnetic domain wall moving element 111. If the thickness t22 of the non-magnetic layer 22 is thicker than the thickness t21 of the non-magnetic layer 21, the difference in read resistance that occurs between the first magnetic domain wall moving element 111 and the second magnetic domain wall moving element 112 due to the difference in width W11 and W12 can be mitigated.

[0147] Here, we have shown an example of mitigating the difference in read resistance caused by the difference in widths W11 and W12 by combining element length, the area of ​​the second magnetization fixed layer, and the thickness of the non-magnetic layer. However, it is not necessary to combine all of the configurations. You can also mitigate the difference in read resistance by changing any one of the above elements.

[0148] In the second embodiment, only the relationship between the first magnetic domain wall moving element 111 and the second magnetic domain wall moving element 112 was shown, but these relationships are not limited to the relationships between these magnetic domain wall moving elements.

[0149] For example, the width of the magnetic domain wall movement layer 10 in each of the multiple magnetic domain wall movement elements may be wider as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall movement elements increases. In other words, the width of the magnetic domain wall movement layer 10 may be narrower for magnetic domain wall movement elements belonging to rows that are closer to the writing circuit 7.

[0150] For example, the element length of each of the multiple magnetic domain wall moving elements may be shorter as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements increases. In other words, the element length of the magnetic domain wall moving elements belonging to rows closer to the writing circuit 7 may be longer.

[0151] Furthermore, for example, the area of ​​the second magnetization fixed layer 50 in each of the multiple magnetic domain wall moving elements may be smaller as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements increases. In other words, the area of ​​the second magnetization fixed layer 50 may be larger for magnetic domain wall moving elements belonging to rows that are closer to the writing circuit 7.

[0152] For example, the thickness of the non-magnetic layer 20 in each of the multiple magnetic domain wall moving elements may be thicker as the length of the writing wiring WL between the writing circuit 7 and each of the multiple magnetic domain wall moving elements increases. In other words, the thickness of the non-magnetic layer 20 may be thinner for magnetic domain wall moving elements belonging to rows that are closer to the writing circuit 7.

[0153] In the magnetic array according to the second embodiment, the variation in writing characteristics at each magnetic domain wall moving element is reduced by adjusting the length of the writing wiring WL and the area of ​​the first portion. Furthermore, in the magnetic array according to the second embodiment, the variation in parasitic resistance is also reduced by changing the width of the magnetic domain wall moving layer of the magnetic domain wall moving element, thereby further reducing the variation in writing characteristics at each magnetic domain wall moving element.

[0154] Furthermore, in the magnetic array according to the second embodiment, the difference in the read resistance of each magnetic wall moving element can be reduced, thereby reducing the difference in the read characteristics of each magnetic wall moving element. By reducing the variation in read characteristics in addition to write characteristics, the reliability of the magnetic array MA can be further improved.

[0155] [Third Embodiment] Figure 16 is a circuit diagram of the integration region 1A of the magnetic array according to the third embodiment. Figure 16 also shows a writing circuit 7 connected to the integration region 1A. The integration region 1A differs from the integration region 1 according to the first embodiment in that it further has a correction resistor R. In the third embodiment, the same configuration as in the first embodiment will not be described, and the differences will be described mainly.

[0156] In the magnetic array according to the third embodiment, when viewed from the z direction, the area of ​​the first portion of the second magnetic domain wall moving element 102 is smaller than the area of ​​the first portion of the first magnetic domain wall moving element 101.

[0157] If the element shape of each magnetic wall moving element 100 is changed in order to change the area of ​​the first part, the read resistance of each magnetic wall moving element 100 may change. The correction resistor R compensates for the difference in read resistance of each magnetic wall moving element 100. The correction resistor R is located between the read wiring RL and the magnetic wall moving element 100.

[0158] The resistance value of the correction resistor R1 connected to the first magnetic domain wall moving element 101 is different from the resistance value of the correction resistor R2 connected to the second magnetic domain wall moving element 102. Also, the resistance value of the correction resistor R2 connected to the second magnetic domain wall moving element 102 is different from the resistance value of the correction resistor R3 connected to the third magnetic domain wall moving element 103.

[0159] For example, as in the magnetic array according to the first embodiment, if the width of the magnetic wall moving layer is narrower for magnetic wall moving elements 100 that are farther from the writing circuit 7, the read resistance will be higher for magnetic wall moving elements 100 that are farther from the writing circuit 7. In this case, the resistance value of the correction resistor R connected to the magnetic wall moving elements 100 that are farther from the writing circuit 7 should be reduced. The correction resistor R reduces the difference in read resistance.

[0160] Furthermore, for example, as in the magnetic array according to the second embodiment, if the width of the domain wall movement layer is wider for domain wall movement elements that are farther from the writing circuit 7, the read resistance will be lower for domain wall movement elements 100 that are farther from the writing circuit 7. In this case, the resistance value of the correction resistor R connected to the domain wall movement elements 100 that are farther from the writing circuit 7 is increased. The correction resistor R reduces the difference in read resistance.

[0161] Here, we have shown an example in which the difference in read resistance is mitigated by the correction resistor R alone. However, as described in the first and second embodiments, the element length, the area of ​​the second magnetization fixed layer, and the thickness of the non-magnetic layer may be changed in addition to the correction resistor R.

[0162] In the magnetic array according to the third embodiment, the variation in writing characteristics at each magnetic domain wall moving element is small by adjusting the length of the writing wiring WL and the area of ​​the first portion. Furthermore, in the magnetic array according to the third embodiment, the difference in reading characteristics at each magnetic domain wall moving element is also small by reducing the difference in reading resistance at each magnetic domain wall moving element with a correction resistor R.

[0163] [Fourth Embodiment] Figure 17 is a cross-sectional view of the vicinity of the first magnetic domain wall moving element 101 in the integrated region 1B according to the fourth embodiment. Figure 18 is a cross-sectional view of the vicinity of the second magnetic domain wall moving element 102 in the integrated region 1B according to the fourth embodiment.

[0164] In the magnetic array according to the fourth embodiment, when viewed from the z direction, the area of ​​the first portion of the second magnetic domain wall moving element 102 is smaller than the area of ​​the first portion of the first magnetic domain wall moving element 101.

[0165] Both the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 are connected to the first switch SW1 via via wiring V. The via wiring V connecting the first magnetic domain wall moving element 101 or the second magnetic domain wall moving element 102 to the first switch SW1 is referred to as the first via wiring V1. The first via wiring V1 is connected, for example, to the first electrode 61 or the first electrode 62 via in-plane wiring IP.

[0166] The shortest distance D1 between the magnetic domain wall moving layer 11 and the first via wiring V1 in the first magnetic domain wall moving element 101 is shorter than the shortest distance D2 between the magnetic domain wall moving layer 12 and the first via wiring V1 in the second magnetic domain wall moving element 102. Parasitic capacitance also occurs between the magnetic domain wall moving layer 11 or the magnetic domain wall moving layer 12 and the first via wiring V1. The parasitic capacitance between the magnetic domain wall moving layer 11 and the first via wiring V1 is greater than the parasitic capacitance between the magnetic domain wall moving layer 12 and the first via wiring V1.

[0167] The parasitic capacitance between the first via wiring V1 and the magnetic domain wall moving layer mitigates the difference between the parasitic capacitance of the first length L1 writing wiring WL and the parasitic capacitance of the second length L2 writing wiring WL. As a result, the variation in the writing characteristics of the first magnetic domain wall moving element 101 and the second magnetic domain wall moving element 102 is reduced.

[0168] In the magnetic array according to the fourth embodiment, the length of the write wiring WL, the area of ​​the first portion, and the distance between the first via wiring V1 and the magnetic wall moving layer are adjusted, resulting in small variations in the write characteristics of each magnetic wall moving element.

[0169] Here, we have shown an example of mitigating the difference in parasitic capacitance caused by the length of the write trace WL by combining the difference in parasitic capacitance caused by the area of ​​the first part and the difference in parasitic capacitance caused by the distance between the first via trace V1 and the magnetic domain wall migration layer. However, the difference in parasitic capacitance caused by the length of the write trace WL may also be mitigated by the difference in parasitic capacitance caused by the distance between the first via trace V1 and the magnetic domain wall migration layer alone.

[0170] [Fifth Embodiment] Figure 19 is a circuit diagram of the integration region 1C of the magnetic array according to the fifth embodiment. Figure 19 also shows a writing circuit 7 connected to the integration region 1C. The integration region 1C differs from the integration region 1 according to the first embodiment in that the writing circuit 7 has a first writing circuit 7A and a second writing circuit 7B. In the fifth embodiment, the same configuration as in the first embodiment will not be described, and the differences will be explained in detail.

[0171] The first programming circuit 7A is connected to the first end of each programming line WL. The second programming circuit 7B is connected to the second end of each programming line WL. The second end is the end of the programming line WL opposite to the first end. The first programming circuit 7A and the second programming circuit 7B are separated, for example, by an integrated region 1C.

[0172] In the magnetic array according to the fifth embodiment, when viewed from the z direction in a plan view, the area of ​​the first portion of the second magnetic domain wall moving element 102 is smaller than the area of ​​the first portion of the first magnetic domain wall moving element 101.

[0173] The waveform of the writing signal becomes rounder as the distance from the writing circuit 7 increases, with the edges of the waveform becoming blurred. By dividing the writing circuit 7 into a first writing circuit 7A and a second writing circuit 7B, and placing them at both ends of the writing wiring WL, the distance between the writing circuit 7 and the magnetic wall moving element 100, which is the furthest from the writing circuit 7, can be shortened. When the distance between the writing circuit 7 and the magnetic wall moving element 100 is short, the writing signal becomes less blurred, and the variation in writing characteristics is reduced.

[0174] In the fifth embodiment, the magnetic array has the length of the writing wiring WL and the area of ​​the first portion adjusted, resulting in less variation in the writing characteristics of each magnetic wall moving element. Furthermore, the magnetic array in the fifth embodiment is designed so that the distance between the writing circuit 7 and the magnetic wall moving element 100 is short, making it less likely for variations in writing characteristics to occur.

[0175] [Sixth Embodiment] Figure 20 is a circuit diagram of the integration region 1D of the magnetic array according to the sixth embodiment. Figure 20 also shows a writing circuit 7 connected to the integration region 1D. In the sixth embodiment, the same configuration as in the first embodiment will not be described, and the differences will be described mainly.

[0176] In the magnetic array according to the sixth embodiment, when viewed from the z direction, the area of ​​the first portion of the second magnetic domain wall moving element 102 is smaller than the area of ​​the first portion of the first magnetic domain wall moving element 101.

[0177] The integrated region 1D differs from the integrated region 1 according to the first embodiment in that the matrix consisting of multiple magnetic domain wall moving elements 100 is divided into two. The multiple magnetic domain wall moving elements 100 are divided into a first group G1 and a second group G2. The first group G1 and the second group G2 each have multiple magnetic domain wall moving elements 100 arranged in a matrix. The first group G1 and the second group G2 are separated by a writing circuit 7.

[0178] The number of columns in the first group G1 and the second group G2 is less than the number of columns in the integrated region 1 according to the first embodiment. By dividing the matrix consisting of multiple magnetic domain wall moving elements 100 into two and placing the writing circuit 7 in the center, the distance between the magnetic domain wall moving element 100 furthest from the writing circuit 7 and the writing circuit 7 can be shortened. When the distance between the writing circuit 7 and the magnetic domain wall moving elements 100 is short, the writing signal is less likely to be blurred, and the variation in writing characteristics is reduced.

[0179] In the magnetic array according to the sixth embodiment, the length of the writing wiring WL and the area of ​​the first portion are adjusted, resulting in less variation in the writing characteristics of each magnetic wall moving element. Furthermore, the magnetic array according to the sixth embodiment is designed so that the distance between the writing circuit 7 and the magnetic wall moving element 100 is short, making it less likely for variations in writing characteristics to occur.

[0180] [Seventh Embodiment] Figure 21 is a cross-section of the first magnetic domain wall moving element 121 cut by the xz plane passing through the center of the width in the y direction of the magnetic domain wall moving layer 11. Figure 22 is a cross-section of the second magnetic domain wall moving element 122 cut by the xz plane passing through the center of the width in the y direction of the magnetic domain wall moving layer 11. In the seventh embodiment, the same configuration as in the first embodiment will not be described, and the differences will be explained mainly.

[0181] The first magnetic domain wall moving element 121 differs from the first magnetic domain wall moving element 101 in the positional relationship between the reference layer 31 and the magnetic domain wall moving layer 11. The reference layer 31 is closer to the substrate Sub than the magnetic domain wall moving layer 11, and the first magnetic domain wall moving element 121 has a top-pin structure. Similarly, the second magnetic domain wall moving element 122 differs from the second magnetic domain wall moving element 102 in the positional relationship between the reference layer 32 and the magnetic domain wall moving layer 12. The reference layer 32 is closer to the substrate Sub than the magnetic domain wall moving layer 12, and the second magnetic domain wall moving element 122 has a top-pin structure.

[0182] In the magnetic array according to the seventh embodiment, when viewed from the z direction, the area of ​​the first portion P1B of the second magnetic domain wall moving element 122 is smaller than the area of ​​the first portion P1A of the first magnetic domain wall moving element 121. The relationship between the area of ​​the second magnetization fixed layer and the thickness of the non-magnetic layer in the first magnetic domain wall moving element 121 and the second magnetic domain wall moving element 122 is the same as in the first embodiment. These relationships may also be the same as in the second embodiment.

[0183] In the top-pin structure, the planar shapes of the non-magnetic layers 21, 22 and the reference layers 31, 32 can be freely designed. The element length L121 of the first magnetic domain wall moving element 121 and the element length L12 of the second magnetic domain wall moving element 122 are equal. For example, the element lengths of each of the multiple magnetic domain wall moving elements belonging to the magnetic array may be equal. Also, the size of the magnetoresistance effect portion when viewed from the z direction may be equal for each of the multiple magnetic domain wall moving elements.

[0184] In the magnetic array according to the seventh embodiment, the length of the writing wiring WL and the area of ​​the first portion are adjusted, resulting in less variation in the writing characteristics of each magnetic wall moving element.

[0185] Although preferred embodiments of this disclosure have been described in detail above, this disclosure is not limited to these embodiments. For example, characteristic configurations of each embodiment may be combined, or parts may be modified without altering the essence of the invention.

[0186] For example, the magnetic domain wall moving elements according to the third to sixth embodiments may be replaced with the magnetic domain wall moving elements according to the second and seventh embodiments. Also, the correction resistor according to the third embodiment may be applied to other embodiments.

[0187] 1, 1A, 1B, 1C, 1D Integrated region 2 Peripheral region 3 Control device 4 Resistance detection device 5 Output section 6 Power supply 7, 7A, 7B Writing circuit 10, 11, 12, 13 Magnetic wall moving layer 20, 21, 22, 23 Non-magnetic layer 30, 31, 32, 33 Reference layer 40, 41, 42, 43 First magnetization fixed layer 50, 51, 52, 53 Second magnetization fixed layer 60, 61, 62, 63 First electrode 70, 71, 72, 73 Second electrode 80, 81, 82, 83 Third electrode 90 Insulating layer 100 Magnetic wall moving element 101, 111, 121 First magnetic wall moving element 102, 112, 122 Second magnetic wall moving element 103 Third magnetic wall moving element 200 Neuromorphic device 201 Sensor 202 Communication unit 300 System CL Common wiring G1 First group G2 Second group MA Magnetic array P1A, P1B, P1C First part P2A, P2B, P2C Second part R, R1, R2, R3 Correction resistors RL Read wiring V, V1 Via wiring WL Write wiring

Claims

It comprises multiple magnetic domain wall moving elements, multiple writing lines, and a writing circuit. The plurality of magnetic domain wall moving elements are arranged in a matrix, Each of the plurality of writing lines connects each of the plurality of magnetic wall moving elements belonging to the same row to the writing circuit. Each of the plurality of magnetic domain wall moving elements comprises a magnetic domain wall moving layer extending in a first direction, a first magnetization fixing layer connected to the magnetic domain wall moving layer, and a first electrode connected to the magnetic domain wall moving layer via the first magnetization fixing layer. Each of the plurality of magnetic domain wall moving elements has a first portion in which the first electrode and the magnetic domain wall moving layer face each other without the first magnetization fixing layer in between. The plurality of domain wall moving elements comprises a first domain wall moving element and a second domain wall moving element, The first length of the writing wiring between the writing circuit and the first magnetic wall moving element is shorter than the second length of the writing wiring between the writing circuit and the second magnetic wall moving element. A magnetic array in which the area of ​​the first portion of the second magnetic domain wall moving element is smaller than the area of ​​the first portion of the first magnetic domain wall moving element. 　 The plurality of magnetic domain wall moving elements further comprises a third magnetic domain wall moving element, The third length of the writing wiring between the writing circuit and the second magnetic wall moving element is longer than the first length and the second length. The magnetic array according to claim 1, wherein the area of ​​the first portion of the third magnetic domain wall moving element is smaller than the area of ​​the first portion of the second magnetic domain wall moving element. 　 The area of ​​the first portion of the magnetic wall moving element with the shortest writing wiring length between it and the writing circuit is larger than the area of ​​the first portion of the other magnetic wall moving elements. The magnetic array according to claim 1, wherein the area of ​​the first portion of the magnetic wall moving element with the longest writing wiring length between it and the writing circuit is smaller than the area of ​​the first portion of the other magnetic wall moving elements. 　 The magnetic array according to claim 1, wherein the area of ​​the first portion in each of the plurality of magnetic domain wall moving elements is narrower as the length of the writing wiring between the writing circuit and each of the plurality of magnetic domain wall moving elements increases. 　 The magnetic array according to claim 1, wherein the width of the second magnetic wall moving layer of the second magnetic wall moving element in a second direction perpendicular to the first direction and the stacking direction is narrower than the width of the magnetic wall moving layer of the first magnetic wall moving element in the second direction. 　 The magnetic array according to claim 1, wherein the width of the magnetic wall moving layer in each of the plurality of magnetic wall moving elements in the first direction and the second direction perpendicular to the stacking direction is narrower as the length of the writing wiring between it and the writing circuit increases. 　 Each of the plurality of magnetic domain wall moving elements further comprises a non-magnetic layer and a reference layer. The magnetic domain wall moving layer and the reference layer are separated by the non-magnetic layer, The magnetic array according to claim 5, wherein the element length in the first direction of the magnetoresistive effect portion of the second magnetic wall moving element, which consists of the magnetic wall moving layer, the non-magnetic layer, and the reference layer, is longer than the element length in the first direction of the magnetoresistive effect portion of the first magnetic wall moving element. 　 Each of the plurality of magnetic domain wall moving elements further comprises a second magnetization fixing layer, The second magnetization fixed layer is connected to the domain wall moving layer at a different position from the first magnetization fixed layer. The magnetic array according to claim 5, wherein the area of ​​the second magnetization fixed layer of the second magnetic domain wall moving element is larger than the area of ​​the second magnetization fixed layer of the first magnetic domain wall moving element. 　 Each of the plurality of magnetic domain wall moving elements further comprises a non-magnetic layer and a reference layer. The magnetic domain wall moving layer and the reference layer are separated by the non-magnetic layer, The magnetic array according to claim 5, wherein the thickness of the non-magnetic layer of the second magnetic wall moving element in the stacking direction is thinner than the thickness of the non-magnetic layer of the first magnetic wall moving element in the stacking direction. 　 The magnetic array according to claim 1, wherein the width of the second magnetic wall moving layer of the second magnetic wall moving element in a second direction perpendicular to the first direction and the stacking direction is wider than the width of the magnetic wall moving layer of the first magnetic wall moving element in the second direction. 　 The magnetic array according to claim 1, wherein the width of the magnetic wall moving layer in each of the plurality of magnetic wall moving elements in the second direction perpendicular to the first direction and the stacking direction is wider as the length of the writing wiring between it and the writing circuit increases. 　 Each of the plurality of magnetic domain wall moving elements further comprises a non-magnetic layer and a reference layer. The magnetic domain wall moving layer and the reference layer are separated by the non-magnetic layer, The magnetic array according to claim 10, wherein the element length in the first direction of the magnetoresistive effect portion of the second magnetic wall moving element, which consists of the magnetic wall moving layer, the non-magnetic layer, and the reference layer, is shorter than the element length in the first direction of the magnetoresistive effect portion of the first magnetic wall moving element. 　 Each of the plurality of magnetic domain wall moving elements further comprises a second magnetization fixing layer, The second magnetization fixed layer is connected to the domain wall moving layer at a different position from the first magnetization fixed layer. The magnetic array according to claim 10, wherein the area of ​​the second magnetization fixed layer of the second magnetic domain wall moving element is smaller than the area of ​​the second magnetization fixed layer of the first magnetic domain wall moving element. 　 Each of the plurality of magnetic domain wall moving elements further comprises a non-magnetic layer and a reference layer. The magnetic domain wall moving layer and the reference layer are separated by the non-magnetic layer, The magnetic array according to claim 10, wherein the thickness of the non-magnetic layer of the second magnetic wall moving element in the stacking direction is greater than the thickness of the non-magnetic layer of the first magnetic wall moving element in the stacking direction. 　 The system further comprises a plurality of correction resistors connected to each of the plurality of writing lines, The magnetic array according to claim 1, wherein the resistance value of the correction resistor connected to the first magnetic wall moving element is different from the resistance value of the correction resistor connected to the second magnetic wall moving element. 　 Each of the plurality of magnetic domain wall moving elements further comprises a non-magnetic layer and a reference layer. The magnetic domain wall moving layer and the reference layer are separated by the non-magnetic layer, Each of the plurality of magnetic domain wall moving elements has a magnetoresistive effect section consisting of the magnetic domain wall moving layer, the non-magnetic layer, and the reference layer. The reference layer of the magnetoresistive effect section is located at a position further away from the substrate than the magnetic domain wall moving layer. The magnetic array according to claim 1, wherein each of the plurality of magnetic wall moving elements has the same size of the magnetoresistive effect portion when viewed from the stacking direction. 　 Each of the plurality of magnetic domain wall moving elements further comprises via wiring electrically connected to the first electrode, The magnetic array according to claim 1, wherein the shortest distance between the magnetic wall moving layer and the via wiring in the first magnetic wall moving element is shorter than the shortest distance between the magnetic wall moving layer and the via wiring in the second magnetic wall moving element. 　 The aforementioned writing circuit includes a first writing circuit and a second writing circuit. The first writing circuit is connected to the first end of the plurality of writing wires, The magnetic array according to claim 1, wherein the second writing circuit is connected to the second end of the plurality of writing wires opposite to the first end. 　 The plurality of magnetic domain wall moving elements are divided into a first group and a second group, The magnetic array according to claim 1, wherein the first group and the second group sandwich the writing circuit. 　 A neuromorphic device having the magnetic array described in claim 1.

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