Magnetic domain wall moving element and magnetic array

Abstract

A magnetic domain wall displacement element and a magnetic array are provided. The magnetic domain wall displacement element includes: a laminate located above a substrate, having a ferromagnetic layer, a nonmagnetic layer, and a magnetic domain wall displacement layer laminated in this order from a side close to the substrate; a first conductive layer; and a first surface layer, the nonmagnetic layer being interposed between the ferromagnetic layer and the magnetic domain wall displacement layer, the first conductive layer being connected to an upper surface of the magnetic domain wall displacement layer, the first surface layer being in contact with at least a portion of the upper surface of the magnetic domain wall displacement layer, the first surface layer having a higher resistivity than the magnetic domain wall displacement layer.

Description

Technical Field

[0001] This invention relates to magnetic domain wall moving elements and magnetic arrays.

[0002] This application claims priority based on Japanese Patent Application No. 2020-207649 filed on December 15, 2020, and U.S. Patent Application No. 17 / 543,314 filed on December 6, 2021, the contents of which are incorporated herein by reference. Background Technology

[0003] Next-generation non-volatile memories, such as flash memory, which have visible limits in miniaturization, are attracting attention. For example, MRAM (Magnetoresistive Random Access Memory), ReRAM (Resistance Random Access Memory), and PCRAM (Phase Change Random Access Memory) are known as next-generation non-volatile memories.

[0004] MRAM uses the resistance change caused by the change in magnetization direction for data recording. In order to achieve large capacity recording memory, miniaturization of the components that make up the memory and multi-value of the recording bits of each component that make up the memory are being studied.

[0005] Patent Document 1 describes a domain wall moving element that can record data in multiple values ​​or digitally by moving the domain walls in the domain wall moving layer (first ferromagnetic layer).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent No. 5445970. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The magnetic reluctance of the domain wall moving element varies depending on the position of the domain wall. If impurities or defects are present in the domain wall moving layer, the domain walls are easily trapped by these impurities or defects. That is, if unexpected impurities or defects exist in the domain wall moving layer, the movement of the domain walls in the domain wall moving element becomes unstable. The domain wall moving element in Patent Document 1 also suffers from the instability caused by impurities or defects in the domain wall moving layer.

[0011] The present invention was made in view of the above-mentioned problems, and its object is to provide a magnetic domain wall moving element and magnetic array that can stabilize the movement of magnetic domain walls.

[0012] Technical means for solving problems

[0013] (1) The domain wall moving element of the first aspect of the present invention includes: a laminate located above a substrate, having a ferromagnetic layer, a non-magnetic layer and a domain wall moving layer sequentially stacked from a side close to the substrate; a first conductive layer; and a first surface layer, wherein the non-magnetic layer is sandwiched between the ferromagnetic layer and the domain wall moving layer, the first conductive layer is connected to the upper surface of the domain wall moving layer, the first surface layer is in contact with at least a portion of the upper surface of the domain wall moving layer, and the resistivity of the first surface layer is higher than the resistivity of the domain wall moving layer.

[0014] (2) The magnetic domain wall moving element described above may also include an insulating layer that contacts the upper surface of the first surface layer.

[0015] (3) In the magnetic domain wall moving element described above, the first surface layer may also contain amorphous or microcrystalline material.

[0016] (4) In the magnetic domain wall moving element of the above-described manner, the first surface layer may also contain at least one element selected from Bi, Ni, Cr, Ti, Zr, and W.

[0017] (5) In the magnetic domain wall moving element described above, the thickness of the first surface layer may be less than 2 nm.

[0018] (6) In the above-described domain wall moving element, the easy magnetization direction of the domain wall moving layer may intersect with the surface extended by the domain wall moving layer.

[0019] (7) In the domain wall moving element of the above-described manner, at least a portion of the first conductive layer may be sandwiched between the first surface layer and the domain wall moving layer.

[0020] (8) The domain wall moving element in the above manner may also have a second surface layer in contact with the upper surface of the first conductive layer, wherein the resistivity of the second surface layer is higher than that of the domain wall moving layer.

[0021] (9) The domain wall moving element described above may also have a third surface layer that contacts the side of the first conductive layer, the resistivity of the third surface layer being higher than that of the domain wall moving layer.

[0022] (10) The magnetic array of the second aspect of the present invention may also have a substrate and a plurality of magnetic domain wall moving elements of the above-described aspects, wherein the plurality of magnetic domain wall moving elements are integrated on the substrate.

[0023] Invention Effects

[0024] The domain wall moving element and magnetic array described above can stabilize the movement of the domain walls in the domain wall moving element. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the magnetic recording array according to the first embodiment.

[0026] Figure 2 This is a cross-sectional view of the main part of the magnetic recording array in the first embodiment.

[0027] Figure 3 This is a cross-sectional view of the domain wall moving element of the first embodiment.

[0028] Figure 4 The results were obtained by electron diffraction of the microcrystals using a transmission electron microscope (TEM).

[0029] Figure 5 The results were obtained by electron diffraction of the amorphous material using a transmission electron microscope (TEM).

[0030] Figure 6 This is a cross-sectional view of the magnetic domain wall moving element of the comparative example.

[0031] Figure 7 This is a cross-sectional view of the magnetic domain wall moving element in Modified Example 1.

[0032] Figure 8 This is a cross-sectional view of the magnetic domain wall moving element in Modified Example 2.

[0033] Figure 9 This is a cross-sectional view of the magnetic domain wall moving element in Modified Example 3.

[0034] Figure 10 This is a cross-sectional view of the domain wall moving element in variation example 4.

[0035] Figure 11 This is a cross-sectional view of the magnetic domain wall moving element in variation example 5.

[0036] Explanation of reference numerals in the attached figures

[0037] 1: Laminated body, 10: Ferromagnetic layer, 20: Nonmagnetic layer, 30: Domain wall moving layer, 30a: Upper surface, 31, 32: Magnetization fixed region, 33: Domain wall moving region, 33A: First magnetic domain, 33B: Second magnetic domain, 50: First surface layer, 60: First conductive layer, 70: Second conductive layer, DW: Domain wall, In: Insulating layer. Detailed Implementation

[0038] Hereinafter, this embodiment will be described in detail with appropriate reference to the accompanying drawings. In the drawings used in the following description, for ease of understanding of the features of this embodiment, some characteristic parts are sometimes shown enlarged for convenience, and the size ratios of each component may differ from the actual dimensions. Furthermore, the materials, dimensions, etc., illustrated in the following description are examples, and the present invention is not limited thereto; appropriate modifications can be made without changing its essence. Additionally, the composition formulas described in the specification are stoichiometric compositions, but deviations from the stoichiometric composition are permitted within a range that maintains the structure.

[0039] First, the directions are defined. The +x direction, -x direction, +y direction, and -y direction are related to the substrate Sub (see below) described later. Figure 2 The x-direction is a direction approximately parallel to the x-direction. The +x-direction is the direction in which the domain wall moving layer 30 (described later) extends, and it extends from the first conductive layer 60 (described later) toward the second conductive layer 70. The -x-direction is the opposite direction to the +x-direction. Without distinguishing between the +x and -x directions, it is simply referred to as the "x-direction". The +y-direction is a direction orthogonal to the x-direction. The -y-direction is the opposite direction to the +y-direction. Without distinguishing between the +y and -y directions, it is simply referred to as the "y-direction". The +z-direction is the direction from the substrate Sub (described later) toward the domain wall moving element 100. The -z-direction is the opposite direction to the +z-direction. Without distinguishing between the +z and -z directions, it is simply referred to as the "z-direction". Furthermore, in this specification, "extending in the x-direction" means, for example, that the dimension in the x-direction is greater than the smallest dimension among the dimensions in the x, y, and z directions. The same applies when extending in other directions.

[0040] Next, the terms used in this embodiment will be defined. In this specification, "connection" refers to a state in which the subject can exert an electrical influence on the object (the object being connected), and is not limited to a state in which the subject and object are in direct contact. Furthermore, in this specification, "contact" refers to a state in which the subject and object are in direct contact. Additionally, "located above" refers to a state in which the subject is located above the object, including either a state in which the subject is above the object and in contact with the object, or a state in which the subject is above the object and the subject and object are separated.

[0041] [First Implementation]

[0042] Figure 1 This is a structural diagram of the magnetic array according to the first embodiment. The magnetic array 200 includes multiple domain wall moving elements 100, multiple first wirings Wp, multiple second wirings Cm, multiple third wirings Rp, multiple first switching elements SW1, multiple second switching elements SW2, and multiple third switching elements SW3. The magnetic array 200 can be used, for example, in magnetic memories, multiply-accumulate arithmetic units, neuromorphic devices, spin memristors, and magneto-optical elements.

[0043] <Wireline 1, Wiring 2, Wiring 3>

[0044] The first wiring line Wp is the write wiring. The first wiring line Wp electrically connects the power supply to one or more domain wall moving elements 100. The power supply is connected to one end of the magnetic array 200 during use.

[0045] The second wiring Cm is a shared wiring. The shared wiring is used for both data writing and reading. Each of the second wirings Cm electrically connects a reference potential to one or more domain wall moving elements 100. The reference potential is, for example, ground. The second wiring Cm can be set individually for multiple domain wall moving elements 100, or it can be set for multiple domain wall moving elements 100.

[0046] The third wiring Rp is the readout wiring. The third wiring Rp electrically connects the power supply to one or more magnetic domain wall moving elements 100. The power supply is connected to one end of the magnetic array 200 during use.

[0047] <First switching element, second switching element, third switching element>

[0048] Figure 1 In this configuration, multiple domain wall moving elements 100 are respectively connected to a first switching element SW1, a second switching element SW2, and a third switching element SW3. The first switching element SW1 is connected between the domain wall moving element 100 and a first wiring Wp. The second switching element SW2 is connected between the domain wall moving element 100 and a second wiring Cm. The third switching element SW3 is connected between the domain wall moving element 100 and a third wiring Rp.

[0049] When the first switching element SW1 and the second switching element SW2 are turned on, a write current flows between the first wiring Wp and the second wiring Cm connected to the specified domain wall moving element 100. When the second switching element SW2 and the third switching element SW3 are turned on, a read current flows between the second wiring Cm and the third wiring Rp connected to the specified domain wall moving element 100.

[0050] Switching elements SW1, SW2, and SW3 are components that control the flow of current. These switching elements are, for example, components that utilize phase transitions in the crystal layer, such as transistors and Ovonic Threshold Switches (OTS); components that utilize changes in band structure, such as Metal-Insulator Transfer (MIT) Switches; components that utilize breakdown voltage, such as Zener diodes and avalanche diodes; and components whose conductivity changes with atomic positions.

[0051] Any one of the first switching element SW1, the second switching element SW2, and the third switching element SW3 can be shared by the domain wall moving element 100 connected to the same wiring. For example, if the first switching element SW1 is shared, a first switching element SW1 is provided upstream (at one end) of the first wiring Wp. For example, if the second switching element SW2 is shared, a second switching element SW2 is provided upstream (at one end) of the second wiring Cm. For example, if the third switching element SW3 is shared, a third switching element SW3 is provided upstream (at one end) of the third wiring Rp.

[0052] Figure 2 This is a cross-sectional view of the main part of the magnetic array 200 in the first embodiment. Figure 2 It is truncated by the xz plane at the center of the width of the moving layer 30 in the y direction through the domain wall. Figure 1 A cross section of a magnetic domain wall moving element 100.

[0053] Figure 2 The first switching element SW1 and the second switching element SW2 shown are transistors Tr. Transistor Tr has a gate electrode G, a gate insulating film GI, and a source region S and a drain region D formed in a substrate Sub. The substrate Sub is, for example, a semiconductor substrate. The third switching element SW3 is electrically connected to the third wiring Rp, for example located at... Figure 2 The position offset in the y-direction.

[0054] Each transistor Tr is electrically connected to the domain wall moving element 100 via wirings w1 and w2. Wirings w1 and w2 contain a conductive material. Wiring w1 is a through-hole wiring extending in the z-direction. Wiring w2 is an in-plane wiring extending in either direction within the xy-plane. Wirings w1 and w2 are formed in openings in the insulating layer In.

[0055] The insulating layer In is an insulating layer that insulates between wirings or components in a multilayer wiring system. The domain wall moving element 100 and the transistor Tr are electrically separated by the insulating layer In, except for wirings w1 and w2. The insulating layer In is, for example, silicon oxide (SiO2). x ), silicon nitride (SiN) x Silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), aluminum oxynitride (AlON), aluminum nitride (AlN), zirconium oxide (ZrO2) x ), magnesium oxide (MgO) x )wait.

[0056] exist Figure 2The example shown is of a domain wall moving element 100 located above the substrate Sub with the insulating layer In in between, but the domain wall moving element 100 may also be located on the substrate Sub.

[0057] [Magnetic domain wall moving element]

[0058] Figure 3 This is a cross-sectional view of the domain wall moving element 100 according to the first embodiment. The domain wall moving element 100 has a laminate 1, a first surface layer 50, a first conductive layer 60, and a second conductive layer 70 stacked on top of a substrate Sub. The first surface layer 50 is stacked on at least a portion of the upper surface of the laminate 1. The first conductive layer 60 and the second conductive layer 70 are stacked on at least a portion of the upper surface of the laminate 1. The laminate 1 has a ferromagnetic layer 10, a non-magnetic layer 20, and a domain wall moving layer 30. Figure 3 This is a cross-sectional view of the domain wall moving element 100, taken from the center of the width in the y-direction of the domain wall moving layer 30 using an xz plane. An example of the domain wall moving element 100 is a storage element.

[0059] (Ferromagnetic layer)

[0060] The ferromagnetic layer 10 faces the non-magnetic layer 20. The ferromagnetic layer 10 has a magnetization M oriented in one direction. 10 Magnetization M of ferromagnetic layer 10 10 When a specified external force is applied, the magnetization M of the domain wall moving layer 30 33A M 33B Compared to orientation, which is difficult to change. The specified external force is, for example, the magnetization force applied by an external magnetic field or the magnetization force applied by a spin-polarized current. Sometimes, the ferromagnetic layer 10 is called the magnetization fixing layer or the magnetization reference layer. Magnetization M 10 For example, it is oriented in the +z direction. In this embodiment, the ferromagnetic layer 10 is sometimes referred to as the first ferromagnetic layer.

[0061] The following explanation uses an example of magnetization aligned along the z-axis, but the magnetization of the domain wall moving layer 30 and the ferromagnetic layer 10 can be aligned in any direction within the xy-plane. When magnetization is aligned in the z-direction, the power consumption and heat generation during operation of the domain wall moving element 100 can be suppressed compared to when it is aligned within the xy-plane. Furthermore, when magnetization is aligned in the z-direction, the movement width of the domain wall DW is smaller when a pulse current of the same intensity is applied, compared to when it is aligned within the xy-plane. On the other hand, when magnetization is aligned in any direction within the xy-plane, the magnitude of the magnetoresistance change (MR ratio) of the domain wall moving element 100 is larger compared to when it is aligned in the z-direction.

[0062] The ferromagnetic layer 10 comprises a ferromagnetic material. As the ferromagnetic material constituting the ferromagnetic layer 10, metals selected from Cr, Mn, Co, Fe, and Ni, alloys containing one or more of these metals, and alloys containing these metals and at least one of B, C, and N can be used. The ferromagnetic layer 10 is, for example, Co-Fe, Co-Fe-B, or Ni-Fe.

[0063] The material constituting the ferromagnetic layer 10 can also be a Heussler alloy. Heussler alloys are half-metals with high spin polarization. They are intermetallic compounds with a chemical composition of XYZ or X2YZ, where X is a transition metal or noble metal element from the Co, Fe, Ni, or Cu group of the periodic table; Y is a transition metal from the Mn, V, Cr, or Ti group or an element of X; and Z is a typical element from Groups III to V. Examples of Heussler alloys include CO2FeSi, CO2FeGe, CO2FeGa, CO2MnSi, and CO2Mn. 1-a Fe a Al b Si 1-b CO2FeGe 1-c Ga c wait.

[0064] When the easy magnetization axis of the ferromagnetic layer 10 is set to the z-direction (set as a perpendicular magnetization film), the film thickness of the ferromagnetic layer 10 can be set to less than 1.5 nm or less than 1.0 nm. If the film thickness of the ferromagnetic layer 10 is made thinner, perpendicular magnetic anisotropy is added to the ferromagnetic layer 10 at the interface between the ferromagnetic layer 10 and other layers (non-magnetic layer 20) (interface perpendicular magnetic anisotropy), and the magnetization of the ferromagnetic layer 10 is easily oriented in the z-direction.

[0065] When the easy magnetization axis of the ferromagnetic layer 10 is set to the z-direction (set as a perpendicular magnetization film), the ferromagnetic layer 10 can be a stack of ferromagnetic materials selected from Co, Fe, and Ni and non-magnetic materials selected from Pt, Pd, Ru, and Rh. Alternatively, an intermediate layer selected from Ir and Ru can be inserted at any position in the stack. If ferromagnetic and non-magnetic materials are stacked, perpendicular magnetic anisotropy can be added. By inserting an intermediate layer, the magnetization of the ferromagnetic layer 10 can be easily oriented in the z-direction.

[0066] (Magnetic domain wall moving layer)

[0067] The domain wall moving layer 30, for example, is a rectangle with the x-axis as its major axis and the y-axis as its minor axis when viewed from above in the z-direction. The domain wall moving layer 30 is a magnetic layer that faces the ferromagnetic layer 10 across the non-magnetic layer 20. The domain wall moving layer 30 is a layer capable of magnetically recording information through changes in its internal magnetic state.

[0068] The domain wall moving layer 30 has magnetization fixed regions 31 and 32 and a domain wall moving region 33. The domain wall moving region 33 is sandwiched between two magnetization fixed regions 31 and 32.

[0069] Magnetization-fixed region 31 is the region in the domain wall moving layer 30 that overlaps with the first conductive layer 60 when viewed from the z-direction. Magnetization-fixed region 32 is the region in the domain wall moving layer 30 that overlaps with the second conductive layer 70 when viewed from the z-direction. The magnetization M of magnetization-fixed regions 31 and 32 is... 31 M 32 The magnetization M of the first magnetic domain 33A and the second magnetic domain 33B of the domain wall moving region 33 described later. 33A M 33B Compared to the difficulty in magnetization reversal, even with the application of magnetization M in the domain wall movement region 33... 33A M 33B Even an external force that triggers a reversal threshold will not cause magnetization reversal. Therefore, it can be said that the magnetization M of the magnetization fixed regions 31 and 32 is... 31 M 32 Magnetization M relative to the domain wall moving region 33 33A M 33B fixed.

[0070] Magnetization M in magnetization fixed region 31 31 Magnetization M in magnetization fixed region 32 32 Oriented in different directions. Magnetization M of magnetization fixed region 31 31 Magnetization M in magnetization fixed region 32 32 For example, orientation in opposite directions. Magnetization M of magnetization fixed region 31 31 For example, oriented in the +z direction, the magnetization M of the magnetization fixed region 32 is... 32 For example, orientation in the -z direction.

[0071] The domain wall moving region 33 is composed of a first magnetic domain 33A and a second magnetic domain 33B. The first magnetic domain 33A is adjacent to the magnetization fixed region 31. The magnetization M of the first magnetic domain 33A... 33A Magnetization M of magnetized fixed region 31 31 The influence, for example, on the magnetization M in the magnetization fixed region 31 31 Oriented in the same direction (parallel). The second magnetic domain 33B is adjacent to the magnetization fixed region 32. The magnetization M of the second magnetic domain 33B 33B Magnetization M of magnetized fixed region 32 32 The influence, for example, on the magnetization M in the magnetization fixed region 32 32 Oriented in the same direction. Therefore, the magnetization M of the first magnetic domain 33A 33A Magnetization M of the second magnetic domain 33B 33B Oriented in the opposite direction (anti-parallel).

[0072] The boundary between the first magnetic domain 33A and the second magnetic domain 33B is the domain wall DW. The domain wall DW moves within the domain wall movement region 33. In principle, the domain wall DW will not intrude into the magnetized fixed regions 31 and 32.

[0073] The domain wall moving element 100 can record data either multi-valued or continuously based on the position of the domain wall DW of the domain wall moving layer 30. The data recorded in the domain wall moving layer 30 is read out as a change in the resistance value of the domain wall moving element 100 when a readout current is applied.

[0074] The ratio of the first magnetic domain 33A to the second magnetic domain 33B in the domain wall moving region 33 changes as the domain wall DW moves. When the domain wall DW moves in the +x direction, the area of ​​the first magnetic domain 33A widens when viewed from the z direction, and the resistance of the domain wall moving element 100 decreases. Conversely, when the domain wall DW moves in the -x direction, the area of ​​the second magnetic domain 33B widens when viewed from the z direction, and the resistance of the domain wall moving element 100 increases.

[0075] The domain wall DW moves by a write current flowing through the domain wall movement region 33 in the x direction. For example, when a write current (e.g., a current pulse) in the +x direction is applied to the domain wall movement region 33, electrons flow in the -x direction opposite to the current, so the domain wall DW moves in the -x direction. When the current flows from the first domain 33A to the second domain 33B, the spin-polarized electrons in the second domain 33B magnetize the first domain 33A. 33A Magnetization reversal. Magnetization M through the first magnetic domain 33A. 33A The magnetization reverses, and the domain walls DW move in the -x direction.

[0076] The domain wall moving layer 30 is composed of a magnetic material. Preferably, the domain wall moving layer 30 contains at least one element selected from Co, Ni, Fe, Pt, Pd, Gd, Tb, Mn, Ge, and Ga. Examples of materials used for the domain wall moving layer 30 include multilayer films of Co and Ni, multilayer films of Co and Pt, multilayer films of Co and Pd, MnGa-type materials, GdCo-type materials, and TbCo-type materials. Ferromagnetic materials such as MnGa-type materials, GdCo-type materials, and TbCo-type materials have low saturation magnetization, resulting in a lower threshold current required for domain wall movement (DW). Furthermore, multilayer films of Co and Ni, multilayer films of Co and Pt, and multilayer films of Co and Pd have high coercivity, leading to slower domain wall movement (DW).

[0077] Preferably, the easy magnetization direction of the domain wall moving layer 30 intersects with the surface extended by the domain wall moving layer 30. That is, it is preferable to set the easy magnetization axis of the domain wall moving layer 30 to the z-direction (set as a perpendicular magnetization film). When the domain wall moving layer 30 is a perpendicular magnetization film, the domain wall DW can be driven with a low current.

[0078] (Non-magnetic layer)

[0079] The non-magnetic layer 20 is located between the ferromagnetic layer 10 and the domain wall moving layer 30. The non-magnetic layer 20 is stacked on one side of the domain wall moving layer 30.

[0080] The nonmagnetic layer 20 is made of, for example, a nonmagnetic insulator, semiconductor, or metal. Examples of nonmagnetic insulators include Al₂O₃, SiO₂, MgO, MgAl₂O₄, and materials in which a portion of the Al, Si, or Mg is replaced by Zn, Be, Ga, etc. These materials have large band gaps and excellent insulation properties. When the nonmagnetic layer 20 is made of a nonmagnetic insulator, it serves as a tunnel barrier layer. Examples of nonmagnetic metals include Cu, Au, and Ag. Examples of nonmagnetic semiconductors include Si, Ge, CuInSe₂, CuGaSe₂, and Cu(In,Ga)Se₂.

[0081] The thickness of the non-magnetic layer 20 is, for example, The above can also be used for That's all. If the non-magnetic layer 20 is thick, the resistive area product (RA) of the domain wall moving element 100 increases. The resistive area product (RA) of the domain wall moving element 100 is, for example, 1 × 10⁻⁶. 5 Ωμm 2 The above can also be 1×10 6 Ωμm 2 The product of resistance and area (RA) of the domain wall moving element 100 is represented by the product of the element resistance of the domain wall moving element 100 and the element cross-sectional area of ​​the domain wall moving element 100 (the area of ​​the cut surface of the non-magnetic layer 20 cut in the xy plane).

[0082] (First surface layer)

[0083] The first surface layer 50 is in contact with at least a portion of the upper surface 30a of the magnetic domain wall moving layer 30. For example, the first surface layer 50 is in contact with at least a portion of a first portion 30a1 in the upper surface 30a. Alternatively, the first surface layer 50 may be in contact with the entire first portion 30a1. Figure 3 In the middle, it indicates the state of overall contact with the first part. The upper surface 30a is the upper surface of the magnetic domain wall moving layer 30 in the z direction, and the first part 30a1 is the part between the first conductive layer 60 and the second conductive layer 70, which will be described later, in the upper surface 30a.

[0084] The first surface layer 50 is sandwiched, for example, in the z-direction between the magnetic domain wall moving layer 30 and the insulating layer In.

[0085] The first surface layer 50 is adjacent to the first conductive layer 60. The first surface layer 50 is sandwiched between the first conductive layer 60 and the second conductive layer 70 in the x direction, for example.

[0086] The resistivity of the first surface layer 50 is higher than that of the domain wall moving layer 30. The resistivity of the first surface layer 50 may, for example, be more than two or three times the resistivity of the domain wall moving layer 30. The resistance value of the first surface layer 50a may be higher than that of the domain wall moving layer 30. The resistance value of the first surface layer 50a may, for example, be more than two or three times the resistance value of the domain wall moving layer 30.

[0087] The first surface layer 50 is a layer containing metallic elements or alloys, such as metals selected from Bi, Ni, Cr, Ti, Zr, and W, or alloys containing one or more of these metallic elements. The first surface layer 50 may also be a layer composed of metallic elements or alloys. By containing these metallic elements or alloys, current flow in the first surface layer 50 can be further suppressed. Furthermore, the current flowing through the magnetic domain wall moving layer 30 can be kept low, stably driving the magnetic domain wall DW.

[0088] As an alloy containing one or more metallic elements selected from Bi, Ni, Cr, Ti, Zr, and W, mannan, nickel-chromium alloys, etc., can be used, for example. From the viewpoint of ease of manufacture, a metal is preferred over an alloy as the first surface layer 50. Furthermore, since the resistivity of an alloy varies depending on the composition ratio of the various elements, a metal is preferred over an alloy from the viewpoint of ease of resistivity control.

[0089] The first surface layer 50 may contain one or more metallic elements selected from Pd, Pt, Mg, Ta, and Ru. Furthermore, at least a portion of the first surface layer 50 may be oxidized or nitrided. That is, at least a portion of the first surface layer 50 may contain oxides or nitrides.

[0090] The first surface layer 50 may contain microcrystalline or amorphous materials. The first surface layer 50 may contain microcrystalline or amorphous materials internally or on its surface. If the first surface layer 50 contains microcrystalline or amorphous materials, crystallization of the first surface layer 50 can be suppressed. That is, by making the first surface layer 50 contain microcrystalline or amorphous materials, the resistivity of the first surface layer 50 can be increased.

[0091] Microcrystals are crystals with extremely small particle sizes. In this embodiment, microcrystals refer to those that cannot be patterned by XRD (X-ray diffraction) but can be patterned by ED (electron diffraction). Conversely, amorphous materials are those for which neither XRD nor ED can produce diffraction patterns. In this embodiment, both microcrystals and amorphous materials are those for which XRD cannot produce diffraction patterns, but which are X-ray amorphous materials that can produce continuous and broad peaks.

[0092] Figure 4 The results were obtained using electron diffraction of the microcrystals using TEM (transmission electron microscopy). Additionally, Figure 5 The results were obtained by electron diffraction of the amorphous material using TEM. Figure 4 and Figure 5 The white areas shown are the diffraction points where diffracted light was detected.

[0093] Microcrystals possess a crystalline structure. Therefore, as... Figure 4 As shown, microcrystals exhibit diffraction patterns associated with their crystal structure in electron diffraction. On the other hand, amorphous materials do not possess a specific crystal structure. Therefore, amorphous materials, such as… Figure 5 As shown, in electron diffraction, a ring-shaped halo pattern was observed, but no diffraction points associated with the crystal structure were identified. However, in the electron diffraction of a single crystal, diffraction points caused by the crystal structure were confirmed. The diffraction points of a single crystal do not form rings.

[0094] Reducing the area of ​​the cross-section perpendicular to the y-direction of the first surface layer 50 can lower its resistance. For example, by thinning the height (thickness) of the first surface layer 50 in the z-direction, the resistance can be reduced. The thickness of the first surface layer 50 can be, for example, less than 2 nm or less than 1 nm. Furthermore, by setting the thickness of the first surface layer 50 within this range, it is easier for the first surface layer 50 to contain amorphous or microcrystalline structures.

[0095] (First conductive layer and second conductive layer)

[0096] The first conductive layer 60 and the second conductive layer 70 are connected to at least a portion of the upper surface 30a of the domain wall moving layer 30. The second conductive layer 70 is separated from the first conductive layer 60 and connected to the domain wall moving layer 30. The second conductive layer 70 is connected to the upper surface 30a of the domain wall moving layer 30, for example. The second conductive layer 70 may also be connected to a surface other than the upper surface 30a, such as a side surface of the domain wall moving layer 30. The first conductive layer 60 and the second conductive layer 70 are connected to the first end and the second end of the domain wall moving layer 30, for example. The first conductive layer 60, the second conductive layer 70, and the domain wall moving layer 30 may be in direct contact or may be separated by other layers.

[0097] At least a portion of the first conductive layer 60 is sandwiched between the first surface layer 50 and the magnetic domain wall moving layer 30. Figure 3 In this configuration, the clamping portion 61 of the first conductive layer 60 is clamped between the overlapping portion 51 of the first surface layer 50 and the magnetic domain wall moving layer 30. At least a portion of the second conductive layer 70 is, for example, clamped between the first surface layer 50 and the magnetic domain wall moving layer 30. Figure 3 In this configuration, the clamping portion 71 of the second conductive layer 70 is sandwiched between the overlapping portion 52 and the magnetic domain wall moving layer 30. That is, the overlapping portion 51 and the clamping portion 61, as well as the overlapping portion 52 and the clamping portion 71, overlap in the z-direction.

[0098] The length of the overlapping portion 51 in the x-direction is, for example, less than 1 / 10 of the length of the first conductive layer 60 in the x-direction. The length of the overlapping portion 52 in the x-direction is, for example, less than 1 / 10 of the length of the second conductive layer 70 in the x-direction.

[0099] The first conductive layer 60 and the second conductive layer 70 are made of conductive materials. For example, the first conductive layer 60 and the second conductive layer 70 may contain a magnetic material. For example, the first conductive layer 60 and the second conductive layer 70 may contain a metal selected from Cr, Mn, Co, Fe, and Ni; an alloy containing one or more of these metals; or an alloy containing these metals and at least one of the elements selected from B, C, and N. For example, the first conductive layer 60 and the second conductive layer 70 may be Co-Fe, Co-Fe-B, Ni-Fe, etc.

[0100] Alternatively, when the easy magnetization axis of the first conductive layer 60 and the second conductive layer 70 is set to the z-direction (set as a perpendicular magnetization film), the first conductive layer 60 and the second conductive layer 70 can also be a stack of ferromagnetic materials selected from Co, Fe, and Ni and non-magnetic materials selected from Pt, Pd, Ru, and Rh. Furthermore, the first conductive layer 60 can also be a synthetic antiferromagnetic structure (SAF structure). A synthetic antiferromagnetic structure consists of two magnetic layers sandwiching a non-magnetic layer. The magnetization of each of the two magnetic layers is fixed, and the directions of the fixed magnetizations are opposite.

[0101] When the first conductive layer 60 contains a magnetic material, the magnetization M of the first conductive layer 60 60 Oriented in one direction. Magnetization M 60 For example, orientation in the +z direction. The first conductive layer 60 fixes the magnetization of the fixed magnetization region 31. 31 Magnetization M of the first conductive layer 60 60 Magnetization M in magnetization fixed region 31 31 For example, orientation in the same direction.

[0102] When the second conductive layer 70 contains a magnetic material, the magnetization M of the second conductive layer 70 70Magnetization M with the first conductive layer 60 60 Oriented in different directions. Magnetization M 70 For example, it can be oriented in the -z direction. In this case, the second conductive layer 70 fixes the magnetization M of the magnetization fixing region 32. 32 Magnetization M of the second conductive layer 70 70 Magnetization M in magnetization fixed region 32 32 For example, they are oriented in the same direction. In the case that the second conductive layer 70 does not contain a magnetic material, the magnetization M of the magnetization fixing region 32... 32 For example, it can be fixed by an external magnetic field.

[0103] Here, both the first conductive layer 60 and the second conductive layer 70 are examples of magnetic materials. The first conductive layer 60 and the second conductive layer 70 may also not be magnetic materials. When the first conductive layer 60 and the second conductive layer 70 are not magnetic materials, the current density of the domain wall moving layer 30 decreases sharply in the portions in contact with the current density of the first conductive layer 60 and the second conductive layer 70, thereby limiting the movement range of the domain wall DW to within the domain wall moving region 33.

[0104] When the easy magnetization direction of the first conductive layer 60, the second conductive layer 70, and the magnetic domain wall moving layer 30 is the z-direction (perpendicular to the magnetization film), the magnetization M of the magnetization fixed regions 31 and 32 is... 31 and M 32 The direction can be fixed in the z direction.

[0105] The magnetization direction of each layer of the domain wall moving element 100 can be determined, for example, by measuring the magnetization curve. The magnetization curve can be measured, for example, using MOKE (Mangeto Optical Kerr Effect). MOKE-based measurement is a measurement method that uses a magneto-optical effect (magneto-Kerr effect) that causes rotation of the polarization direction by incident directly polarized light onto the object being measured.

[0106] Next, the manufacturing method of the domain wall moving element 100 will be described. The domain wall moving element 100 is formed by a layer stacking process and a processing process of machining a portion of each layer into a predetermined shape. The layer stacking can be performed using sputtering, chemical vapor deposition (CVD), electron beam evaporation (EB evaporation), atomic laser deposition, etc. The machining of each layer can be performed using photolithography, ion milling, etc.

[0107] First, a ferromagnetic layer, a non-magnetic layer, a domain wall moving layer, and a conductive layer are sequentially stacked on top of the substrate Sub. Next, for example, by removing unwanted portions in the x and y directions of these layers using photolithography, each layer is processed into a predetermined shape: the ferromagnetic layer becomes ferromagnetic layer 10, the non-magnetic layer becomes non-magnetic layer 20, and the domain wall moving layer becomes domain wall moving layer 30. Next, for example, by ion milling, portions of the conductive layer, excluding the two portions overlapping the ends of the domain wall moving layer 30, are removed. That is, the portion corresponding to the first portion 30a1 on the upper surface 30a of the domain wall moving layer 30 is exposed. Through this process, the conductive layers become the first conductive layer 60 and the second conductive layer 70. Next, a first surface layer 50 is stacked on the first portion 30a1. Then, the upper surfaces of the first surface layer, the first conductive layer 60, and the second conductive layer 70 may also be covered by an insulating layer In. That is, the domain wall moving element 100 may also include an insulating layer In that contacts the upper surface of the first surface layer 50. Thus, the following is obtained: Figure 3 The magnetic domain wall moving element 100 is shown. Figure 1 and Figure 2 The magnetic array 200 shown is manufactured using the manufacturing method of the domain wall moving element 100 of this embodiment and a known magnetic array manufacturing method.

[0108] According to the domain wall moving element 100 of the first embodiment, the operation of the domain wall DW can be stabilized. The operation of the domain wall DW refers to, for example, the controllability of the domain wall DW, such as the ease of movement of the domain wall DW. When the controllability of the domain wall DW is improved, malfunctions such as accidental writing can be prevented, and the reliability of the domain wall moving element 100 is improved. The reasons why the domain wall moving element 100 of this embodiment can achieve the above-mentioned effects will be explained using comparative examples.

[0109] Figure 6 This is a cross-sectional view of the comparative example domain wall moving element 300. The comparative example domain wall moving element 300 is a bottom pin type domain wall moving element. The comparative example domain wall moving element 300 differs from the domain wall moving element 100 of the first embodiment in that it does not have a first surface layer 50, and the insulating layer In′ is in contact with the first portion 30a1′. In the domain wall moving element 300, the same reference numerals are used for structures identical to those in the domain wall moving element 100, and descriptions are omitted.

[0110] In its manufacturing process, the domain wall moving element 300 forms an insulating layer In' after the formation of the domain wall moving layer 30'. Silicon oxide (SiO2) is used as the insulating layer In'. x ), silicon nitride (SiN) x Silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO2)x ), magnesium oxide (MgO) x Therefore, during the process of forming the insulating layer In′, the upper surface 30a′ of the domain wall moving layer 30′ may be oxidized or nitrided. During the process of forming the insulating layer In′, defects may occur on the upper surface 30a′ of the domain wall moving layer 30′. That is, sometimes the first part 30a1′ of the upper surface 30a′ contains impurities or defects such as oxides and nitrides.

[0111] Impurities and defects in the domain wall moving layer 30' are trapping factors for the domain wall DW. If trapping factors exist in the domain wall moving layer 30', the domain wall DW may be strongly trapped near the trapping factors. When the domain wall DW is strongly trapped, even if a current of a specified current density is applied to the domain wall moving layer 30', the domain wall DW cannot operate smoothly. That is, when the domain wall DW is trapped due to defects, the domain wall moving element 300 requires sufficient energy to move the domain wall DW, and it will not operate stably unless a current of a reversing current density or higher is applied.

[0112] In contrast, in the domain wall moving element 100 of the first embodiment, the first surface layer 50 is in contact with at least a portion of the upper surface 30a of the domain wall moving layer 30. Therefore, in the domain wall moving element 100, an insulating layer In is formed after the first surface layer 50 is formed. Therefore, during the manufacturing process of the domain wall moving element 100, the generation of impurities and defects such as oxides and nitrides on the upper surface 30a can be suppressed. Therefore, in the domain wall moving element 100 of the first embodiment, the formation of trapping factors on the domain wall moving layer 30 can be suppressed.

[0113] Therefore, in the domain wall moving element 100 of the first embodiment, the operation of the domain wall DW can be stabilized.

[0114] Furthermore, in the domain wall moving element 100 of the first embodiment, the domain wall moving layer, the first conductive layer, and the second conductive layer can be stacked together, thus stabilizing the magnetic coupling between the domain wall moving layer 30 and the first conductive layer 60 and the second conductive layer 70. Additionally, in the domain wall moving element 100 of the first embodiment, the oxidation or nitriding of the insulating layer In by the clamping portions 61 and 71 can be suppressed.

[0115] The resistivity of the first surface layer 50 is higher than that of the domain wall moving layer 30. Therefore, in the domain wall moving element 100, it is possible to suppress current shunting to the first surface layer 50 when a write current is applied to the domain wall moving layer 30 in the x direction.

[0116] [First Variation]

[0117] Figure 7This is a cross-sectional view of the domain wall moving element 101 in the first modified example. The shapes of the first surface layer 50a, the first conductive layer 60a, and the second conductive layer 70a of the domain wall moving element 101 are different from those of the domain wall moving element 100 in the first embodiment. In the domain wall moving element 101, the same reference numerals are used for structures that are the same as those in the domain wall moving element 100, and descriptions are omitted.

[0118] exist Figure 7 In the domain wall moving element 101 shown, at least a portion of the first surface layer 50a is sandwiched between the first conductive layer 60a and the domain wall moving layer 30. Additionally, at least a portion of the first surface layer 50a is sandwiched between the second conductive layer 70a and the domain wall moving layer 30.

[0119] To fabricate the domain wall moving element 101, for example, a ferromagnetic layer, a non-magnetic layer, a domain wall moving layer, and a surface layer are sequentially stacked on a substrate Sub and an insulating layer In. Next, unwanted portions in the x and y directions of these layers are removed using photolithography. Then, for example, two portions of the surface layer overlapping the ends of the domain wall moving layer 30 are removed by ion milling. That is, the portion corresponding to the end on the upper surface 30a of the domain wall moving layer 30 is exposed. Through this process, the surface layer becomes a first surface layer 50a. Next, a conductor is filled into the exposed ends of the domain wall moving layer 30 to form a first conductive layer 60a and a second conductive layer 70a. Then, the first surface layer 50a, the first conductive layer 60a, and the second conductive layer 70a may be covered with the insulating layer In. The difference in shape between the first conductive layer 60 and the second conductive layer 70 of the domain wall moving element 100 and the first conductive layer 60a and the second conductive layer 70a of the domain wall moving layer 101 is due to the different order of their manufacturing processes.

[0120] The domain wall moving element 101 in the first modification example can also achieve the same effects as the domain wall moving element 100 in the first embodiment. In particular, in the domain wall moving element 101, since the first surface layer 50a is formed before the first conductive layer 60a and the second conductive layer 70a, it is possible to suppress the first portion 30a1 of the upper surface 30a of the domain wall moving layer 30 from becoming rough due to ion milling. Therefore, in the first modification example, the surface of the upper surface 30a of the domain wall moving layer 30 can be made smooth. Therefore, the operation of the domain wall DW can be made more stable.

[0121] Furthermore, in the domain wall moving element 101, after the surface layer is stacked, the portions corresponding to the first conductive layer 60a and the second conductive layer 70a in the surface layer are removed by ion milling or the like, and then the first conductive layer 60a and the second conductive layer 70a are formed. Therefore, the surfaces of the domain wall moving layer 30a that contact the first conductive layer 60a and the surfaces that contact the second conductive layer 70a are rougher than the first portion 30a1. If the surfaces of the domain wall moving layer 30a that contact the first conductive layer 60a and the surfaces that contact the second conductive layer 70a become rougher, the domain wall DW can be easily fixed in the magnetization fixing regions 31 and 32. That is, it is possible to further suppress the intrusion of the domain wall DW into the magnetization fixing regions 31 and 32.

[0122] In addition, Figure 7 The diagram illustrates an example where at least a portion of the first conductive layer 60a and the first surface layer 50a, and at least a portion of the second conductive layer 70a and the first surface layer 50a, overlap in the z-direction; however, the invention is not limited to this example. For instance, it could also be a structure where the first surface layer 50a does not overlap with the first conductive layer 60a and the second conductive layer 70a in the z-direction.

[0123] [Second Variation]

[0124] Figure 8 This is a cross-sectional view of the domain wall moving element 102 of the second modification. The domain wall moving element 102 differs from the domain wall moving element 100 of the first embodiment in that it has second surface layers 53 and 54. The second surface layers 53 and 54 are in contact with the upper surface 62 of the first conductive layer 60 and the upper surface 72 of the second conductive layer 70. In the domain wall moving element 102, the same reference numerals are used for structures identical to those in the domain wall moving element 100, and descriptions are omitted.

[0125] The second surface layers 53 and 54 can be made of the same material as the first surface layer 50. The resistivity of the second surface layers 53 and 54 is, for example, higher than that of the magnetic domain wall moving layer 30. The resistivity of the second surface layers 53 and 54 can also be more than two or three times that of the magnetic domain wall moving layer 30. Furthermore, the second surface layers 53 and 54 can be formed on at least a portion of the upper surfaces 62 and 72, or they can be formed entirely on the upper surfaces 62 and 72.

[0126] The domain wall moving element 102 is manufactured, for example, by forming a hole in the insulating layer In at a position overlapping with the first conductive layer 60 or the second conductive layer 70 after the formation of the domain wall moving element 101, and filling the hole in the same way as the first surface layer 50a. Alternatively, the insulating layer In may be used to cover the second surface layers 53 and 54 after they are stacked.

[0127] The domain wall moving element 102 in the second modification can also achieve the same effect as the domain wall moving element 100 in the first embodiment. Furthermore, in the domain wall moving element 102, oxidation or nitriding of the upper surfaces 62 and 72 of the first conductive layer 60 and the second conductive layer 70 can be suppressed. Therefore, the magnetization M of the magnetization fixing regions 31 and 32 can be more strongly fixed through the first conductive layer 60 and the second conductive layer 70. 31 M 32 Magnetization. That is, it can further suppress the invasion of domain walls DW into the magnetization fixation regions 31 and 32.

[0128] [3rd Variation]

[0129] Figure 9 This is a cross-sectional view of the domain wall moving element 103 in the third modification. The domain wall moving element 103 differs from the domain wall moving element 102 in that it has third surface layers 56 and 57 that are in contact with the sides of the first conductive layer 60 and the second conductive layer 70. In the domain wall moving element 103, the same reference numerals are used for structures identical to those in the domain wall moving element 102, and descriptions are omitted. Figure 9 The illustration shows an example where a third surface layer 56, 57 is formed on both sides of the first conductive layer 60 and the second conductive layer 70, but it is sufficient to form the third surface layer 56, 57 on at least one side of the first conductive layer 60 and the second conductive layer 70. Furthermore, in Figure 9 The example illustrates a case where the first surface layer 50, the second surface layers 53 and 54, and the third surface layers 56 and 57 are integrated, but they can also be separate independent structures.

[0130] The third surface layers 56 and 57 can be made of the same material as the first surface layer 50. The resistivity of the third surface layers 56 and 57 is higher than that of the magnetic domain wall moving layer 30. The resistivity of the third surface layers 56 and 57 can also be more than 2 or 3 times that of the magnetic domain wall moving layer 30. The third surface layers 56 and 57 can be formed on both sides of the first conductive layer 60 and the second conductive layer 70 in the x-direction, or they can be formed on one side.

[0131] The domain wall moving element 103 of the third modification is manufactured, for example, using the same method as the domain wall moving element 100 of the first embodiment. That is, the domain wall moving element 103 is manufactured by forming a surface layer on the first conductive layer 60, the second conductive layer 70 and the first portion 30a1 of the domain wall moving layer 30 after forming the first conductive layer 60 and the second conductive layer 70, and then covering it with an insulating layer In.

[0132] The domain wall moving element 103 in the third modification can also achieve the same effect as the domain wall moving element 100 in the first embodiment. Furthermore, in the domain wall moving element 103, the insulating layer In can suppress the side oxidation or nitriding of the first conductive layer 60 and the second conductive layer 70. Therefore, the first conductive layer 60 and the second conductive layer 70 can more strongly fix the magnetization M in the magnetization fixing regions 31 and 32. 31 M 32 Magnetization. That is, it can further suppress the invasion of domain walls DW into the magnetization fixation regions 31 and 32.

[0133] [4th Variation]

[0134] Figure 10 This is a cross-sectional view of the domain wall moving element 104 in the fourth variation. The domain wall moving element 104 differs from the domain wall moving element 100 in that at least a portion of the first surface layer 50b is sandwiched between the first conductive layer 60b, the second conductive layer 70b, and the domain wall moving layer 30. In the domain wall moving element 104, the same reference numerals are used for structures identical to those in the domain wall moving element 100, and descriptions are omitted.

[0135] When viewed from above in the z-direction, the first surface layer 50b may be formed over the entire area overlapping the first conductive layer 60b and the second conductive layer 70b, or it may be formed in a manner that includes only a portion of the area overlapping the first conductive layer 60b and the second conductive layer 70b.

[0136] The first surface layer 50b can use the same material as the first surface layer 50. The first conductive layer 60b and the second conductive layer 70b are respectively connected to the magnetic domain wall moving layer 30.

[0137] The thicknesses of the first conductive layer 60b and the second conductive layer 70b in the z direction are smaller than those of the first conductive layer 60 and the second conductive layer 70, respectively.

[0138] The domain wall moving element 104 of the fourth modification can also achieve the same effect as the domain wall moving element 100 of the first embodiment.

[0139] [Variation Example 5]

[0140] Figure 11 This is a cross-sectional view of the domain wall moving element 105 in Modified Example 5. The domain wall moving element 105 differs from the domain wall moving element 100 in that it does not have a second conductive layer 70. In the domain wall moving element 105, the same reference numerals are used for structures identical to those in the domain wall moving element 100, and descriptions are omitted.

[0141] The domain wall moving element 105 has only one first conductive layer 60. The magnetized fixed region 32 of the domain wall moving element 105 is fixed, for example, by an external magnetic field.

[0142] Alternatively, the domain wall moving element 105 may not have the magnetization fixing region 32. In the domain wall moving element 105 without the magnetization fixing region 32, the operation of the domain wall DW can be controlled by controlling the magnitude of the applied current pulse.

[0143] The domain wall moving element 105 of this embodiment can also achieve the same effect as the domain wall moving element 100 of the first embodiment. That is, if it has at least one conductive layer like the domain wall moving element 105, the operation of the domain wall DW can be stabilized.

[0144] In addition, Figure 11 The example shown is of a magnetic domain wall moving element 105 having only a first conductive layer 60, but it may also have only a second conductive layer 70.

[0145] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to specific embodiments. Various modifications and alterations can be made within the scope of the spirit of the present invention as described in the claims.

[0146] For example, the characteristic structures in the first embodiment and variations 1 to 5 can be combined respectively.

Claims

1. A magnetic domain wall moving element, comprising: A laminate located above a substrate, having a ferromagnetic layer, a non-magnetic layer and a magnetic domain wall moving layer stacked sequentially from the side closest to the substrate. First conductive layer; First surface layer; and The second conductive layer is disposed separately from the first conductive layer in the extending direction of the domain wall moving layer. The non-magnetic layer is sandwiched between the ferromagnetic layer and the magnetic domain wall moving layer. The first conductive layer is connected to the upper surface of the magnetic domain wall moving layer. When viewed from above, the first surface layer is in contact with the entire area between the first conductive layer and the second conductive layer on the upper surface of the magnetic domain wall moving layer. The resistivity of the first surface layer is higher than that of the magnetic domain wall moving layer.

2. The domain wall moving element as claimed in claim 1, wherein, It also includes an insulating layer that contacts the upper surface of the first surface layer.

3. The domain wall moving element as described in claim 1, wherein, The first surface layer comprises amorphous or microcrystalline material.

4. The domain wall moving element as claimed in claim 1, wherein, The first surface layer contains at least one element selected from Bi, Ni, Cr, Ti, Zr, and W.

5. The domain wall moving element as claimed in claim 1, wherein, The thickness of the first surface layer is less than 2 nm.

6. The domain wall moving element as claimed in claim 1, wherein, The easy magnetization direction of the domain wall moving layer intersects with the surface extended by the domain wall moving layer.

7. The domain wall moving element as claimed in claim 1, wherein, At least a portion of the first conductive layer is sandwiched between the first surface layer and the magnetic domain wall moving layer.

8. The domain wall moving element as claimed in claim 1, wherein, It also has a second surface layer that contacts the upper surface of the first conductive layer. The resistivity of the second surface layer is higher than that of the magnetic domain wall moving layer.

9. The domain wall moving element as claimed in claim 1, wherein, It also has a third surface layer that contacts the side surface of the first conductive layer. The resistivity of the third surface layer is higher than that of the magnetic domain wall moving layer.

10. A magnetic array having: substrate; and The magnetic domain wall moving element according to any one of claims 1 to 9, Multiple of the aforementioned domain wall moving elements are integrated on the substrate.

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