Magnetic device

Abstract

The magnetic device of the present application has a laminate having a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer sandwiched by the first ferromagnetic layer and the second ferromagnetic layer, and an insulator covering at least a part of a side surface of the laminate, the insulator having a space at a more outer side than the side surface of the laminate.

Description

Technical Field

[0001] This invention relates to a magnetic device. Background Technology

[0002] As magnetoresistive elements, known examples include giant magnetoresistive (GMR) elements composed of multilayer films with ferromagnetic and nonmagnetic layers, and tunnel magnetoresistive (TMR) elements that use insulating layers (tunnel blocking layers, blocking layers) in the nonmagnetic layers. Magnetoresistive elements can be applied to magnetic sensors, high-frequency components, magnetic heads, and non-volatile random access memory (MRAM).

[0003] MRAM is a memory device that integrates a magnetoresistive element. MRAM utilizes the property that the resistance of the magnetoresistive element changes when the mutual magnetization direction of the two ferromagnetic layers sandwiching the non-magnetic layer in the magnetoresistive element changes, in order to read and write data.

[0004] For example, Japanese Patent Application Publication No. 2017-216286 discloses a magnetoresistive effect element that uses spin-orbit torque (SOT) for writing. Summary of the Invention

[0005] Magnetoresistive elements sometimes generate heat during data writing. The heat generated by magnetoresistive elements can adversely affect control components and other magnetoresistive elements.

[0006] The present invention was made in view of the above circumstances, and its object is to provide a magnetic device that can suppress the heat generated by the magnetoresistive element from affecting other components.

[0007] To address the aforementioned issues, the present invention provides the following means.

[0008] (1) The magnetic device involved in the first method comprises: a laminate having a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; and an insulator covering at least a portion of the side surface of the laminate, the insulator having space further outward than the side surface of the laminate.

[0009] (2) In the magnetic device involved in the above method, it is also possible that there are multiple spaces in the insulator, and the laminate is sandwiched between two spaces in the first direction.

[0010] (3) The magnetic device involved in the above method may also include wiring connected to the laminate, the wiring extending along the first direction.

[0011] (4) In the magnetic device involved in the above manner, the space may also surround the side of the stacked body.

[0012] (5) In the magnetic device involved in the above method, the space may also be connected to the stacked body.

[0013] (6) The magnetic device involved in the above method may also include an electrode connected to the laminate, and the space is connected to the electrode.

[0014] (7) The magnetic device involved in the above method may also be a plurality of said stacked bodies, wherein the space is located between two of the plurality of said stacked bodies.

[0015] (8) In the magnetic devices involved in the above manner, the space may also be located between the closest stacked bodies. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the magnetic device involved in the first embodiment.

[0017] Figure 2 This is a cross-sectional view of the magnetic device involved in the first embodiment.

[0018] Figure 3 This is another cross-sectional view of the magnetic device involved in the first embodiment.

[0019] Figure 4 This is an enlarged cross-sectional view of the vicinity of the magnetoresistive element of the magnetic device according to the first embodiment.

[0020] Figure 5 This is a diagram illustrating the manufacturing method of the magnetic device according to the first embodiment.

[0021] Figure 6 This is a diagram illustrating the manufacturing method of the magnetic device according to the first embodiment.

[0022] Figure 7 This is a diagram illustrating the manufacturing method of the magnetic device according to the first embodiment.

[0023] Figure 8 This is a diagram illustrating the manufacturing method of the magnetic device according to the first embodiment.

[0024] Figure 9 It is an enlarged cross-sectional view of the vicinity of the magnetoresistive element of the magnetic device involved in the first variation.

[0025] Figure 10 This is a cross-sectional view of the magnetic device involved in the second variation.

[0026] Figure 11 This is a diagram used to illustrate the manufacturing method of the magnetic device involved in the second variation.

[0027] Figure 12 This is a diagram used to illustrate the manufacturing method of the magnetic device involved in the second variation.

[0028] Figure 13 This is a cross-sectional view of the magnetic device involved in the third variation.

[0029] Figure 14 This is a diagram used to illustrate the manufacturing method of the magnetic device involved in the third variation.

[0030] Figure 15 This is a diagram used to illustrate the manufacturing method of the magnetic device involved in the third variation.

[0031] Figure 16 This is an enlarged cross-sectional view of the vicinity of the magnetoresistive element of the magnetic device involved in the second embodiment.

[0032] Figure 17 This is a schematic diagram of the magnetic device involved in the third embodiment.

[0033] Figure 18 This is a cross-sectional view of the magnetic device involved in the third embodiment.

[0034] Symbol Explanation

[0035] 1, 51…First ferromagnetic layer; 2, 52…Second ferromagnetic layer; 3, 53…Non-magnetic layer; 10, 50…Laminated structure; 20…Spin-orbit torque wiring; 31, 32, 33…Electrodes; 40, 41, 42, 43…Space; 81, 82…Magnetic layer; 83…Non-magnetic layer; 84, 86…Hard mask; 85…Conductive layer; 90, 91, 93, 94…Insulating layer; 100, 101, 102, 110, 120…Magnetic reluctance element; 200, 202, 203, 220…Magnetic device; BL…Bit line; CL…Common line; In…Insulator; RL…Readout line; SL…Source line; Sub…Substrate; Sw1…First switching element; Sw2…Second switching element; Sw3…Third switching element; Sw4…Fourth switching element; WL…Write line. Detailed Implementation

[0036] 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, some parts of the features are sometimes shown as enlarged, and the size ratios of the constituent elements may differ from the actual dimensions. The materials, dimensions, etc., illustrated in the following description are examples, and the present invention is not limited thereto; appropriate modifications can be made to achieve the effects of the present invention.

[0037] First, the orientation is defined. The substrate Sub (refer to...) will be described later. Figure 2 One direction of one side of the magnetoresistive element is designated as the x-direction, and the direction orthogonal to the x-direction is designated as the y-direction. The x-direction, for example, is the direction from electrode 31 towards electrode 32. The z-direction is the direction orthogonal to both the x- and y-directions. The z-direction is an example of the stacking direction. The direction from the substrate Sub towards the magnetoresistive element 100 is designated as the +z-direction. Hereinafter, the +z-direction is sometimes referred to as "up" and the -z-direction as "down." Up and down are not necessarily consistent with the direction in which gravity is applied.

[0038] In this specification, "extending along the x-direction" means, for example, that the dimension in the x-direction is larger than the smallest of the dimensions in the x, y, and z directions. The same applies to extensions in other directions.

[0039] (First Implementation)

[0040] Figure 1 This is a structural diagram of the magnetic device 200 according to the first embodiment. The magnetic device 200 includes multiple magnetoresistive elements 100, multiple write lines WL, multiple common lines CL, multiple read lines RL, multiple first switching elements Sw1, multiple second switching elements Sw2, and multiple third switching elements Sw3. The magnetic device 200 can be used in rotating memory, magnetic memory, IoT devices, neuromorphic devices, etc.

[0041] The magnetoresistive elements 100 are arranged in a matrix, for example. Each of the magnetoresistive elements 100 is connected to each of the write line WL, the read line RL, and the common line CL.

[0042] The write line WL electrically connects the power supply to one or more magnetoresistive elements 100. The common line CL is the wiring used for both writing and reading data. The common line CL electrically connects the reference potential to one or more magnetoresistive elements 100. The reference potential is, for example, ground. The common line CL can be provided on multiple magnetoresistive elements 100 individually or across multiple magnetoresistive elements 100. The read line RL electrically connects the power supply to one or more magnetoresistive elements 100. The power supply is connected to the magnetic device 200 during use.

[0043] Each magnetoresistive element 100 is connected to a first switching element Sw1, a second switching element Sw2, and a third switching element Sw3, respectively. The first switching element Sw1 is connected between the magnetoresistive element 100 and the write line WL. The second switching element Sw2 is connected between the magnetoresistive element 100 and the common line CL. The third switching element Sw3 is connected to the read line RL that spans multiple magnetoresistive elements 100.

[0044] When the first switching element Sw1 and the second switching element Sw2 are both ON, a write current flows between the write line WL and the common line CL, which are connected to the specified magnetoresistive effect element 100. When the write current flows through the magnetoresistive effect element 100, data is recorded in the magnetoresistive effect element 100. When the second switching element Sw2 and the third switching element Sw3 are both ON, a read current flows between the common line CL and the read line RL, which are connected to the specified magnetoresistive effect element 100. When the read current flows through the magnetoresistive effect element 100, data is read from the magnetoresistive effect element 100.

[0045] The first switching element Sw1, the second switching element Sw2, and the third switching element Sw3 are elements that control the flow of current. The first switching element Sw1, the second switching element Sw2, and the third switching element 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 the band structure, such as Metal-Insulator Transfer (MIT) Switches; elements that utilize breakdown voltage, such as Zener Diodes and Avalanche Diodes; and elements whose conductivity changes with changes in atomic positions.

[0046] Figure 1 The magnetic device 200 shown shares a third switching element Sw3 with the magnetoresistive effect element 100 connected to the same wiring. The third switching element Sw3 can also be provided on each magnetoresistive effect element 100. Alternatively, the third switching element Sw3 can be provided on each magnetoresistive effect element 100, and the magnetoresistive effect element 100 connected to the same wiring can share a first switching element Sw1 or a second switching element Sw2.

[0047] Figure 2 This is a cross-sectional view of the magnetic device 200 according to the first embodiment. Figure 2 It is the cross section of the magnetic device 200 cut off in the xz plane at the center of the width of the spin-orbit torque wiring 20 in the y direction, which will be described later.

[0048] Figure 2 The first switching element Sw1 and the second switching element Sw2 shown are transistors Tr. The third switching element Sw3 is connected to the readout line RL, for example, in the position shown. Figure 2 Different positions in the x-direction. A transistor Tr, for example, is a field-effect transistor, having a gate electrode G, a gate insulating film GI, and source electrodes S and drain electrodes D formed on a substrate Sub. The positional relationship between the source S and drain D is one example; it can be reversed. The substrate Sub is, for example, a semiconductor substrate.

[0049] Transistor Tr and magnetoresistive element 100 are electrically connected via via wiring V and electrodes 31 and 32. Additionally, transistor Tr is connected to write line WL or common line CL via via wiring V. Furthermore, read line RL and magnetoresistive element 100 are electrically connected via electrode 33. Via wiring V and electrodes 31, 32, and 33 are made of a conductive material.

[0050] The magnetoresistive element 100 and the transistor Tr are surrounded by an insulator In. The insulator In is an insulating layer that insulates between wirings and between components in multilayer wiring. The insulator 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), zirconium oxide (ZrO2) x )wait.

[0051] A space 40 is provided within the insulator In. The space 40 is a portion surrounded by the insulator In. For example, multiple spaces 40 exist within the insulator In. The space 40 is located, for example, above the electrodes 31 and 32. The interior of the space 40 is filled with a vacuum or gas, and the space 40 is surrounded by a solid material.

[0052] Vacuum has poor thermal conductivity. When space 40 is a vacuum, the heat generated by the component is difficult to transfer to other components. Furthermore, even if space 40 is filled with gas, as long as the gas pressure is sufficiently low, thermal conductivity is reduced, achieving the same effect as a vacuum. Moreover, space 40 can also be filled with liquid. Space 40 is surrounded by a solid material, allowing for liquid filling. Liquids have lower thermal conductivity than solids, making it difficult to transfer the heat generated by the component to other components. Additionally, using liquid inside space 40 maintains a smooth thermal conduction through space 40. As a result, heat can be quickly removed from the heated component after processes such as writing. This promotes heat dissipation from the component, improves data retention characteristics, and increases the stability of data writing.

[0053] Figure 3 This is another cross-sectional view of the magnetic device 200 according to the first embodiment. Figure 3 It is a cross-sectional view of the magnetic device 200 cut along the xy plane passing through the first ferromagnetic layer 1 of the laminate 10.

[0054] In the xy plane, the stacked bodies 10 constituting the magnetoresistive effect element 100 are arranged in a matrix. Space 40 is located between two of the stacked bodies 10. Figure 3In the example shown, space 40 is located between adjacent stacks 10 in the x-direction. Space 40 is, for example, located between the closest stacks 10.

[0055] Figure 4 This is an enlarged cross-sectional view of the vicinity of the magnetoresistive element 100 of the magnetic device 200 according to the first embodiment. Figure 4 The cross section of the magnetoresistive element 100 is cut off by the xz plane at the center of the width of the spin-orbit torque wiring 20 in the y direction.

[0056] The magnetoresistive element 100 includes, for example, a stack 10 and a spin-orbit torque wiring 20. The resistance value in the z-direction of the stack 10 is varied by injecting spin from the spin-orbit torque wiring 20 into the stack 10. The magnetoresistive element 100 is a magnetoresistive element utilizing spin-orbit torque (SOT), and is sometimes referred to as a spin-orbit torque type magnetoresistive element, a spin-injection type magnetoresistive element, or a spin-current magnetoresistive element.

[0057] The magnetoresistive element 100 is a three-terminal device connected to three electrodes 31, 32, and 33. Electrodes 31, 32, and 33 are made of a conductive material. Electrodes 31, 32, and 33 may, for example, contain any material selected from Al, Cu, Ta, Ti, Zr, NiCr, and nitrides (e.g., TiN, TaN, SiN). Electrode 33 may also serve as a hard mask used in the manufacturing process of the magnetoresistive element 100. Electrode 33 may, for example, be made of a transparent electrode material.

[0058] When viewed from above in the z-direction, electrodes 31 and 32 are connected in the x-direction to the position where they clamp the stack 10, and to the spin-orbit torque wiring 20. Electrode 33 is connected to the stack 10. The stack 10 is connected to the readout line RL via electrode 33. The readout line RL extends in the x-direction. Space 40 is, for example, located at a position overlapping with the readout line RL when viewed from the z-direction.

[0059] Space 40 is located within the insulator In surrounding the laminate 10. Space 40 is located further outward than the sides of the laminate 10. Insulator In exists between space 40 and the laminate 10. Space 40, for example, clamps the laminate 10 in the x-direction. Figure 4 In this example, space 40 is located above the upper surface of the spin-orbit torque wiring 20 in the z-direction. Space 40 is, for example, atmosphere or vacuum.

[0060] The height h in the z-direction of space 40 40 For example, the height h in the z-direction of the stack 10. 10 That's all. The height h in the z-direction of space 40. 40 For example, a height h in the z-direction greater than that of the laminate 10.10 The surface of space 40 opposite to the side of the laminate 10 is, for example, curved. The inclination direction of the curved surface of space 40 relative to the z-direction is, for example, the same as the inclination direction of the side of the laminate 10 relative to the curved surface in the z-direction. For example, the upper surface of space 40 is wider than the lower surface, and the upper surface and the lower surface are connected by the curved surface.

[0061] The laminate 10 is held in the z-direction by the spin-orbit torque wiring 20 and the electrode 33. The laminate 10 is cylindrical. The shape of the laminate 10 viewed from the z-direction is, for example, circular, elliptical, or quadrilateral. The side of the laminate 10 is, for example, inclined relative to the z-direction.

[0062] The laminate 10, for example, has a first ferromagnetic layer 1, a second ferromagnetic layer 2, and a nonmagnetic layer 3. The first ferromagnetic layer 1 is, for example, connected to and stacked on a spin-orbit torque wiring 20. The spin-orbit torque wiring 20 injects spin into the first ferromagnetic layer 1. The first ferromagnetic layer 10 is magnetized by the injected spin and receives spin-orbit torque (SOT), causing a change in its orientation. The first ferromagnetic layer 1 and the second ferromagnetic layer 2 sandwich the nonmagnetic layer 3 in the z-direction.

[0063] The first ferromagnetic layer 1 and the second ferromagnetic layer 2 are respectively magnetized. When a specified external force is applied, the orientation of the second ferromagnetic layer 2 is less likely to change compared to the magnetization of the first ferromagnetic layer 1. The first ferromagnetic layer 1 is referred to as the magnetization-free layer, and the second ferromagnetic layer 2 is sometimes referred to as the magnetization-fixed layer or the magnetization-reference layer. The resistance value of the laminate 10 varies depending on the relative angle of magnetization between the first ferromagnetic layer 1 and the second ferromagnetic layer 2 that hold the non-magnetic layer 3.

[0064] The first ferromagnetic layer 1 and the second ferromagnetic layer 2 contain a ferromagnetic material. The ferromagnetic material may be, for example, 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. Examples of ferromagnetic materials include Co-Fe, Co-Fe-B, Ni-Fe, Co-Ho alloys, Sm-Fe alloys, Fe-Pt alloys, Co-Pt alloys, and CoCrPt alloys.

[0065] The first ferromagnetic layer 1 and the second ferromagnetic layer 2 may contain Whistler alloys. Whistler alloys contain intermetallic compounds with a chemical composition of XYZ or X2YZ. 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 Whistler alloys include Co2FeSi, Co2FeGe, Co2FeGa, Co2MnSi, and Co2Mn. 1-a Fea Al b Si 1-b Co2FeGe 1-c Ga c Etc. Whistler alloys exhibit high spin polarization.

[0066] The non-magnetic layer 3 comprises a non-magnetic material. When the non-magnetic layer 3 is an insulator (in the case of a tunneling barrier layer), materials such as Al₂O₃, SiO₂, MgO, and MgAl₂O₄ can be used. In addition to these, materials in which a portion of Al, Si, or Mg is replaced by Zn, Be, etc., can also be used. Among these, MgO and MgAl₂O₄ are materials capable of coherent tunneling, thus enabling efficient spin injection. When the non-magnetic layer 3 is a metal, materials such as Cu, Au, and Ag can be used. Furthermore, when the non-magnetic layer 3 is a semiconductor, materials such as Si, Ge, CuInSe₂, CuGaSe₂, and Cu(In,Ga)Se₂ can be used.

[0067] The laminate 10 may also have layers other than the first ferromagnetic layer 1, the second ferromagnetic layer 2, and the nonmagnetic layer 3. For example, a base layer may be provided between the spin-orbit torque wiring 20 and the first ferromagnetic layer 1. The base layer improves the crystallinity of each layer constituting the laminate 10. In addition, for example, a capping layer may be provided on the top layer of the laminate 10.

[0068] Alternatively, the laminate 10 may also have a ferromagnetic layer disposed on the side of the second ferromagnetic layer 2 opposite to the non-magnetic layer 3, separated by a spacer layer. The second ferromagnetic layer 2, the spacer layer, and the ferromagnetic layer constitute a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure consists of two magnetic layers sandwiching a non-magnetic layer. Due to antiferromagnetic coupling between the second ferromagnetic layer 2 and the ferromagnetic layer, the coercivity of the second ferromagnetic layer 2 is increased compared to the case without a ferromagnetic layer. The ferromagnetic layer may be, for example, IrMn or PtMn. The spacer layer may contain, for example, at least one selected from Ru, Ir, and Rh.

[0069] The spin-orbit torque wiring 20 extends, for example, along the x-direction. Write current flows along the spin-orbit torque wiring 20. At least a portion of the spin-orbit torque wiring 20 clamps the first ferromagnetic layer 1 together with the nonmagnetic layer 3 in the z-direction.

[0070] The spin-orbit torque wiring 20 generates a spin current through the spin Hall effect when current I flows, injecting spin into the first ferromagnetic layer 1. For example, the spin-orbit torque wiring 20 imparts a spin-orbit torque (SOT) to the first ferromagnetic layer 1, which can only reverse the magnetization of the first ferromagnetic layer 1. The spin Hall effect is a phenomenon in which a spin current is induced in a direction orthogonal to the direction of current flow based on spin-orbit interaction when current flows. The spin Hall effect is similar to the conventional Hall effect in that the direction of motion (moving) charges (electrons) is bent in the direction of motion (movement). In the conventional Hall effect, the direction of motion of charged particles moving in a magnetic field is bent by the Lorentz force. In contrast, the spin Hall effect, even in the absence of a magnetic field, where electrons merely move (only current flows), the direction of spin movement is bent, etc.

[0071] For example, when current flows in the spin-orbit torque wiring 20, the first spin oriented in one direction and the second spin oriented in the opposite direction to the first spin are bent in directions orthogonal to the direction of current flow by the spin Hall effect. For example, the first spin oriented in the -y direction bends in the +z direction, and the second spin oriented in the +y direction bends in the -z direction.

[0072] In non-magnetic materials (materials that are not ferromagnetic), the number of electrons with the first spin generated by the spin Hall effect is equal to the number of electrons with the second spin. That is, the number of electrons with the first spin in the +z direction is equal to the number of electrons with the second spin in the -z direction. The first and second spins flow in the direction that eliminates the spin deflection. During the movement in the z-direction of the first and second spins, the flow of charge cancels each other out, so the current is zero. Spin current without accompanying current is specifically called pure spin current.

[0073] If the flow of electrons with the first spin is expressed as J ↑ The flow of electrons with the second spin is expressed as J ↓ The spin flow is represented as J s Then J s =J ↑ (J ↓ Definition. Spin flow J s It is generated in the z-direction. The first spin is injected into the first ferromagnetic layer 1 from the spin-orbit torque wiring 20.

[0074] The spin-orbit torque wiring 20 includes any one of the following: metal, alloy, intermetallic compound, metal boride, metal carbide, metal silicide, and metal phosphide, which has the function of generating spin flow due to the spin Hall effect when current I flows.

[0075] The spin-orbit torque distribution 20, for example, contains non-magnetic heavy metals as its main component. Heavy metals refer to metals with a specific gravity greater than yttrium (Y). Non-magnetic heavy metals are, for example, large non-magnetic metals with an atomic number of 39 or higher and possessing d or f electrons in their outermost shell. The spin-orbit torque distribution 20 is, for example, composed of Hf, Ta, and W. Non-magnetic heavy metals generate stronger spin-orbit interactions compared to other metals. The spin Hall effect arises from torsional orbital interactions, and spins tend to deflect into the spin-orbit torque distribution 20, easily generating spin current J. s .

[0076] In addition to the spin-orbit torque wiring 20, it may also contain a magnetic metal. The magnetic metal is either ferromagnetic or antiferromagnetic. The trace amount of magnetic metal contained in a non-magnetic body becomes a scattering factor of the spin. The trace amount is, for example, less than 3% of the total molar ratio of the elements constituting the spin-orbit torque wiring 20. When the spin is scattered by the magnetic metal, the spin-orbit interaction is enhanced, and the generation efficiency of the spin current relative to the electric current becomes higher.

[0077] The spin-orbit torque wiring 20 can also include topological insulators. A topological insulator is a metallic substance whose interior is an insulator or high-resistivity material, but which exhibits spin polarization on its surface. Topological insulators generate an internal magnetic field due to spin-orbit interactions. Even without an external magnetic field, topological insulators exhibit a new topological phase due to the effects of spin-orbit interactions. Topological insulators can efficiently generate pure spin currents through strong spin-orbit interactions and the breaking of inversion symmetry at their edges.

[0078] Topological insulators include SnTe and Bi. 1.5 Sb 0.5 Te 1.7 Se 1.3 ,TlBiSe2,Bi2Te3,Bi 1-x Sb x 、(Bi 1-x Sb x )2Te3, etc. Topological insulators can generate spin currents with high efficiency.

[0079] Next, the manufacturing method of the magnetic device 200 will be described. The magnetic device 200 is formed through a layer stacking process and a processing process in which a portion of each layer is processed into a specified shape. The layer stacking can be performed using sputtering, chemical vapor deposition (CVD), electron beam evaporation (EB evaporation), atomic laser deposition, etc. The processing of each layer can be performed using photolithography, etc.

[0080] The following uses Figures 5-8 The fabrication method near the magnetoresistive element 100 of the magnetic device 200 will be described. Figures 5-8These are figures illustrating the manufacturing method of the magnetic device 200 according to the first embodiment. Figures 5-8 The top image is a top view taken from the z-direction, and the bottom image is a cross-sectional view of the xz direction.

[0081] like Figure 5 As shown, an opening is formed in the insulating layer 90, and a conductor is embedded in the opening to form electrodes 31 and 32. Next, a conductive film is formed on the insulating layer 90 and electrodes 31 and 32, and processed into a predetermined shape to form the spin axial torque wiring 20. Then, the area around the spin orbital torque wiring 20 is filled with the insulating layer 91.

[0082] Next, the upper surface of the spin-orbit torque wiring 20 is exposed by chemical mechanical polishing (CMP). Then, a magnetic layer 81, a non-magnetic layer 83, and a magnetic layer 82 are sequentially stacked on the spin-orbit torque wiring 20 and the insulating layer 91. Finally, a hard mask 84 is formed at a predetermined position on the magnetic layer 82.

[0083] Next, the magnetic layer 81, non-magnetic layer 83, and magnetic layer 82 are processed using a hard mask 84. For example... Figure 6 As shown, magnetic layer 81 becomes the first ferromagnetic layer 1, non-magnetic layer 83 becomes the non-magnetic layer 3, and magnetic layer 82 becomes the second ferromagnetic layer 2, forming a laminate 10. Hard mask 84 becomes electrode 33. Insulating layer 93 is formed to cover laminate 10 and electrode 33, and resist R is formed thereon.

[0084] Next, a portion of the resist R and insulating layer 93 is removed by chemical mechanical polishing (CMP) to expose electrode 33. Then, a conductive layer is formed on electrode 33, insulating layer 93, and resist R. This is achieved by removing a portion of the conductive layer, such as... Figure 7 The readout line RL is formed as shown. In the portion that does not overlap with the readout line RL, the resist R is exposed. In the portion that does not overlap with the readout line RL, the resist R and the upper surface of the insulating layer 93 can be excessively etched in such a way that the upper surface of the resist R and the insulating layer 93 are located further below the lower surface of the readout line RL.

[0085] Next, as Figure 8 As shown, the resist R is removed. After removing the resist R, an insulating layer is formed across the entire surface via the readout line RL. The portion below the readout line RL is filled with the insulating layer, leaving a space 40 below the readout line RL.

[0086] Insulation layers 90, 91, and 93 become Figure 2 and Figure 4 The insulator In is used. By following the steps described above, a magnetic device 200 having a space 40 within the insulator In can be obtained.

[0087] The magnetic device 200 according to the first embodiment has a space 40 on the outside of the laminate 10. The space 40 is made of atmosphere or vacuum and has excellent thermal insulation. The space 40 can suppress the heat generated in the laminate 10 from being transferred to the surroundings and can suppress the heat generated by the magnetoresistive effect element from affecting other components.

[0088] (First variation)

[0089] Figure 9 This is an enlarged cross-sectional view of the vicinity of the magnetoresistive element 101 of the magnetic device involved in the first modified example. Figure 9 In the middle, to and Figure 4 The same structures are labeled with the same reference numerals, and the descriptions are omitted.

[0090] The magnetoresistive element 101 is covered by an insulator In. A space 41 is provided within the insulator In. The space 41 is located further outward than the sides of the laminate 10. Unlike space 40, a portion of space 41 is in contact with the laminate 10. This contact between space 41 and the laminate 10 further suppresses heat transfer generated within the laminate 10 to the surrounding environment. Additionally, space 41 is also in contact with electrode 33. This connection between space 41 and electrode 33 controls the flow of heat generated within the laminate 10, with most of the heat dissipated via electrode 33 and the readout line RL.

[0091] The magnetoresistive element 101 can be controlled Figure 6 It is made with an insulation layer thickness of 93.

[0092] The magnetic device involved in the first modification can achieve the same effect as the magnetic device 200 involved in the first embodiment. In addition, by controlling the flow of heat generated in the laminate 10, it is possible to suppress the influence of heat generated by the magnetoresistive element on other components.

[0093] (Second variation)

[0094] Figure 10 This is an enlarged cross-sectional view of the vicinity of the magnetoresistive element 102 of the magnetic device involved in the second variation. Figure 10 In the middle, to and Figure 4 The same structures are labeled with the same reference numerals, and the descriptions are omitted.

[0095] The magnetoresistive element 102 is covered by an insulator In. A space 42 is present within the insulator In. Space 42 is located further outward than the sides of the laminate 10. A portion of space 42 extends further downward than the upper surface of the spin-orbit torque wiring 20, unlike space 40.

[0096] Figure 11 as well as Figure 12This diagram illustrates the manufacturing method of the magnetic device according to the second modification. In the second modification, a conductive layer 85, a magnetic layer 81, a non-magnetic layer 83, and a magnetic layer 82 are sequentially stacked on the insulating layer 90 and the electrodes 31 and 32, and processed simultaneously through a hard mask 86. The conductive layer 85 is processed to form a spin-orbit torque wiring 20. Furthermore, a hard mask is formed at a predetermined position of the processed magnetic layer 82, and the magnetic layer 81, the non-magnetic layer 83, and the magnetic layer 82 are processed through the hard mask, thereby obtaining the laminate 10.

[0097] Then, as Figure 12 As shown, an insulating layer 93 and a resist R are formed in a manner that covers the laminate 10 and the spin-orbit torque wiring 20. Then, through a process involving... Figure 7 as well as Figure 8 The same steps can be used to manufacture the magnetic device involved in the second variation.

[0098] The magnetic device involved in the second modification can achieve the same effect as the magnetic device 200 involved in the first embodiment.

[0099] (Third variation)

[0100] Figure 13 This is a cross-sectional view of the magnetic device 203 involved in the third variation. Figure 13 In the middle, to and Figure 3 The same structures are labeled with the same reference numerals, and the descriptions are omitted. Figure 13 It is a cross-sectional view of the magnetic device 203 cut along the xy plane passing through the first ferromagnetic layer 1 of the laminate 10.

[0101] In the xy plane, the stacked bodies 10 constituting the magnetoresistive effect element are arranged in a matrix. Space 43 surrounds the stacked bodies 10. Space 43 is, for example, an annular shape surrounding the stacked bodies 10. Figure 13 The image shows an example where space 43 surrounds the entire perimeter of the stack 10, but space 43 may not surround the entire perimeter of the stack 10.

[0102] Figure 14 as well as Figure 15 This diagram illustrates the manufacturing method of the magnetic device according to the third modification. The third modification differs from the first embodiment in that an insulating layer 93, a photoresist R, and an insulating layer 94 are sequentially stacked to cover the laminate 10 and the electrode 33. (As shown...) Figure 15 As shown, by removing the resist R, a space 43 is formed that surrounds the laminate 10.

[0103] The magnetic device 202 in the third modification can achieve the same effect as the magnetic device 200 in the first embodiment. In addition, by surrounding the laminate 10 with space 43, heat propagation can be further suppressed.

[0104] (Second Implementation)

[0105] Figure 16 This is an enlarged cross-sectional view of the vicinity of the magnetoresistive effect element 110 of the magnetic device according to the second embodiment. Figure 16 The structure of the magnetoresistive element 110 and Figure 4 different.

[0106] The magnetoresistive element 110 in the second embodiment is composed of a laminate 50. The laminate 50 is composed of a first ferromagnetic layer 51, a second ferromagnetic layer 52, and a non-magnetic layer 53. The non-magnetic layer 53 is located between the first ferromagnetic layer 51 and the second ferromagnetic layer 52.

[0107] The first ferromagnetic layer 51 has domain walls DW. The resistance value of the magnetoresistive element 110 varies depending on the position of the domain walls DW. The magnetoresistive element 110 is sometimes referred to as a domain wall moving element.

[0108] The magnetoresistive element 110 is covered by an insulator In. A space 40 is located further outward than the sides of the laminate 50.

[0109] The magnetic device involved in the second embodiment differs only in that the magnetoresistive effect element 110 is a magnetic domain wall moving type magnetoresistive effect element, and can achieve the same effect as the magnetic device 200 involved in the first embodiment.

[0110] (Third Implementation)

[0111] Figure 17 This is a schematic diagram of the magnetic device 220 according to the third embodiment. The magnetic device 220 includes a plurality of magnetoresistive effect elements 120, a plurality of source lines SL, a plurality of bit lines BL, and a plurality of fourth switching elements Sw4.

[0112] The magnetoresistive elements 120 are arranged in a matrix, for example. The magnetoresistive elements 120 are connected to the source line SL and the bit line BL, respectively.

[0113] The flow of current to the magnetoresistive element 120 is controlled by the fourth switching element Sw4. The magnetoresistive element 120 performs data writing and reading by turning on the fourth switching element Sw4. The magnetoresistive element 120 writes data using spin-transfer torque by having current flow through it in the stacking direction. The fourth switching element Sw4 is the same as the first switching element Sw1, etc.

[0114] Figure 18 This is a cross-sectional view of the magnetic device 220 according to the third embodiment. The magnetoresistive element 100 and the transistor Tr are surrounded by an insulator In. A space 40 is formed within the insulator In.

[0115] The magnetic device 220 according to the third embodiment differs only in that the magnetoresistive effect element is a spin-transfer type magnetoresistive effect element, and can achieve the same effect as the magnetic device 200 according to the first embodiment.

[0116] Thus far, preferred embodiments of the present invention have been illustrated based on the first to third embodiments, but the present invention is not limited to these embodiments. For example, the characteristic structures in each embodiment and its variations can be applied to other embodiments.

Claims

1. A magnetic device, wherein, have: A laminate comprising a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; and An insulator that covers at least a portion of the sides of the laminate. The insulator has space on the outer side relative to the sides of the laminate. Between the laminate and the space, there exists a portion of the insulator. The surface of the space opposite to the side of the laminate is curved. The inclination direction of the curved surface of the space relative to the stacking direction of the laminate is the same as the inclination direction of the side surface of the laminate opposite to the curved surface relative to the stacking direction.

2. The magnetic device according to claim 1, wherein, Within the insulator, there are multiple spaces. The stacked body is held between the two spaces in the first direction.

3. The magnetic device according to claim 2, wherein, It also has: Wiring, which is connected to the laminate, The wiring extends along the first direction.

4. The magnetic device according to claim 1, wherein, The space surrounds the sides of the stack.

5. The magnetic device according to claim 1, wherein, It also has: Electrodes, which are connected to the laminate, The space is connected to the electrode.

6. The magnetic device according to claim 1, wherein, Having multiple of the aforementioned stacked bodies, The space is located between two of the plurality of stacked bodies.

7. The magnetic device according to claim 6, wherein, The space is located between the closest stacked bodies.

Images