Patent ID: 12201035

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present embodiment will be described in detail while referring the drawings as appropriate. In the drawings used in the following description, in some cases, the featured portion may be enlarged for convenience to make the feature easy to understand, and a dimensional ratio or the like of each component may be different from the actual one. Materials, dimensions, and the like exemplified in the following description are examples, the present invention is not limited thereto, and can be appropriately modified and carried out within the range in which the effects of the present invention are exhibited.

First, the direction will be defined. One direction of one surface of a substrate Sub (seeFIG.2) to be described later is defined as an x direction, and a direction orthogonal to the x direction is defined as a y direction. The x direction is, for example, a direction from an electrode31toward an electrode32. A z direction is a direction orthogonal to the x direction and the y direction. The z direction is an example of a stacking direction. The direction from the substrate Sub toward a magnetoresistance effect element100is defined as a +z direction. Hereinafter, in some cases, the +z direction may be expressed as “top” and a −z direction may be expressed as “bottom”. The top and bottom do not always coincide with the direction in which gravity is applied. In the present specification, “extending in the x direction” means, for example, that a dimension in the x direction is larger than a minimum dimension among dimensions in the x direction, the y direction, and the z direction. The same also applies to a case of extending in the other direction.

First Embodiment

FIG.1is a configuration diagram of a magnetic device200according to the first embodiment. The magnetic device200is equipped with a plurality of magnetoresistance effect elements100, a plurality of writing lines WL, a plurality of common lines CL, a plurality of reading lines RL, a plurality of first switching elements Sw1, a plurality of second switching elements Sw2, and a plurality of third switching elements Sw3. The magnetic device200can be used for a spin memoristor, a magnetic memory, an IoT device, a neuromorphic device, and the like.

The magnetoresistance effect element100is arranged, for example, in a matrix. Each of the magnetoresistance effect elements100is connected to each of the writing line WL, the reading line RL, and the common line CL.

The writing line WL electrically connects a power supply and one or more magnetoresistance effect elements100. The common line CL is a wiring used both when writing data and when reading data. The common line CL electrically connects a reference potential and one or more magnetoresistance effect elements100. The reference potential is, for example, ground. The common line CL may be provided in each of the plurality of magnetoresistance effect elements100, or may be provided over the plurality of magnetoresistance effect elements100. The reading line RL electrically connects the power supply and one or more magnetoresistance effect elements100. The power supply is connected to the magnetic device200during use.

Each magnetoresistance effect element100is connected to each of the first switching element Sw1, the second switching element Sw2, and the third switching element Sw3. The first switching element Sw1is connected between the magnetoresistance effect element100and the writing line WL. The second switching element Sw2is connected between the magnetoresistance effect element100and the common line CL. The third switching element Sw3is connected to a reading line RL extending over the plurality of magnetoresistance effect elements100.

When the first switching element Sw1and the second switching element Sw2are turned on, a writing current flows between the writing line WL and the common line CL connected to the predetermined magnetoresistance effect element100. When the writing current flows through the magnetoresistance effect element100, data is recorded in the magnetoresistance effect element100. When the second switching element Sw2and the third switching element Sw3are turned on, a reading current flows between the common line CL and the reading line RL connected to the predetermined magnetoresistance effect element100. When a reading current flows through the magnetoresistance effect element100, data is read from the magnetoresistance effect element100.

The first switching element Sw1, the second switching element Sw2, and the third switching element Sw3are elements that control the flow of current. The first switching element Sw1, the second switching element Sw2, and the third switching element Sw3are, for example, a transistor, an element such as an ovonic threshold switch (OTS) that utilizes a phase change of a crystal layer, an element such as a metal insulator transition (MIT) switch that utilizes a change in band structure, an element such as a Zener diode and an avalanche diode that utilizes a breakdown voltage, and an element whose conductivity changes with a change in atomic position.

In the magnetic device200shown inFIG.1, the magnetoresistance effect element100connected to the same wiring shares the third switching element Sw3. The third switching element Sw3may be provided in each magnetoresistance effect element100. Further, the third switching element Sw3may be provided in each magnetoresistance effect element100, and the first switching element Sw1or the second switching element Sw2may be shared by the magnetoresistance effect element100connected to the same wiring.

FIG.2is a cross-sectional view of the magnetic device200according to the first embodiment.FIG.2is a cross section of the magnetic device200taken along a xz plane passing through a center of a width of a spin-orbit torque wiring20to be described below in the y direction.

The first switching element Sw1and the second switching element Sw2shown inFIG.2are transistors Tr. The third switching element Sw3is connected to the reading line RL, and is located, for example, at a different position in the x direction ofFIG.2. The transistor Tr is, for example, a field effect transistor, and has a gate electrode G, a gate insulating film GI, a source S formed on the substrate Sub, and a drain D on the substrate Sub. A positional relationship between the source S and the drain D is an example, and may be opposite to each other. The substrate Sub is, for example, a semiconductor substrate.

The transistor Tr and the magnetoresistance effect element100are electrically connected to each other via a via wiring V and electrodes31and32. Further, the transistor Tr and the writing line WL or the common line CL are connected to each other by a via wiring V. Further, the reading line RL and the magnetoresistance effect element100are electrically connected to each other via an electrode33. The via wiring V and the electrodes31,32and33include a conductive material.

The periphery of the magnetoresistance effect element100and the transistor Tr is covered with an insulator In. The insulator In is an insulating layer that insulates between the wirings of the multilayer wiring and between the elements. The insulator In is, for example, silicon oxide (SiOx), silicon nitride (SiNx), silicon carbide (SiC), chromium nitride, silicon carbide (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrOx) and the like.

FIGS.3and4are cross-sectional views of the magnetic device200according to the first embodiment.FIG.3is a cross section of the magnetoresistance effect element100taken along the xz plane passing through the center of the width of the spin-orbit torque wiring20in the y direction.FIG.4is a cross section of the magnetoresistance effect element100taken along the yz plane passing through the center of the width of the stacked body10in the x direction.FIG.5is a plan view of the magnetoresistance effect element100as viewed from the z direction.

The magnetoresistance effect element100is equipped with, for example, the stacked body10and the spin-orbit torque wiring20. The resistance value of the stacked body10in the z direction changes as spin is injected into the stacked body10from the spin-orbit torque wiring20. The magnetoresistance effect element100is a magnetoresistance effect element that utilizes a spin orbit torque (SOT) and may be referred to as a spin orbit torque type magnetoresistance effect element, a spin injection type magnetoresistance effect element, or a spin current magnetoresistance effect element.

The magnetoresistance effect element100is a three-terminal type element to which three electrodes31,32, and33are connected. The electrodes31,32, and33are made of a conductive material. The electrodes31,32, and33include any selected from the group consisting of, for example, Al, Cu, Ta, Ti, Zr, NiCr, and nitrides (e.g., TiN, TaN, and SiN). The electrode33may also serve as a hard mask used in the manufacturing process of the magnetoresistance effect element100. The electrode33may be made of, for example, a transparent electrode material.

The electrode31and the electrode32are connected to the spin-orbit torque wiring20at a position where the stacked body10is sandwiched in the x direction in a plan view from the z direction. The electrode33is connected to the stacked body10. The stacked body10is connected to the reading line RL via the electrode33. The reading line RL extends in the x direction.

A radiator40is in the vicinity of the magnetoresistance effect element100. The radiator40is located outside a first insulating layer90that covers the side surface of the stacked body10with the stacked body10as a reference. The first insulating layer90is located between the stacked body10and the radiator40and is part of the insulator In.

The radiator40is, for example, a layer extending in the x direction. There are two radiators40shown inFIG.4, and the two radiators40sandwich the stacked body10in the y direction.

The radiator40is in the vicinity of the side surface of the stacked body10, and the shortest distance between the stacked body10and the radiator40in the x direction differs depending on the position in the z direction. Since the distance between the stacked body10and the radiator40in the x direction differs depending on the position in the z direction, it is possible to prevent the side surface of the stacked body10and the radiator40from coming into contact with each other on the surface, and prevent a short circuit of the stacked body10.

The radiator40is inclined with respect to the z direction. The radiator40is inclined toward the stacked body10, and for example, an upper end thereof is closer to a stacked body10than a lower end. An inclination direction of the radiator40with respect to the z direction is, for example, the same as the inclination direction of the adjacent side surfaces of the stacked body10with respect to the z direction.

The thickness of the radiator40is narrower than the width of the stacked body10. The thickness of the radiator40is an average value of a thickness of the radiator40in a direction orthogonal to a tangential plane of the radiator40, and the average value is an average of the thicknesses at five different points in the z direction. The width of the stacked body10is, for example, a width of the stacked body10in the x direction or the y direction, and may be a diameter.

When the thickness of the radiator40is thin, a ratio occupied by the radiator40with respect to the whole decreases, and an integration property of the entire magnetic device200is improved. For example, the thickness of the radiator40is thicker at the lower end than at the upper end. When the film thickness of the radiator40is thick in a portion close to the spin-orbit torque wiring20that tends to generate heat at the time of the writing operation, heat can be efficiently dissipated.

The height of the radiator40in the z direction is, for example, higher than that of the stacked body10. When the height of the radiator40is higher than that of the stacked body10, heat can be efficiently dissipated from any position of the stacked body in the z direction.

The radiator40has better thermal conductivity than the first insulating layer90. The radiator40includes, for example, metal. The radiator40includes, for example, any of copper, cobalt, tungsten, tantalum, ruthenium, and aluminum. The radiator40is, for example, a non-magnetic material. If the radiator40is a non-magnetic material, it is possible to prevent the leakage magnetic field from being applied from the radiator40to the stacked body10.

The radiator40preferably contains, for example, fine particles having an average particle size of 10 nm or less, and preferably contains fine particles having an average particle size of 5 nm or less. A contact resistance occurs at a contact interface of different particles. Since the radiator40contains the fine particles, the resistance increases, while ensuring the thermal conductivity. When the resistance of the radiator40increases, an occurrence of a short circuit via the radiator40is suppressed.

The radiator40is in contact with, for example, the spin-orbit torque wiring20. The spin-orbit torque wiring20is a portion through which a write current flows, and tends to generate heat. By dissipating heat from the spin-orbit torque wiring20via the radiator40, a breaking or the like of the spin-orbit torque wiring20can be suppressed. Further, since the radiator40is located in the vicinity of the first ferromagnetic layer1whose magnetization is inverted, it is possible to suppress the deterioration of the magnetization stability of the first ferromagnetic layer1.

The stacked body10is sandwiched between the spin-orbit torque wiring20and the electrode33in the z direction. The stacked body10is a columnar body. A shape of the stacked body10from the z direction when viewed in a plan view is, for example, a circle, an ellipse, or a quadrangle. The side surface of the stacked body10is, for example, inclined with respect to the z direction.

The stacked body10has, for example, a first ferromagnetic layer1, a second ferromagnetic layer2, and a non-magnetic layer3. The first ferromagnetic layer1is in contact with, for example, the spin-orbit torque wiring20and is stacked on the spin-orbit torque wiring20. Spin is injected into the first ferromagnetic layer1from the spin-orbit torque wiring20. The magnetization of the first ferromagnetic layer1receives spin-orbit torque (SOT) due to the injected spin, and an orientation direction thereof changes. The first ferromagnetic layer1and the second ferromagnetic layer2sandwich the non-magnetic layer3in the z direction.

The first ferromagnetic layer1and the second ferromagnetic layer2each have magnetization. The magnetization of the second ferromagnetic layer2is less likely to change in the orientation direction than the magnetization of the first ferromagnetic layer1when a predetermined external force is applied. The first ferromagnetic layer1is called a magnetization free layer, and the second ferromagnetic layer2is sometimes called a magnetization fixed layer or a magnetization reference layer. A resistance value of the stacked body10changes depending on a difference in relative angles of magnetization between the first ferromagnetic layer1and the second ferromagnetic layer2sandwiching the non-magnetic layer3.

The first ferromagnetic layer1and the second ferromagnetic layer2include a ferromagnetic material. The ferromagnetic material is, for example, a metal selected from a group consisting of Cr, Mn, Co, Fe and Ni, an alloy containing at least one of these metals, and an alloy containing at least one or more elements of these metals and B, C, and N. The ferromagnetic material is, for example, Co—Fe, Co—Fe—B, Ni—Fe, Co—Ho alloy, Sm—Fe alloy, Fe—Pt alloy, Co—Pt alloy, and CoCrPt alloy.

The first ferromagnetic layer1and the second ferromagnetic layer2may contain a Heusler alloy. The Heusler alloy includes intermetallic compounds with a chemical composition of XYZ or X2YZ. X is a transition metal element or a noble metal element of Group Co, Fe, Ni, or Cu on the periodic table, Y is a transition metal of Group Mn, V, Cr or Ti, or an elemental species of X, and Z is a typical element of group III to Group V. The Heusler alloy is, for example, Co2FeSi, Co2FeGe, Co2FeGa, Co2MnSi, Co2Mn1-aFeaAlbSi1-b, Co2FeGe1-cGacand the like. The Heusler alloy have a high spin polarizability.

The non-magnetic layer3contains a non-magnetic material. When the non-magnetic layer3is an insulator (when it is a tunnel barrier layer), for example, Al2O3, SiO2, MgO, MgAl2O4and the like can be used as the material thereof. In addition to these, it is also possible to use a material in which part of Al, Si, and Mg is replaced with Zn, Be, and the like. Among them, since MgO and MgAl2O4are materials that can realize a coherent tunnel, spin can be efficiently injected. When the non-magnetic layer3is a metal, Cu, Au, Ag or the like can be used as the material. Further, when the non-magnetic layer3is a semiconductor, Si, Ge, CuInSe2, CuGaSe2, Cu (In, Ga) Se2and the like can be used as the material thereof.

The stacked body10may have layers other than the first ferromagnetic layer1, the second ferromagnetic layer2, and the non-magnetic layer3. For example, a base layer may be provided between the spin-orbit torque wiring20and the first ferromagnetic layer1. The base layer enhances the crystallinity of each layer constituting the stacked body10. Further, for example, a cap layer may be provided on the uppermost surface of the stacked body10.

Further, the stacked body10may be provided with a ferromagnetic layer on the surface of the second ferromagnetic layer2opposite to the non-magnetic layer3via a spacer layer. The second ferromagnetic layer2, the spacer layer, and the ferromagnetic layer have a synthetic antiferromagnetic structure (SAF structure). The synthetic antiferromagnetic structure consists of two magnetic layers sandwiching the non-magnetic layer. The antiferromagnetic coupling between the second ferromagnetic layer2and the ferromagnetic layer increases the coercive force of the second ferromagnetic layer2as compared with a case of having no ferromagnetic layer. The ferromagnetic layer is, for example, IrMn, PtMn, or the like. The spacer layer contains, for example, at least one selected from the group consisting of Ru, Ir, and Rh.

The spin-orbit torque wiring20extends, for example, in the x direction. The write current flows along the spin-orbit torque wiring20. At least part of the spin-orbit torque wiring20sandwiches the first ferromagnetic layer1together with the non-magnetic layer3in the z direction.

The spin-orbit torque wiring20generates a spin current by a spin Hall effect when the current I flows, and injects spin into the first ferromagnetic layer1. The spin-orbit torque wiring20applies, for example, spin-orbit torque (SOT) sufficient to reverse the magnetization of the first ferromagnetic layer1to the magnetization of the first ferromagnetic layer1. The spin Hall effect is a phenomenon in which a spin current is induced in a direction orthogonal to the direction in which a current flows, on the basis of the spin-orbit interaction when a current flows. The spin Hall effect is common to a normal Hall effect in that a motion (moving) charge (electron) bend a motion (moving) direction. In the normal Hall effect, the motion direction of a charged particle moving in a magnetic field is bent by a Lorentz force. On the other hand, in the spin Hall effect, even in the absence of a magnetic field, the movement direction of spin is bent only by the movement of electrons (only the flow of current).

For example, when a current flows through the spin-orbit torque wiring20, a first spin oriented in one direction and a second spin oriented in a direction opposite to the first spin are each bent by a spin hole effect in the direction orthogonal to the direction in which the current flows. For example, the first spin oriented in a −y direction is bent in a +z direction, and the second spin oriented in a +y direction is bent in a −z direction.

In a non-magnetic material (a material that is not a ferromagnetic material), the number of electrons of the first spin and the number of electrons of the second spin generated by the spin Hall effect are equal. That is, the number of electrons of the first spin oriented in the +z direction is equal to the number of electrons of the second spin oriented in the −z direction. The first spin and the second spin current in a direction of eliminating the uneven distribution of spins. In the movement of the first spin and the second spin in the z direction, because the flows of charge cancel each other out, the amount of current becomes zero. A spin current without the current is particularly called a pure spin current.

When flow of the electron of the first spin is expressed by J↑, the electron flow of the second spin is expressed by J↓, and the spin current is expressed by JS, they are defined as JS=J↑−J↓. The spin current JSoccurs in the z direction. The first spin is injected into the first ferromagnetic layer1from the spin-orbit torque wiring20.

The spin-orbit torque wiring20contains any one of metal, alloy, intermetallic compound, metal boroide, metal carbide, metal silicide, and metal phosphide having a function of generating a spin current by the spin Hall effect when the current I flows.

The spin-orbit torque wiring20contains, for example, a non-magnetic heavy metal as a main component. The heavy metal means a metal having a specific gravity of yttrium (Y) or more. The non-magnetic heavy metal is, for example, a non-magnetic metal having a d-electron or an f-electron in the outermost shell and having a large atomic number of 39 or more. The spin-orbit torque wiring20is made up of, for example, Hf, Ta, and W. Non-magnetic heavy metals have stronger spin-orbit interaction than other metals. The spin-hole effect is generated by the spin-orbit interaction, and spins are likely to be unevenly distributed in the spin-orbit torque wiring and spin current JSis likely to occur.

The spin-orbit torque wiring20may also contain a magnetic metal. The magnetic metal is a ferromagnetic metal or an antiferromagnetic metal. A small amount of magnetic metal contained in the non-magnetic material becomes a spin scattering factor. The small amount is, for example, 3% or less of a total molar ratio of the elements constituting the spin-orbit torque wiring20. When the spins are scattered by the magnetic metal, the spin-orbit interaction is enhanced, and the generation efficiency of spin current with respect to the current is increased.

The spin-orbit torque wiring20may include a topological insulator. The topological insulator is a substance in which the inside of the substance is an insulator or a high resistor, but a metallic state in which spin polarization occurs on the surface thereof. In the topological insulator, an internal magnetic field is generated by the spin-orbit interaction. The topological insulator develops a new topological phase due to the effect of spin-orbit interaction even in the absence of an external magnetic field. The topological insulator can generate pure spin currents with high efficiency due to strong spin-orbit interaction and breaking of inversion symmetry at the edges.

The topological insulator is, for example, SnTe, Bi1.5Sb0.5Te1.7Se1.3, TlBise2, Bi2Te3, Bi1-xSbx, (Bi1-xSbx)2Te3and the like. The topological insulator can generate spin currents with high efficiency.

Next, a method of manufacturing the magnetic device200will be described. The magnetic device200is formed by a stacking process of each layer, and a processing process of processing part of each layer into a predetermined shape. Each layer can be stacked, using a sputtering method, a chemical vapor deposition (CVD) method, an electron beam vapor deposition method (EB vapor deposition method), an atomic laser deposit method, or the like. Each layer can be processed, using photolithography or the like.

Hereinafter, a method for manufacturing the vicinity of the magnetoresistance effect element100will be described. First, a conductive film is formed on the insulating layer and the electrodes31and32and processed into a predetermined shape to form the spin-orbit torque wiring20. Further, the periphery of the spin-orbit torque wiring20is filled with an insulating layer.

Next, an upper surface of the spin-orbit torque wiring20is exposed by chemical mechanical polishing (CMP). Next, the magnetic layer, the non-magnetic layer, and the magnetic layer are stacked sequentially on the spin-orbit torque wiring20and the insulating layer. Further, a hard mask is formed at a predetermined position on the magnetic layer.

Next, the magnetic layer, the non-magnetic layer, and the magnetic layer are processed via a hard mask. Each of the magnetic layers becomes the first ferromagnetic layer1and the second ferromagnetic layer, the non-magnetic layer becomes the non-magnetic layer3, and the stacked body10is formed. The hard mask becomes, for example, part of the electrode33. The first insulating layer90is formed so as to cover the stacked body10and the electrode33. Next, a conductive layer and an insulating layer are formed to cover the first insulating layer90.

Next, some parts of the first insulating layer90, the conductive layer, and the insulating layer are removed by chemical mechanical polishing (CMP) to expose the electrode33. The conductive layer on the first insulating layer90becomes the radiator A reading line RL is formed on the electrode33and the insulating layer. The magnetoresistance effect element100shown inFIGS.3to5can be obtained by the above procedure.

The magnetic device200according to the first embodiment has a radiator40on the outside of the stacked body10. The radiator40has better heat radiating properties than the first insulating layer90, and radiates heat from the vicinity of the magnetoresistance effect element100. By radiating heat from the vicinity of the magnetoresistance effect element100, the magnetization stability of the first ferromagnetic layer1and the second ferromagnetic layer2is improved. Further, it is possible to suppress the accumulation of heat in the spin-orbit torque wiring20which tends to generate heat when writing, and prevent disconnection or the like of the spin-orbit torque wiring20.

First Modified Example

FIG.6is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element101of the magnetic device according to the first modified example. InFIG.6, the same components as those ofFIG.4are designated by the same reference numerals, and the description thereof will not be provided.

A radiator41is provided in the vicinity of the magnetoresistance effect element101. The radiator41is different from the radiator40according to the first embodiment in that the radiator41is in contact with the reading line RL rather than the spin-orbit torque wiring20.

The electrodes31,32, and33are in contact with the reading line RL or a via wiring V having a large heat capacity. Therefore, most of the heat generated by the magnetoresistance effect element101escapes via the electrodes31,32, and33. When the radiator40comes into contact with the reading line RL, the heat collected in the radiator40can be efficiently dissipated from the radiator40to the reading line RL.

The magnetoresistance effect element101according to the first modified example can efficiently dissipate the generated heat, as in the magnetoresistance effect element100according to the first embodiment.

Second Modified Example

FIG.7is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element102of the magnetic device according to the second modified example. InFIG.7, the same components as those ofFIG.4are designated by the same reference numerals, and the description thereof will not be provided.

A radiator42is provided in the vicinity of the magnetoresistance effect element102. The radiator42is different from the radiator40according to the first embodiment in that the radiator42is in contact with the stacked body10rather than the spin-orbit torque wiring20. The radiator42is in contact with either one of the first ferromagnetic layer1and the second ferromagnetic layer2of the stacked body10. When the radiator42is in contact with only one of the first ferromagnetic layer1and the second ferromagnetic layer2, a short circuit via the radiator42can be prevented.

The magnetoresistance effect element102according to the second modified example can efficiently dissipate the generated heat, as in the magnetoresistance effect element100according to the first embodiment.

Third Modified Example Example

FIG.8is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element103of the magnetic device according to the third modified example. InFIG.8, the same components as those ofFIG.4are designated by the same reference numerals, and the description thereof will not be provided.

The magnetoresistance effect element103differs from the magnetoresistance effect element100according to the first embodiment in the stacking order of each layer. The second ferromagnetic layer2is closer to a substrate Sub than the first ferromagnetic layer1whose magnetization direction changes. Such a magnetoresistance effect element103is called a bottom pin structure. The spin-orbit torque wiring21is formed on the stacked body10.

The radiator43extends in the x direction and sandwiches the stacked body10in the y direction. A distance between the radiator43and the stacked body11differs depending on the position in the z direction. The distance between the radiator43and the first ferromagnetic layer1is shorter than the distance between the radiator43and the second ferromagnetic layer2. The magnetization stability of the first ferromagnetic layer1is lower than the magnetization stability of the second ferromagnetic layer2. Since the radiator43exists near the first ferromagnetic layer1having low magnetization stability, the magnetic stability of the magnetoresistance effect element103is improved. Since the magnetoresistance effect element103stores data depending on the direction of magnetization of the first ferromagnetic layer1, improvement of the magnetization stability of the first ferromagnetic layer1leads to improvement of data reliability.

The magnetoresistance effect element103according to the third modified example can efficiently dissipate the generated heat, as in the magnetoresistance effect element100according to the first embodiment.

Fourth Modified Example

FIG.9is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element104of the magnetic device according to the fourth modified example. InFIG.9, the same components as those ofFIG.4are designated by the same reference numerals, and the description thereof will not be provided.

In the magnetoresistance effect element104, the side surfaces of the stacked body10and the spin-orbit torque wiring20in the y direction are continuous. The structure is obtained by simultaneously processing the shapes of the stacked body10and the spin-orbit torque wiring20in the y direction.

A radiator44is provided in the vicinity of the magnetoresistance effect element104. A height of the radiator44in the z direction is higher than, for example, a total height of the spin-orbit torque wiring20and the stacked body10.

The magnetoresistance effect element104according to the fourth modified example can efficiently dissipate the generated heat, as in the magnetoresistance effect element100according to the first embodiment.

Fifth Modified Example

FIG.10is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element105of the magnetic device according to the fifth modified example. InFIG.10, the same components as those ofFIG.4are designated by the same reference numerals, and the description thereof will not be provided.

A plurality of radiators45are provided in the vicinity of the magnetoresistance effect element105. A plurality of radiators45are provided toward the outside with respect to the stacked body10. The insulating layer and the radiator45alternately cover the side surfaces of the stacked body10.

The magnetoresistance effect element105according to the fifth modified example can efficiently dissipate the generated heat, as in the magnetoresistance effect element100according to the first embodiment. Further, since the number of radiators is large, the magnetoresistance effect element105is exceptional in heat radiating properties.

Sixth Modified Example

FIG.11is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element106of the magnetic device according to the sixth modified example. InFIG.11, the same components as those ofFIG.4are designated by the same reference numerals, and the description thereof will not be provided.

The magnetoresistance effect element106has a space50. The space50is located outside the radiator40with respect to the stacked body10. The space50is in contact with, for example, the radiator40. That is, part of the radiator40is exposed to the space50. The space50is, for example, located below the reading line RL. The space50is obtained by forming a resist on the radiator40, forming the reading line RL, and then removing the resist. The inside of the space50is a vacuum or an atmosphere, and has exceptional heat insulating properties.

As in the magnetoresistance effect element100according to the first embodiment, the magnetoresistance effect element106according to the sixth modified example can suppress the heat from being transferred to the surrounding elements, while efficiently dissipating the generated heat.

The space50suppresses heat conduction from the radiator40to the surroundings. Therefore, the heat generated by the magnetoresistance effect element106reaches the radiator40and then goes in the z direction. That is, the magnetoresistance effect element106according to the sixth modified example can control the flow of heat.

Seventh Modified Example

FIG.12is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element107of the magnetic device according to the seventh modified example. InFIG.12, the same components as those ofFIG.11are designated by the same reference numerals, and the description thereof will not be provided.

The magnetoresistance effect element107has a space51. The space51is located outside the radiator40with respect to the stacked body10. The space51is different from the sixth modified example in that it is not in contact with the radiator40.

The magnetoresistance effect element107according to the seventh modified example has the same effect as that of the sixth modified example. Further, by covering the radiator40with the insulator In, it is possible to prevent the radiator40from being unintentionally peeled off.

Second Embodiment

FIG.13is an enlarged cross-sectional view of the vicinity of a magnetoresistance effect element110of the magnetic device according to the second embodiment. InFIG.13, the configuration of the magnetoresistance effect element110is different from that ofFIG.4.

The magnetoresistance effect element110according to the second embodiment is made of a stacked body12. The stacked body12includes a first ferromagnetic layer4, a second ferromagnetic layer5, and a non-magnetic layer6. The non-magnetic layer6is located between the first ferromagnetic layer4and the second ferromagnetic layer5.

The first ferromagnetic layer4has a domain wall DW. A resistance value of the magnetoresistance effect element110changes depending on the position of the domain wall DW. In some cases, the magnetoresistance effect element110may be referred to as a domain wall moving element.

The magnetoresistance effect element110is coated with the insulator In. A radiator46is located outside the outer surface of the stacked body12.

The magnetic device according to the second embodiment is different in that the magnetoresistance effect element110is a domain wall moving type magnetoresistance effect element, and the same effect as that of the magnetic device200according to the first embodiment can be obtained.

Third Embodiment

FIG.14is a schematic view of a magnetic device220according to the third embodiment. The magnetic device220includes a plurality of magnetoresistance effect elements120, a plurality of source lines SL, a plurality of bit lines BL, and a plurality of fourth switching elements Sw4.

The magnetoresistance effect elements120are arranged, for example, in a matrix. Each of the magnetoresistance effect elements120is connected to the source line SL and the bit line BL.

The flow of current to the magnetoresistance effect element120is controlled by a fourth switching element Sw4. The magnetoresistance effect element120writes and reads data by turning on the fourth switching element Sw4. The magnetoresistance effect element120writes the data, using a spin transfer torque when a current flows in the stacking direction. The fourth switching element Sw4is the same as the first switching element Sw1or the like.

FIG.15is a cross-sectional view of the magnetic device220according to the third embodiment. The periphery of the magnetoresistance effect element100and the transistor Tr is covered with an insulator In. A radiator47is formed inside the insulator In.

FIG.16is an enlarged cross-sectional view of the vicinity of the magnetoresistance effect element120of the magnetic device220according to the third embodiment.FIG.16is a cut surface taken along the xy plane passing through the first ferromagnetic layer1.

The radiator47surrounds the side surface of the stacked body10. The radiator47shown inFIG.16surrounds the entire circumference of the stacked body10, but may partially surround the stacked body10. A first insulating layer90is provided between the radiator47and the stacked body10.

The magnetic device220according to the third embodiment is different in that the magnetoresistance effect element is a spin transfer type magnetoresistance effect element, and the same effect as that of the magnetic device200according to the first embodiment can be obtained.

Although preferred embodiments of the present invention have been shown here based on the first to third embodiments, the present invention is not limited to these embodiments. For example, the characteristic configurations in each embodiment and modified example may be applied to other embodiments.

EXPLANATION OF REFERENCES

1,4First ferromagnetic layer2,5Second ferromagnetic layer3,6Non-magnetic layer10,11,12Stacked body20,21spin-orbit torque wiring31,32,33Electrode40,41,42,43,44,45,46,47Radiator50,51Space90First insulating layer100,101,102,103,104,105,106,107,110,120Magnetoresistance effect element200,220Magnetic deviceBL Bit lineCL Common lineIn InsulatorRL Reading lineSL Source lineSub SubstrateWL Writing line