Spin inductor

Abstract

This spin inductor comprises a first wiring layer, a first ferromagnetic layer that is in contact with a first surface of the wiring layer, and a second ferromagnetic layer that is in contact with a second surface on the opposite side from the first surface of the first wiring layer. The magnetization of the first ferromagnetic layer and the magnetization of the second ferromagnetic layer have an anti-parallel relationship. The first wiring layer includes any one or more elements selected from the group consisting of Cr, Mo, and Re.

Description

Spin inductor

[0001] The present disclosure relates to spin inductors.

[0002] Inductors, along with resistors and capacitors, are major electronic components used in a variety of electronic devices. A coil is one example of an inductor. There is a trade-off between the size of a coil and the strength of its inductance, and it is difficult to achieve large inductance with a small coil.

[0003] In recent years, attention has been focused on new types of inductors that do not use coils. New types of inductors that do not use coils are sometimes called emergent inductors. For example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2 disclose new inductors that utilize spin vibrations (hereinafter referred to as spin inductors). Spin inductors have attracted attention because the smaller the element size, the stronger the inductance strength, making it possible to achieve both miniaturization and inductance strength.

[0004] International Publication No. 2022 / 181069

[0005] Yuta Yamane, Shunsuke Fukami, and Junichi Ieda, Physical Review Letters 128,147201 (202).Yasufumi Araki and Jun'ichi Ieda, Journal of the Physical Society of Japan 92, 074705 (2023).

[0006] There is a demand for inductors that are small and have large inductance. To achieve both of these characteristics, there is a demand for inductors that can provide large inductance more efficiently.

[0007] The present disclosure has been made in view of the above circumstances, and has an object to provide a spin inductor that efficiently exhibits large inductance.

[0008] To solve the above problems, the present disclosure provides the following means.

[0009] A spin inductor according to a first aspect includes a first wiring layer, a first ferromagnetic layer in contact with a first surface of the first wiring layer, and a second ferromagnetic layer in contact with a second surface of the first wiring layer opposite the first surface. The magnetization of the first ferromagnetic layer and the magnetization of the second ferromagnetic layer are antiparallel. The first wiring layer includes at least one selected from the group consisting of Cr, Mo, and Re.

[0010] 1 is a perspective view of a spin inductor according to a first embodiment. FIG. 2 is a cross-sectional view of a spin inductor according to the first embodiment. FIG. 3 is a plan view of a spin inductor according to the first embodiment. FIG. 4 is a schematic diagram for explaining the function of the spin inductor according to the first embodiment. FIG. 5 is a cross-sectional view of a spin inductor according to a second embodiment. FIG. 6 is a cross-sectional view of a spin inductor according to a third embodiment. FIG. 7 is a perspective view of a spin inductor according to a fourth embodiment. FIG. 8 is a cross-sectional view of a spin inductor according to the fourth embodiment. FIG. 9 is a perspective view of a spin inductor according to a fifth embodiment. FIG. 10 is a plan view of a spin inductor according to the fifth embodiment. FIG. 11 is a cross-sectional view of a spin inductor according to the fifth embodiment. FIG. 12 is a schematic diagram for explaining the function of the spin inductor according to the fifth embodiment. FIG. 13 is a plan view of a first modified example of the spin inductor according to the fifth embodiment. FIG. 14 is an example of use of the spin inductor according to this embodiment.

[0011] The present embodiment will be described in detail below with reference to the accompanying drawings. The drawings used in the following description may show characteristic portions enlarged for ease of understanding, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present disclosure is not limited thereto. Appropriate modifications can be made within the scope of the present disclosure.

[0012] First, the directions are defined. The x-direction is one direction of the plane in which each layer extends. Furthermore, the y-direction is the direction perpendicular to the x-direction in the plane in which each layer extends. For example, the x-direction is the direction connecting the first terminal 20 and the second terminal 30. The x-direction is an example of the first direction. Furthermore, the thickness direction of each layer is the z-direction. The z-direction is perpendicular to the x-direction and y-directions. The z-direction is an example of the stacking direction.

[0013] In this specification, "extending in the x-direction" means that the dimension in the x-direction is greater than the smallest dimension among the dimensions in the x-direction, y-direction, and z-direction. The same applies to extending in other directions.

[0014] "First Embodiment" Fig. 1 is a perspective view of a spin inductor 100 according to a first embodiment. Fig. 2 is a cross-sectional view of the spin inductor 100 according to the first embodiment. Fig. 3 is a plan view of the spin inductor 100 according to the first embodiment.

[0015] The spin inductor 100 is an inductor that operates by the vibration of magnetization in a magnetic material. The spin inductor 100 cuts the high-frequency component of a current and passes the constant component of the current. The current flows between a first terminal 20 and a second terminal 30. The spin inductor 100 is disposed in a portion where it is desired to cut off the high-frequency current. The high-frequency current is cut by the spin inductor 100, but a direct current flows through the spin inductor 100. For a direct current, the spin inductor 100 is a resistor.

[0016] The spin inductor 100 has a laminate 10 , a first terminal 20 and a second terminal 30 .

[0017] The first terminal 20 contacts the first side surface 10A of the laminate 10. The first terminal 20 contacts the first wiring layer 1, the first ferromagnetic layer 2, and the second ferromagnetic layer 3 of the laminate 10. The first side surface 10A is inclined with respect to the z direction. The first side surface 10A is inclined with respect to the yz plane.

[0018] The first terminal 20 is a conductor. Current flows from the first terminal 20 to the laminate 10. The laminate 10 is a laminate in which thin films are stacked. By tilting the first side surface 10A, the contact area between the thin films constituting the laminate 10 and the first terminal 20 becomes larger, and the electrical connection between the thin films constituting the laminate 10 and the first terminal 20 becomes stable.

[0019] The second terminal 30 contacts the second side surface 10B of the laminate 10. The second side surface 10B is a side surface different from the first side surface 10A of the laminate 10. The second side surface 10B is, for example, a side surface opposite the first side surface 10A in the x direction. The second terminal 30 contacts the first wiring layer 1, the first ferromagnetic layer 2, and the second ferromagnetic layer 3 of the laminate 10. The second side surface 10B is inclined with respect to the z direction. The second side surface 10B is inclined with respect to the yz plane.

[0020] The second terminal 30 is a conductor. Current flows from the laminate 10 to the second terminal 30. The inclination of the second side surface 10B increases the contact area between the thin film constituting the laminate 10 and the second terminal 30, stabilizing the electrical connection between the thin film constituting the laminate 10 and the second terminal 30.

[0021] Here, an example has been shown in which the first terminal 20 and the second terminal 30 are formed on the side surfaces of the laminate 10, but the first terminal 20 and the second terminal 30 are not limited to this example. For example, the first terminal 20 and the second terminal 30 may be connected to the upper surface or the lower surface of the laminate 10. In this case, via wiring that contacts the laminate 10 and extends in the z direction becomes the first terminal 20 and the second terminal 30.

[0022] The stack 10 includes a first wiring layer 1 , a first ferromagnetic layer 2 , and a second ferromagnetic layer 3 .

[0023] For example, the length of the first wiring layer 1 in the x direction is shorter than the length in the y direction. For example, the length of the stacked body 10 in the x direction is shorter than the length in the y direction. If the length of the first wiring layer 1 in the y direction is long, the current density of the current flowing through the first wiring layer 1 becomes small. Furthermore, if the length of the first wiring layer 1 in the x direction is short, the resistance of the spin inductor 100 becomes low.

[0024] The first wiring layer 1 includes any of a metal, alloy, intermetallic compound, metal boride, metal carbide, metal silicide, and metal phosphide, which have the function of generating a spin current by the spin Hall effect when a current flows. The first wiring layer 1 is sometimes called a spin orbit torque wiring.

[0025] The first wiring layer 1 contains one or more elements selected from the group consisting of Cr, Mo, and Re. Cr, Mo, and Re are the main components in the first wiring layer 1. The term "main component" means that they account for 50% or more of the elements in the first wiring layer 1. For example, when the first wiring layer 1 contains both Cr and Mo, the total of these elements needs to account for 50% or more. The first wiring layer 1 may also be a metal film of Cr, Mo, or Re, or an alloy containing Cr, Mo, and Re. It is particularly preferable that the first wiring layer 1 be a metal film of Mo.

[0026] Cr, Mo, and Re have stronger spin-orbit interactions than other metals. The spin-Hall effect is caused by the spin-orbit interaction. When spins tend to be unevenly distributed in the first wiring layer 1 due to the spin-Hall effect, the spin current J Ｓ is more likely to occur.

[0027] Furthermore, when the first wiring layer 1 satisfies the above-described configuration, the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are antiparallel to each other. This is because an exchange bias acts between the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3, causing antiferromagnetic coupling between the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3. As will be described in detail later, when the magnetization M2 and the magnetization M3 precess while maintaining antiferromagnetic coupling, the precessions of the magnetization M2 and the magnetization M3 are synchronized. The synchronous precession of the magnetization M2 and the magnetization M3 allows the spin inductor 100 to exhibit a large inductance.

[0028] The thickness of the first wiring layer 1 is, for example, 0.1 nm to 10 nm, preferably 0.2 nm to 3 nm. When the thickness of the first wiring layer 1 satisfies a predetermined relationship, it becomes easier to maintain the antiferromagnetically coupled state between the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3.

[0029] The first ferromagnetic layer 2 contacts the first surface of the first wiring layer 1. The first ferromagnetic layer 2 contacts, for example, the bottom surface of the first wiring layer 1.

[0030] The first ferromagnetic layer 2 is a ferromagnetic material. The ferromagnetic material is, for example, a metal selected from the group consisting of Cr, Mn, Co, Fe, and Ni, an alloy containing one or more of these metals, or an alloy containing one or more of these metals and at least one of B, C, and N. The ferromagnetic material preferably contains one or more elements selected from the group consisting of Co, Fe, Ni, Mn, Nd, Gd, and Tb.

[0031] Examples of the ferromagnetic material include Co—Fe, Co—Fe—B, Ni—Fe, Co—Ho alloy, Sm—Fe alloy, Fe—Pt alloy, Co—Pt alloy, and CoCrPt alloy. ０ CoFe alloys of this type have large saturation magnetization and strong magnetic anisotropy, and when used for the first ferromagnetic layer 2, the resonant frequency of the spin inductor 100 becomes high.

[0032] The first ferromagnetic layer 2 may also be a magnetic insulator. The first ferromagnetic layer 2 may also be a ferrimagnetic insulator or an antiferromagnetic insulator. When the first ferromagnetic layer 2 is an antiferromagnetic insulator, the resonance frequency of the first ferromagnetic layer 2 becomes high. In this case, resonance does not occur even in the high frequency range of 10 GHz or more. Therefore, a spin inductor in which the first ferromagnetic layer 2 is an antiferromagnetic insulator can exhibit stable inductance over a wide frequency band. For example, antiferromagnetic insulators can be made of NiO, MnO, Cr ２ O ３ , oxides containing magnetic elements such as ferrite and garnet, sulfides containing magnetic elements such as MnS, FeCl ２ These include chlorides containing magnetic elements such as:

[0033] The second ferromagnetic layer 3 contacts the second surface of the first wiring layer 1. The second surface is the surface of the first wiring layer 1 that faces the first surface. The second ferromagnetic layer 3 covers, for example, the entire upper surface of the first wiring layer 1.

[0034] The second ferromagnetic layer 3 includes the same material as the first ferromagnetic layer 2. The second ferromagnetic layer 3 may include the same material as the first ferromagnetic layer 2, or may include a different material.

[0035] The magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are oriented in opposite directions when no current flows through the first wiring layer 1 and no external magnetic field is applied (hereinafter referred to as the initial state). Here, "no current flows" refers to a state in which no potential difference is applied to the first wiring layer 1. Also, "no external magnetic field is applied" refers to a state in which no intentional magnetic field is applied to the first ferromagnetic layer 2 and the second ferromagnetic layer 3. In the initial state, the magnetization M2 of the first ferromagnetic layer 2 is oriented in the opposite direction to the magnetization M3 of the second ferromagnetic layer 3. In other words, the magnetization M2 and the magnetization M3 are in an antiparallel relationship in the initial state. The antiparallel relationship between the magnetization M2 and the magnetization M3 is basically maintained even when the magnetizations M2 and M3 precess.

[0036] 2, the magnetization M2 is oriented in the −z direction and the magnetization M3 is oriented in the +z direction, but these relationships may be reversed. Furthermore, the magnetizations M2 and M3 may be oriented in any direction within the xy plane or in a direction tilted from the xy plane toward the z direction.

[0037] From the viewpoint of maintaining the precession of the magnetization M2 and the magnetization M3, it is preferable that the magnetization M2 and the magnetization M3 have a component oriented in the x direction or the z direction in the initial state, and it is more preferable that they are oriented in the x direction or the z direction.

[0038] When the magnetization M2 and the magnetization M3 are oriented in the y direction, the magnetization M2 and the magnetization M3 are more likely to reverse than when the magnetization M2 and the magnetization M3 are oriented in other directions. When the magnetization reversal occurs, the precession of the magnetization M2 and the magnetization M3 is no longer maintained. Because the spin inductor 100 exhibits its inductor function by utilizing energy conversion between a magnetic moment and a current, if the precession of the magnetization stops, the inductor function is not fully exhibited.

[0039] Even when magnetization M2 and magnetization M3 are oriented in the y direction, the precession of magnetization M2 and magnetization M3 can be maintained by adjusting the current density of the current flowing through the first wiring layer 1, the coercive force of magnetization M2 and magnetization M3, etc.

[0040] Next, a description will be given of the function of the spin inductor 100. FIG.

[0041] The spin inductor 100 functions as an inductor when a current I1 flows along the first wiring layer 1. When a current is applied between the first terminal 20 and the second terminal 30, the current I1 flows within the plane of the first wiring layer 1.

[0042] The current I1 flowing in the first wiring layer 1 generates a spin current due to the spin Hall effect.

[0043] The spin Hall effect is a phenomenon in which, when an electric current is passed through it, a spin current is induced in a direction perpendicular to the direction of the current flow (for example, the z direction) due to spin-orbit interaction. The spin Hall effect is similar to the standard Hall effect in that the direction of movement of moving charges (electrons) is bent. In the standard Hall effect, the direction of movement of charged particles moving in a magnetic field is bent by the Lorentz force. In contrast, in the spin Hall effect, the direction of spin movement is bent simply by the movement of electrons (the flow of electric current), even in the absence of a magnetic field.

[0044] For example, when a current I1 flows in the x direction of the first wiring layer 1, the spins S1 polarized in the -y direction are bent in the +z direction relative to the direction of travel, and the spins S2 polarized in the +y direction are bent in the -z direction relative to the direction of travel.

[0045] The spins S2 are injected from the first surface 1A into the adjacent second ferromagnetic layer 3. The spins S1 are injected from the second surface 1B into the adjacent first ferromagnetic layer 2. When the distance between the first wiring layer 1 and the first ferromagnetic layer 2 is equal to or shorter than the spin diffusion length of the spins S2, the spins S2 generated in the first wiring layer 1 can be efficiently injected into the first ferromagnetic layer 2. Furthermore, when the distance between the first wiring layer 1 and the second ferromagnetic layer 3 is equal to or shorter than the spin diffusion length of the spins S1, the spins S1 generated in the first wiring layer 1 can be efficiently injected into the second ferromagnetic layer 3. An intermediate layer may be provided between the first wiring layer 1 and the first ferromagnetic layer 2 or between the first wiring layer 1 and the second ferromagnetic layer 3.

[0046] The magnetization M2 of the first ferromagnetic layer 2 precesses due to the spins S2 injected from the first wiring layer 1. The coercive force of the magnetization M2 and the magnitude of the current flowing through the first wiring layer 1 are adjusted so that the magnetization M2 precesses without being reversed due to the injected spins S2.

[0047] The magnetization M3 of the second ferromagnetic layer 3 precesses due to the spins S1 injected from the first wiring layer 1. The coercive force of the magnetization M3 and the magnitude of the current flowing through the first wiring layer 1 are adjusted so that the magnetization M3 precesses without being reversed by the injected spins S1.

[0048] The magnetization M2 and the magnetization M3 are antiparallel to each other. Furthermore, the spin S2 acting on the magnetization M2 and the spin S1 acting on the magnetization M3 are polarized in opposite directions. Therefore, the magnetization M2 and the magnetization M3 precess in the same direction. By aligning the rotation directions of the precession of the magnetization M2 and the magnetization M3, it is possible to prevent the inductor functions generated in the first ferromagnetic layer 2 and the second ferromagnetic layer 3 from weakening each other.

[0049] When the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 precess, energy conversion occurs between the magnetic moment and current, and the spin inductor 100 exhibits an inductor function. When the first ferromagnetic layer 2 and the second ferromagnetic layer 3 are magnetic insulators, localized spins contained in the magnetic insulator precess, and energy conversion occurs between the spin waves propagating from the vibrations of the spins and the current, and the spin inductor 100 exhibits an inductor function.

[0050] Furthermore, a force acts between the magnetizations M2 and M3 to maintain the antiparallel relationship even during precession, so that the precession of the magnetizations M2 and M3 is synchronized, and the spin inductor 100 exhibits a large inductance.

[0051] Because the spin inductor 100 generates a resonance phenomenon at the ferromagnetic resonance frequency of the first ferromagnetic layer 2 and the second ferromagnetic layer 3, stable operation as an inductor is difficult near the resonance frequency. Therefore, the spin inductor 100 is used at a frequency sufficiently lower or sufficiently higher than the ferromagnetic resonance frequency of the spin inductor 100. This sufficiently low or sufficiently high frequency generally indicates a frequency that is deviated from the ferromagnetic resonance frequency by 5% or more, with the ferromagnetic resonance frequency as the reference. The spin inductor 100 can generate inductance even at frequencies exceeding 10 GHz or THz, for example. Furthermore, the inductance generated by the spin inductor 100 functions satisfactorily even at 1 nH or less.

[0052] Next, a method for manufacturing the spin inductor 100 according to this embodiment will be described.

[0053] The spin inductor 100 can be fabricated by repeatedly depositing and processing each layer. For depositing each layer, for example, sputtering, chemical vapor deposition (CVD), electron beam evaporation (EB evaporation), atomic laser deposition, etc. can be used. For processing each layer, for example, photolithography, etc. can be used.

[0054] For example, the first ferromagnetic layer 2, the first wiring layer 1, and the second ferromagnetic layer 3 are stacked in this order and processed into a predetermined shape to obtain the stacked body 10. When the first wiring layer 1 is made of a predetermined material, the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are antiparallel to each other at the time the stacked body 10 is formed. That is, in the manufacturing process of the spin inductor 100 according to this embodiment, it is not necessary to control the orientation directions of the magnetizations M2 and M3 by an external magnetic field or the like.

[0055] Next, a conductive layer is applied to cover the laminate 10, and the central portion of the conductive layer in the x direction is removed to form the first terminal 20 and the second terminal 30. By this procedure, the spin inductor 100 according to this embodiment can be fabricated.

[0056] In the spin inductor 100 according to this embodiment, the first wiring layer 1 satisfies certain conditions, thereby generating a large spin-orbit interaction and making the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 antiparallel to each other.

[0057] The magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 precess even at a small current density due to the large spin-orbit interaction that occurs in the first wiring layer 1. When energy conversion occurs between the magnetic moments of the precessing magnetizations M2 and M3 and the current, the spin inductor 100 functions as an inductor.

[0058] Furthermore, the spin inductor according to this embodiment utilizes spins generated from both sides of the first wiring layer 1, and therefore exhibits a larger inductance than when using only spins generated from one side. Furthermore, by maintaining an antiparallel relationship between the magnetization M2 and the magnetization M3, the precession of the magnetization M2 and the magnetization M3 is synchronized, and the spin inductor 100 exhibits a large inductance.

[0059] Furthermore, the spin inductor according to this embodiment exhibits inductor function by utilizing energy conversion between current and magnetic moment, and therefore can exhibit strong inductance even in a small size. For example, even if the maximum width of the laminate 10 when viewed in a planar view from the z direction is 0.003 mm or less, it can exhibit an inductance of 0.1 μH to 10 μH. Small inductance elements are particularly desired in areas where it is difficult to incorporate large elements, such as space and cryogenic temperatures. Furthermore, even if the maximum width of the spin inductor 10 when viewed in a planar view from the z direction is several tens of nanometers and the length is several hundred nanometers, the spin inductor 100 exhibits an inductance of several nH to several hundred nH.

[0060] 5 is a cross-sectional view of a spin inductor 101 according to a second embodiment. In the spin inductor 101 according to the second embodiment, the same components as those in the spin inductor 100 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0061] The spin inductor 101 according to the second embodiment includes a stacked body 11, a first terminal 20, and a second terminal 30. The stacked body 11 includes a first wiring layer 1, a first ferromagnetic layer 2, a second ferromagnetic layer 3, and a stacked film 6. The stacked film 6 includes a wiring layer 4 and a ferromagnetic layer 5. The wiring layer 4 is in contact with the second ferromagnetic layer 3. The ferromagnetic layer 5 is stacked on the wiring layer 4.

[0062] The wiring layer 4 has the same configuration as the first wiring layer 1. The wiring layer 4 contains, for example, one or more elements selected from the group consisting of Cr, Mo, and Re. The thickness of the wiring layer 4 is, for example, not less than (0.1) nm and not more than (10) nm.

[0063] The ferromagnetic layer 5 has the same configuration as the first ferromagnetic layer 2. The magnetization M5 of the ferromagnetic layer 5 is antiparallel to the magnetization M3 of the second ferromagnetic layer 3. The magnetization M5 of the ferromagnetic layer 5 precesses when spins generated by a current flowing through the wiring layer 4 are injected into the ferromagnetic layer 5.

[0064] The spin inductor 101 according to the second embodiment has the same effects as the spin inductor 100 according to the first embodiment. Furthermore, the spin inductor 101 has the wiring layer 4, which can reduce the resistance between the first terminal 20 and the second terminal 30. Furthermore, the spin inductor 101 has the ferromagnetic layer 5, which increases the number of locations within the spin inductor 101 where energy conversion occurs between the magnetic moment and current, thereby increasing the inductance of the spin inductor 101. As a result, the spin inductor 101 can exhibit a high Q value (Quality Factor).

[0065] 6 is a cross-sectional view of a spin inductor 102 according to a third embodiment. In the spin inductor 102 according to the third embodiment, the same components as those in the spin inductor 100 according to the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0066] The spin inductor 101 according to the second embodiment includes a stack 12, a first terminal 20, and a second terminal 30. The stack 12 includes a first wiring layer 1, a first ferromagnetic layer 2, a second ferromagnetic layer 3, and a plurality of stacked films 6. Each of the stacked films 6 includes a wiring layer 4 and a ferromagnetic layer 5. The wiring layer 4 is stacked on the second ferromagnetic layer 3 or the ferromagnetic layer 5. The ferromagnetic layer 5 is stacked on the wiring layer 4. In the stack 12, the wiring layers 4 and the ferromagnetic layers 5 are stacked alternately in this order.

[0067] The wiring layer 4 has the same configuration as the first wiring layer 1. The wiring layer 4 contains, for example, one or more elements selected from the group consisting of Cr, Mo, and Re. The thickness of the wiring layer 4 is, for example, not less than (0.1) nm and not more than (10) nm.

[0068] The ferromagnetic layer 5 has the same configuration as the first ferromagnetic layer 2. The magnetization M5 of the ferromagnetic layer 5 closest to the second ferromagnetic layer 3 is antiparallel to the magnetization M3 of the second ferromagnetic layer 3. The magnetizations M5 of adjacent ferromagnetic layers 5 are also antiparallel to each other. The magnetization M5 of the ferromagnetic layer 5 precesses when spins generated by the current flowing through the wiring layer 4 are injected into the ferromagnetic layer 5.

[0069] The spin inductor 102 according to the third embodiment has the same effects as the spin inductor 100 according to the first embodiment. Furthermore, the spin inductor 101 has the wiring layer 4, which can reduce the resistance between the first terminal 20 and the second terminal 30. Furthermore, the spin inductor 102 has the ferromagnetic layer 5, which increases the number of locations within the spin inductor 102 where energy conversion occurs between the magnetic moment and current, thereby increasing the inductance of the spin inductor 102. As a result, the spin inductor 102 can exhibit a high Q value (Quality Factor).

[0070] "Fourth embodiment" Fig. 7 is a perspective view of a spin inductor 103 according to a fourth embodiment. Fig. 8 is a cross-sectional view of the spin inductor 103 according to the fourth embodiment. In the spin inductor 103 according to the fourth embodiment, the same components as those in the spin inductor 100 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0071] The spin inductor 103 has a stack 10, a first terminal 20, a second terminal 30, a magnetic shield 40, an insulating layer 44, and an insulating layer 45. The spin inductor 103 differs from the spin inductor 100 in that it has a magnetic shield 40.

[0072] The magnetic shield 40 includes, for example, a first yoke 41 , a second yoke 42 , and a via 43 .

[0073] The first yoke 41 is spaced apart from the stack 10 in the z direction. The first yoke 41 is spaced apart from the first ferromagnetic layer 2 and the second ferromagnetic layer 3 in the z direction.

[0074] For example, an insulating layer 44 is provided between the laminate 10 and the first yoke 41. The insulating layer 44 is an insulating layer that insulates the laminate 10 from the magnetic shield 40. The insulating layer 44 is made of, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al ２ O ３ ), zirconium oxide (ZrO ｘ ), magnesium oxide (MgO), aluminum nitride (AlN), etc.

[0075] The second yoke 42 is spaced apart from the laminate 10 in the z direction. The first yoke 41 and the second yoke 42 sandwich the laminate 10 in the z direction.

[0076] Between the laminate 10 and the second yoke 42, for example, there is an insulating layer 45. The insulating layer 45 is an insulating layer that insulates the laminate 10 from the magnetic shield 40. The insulating layer 45 includes the same material as the insulating layer 44.

[0077] The first yoke 41 and the second yoke 42 suppress the influence of an external magnetic field on the stack 10. The first yoke 41 and the second yoke 42 also facilitate orienting the magnetization of the first ferromagnetic layer 2 and the second ferromagnetic layer 3 in the z direction. When the magnetization is strongly oriented in the z direction, the axes of the precession of the magnetization M2 and the magnetization M3 become stable, and the spin inductor 103 exhibits a large inductance.

[0078] The via 43 connects the first yoke 41 and the second yoke 42. When the first yoke 41 and the second yoke 42 are connected by the via 43, magnetic flux returns along the magnetic shield 40. As a result, the magnetization M2 and the magnetization M3 are more strongly oriented in the z direction, and the spin inductor 103 exhibits a large inductance.

[0079] The spin inductor 103 according to the fourth embodiment has the same effects as the spin inductor 100 according to the first embodiment. Furthermore, the magnetic shield 40 can reduce the influence of an external magnetic field on the magnetization M2 and the magnetization M3. Furthermore, when the magnetic shield 40 is configured as described above, the precession of the magnetization M2 and the magnetization M3 is stabilized, and the spin inductor 103 exhibits a large inductance.

[0080] 7 and 8. For example, the magnetic shield 40 may include only the first yoke 41 or the second yoke 42. The magnetic shield 40 may also be applied to the spin inductors according to the second and third embodiments.

[0081] Fifth Embodiment Fig. 9 is a perspective view of a spin inductor 110 according to a fifth embodiment. Fig. 10 is a plan view of the spin inductor 110 according to the fifth embodiment.

[0082] The spin inductor 110 includes a first magnetic core 50 and a first inductor wiring 60. In the spin inductor 110, a current flows between a first end e1 and a second end e2. For example, a first terminal 20 is connected to the first end e1, and a second terminal 30 is connected to the second end e2.

[0083] The first magnetic core 50 extends in the y direction, with the y direction being its axial direction. The first magnetic core 50 includes, for example, iron, nickel, cobalt, ferrite, or the like.

[0084] The first inductor wiring 60 has its axial direction in the y direction and is wound around the first magnetic core 50. When a current is passed along the first inductor wiring 60, the spin inductor 110 functions as an inductor.

[0085] The first inductor wiring 60 has a first spin inductor wiring 61, a second spin inductor wiring 62, a first connection wiring 63, and a second connection wiring 64. The first inductor wiring 60 may have a plurality of units U, each of which is made up of the first spin inductor wiring 61, the second spin inductor wiring 62, and the first connection wiring 63. Each of the plurality of units U is connected by a second connection wiring 64. For example, the first unit U1 and the second unit U2 are connected by the second connection wiring 64. Each of the first unit U1 and the second unit U2 is one of the plurality of units U.

[0086] The first spin inductor wiring 61 is located below the first magnetic core 50. The second spin inductor wiring 62 is located above the first magnetic core 50. The first spin inductor wiring 61 and the second spin inductor wiring 62 are located on either side of the first magnetic core 50 in the z direction. When viewed from the z direction, the position where the first spin inductor wiring 61 and the first magnetic core 50 overlap may be different from the position where the second spin inductor wiring 62 and the first magnetic core 50 overlap.

[0087] The first spin inductor wire 61 extends in the x direction. For example, the first spin inductor wire 61 is perpendicular to the first magnetic core 50 when viewed from the z direction. The first spin inductor wire 61 may be inclined in the y direction with respect to the x direction.

[0088] The second spin inductor wire 62 extends in the a-direction. The a-direction is a direction inclined with respect to the x-direction and the y-direction in the xy plane. When the first spin inductor wire 61 is inclined with respect to the y-direction with respect to the x-direction, the second spin inductor wire 62 does not need to be inclined with respect to the x-direction.

[0089] For example, the x-direction component of the current flowing in the first spin inductor wire 61 flows in the +x direction, and the x-direction component of the current flowing in the second spin inductor wire 62 flows in the −x direction. In the x direction, the direction of the current flowing in the first spin inductor wire 61 (for example, the +x direction) is opposite to the direction of the current flowing in the second spin inductor wire 62 (for example, the −x direction).

[0090] The first connection wiring 63 connects the first spin inductor wiring 61 and the second spin inductor wiring 62. The first connection wiring 63 connects, for example, the first spin inductor wiring 61 and the second spin inductor wiring 62 in the same unit U. The first connection wiring 63 extends, for example, in the z direction. The first connection wiring 63 may be made of any material as long as it is conductive.

[0091] The second connection wiring 64 connects the first spin inductor wiring 61 and the second spin inductor wiring 62. The second connection wiring 64 connects, for example, the first spin inductor wiring 61 and the second spin inductor wiring 62 between different units U. The second connection wiring 64 extends, for example, in the z direction. The second connection wiring 64 may be made of any material as long as it is conductive.

[0092] 11 is a cross-sectional view of the spin inductor 110 according to the first embodiment. FIG. 11 is a cross-sectional view of a first cross section of the spin inductor 110 taken along line A-A in FIG. 10. In FIG. 11, the second spin inductor wiring 62 on the left side of the paper is the second spin inductor wiring 62 of the first unit U1, and extends in the +x direction toward the front side of the paper. In FIG. 11, the second spin inductor wiring 62 on the right side of the paper is the second spin inductor wiring 62 of the second unit U2, and extends in the -x direction toward the back side of the paper.

[0093] 11 , the first magnetic core 50 and the first inductor wiring 60 are surrounded by an insulator 90. The first magnetic core 50 and the first inductor wiring 60 are insulated from each other by the insulator 90. The insulator 90 can be made of the same material as the insulating layers 44 and 45.

[0094] The first spin inductor wiring 61 includes a first wiring layer 611, a first ferromagnetic layer 612, and a second ferromagnetic layer 613. The first wiring layer 611 corresponds to the first wiring layer 1 according to the first embodiment, the first ferromagnetic layer 612 corresponds to the first ferromagnetic layer 2 according to the first embodiment, and the second ferromagnetic layer 613 corresponds to the second ferromagnetic layer 3 according to the first embodiment.

[0095] The second spin inductor wiring 62 includes a first wiring layer 621, a first ferromagnetic layer 622, and a second ferromagnetic layer 623. The first wiring layer 621 corresponds to the first wiring layer 1 according to the first embodiment, the first ferromagnetic layer 622 corresponds to the first ferromagnetic layer 2 according to the first embodiment, and the second ferromagnetic layer 623 corresponds to the second ferromagnetic layer 3 according to the first embodiment.

[0096] The magnetization M612 of the first ferromagnetic layer 612 of the first spin inductor wiring 61 and the magnetization M622 of the first ferromagnetic layer 622 of the second spin inductor wiring 62 are oriented in opposite directions in the initial state. Also, the magnetization M613 of the second ferromagnetic layer 613 of the first spin inductor wiring 61 and the magnetization M623 of the second ferromagnetic layer 623 of the second spin inductor wiring 62 are oriented in opposite directions in the initial state.

[0097] The spin inductor 110 functions as an inductor when a current flows along the first inductor wiring 60. The spin inductor 110 functions as an inductor due to a first effect caused by self-induction due to a current flowing through the first inductor wiring 60 wound in a coil shape, and a second effect caused by precession (vibration) of magnetization in the magnetic material.

[0098] The first effect is the same as the principle by which a general coil generates inductance. When a current flows through the first inductor wiring 60 arranged in a coil shape, a magnetic field in the -y direction is generated within the first magnetic core 50. This magnetic field generates an induced voltage in a direction that opposes changes in the current. This effect generates inductance in the spin inductor 110.

[0099] The second effect is the same as the principle by which an inductance is generated in the spin inductor 100 in the first embodiment. The second effect is generated by a current flowing in the plane of the first wiring layer 611 and the first wiring layer 621. The current flowing in the first wiring layer 611 and the first wiring layer 621 generates a spin current due to the spin Hall effect.

[0100] 12 , a current I1 flows in the +x direction through the first wiring layer 611. Spins S1 are accumulated at the interface between the first wiring layer 611 and the second ferromagnetic layer 613 and are injected into the second ferromagnetic layer 613. Spins S2 are accumulated at the interface between the first wiring layer 611 and the first ferromagnetic layer 612 and are injected into the first ferromagnetic layer 612.

[0101] The magnetization M613 of the second ferromagnetic layer 613 precesses due to the spins S1 injected from the first wiring layer 611. The magnetization M612 of the first ferromagnetic layer 612 precesses due to the spins S2 injected from the first wiring layer 611.

[0102] 13, a current I2 having a −x-direction component flows through the first wiring layer 621. The flow direction (+x direction) of the x-direction component of the current I1 flowing through the first wiring layer 611 is opposite to the flow direction (−x direction) of the x-direction component of the current I2 flowing through the first wiring layer 621.

[0103] The spins S1 are accumulated at the interface between the first wiring layer 621 and the first ferromagnetic layer 622 and are injected into the first ferromagnetic layer 622. The spins S2 are accumulated at the interface between the first wiring layer 621 and the second ferromagnetic layer 623 and are injected into the second ferromagnetic layer 623.

[0104] The magnetization M623 of the second ferromagnetic layer 623 precesses due to the spins S2 injected from the first wiring layer 621. The magnetization M622 of the first ferromagnetic layer 622 precesses due to the spins S1 injected from the first wiring layer 621.

[0105] As the magnetization M612, the magnetization M613, the magnetization M622, and the magnetization M623 precess, energy conversion occurs between the magnetic moment and the current (second action). The magnetization M612, the magnetization M613, the magnetization M622, and the magnetization M623 each precess in the same rotation direction. This is because the relationship between the direction of the injected spin and the orientation direction of the magnetization satisfies a predetermined relationship. By aligning the rotation directions of the precessions, it is possible to suppress the weakening of the inductor functions occurring in each part.

[0106] The spin inductor 110 according to the fifth embodiment has the same effects as the spin inductor 100 according to the first embodiment. Furthermore, the spin inductor 110 according to the fifth embodiment functions as an inductor due to the first and second effects. By utilizing both the first and second effects, the spin inductor 110 according to the fifth embodiment can achieve a large inductance even in a small element. As a result, the spin inductor 110 according to the fifth embodiment can achieve a high Q value.

[0107] The configurations of the spin inductors according to the first to third embodiments can be applied to the first spin inductor wiring 61 and the second spin inductor wiring 62 of the spin inductor 110 according to the fifth embodiment. In addition, the magnetic shield 40 according to the fourth embodiment may be provided for the spin inductor 110 according to the fifth embodiment.

[0108] 14 is a plan view of a first modified example of the spin inductor 111 according to the fifth embodiment. In the spin inductor 111 of the first modified example, the same components as those in the spin inductor 110 according to the fifth embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0109] The spin inductor 111 differs from the first inductor wiring 60 of the spin inductor 110 in the shape of the first inductor wiring 60A.

[0110] The first spin inductor wiring 61A has a different shape from the first spin inductor wiring 61 when viewed from the Z direction. The first spin inductor wiring 61A has a length L1 in the y direction that is longer than a length L2 in the x direction. Current flows in the +x direction within the first spin inductor wiring 61A. The first spin inductor wiring 61A has a length L1 in the width direction that is perpendicular to the current flow direction that is longer than a length L2 in the flow direction. When the length L1 is longer than the length L2, the current density of the current flowing through the first spin inductor wiring 61A decreases.

[0111] Similarly, the shape of the second spin inductor wire 62A when viewed from the z direction is different from that of the second spin inductor wire 62. The second spin inductor wire 62A has a length L3 in the width direction perpendicular to the current flow direction that is longer than a length L4 in the flow direction. When the length L3 is longer than the length L4, the current density of the current flowing through the second spin inductor wire 62A decreases.

[0112] The spin inductor 111 has a lower resistance than the spin inductor 110. A spin inductor with a high resistance has difficulty in achieving a high Q value. In contrast, the spin inductor 111 has a low resistance and can easily achieve a high Q value. Furthermore, when a direct current is applied, the spin inductor 111 functions as a resistor. If the resistance of the spin inductor 111 is low, the current loss when a direct current is applied can be reduced. Furthermore, if the current density of the current flowing through the first spin inductor wiring 61A and the second spin inductor wiring 62A is low, the torque acting on the magnetization of the first ferromagnetic layer and the second ferromagnetic layer is reduced, and magnetization reversal can be suppressed.

[0113] Here, an example is shown in which the widthwise lengths L1 and L3 of both the first spin inductor wiring 61A and the second spin inductor wiring 62A are longer than the flowwise lengths L2 and L4, but only one of them may satisfy this relationship.

[0114] The first to fifth embodiments have been illustrated above, and specific configurations of spin inductors have been described. The spin inductor according to the present disclosure is not limited to these exemplary configurations, and various modifications are possible as long as the spirit of the invention is met. Furthermore, the spin inductor according to the present disclosure can be incorporated into a module for use, for example. Figure 15 shows an example of use of the spin inductor according to this embodiment.

[0115] In recent years, there has been a growing interest in integrating semiconductor circuits and devices with specific functions, such as memory, into a single chip. The technology for integrating semiconductor circuits and devices such as memory into a single chip is called "chiplet" or "heterointegration." Integrating these into a single chip reduces latency, power consumption, and costs. Even with these technologies, passive components must be separately placed around the chip for it to function. Therefore, even if the chip is highly integrated, passive components can become a challenge in miniaturizing the module. By incorporating passive components into chiplets and heterointegration, further miniaturization of modules is expected.

[0116] The chip C shown in FIG. 15 includes a semiconductor circuit LY1, a connection layer LY2, a wiring layer LY3, a memory layer LY4, a sensor layer LY5, an LCR (passive component) layer LY6, and an all-solid-state thin-film battery layer LY7, which are stacked in this order. Although each layer is bonded to form a single chip, spacing is provided in FIG. 15 for ease of understanding. The spin inductor according to the present disclosure is formed, for example, in the LCR layer LY6. The LCR layer LY6 may form not only passive components such as conventional electronic components, such as inductance, capacitance, and resistance, but also spin inductors and spin-tunable capacitances. The LCR layer LY6 is connected to other layers via contact vias, and the entire chip C is utilized as a single module. The spin inductor according to the present disclosure can be applied to devices that also include sensors and power sources, as shown in FIG. 15, and can autonomously collect information.

[0117] 1, 611, 621 First wiring layer 1A First surface 1B Second surface 2, 612, 622 First ferromagnetic layer 3, 613, 623 Second ferromagnetic layer 4 Wiring layer 5 Ferromagnetic layer 6 Stacked film 10, 11, 12 Stacked body 20 First terminal 30 Second terminal 40 Magnetic shield 50 First magnetic core 60, 60A First inductor wiring 61, 61A First spin inductor wiring 62, 62A Second spin inductor wiring 63 First connecting wiring 64 Second connecting wiring 100, 101, 102, 103, 110, 111 Spin inductor

Claims

1. A spin inductor comprising: a first wiring layer; a first ferromagnetic layer in contact with a first surface of the first wiring layer; and a second ferromagnetic layer in contact with a second surface of the first wiring layer opposite the first surface, wherein the magnetization of the first ferromagnetic layer and the magnetization of the second ferromagnetic layer are antiparallel to each other, and the first wiring layer includes one or more selected from the group consisting of Cr, Mo, and Re.

2. The spin inductor according to claim 1, wherein the first ferromagnetic layer and the second ferromagnetic layer contain at least one selected from the group consisting of Co, Fe, Ni, Mn, Nd, Gd, and Tb.

3. A spin inductor as described in claim 1, further comprising a stacked film having a wiring layer and a ferromagnetic layer stacked on the wiring layer, the stacked film being stacked on the second ferromagnetic layer, and the wiring layer being in contact with the second ferromagnetic layer.

4. A spin inductor as described in claim 1, further comprising a plurality of laminated films, each of which has a wiring layer and a ferromagnetic layer laminated on the wiring layer, and the plurality of laminated films are laminated on the second ferromagnetic layer so that the wiring layer and the ferromagnetic layer are arranged in that order.

5. A spin inductor as described in claim 1, wherein, when the direction of current flowing through the first ferromagnetic layer is defined as a first direction, the magnetization of the first ferromagnetic layer and the magnetization of the second ferromagnetic layer are oriented in the first direction or stacking direction when no external magnetic field is applied and no current is flowing.

6. The spin inductor according to claim 1, further comprising a magnetic shield layer, the magnetic shield layer being spaced apart from the first ferromagnetic layer and the second ferromagnetic layer in the stacking direction.

7. A spin inductor as described in claim 1, wherein the first wiring layer is configured so that spins can be injected into the first ferromagnetic layer and the second ferromagnetic layer, and the magnetizations of the first ferromagnetic layer and the second ferromagnetic layer are configured so that precession can occur due to the injected spins.

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