Spin inductor

Abstract

The spin inductor includes: a wiring layer; a first ferromagnetic layer in contact with a first surface of the wiring layer; and a second ferromagnetic layer in contact with a second surface of the wiring layer, the second surface facing the first surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a spin inductor. BACKGROUND

[0002] Inductors, along with resistors and capacitors, are primary electronic components used in various electronic devices. A coil is an example of an inductor. The size of a coil is in a trade-off relationship with the strength of inductance, and it is difficult to achieve large inductance with a small coil.

[0003] In recent years, a new form of inductor that does not use a coil has attracted attention. The new form of inductor that does not use a coil is sometimes referred to as an emerging inductor. For example, in Patent Literature 1, Non-Patent Literature 1, and Non-Patent Literature 2, a new inductor that utilizes vibrations of spins (hereinafter, referred to as a spin inductor) is disclosed. The smaller the element size of the spin inductor, the stronger the inductance, and it is attracting attention in terms of being able to balance miniaturization and inductance strength.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2022 / 181069

[0007] NON-PATENT LITERATURE

[0008] Non-Patent Literature 1: Yuta Yamane, Shunsuke Fukami, and Junichi Ieda, Physical Review Letters 128, 147201 (202).

[0009] Non-Patent Literature 2: Yasufumi Arai and Jun'ichi Ieda, Journal of the Physical Society of Japan 92, 074705 (2023). SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] An inductor that is small and exhibits large inductance is sought. In order to balance these features, an inductor that more effectively exhibits large inductance is required.

[0012] The present disclosure was completed in view of the above circumstances, and an object thereof is to provide a spin inductor that effectively exhibits large inductance.

[0013] TECHNICAL MEANS FOR SOLVING THE PROBLEMS

[0014] The present disclosure provides the following technical means in order to solve the above problems.

[0015] (1) The spin inductive device according to the first aspect includes: a 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 of the wiring layer that is opposite to the first surface.

[0016] (2) The spin inductive device according to the above aspect can be such that the magnetization of the first ferromagnetic layer is oriented in a direction opposite to the magnetization of the second ferromagnetic layer.

[0017] (3) The spin inductive device according to the above aspect can further include a third ferromagnetic layer and a magnetic coupling layer. The magnetic coupling layer is located between the second ferromagnetic layer and the third ferromagnetic layer.

[0018] (4) The spin inductive device according to the above aspect can be such that the magnetization of the first ferromagnetic layer is oriented in the same direction as the magnetization of the third ferromagnetic layer.

[0019] (5) In the spin inductive device according to the above aspect, the third ferromagnetic layer can have a film thickness that is thicker than the film thickness of the second ferromagnetic layer.

[0020] (6) In the spin inductive device according to the above aspect, the wiring layer can be a laminated structure in which a first layer and a second layer are laminated.

[0021] (7) In the spin inductive device according to the above aspect, the sign of the spin current generated in the first layer can be different from the sign of the spin current generated in the second layer.

[0022] (8) The spin inductive device according to the above aspect can be such that the magnetization of the first ferromagnetic layer is oriented in the same direction as the magnetization of the second ferromagnetic layer.

[0023] (9) The spin inductive device according to the above aspect can further include a magnetic shield layer. The magnetic shield layer is separated from the first ferromagnetic layer and the second ferromagnetic layer in the lamination direction.

[0024] (10) In the spin inductive device according to the above aspect, the wiring layer can be configured to inject spins into the first ferromagnetic layer and the second ferromagnetic layer, and the first ferromagnetic layer and the second ferromagnetic layer can be configured such that precessions are performed by the injected spins. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a perspective view of a spin inductive device according to a first embodiment.

[0026] Figure 2 is a cross-sectional view of the spin inductive device according to the first embodiment.

[0027] Figure 3 This is a top view of the spin inductor according to the first embodiment.

[0028] Figure 4 This is a schematic diagram illustrating the function of the spin inductor in the first embodiment.

[0029] Figure 5 This is a diagram illustrating the manufacturing method of the spin inductor according to the first embodiment.

[0030] Figure 6 This is a diagram illustrating the manufacturing method of the spin inductor according to the first embodiment.

[0031] Figure 7 This is a diagram illustrating the manufacturing method of the spin inductor according to the first embodiment.

[0032] Figure 8 This is a cross-sectional view of the spin inductor according to the second embodiment.

[0033] Figure 9 This is a cross-sectional view of the spin inductor according to the third embodiment.

[0034] Figure 10 This is a schematic diagram illustrating the function of the spin inductor in the third embodiment.

[0035] Figure 11 This is a perspective view of the spin inductor according to the fourth embodiment.

[0036] Figure 12 This is a cross-sectional view of the spin inductor according to the fourth embodiment.

[0037] Figure 13 This is a top view of the spin inductor according to the fourth embodiment.

[0038] Figure 14 This is an example of the use of the spin inductor in this embodiment. Detailed Implementation

[0039] The following is a brief reference to the appendix. Figure 1 The following is a detailed description of this embodiment. The accompanying drawings used in the following description are sometimes enlarged representations of features for ease of understanding, and the dimensional ratios of the constituent elements may differ from the actual dimensions. The materials, dimensions, etc., illustrated in the following description are examples only, and this disclosure is not limited to these; appropriate modifications and implementations can be made within the scope of achieving the effects of this disclosure.

[0040] First, the directions are defined. One direction of the extended surface of each layer is designated as the x-direction, and the direction orthogonal to the x-direction is designated as the y-direction. For example, the first direction connecting the first terminal 20 and the second terminal 30 is designated as the x-direction. A second direction orthogonal to the first direction is designated, for example, the y-direction. Additionally, the thickness direction of each layer is designated as the z-direction. The z-direction is orthogonal to both the x- and y-directions.

[0041] (First Implementation)

[0042] Figure 1 This is a perspective view of the spin inductor 100 according to the first embodiment. Figure 2 This is a cross-sectional view of the spin inductor 100 according to the first embodiment. Figure 3 This is a top view of the spin inductor 100 according to the first embodiment.

[0043] The spin inductor 100 is an inductor that operates by magnetizing vibrations within a magnetic body. The spin inductor 100 interrupts the high-frequency component of the current, allowing the constant component of the current to pass. Current flows between the first terminal 20 and the second terminal 30. The spin inductor 100 is positioned where the high-frequency current is to be interrupted. The high-frequency current is interrupted by the spin inductor 100, but direct current flows through it. For direct current, the spin inductor 100 acts as a resistor.

[0044] The spin inductor 100 has a stack 10, a first terminal 20 and a second terminal 30.

[0045] The first terminal 20 is connected to the first side surface 10A of the laminate 10. The first terminal 20 extends over the wiring layer 1, the first ferromagnetic layer 2, and the second ferromagnetic layer 3 of the laminate 10 and is connected thereto. The first terminal 20 may also be connected to the third ferromagnetic layer 5. The first side surface 10A is inclined relative to the z-direction. The first side surface 10A is inclined relative to the yz plane.

[0046] The first terminal 20 is a conductor. Current flows from the first terminal 20 to the laminate 10. The laminate 10 is a laminate containing a thin film. By tilting the first side 10A, the contact area between the thin film constituting the laminate 10 and the first terminal 20 increases, thereby stabilizing the electrical connection between the thin film constituting the laminate 10 and the first terminal 20.

[0047] The second terminal 30 is connected to the second side surface 10B of the laminate 10. The second side surface 10B is a side of the laminate 10 that is different from the first side surface 10A. For example, the second side surface 10B is the side opposite to the first side surface 10A in the x-direction. The second terminal 30 is connected to the wiring layer 1, the first ferromagnetic layer 2, and the second ferromagnetic layer 3 of the laminate 10. The second terminal 30 may also be connected to the third ferromagnetic layer 5. The second side surface 10B is inclined relative to the z-direction. The second side surface 10B is inclined relative to the yz plane.

[0048] The second terminal 30 is a conductor. Current flows from the laminate 10 to the second terminal 30. As the second side 10B is tilted, the contact area between the film constituting the laminate 10 and the second terminal 30 increases, and the electrical connection between the film constituting the laminate 10 and the second terminal 30 is stabilized.

[0049] Here, an example is shown where the first terminal 20 and the second terminal 30 are formed on the side 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 also be connected to the upper or lower surface of the laminate 10. In this case, the through-hole wiring that is connected to the laminate 10 and extends in the z-direction becomes the first terminal 20 and the second terminal 30.

[0050] The laminate 10 comprises a wiring layer 1, a first ferromagnetic layer 2, a second ferromagnetic layer 3, a magnetic coupling layer 4, and a third ferromagnetic layer 5. The laminate 10 may also have multiple units, each composed of the wiring layer 1, the first ferromagnetic layer 2, the second ferromagnetic layer 3, the magnetic coupling layer 4, and the third ferromagnetic layer 5. Spacer layers may be sandwiched between adjacent units, for example. These spacer layers can be conductors, semiconductors, or insulators.

[0051] For example, the length of wiring layer 1 in the x-direction is shorter than its length in the y-direction. Similarly, the length of the laminate 10 in the x-direction is shorter than its length in the y-direction. If the length of wiring layer 1 in the y-direction is longer, the current density flowing through wiring layer 1 becomes smaller. Conversely, if the length of wiring layer 1 in the x-direction is shorter, the spin inductor 100 becomes a low-resistance inductor.

[0052] Wiring layer 1 comprises any one of the following: metal, alloy, intermetallic compound, metal boride, metal carbide, metal silicide, or metal phosphide, which has the function of generating spin current through the spin Hall effect when current flows. Wiring layer 1 is also sometimes referred to as spin-orbit torque wiring.

[0053] Wiring layer 1 may contain, for example, a non-magnetic heavy metal as its main component. Heavy metals refer to metals with a specific gravity greater than yttrium (Y). Non-magnetic heavy metals are, for example, large non-magnetic metals with an atomic number greater than 39 that have d or f electrons in their outermost shell. Wiring layer 1 may be composed of, for example, Hf, Ta, and W. Non-magnetic heavy metals generate stronger spin-orbit interactions compared to other metals. The spin Hall effect is generated through spin-orbit interactions. If the spin becomes uneven within wiring layer 1 due to the spin Hall effect, a spin current J is easily generated. S .

[0054] In addition, wiring layer 1 may also contain a magnetic metal. The magnetic metal is either ferromagnetic or antiferromagnetic. The trace amounts of magnetic metal contained in a non-magnetic body become a spin scattering factor. "Trace" refers to, for example, less than 3% of the total molar ratio of the elements constituting the wiring layer. If the spin is scattered by the magnetic metal, the spin-orbit interaction is enhanced, and the efficiency of spin current generation relative to the current becomes higher.

[0055] Wiring layer 1 may also include a topological insulator. A topological insulator is a material whose interior is an insulator or a high-resistivity material, but which exhibits a spin-polarized metallic state at its surface. Topological insulators generate an internal magnetic field through spin-orbit interactions. Even without an external magnetic field, topological insulators exhibit a new topological phase due to the effects of spin-orbit interactions. Through strong spin-orbit interactions and the breaking of edge inversion symmetry, topological insulators can efficiently generate pure spin current. Furthermore, since current flows only through the surface of a topological insulator, high current density can be achieved with a relatively small current quantity.

[0056] Topological insulators include Sn, SnTe, and Bi. 1.5 Sb 0.5 Te 1.7 Se 1.3 ,TlBiSe2,Bi2Te3,Bi 1-x Sb x 、(Bi 1- x Sb x )2Te3, etc. Topological insulators can efficiently generate spin currents.

[0057] The first ferromagnetic layer 2 is in contact with the first surface 1A of the wiring layer 1. The first ferromagnetic layer 2 is, for example, in contact with the lower surface of the wiring layer 1.

[0058] The first ferromagnetic layer 2 is a ferromagnetic material. Ferromagnetic materials may be, for example, metals selected from Cr, Mn, Co, Fe and Ni, alloys containing one or more of these metals, alloys containing these metals and at least one of the elements selected from B, C and N.

[0059] Ferromagnetic materials include, for example, Co-Fe, Co-Fe-B, Ni-Fe, Co-Ho alloys, Sm-Fe alloys, Fe-Pt alloys, Co-Pt alloys, and CoCrPt alloys. CoCrPt alloys and L10-type CoFe alloys have high saturation magnetization and strong magnetic anisotropy. If they are used in the first ferromagnetic layer 2, the resonant frequency of the spin inductor 100 will be higher.

[0060] Alternatively, the first ferromagnetic layer 2 can also be a magnetic insulator. When the first ferromagnetic layer 2 is a magnetic insulator, the wiring layer 1 is particularly preferably a topological insulator. Since current flows only at the interface between the magnetic insulator and the topological insulator, current loss and energy loss caused by heating, etc., can be suppressed.

[0061] Alternatively, the first ferromagnetic layer 2 can also be a ferrimagnetic insulator or an antiferromagnetic insulator. When the first ferromagnetic layer 2 is an antiferromagnetic insulator, the wiring layer 1 is particularly preferably a topological insulator. Since the current flows only at the interface between the antiferromagnetic insulator and the topological insulator, current loss and energy loss caused by heating are suppressed. Furthermore, when the first ferromagnetic layer 2 is an antiferromagnetic insulator, the resonant frequency of the first ferromagnetic layer 2 becomes higher, and resonance does not occur even in high-frequency regions above 10 GHz. Therefore, a spin inductor with an antiferromagnetic insulator as the first ferromagnetic layer 2 can stably exhibit inductance over a wide frequency band. For example, the antiferromagnetic insulator can be an oxide containing magnetic elements such as NiO, MnO, Cr2O3, ferrite, or garnet; a sulfide containing magnetic elements such as MnS; or a chloride containing magnetic elements such as FeCl2.

[0062] The second ferromagnetic layer 3 is in contact with the second surface 1B of the wiring layer 1. The second surface 1B is the surface of the wiring layer 1 opposite to the first surface 1A. The second ferromagnetic layer 3, for example, covers the entire upper surface of the wiring layer 1.

[0063] The second ferromagnetic layer 3 contains the same material as the first ferromagnetic layer 2. The second ferromagnetic layer 3 may contain the same material as the first ferromagnetic layer 2, or it may contain a different material.

[0064] The magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are oriented in opposite directions in a state where no current flows through the wiring layer 1 and no external magnetic field is applied (hereinafter referred to as the initial state). Here, "no current flows" means that no potential difference is applied to the wiring layer 1. Furthermore, "no external magnetic field applied" means that no intentional magnetic field is applied to the first ferromagnetic layer 2 and the second ferromagnetic layer 3. 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 the initial state. Figure 2 The example shown illustrates magnetization M2 oriented in the -z direction and magnetization M3 oriented in the +z direction, but their orientation can also be reversed. Alternatively, magnetizations M2 and M3 can also be oriented in any direction within the xy plane, in a direction inclined from the xy plane towards the z direction.

[0065] The magnetic coupling layer 4 is located, for example, between the second ferromagnetic layer 3 and the third ferromagnetic layer 5. The magnetic coupling layer 4 is a layer that does not impede the magnetic coupling between the second ferromagnetic layer 3 and the third ferromagnetic layer 5.

[0066] The magnetic coupling layer 4 may contain at least one material selected from Ru, Ir, and Rh. The magnetic coupling layer 4 may be a metal film of Ru, Ir, or Rh.

[0067] For example, the second ferromagnetic layer 3 and the third ferromagnetic layer 5 are antiferromagnetically coupled by a magnetic coupling layer 4. In this case, the second ferromagnetic layer 3, the magnetic coupling layer 4, and the third ferromagnetic layer 5 form a synthetic antiferromagnetic structure (SAF structure). By antiferromagnetically coupling the second ferromagnetic layer 3 with the third ferromagnetic layer 5, the coercivity of the second ferromagnetic layer 3 is increased compared to the case without the third ferromagnetic layer 5, and a coercivity difference can be generated between the first ferromagnetic layer 2 and the second ferromagnetic layer 3.

[0068] The second ferromagnetic layer 3 and the third ferromagnetic layer 5 can also be sandwiched with the magnetic coupling layer 4 to achieve ferromagnetic coupling.

[0069] The third ferromagnetic layer 5, sandwiching the magnetic coupling layer 4, is located opposite the second ferromagnetic layer 3. The third ferromagnetic layer 5 contains the same material as the first ferromagnetic layer 2. The third ferromagnetic layer 5 may contain the same material as the first ferromagnetic layer 2, or it may contain a different material.

[0070] The magnetization M5 of the third ferromagnetic layer 5 is initially oriented in the same direction as the magnetization M2 of the first ferromagnetic layer 2. Furthermore, the magnetization M5 of the third ferromagnetic layer 5 is initially oriented in the opposite direction to the magnetization M3 of the second ferromagnetic layer 3. Figure 2 The example shown illustrates magnetization M5 oriented in the -z direction, but magnetization M5 can also be oriented in the +z direction, in any direction within the xy plane, or in a direction inclined from the xy plane to the z direction.

[0071] The thickness of the third ferromagnetic layer 5 in the z-direction is, for example, greater than the thickness of the second ferromagnetic layer 3 in the z-direction. By making the thickness of the third ferromagnetic layer 5 greater than that of the second ferromagnetic layer 3, it is easier to set the magnetization orientations of the first ferromagnetic layer 2 and the second ferromagnetic layer 3 to be opposite when manufacturing the spin inductor 100.

[0072] Next, the function of the spin inductor 100 will be explained. Figure 4 This is a schematic diagram used to illustrate the function of the spin inductor 100.

[0073] The spin inductor 100 functions as an inductor when current flows along the wiring layer 1. If current is applied between the first terminal 20 and the second terminal 30, the current flows in the plane of the wiring layer 1.

[0074] The current flowing within wiring layer 1 generates a spin current through the spin Hall effect.

[0075] The spin Hall effect is a phenomenon inducing a spin current in a direction orthogonal to the direction of current flow (e.g., the z-direction) when an electric current flows through it, based on the spin-orbit interaction. The spin Hall effect is similar to the ordinary Hall effect in that the direction of motion of the moving (moving) charge (electron) is bent. In the ordinary Hall effect, the direction of motion of a charged particle moving in a magnetic field is bent by the Lorentz force. In contrast, the spin Hall effect bends the direction of spin movement even in the absence of a magnetic field, simply by the movement of electrons (only the flow of current).

[0076] For example, when current flows in the x direction of wiring layer 1, for example, spin S1 polarized in the -y direction bends in the +z direction relative to the direction of travel, and spin S2 polarized in the +y direction bends in the -z direction relative to the direction of travel.

[0077] Spin S2 is injected from the first surface 1A into the adjacent second ferromagnetic layer 3. Spin S1 is injected from the second surface 1B into the adjacent first ferromagnetic layer 2. Since the distance between the wiring layer 1 and the first ferromagnetic layer 2 is less than or equal to the spin diffusion length of spin S2, spin S2 generated in the wiring layer 1 can be effectively injected into the first ferromagnetic layer 2. Similarly, since the distance between the wiring layer 1 and the second ferromagnetic layer 3 is less than or equal to the spin diffusion length of spin S1, spin S1 generated in the wiring layer 1 can be effectively injected into the second ferromagnetic layer 3.

[0078] The magnetization M2 of the first ferromagnetic layer 2 is precessed by the spin S2 injected from the wiring layer 1. The coercivity of the magnetization M2 and the magnitude of the current flowing through the wiring layer 1 are adjusted, and the magnetization M2 is configured to precess without reversing due to the injected spin S2.

[0079] The magnetization M3 of the second ferromagnetic layer 3 precesses by the spin S1 injected from the wiring layer 1. The coercivity of the magnetization M3 and the magnitude of the current flowing through the wiring layer 1 are adjusted, and the magnetization M3 is configured to precess without reversing due to the injected spin S1.

[0080] If the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 precess, an energy conversion occurs between the magnetic moment and the current, and the spin inductor 100 exhibits inductor function. When the first ferromagnetic layer 2 and the second ferromagnetic layer 3 are magnetic insulators, the local spins contained within the magnetic insulator precess, and an energy conversion occurs between the spin wave transmitted by the vibration of this spin and the current, and the spin inductor 100 exhibits inductor function.

[0081] From the viewpoint of maintaining the precession of magnetization M2 and magnetization M3, magnetization M2 and magnetization M3 preferably have a component oriented in the z-direction in the initial state, more preferably oriented in the z-direction. When magnetization M2 and magnetization M3 are oriented in the x-direction or y-direction, magnetization reversal may sometimes occur even without an applied external magnetic field, making it impossible to maintain magnetization precession. When magnetization M2 and magnetization M3 are oriented in the z-direction, magnetization reversal is difficult to occur in the absence of a magnetic field. The spin inductor 100 utilizes the energy conversion between magnetic moment and current to manifest inductor function; therefore, if magnetization precession stops, the inductor function cannot be fully manifested.

[0082] Furthermore, even if magnetization M2 and magnetization M3 are oriented in the x or y direction, the precession of magnetization can be maintained by adjusting the current density flowing through wiring layer 1.

[0083] The spin inductor 100 resonates at the ferromagnetic resonance frequency of the first ferromagnetic layer 2 and the second ferromagnetic layer 3, making stable operation as an inductor difficult near the resonance frequency. Therefore, the spin inductor 100 is used at frequencies sufficiently lower or sufficiently higher than its ferromagnetic resonance frequency. This sufficiently low or sufficiently high frequency generally refers to a frequency deviating from the ferromagnetic resonance frequency by more than 5% relative to it. 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 adequately even below 1 nH.

[0084] Furthermore, the magnetization M5 of the third ferromagnetic layer 5, which is antiferromagnetically coupled to the second ferromagnetic layer 3, can also precess along with the magnetization M3 of the second ferromagnetic layer 3. If the magnetization M5 of the third ferromagnetic layer 5 precesses, the spin inductor 100 exhibits a larger inductance. Additionally, when the precession period of the magnetization M5 of the third ferromagnetic layer 5 differs from the precession periods of the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3, the spin inductor 100 exhibits inductor function for higher frequency currents over a wider bandwidth.

[0085] Next, the manufacturing method of the spin inductor 100 of this embodiment will be described.Figures 5-7 This is a schematic diagram illustrating the manufacturing method of the spin inductor in this embodiment.

[0086] First, such as Figure 5 As shown, a ferromagnetic layer 92, a conductive layer 91, a ferromagnetic layer 93, an intermediate layer 94, and a ferromagnetic layer 95 are stacked sequentially. The stacking methods for each layer can include, for example, sputtering, chemical vapor deposition (CVD), electron beam evaporation (EB evaporation), and atomic laser deposition.

[0087] Next, as Figure 6 As shown, the laminate is processed into a specified shape. The processing of each layer can be performed, for example, by photolithography. Through this processing, the ferromagnetic layer 92 becomes the first ferromagnetic layer 2, the conductive layer 91 becomes the wiring layer 1, the ferromagnetic layer 93 becomes the second ferromagnetic layer 3, the intermediate layer 94 becomes the magnetic coupling layer 4, and the ferromagnetic layer 95 becomes the third ferromagnetic layer 5.

[0088] In addition, such as Figure 6 As shown, an external magnetic field E is applied to the laminate. The external magnetic field E can be applied after processing the laminate or before processing. The strength of the external magnetic field E is set to the strength of the magnetization of each layer when it is fully oriented in the direction of the applied magnetic field. The magnetization M2 of the first ferromagnetic layer 2, the magnetization M3 of the second ferromagnetic layer 3, and the magnetization M5 of the third ferromagnetic layer 5 are oriented in the direction of the applied external magnetic field E.

[0089] Next, as Figure 7 As shown, the external magnetic field E is stopped being applied to the laminate. The second ferromagnetic layer 3 and the third ferromagnetic layer 5 are antiferromagnetically coupled by a magnetic coupling layer 4. Therefore, the magnetization M3 of the second ferromagnetic layer 3, which has a smaller coercivity than the third ferromagnetic layer 5, reverses when the application of the external magnetic field E is stopped. The magnetization M3 of the second ferromagnetic layer 3 and the magnetization M5 of the third ferromagnetic layer 5 are antiparallel.

[0090] Next, to cover Figure 7 The conductive layer is coated onto the laminate 10 fabricated in the middle. Then, the central portion of the conductive layer in the x-direction is removed to form the first terminal 20 and the second terminal 30. Through these steps, the spin inductor 100 of this embodiment can be fabricated.

[0091] As described above, the spin inductor 100 of this embodiment precesses the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 through spin injected from the wiring layer 1. By converting energy between the magnetic moments of the precessing magnetizations M2 and M3 and the current, the spin inductor 100 functions as an inductor. Furthermore, since the spin inductor of this embodiment utilizes both sides of the spin generated from both sides of the wiring layer 1, it exhibits a larger inductance compared to the case where only a spin generated from one side is used.

[0092] Furthermore, the spin inductor of this embodiment utilizes the energy conversion between current and magnetic moment to exhibit inductance, thus enabling it to exhibit strong inductance even in small sizes. For example, even when the maximum width of the stack 10 viewed from the z-direction is less than 0.003 mm, it can exhibit an inductance of 0.1 μH or more and less than 10 μH. Small inductor components are particularly needed in regions where it is difficult to fit large components, such as space and extremely low temperatures. In addition, even when the maximum width of the spin inductor 10 viewed from the z-direction is tens of nm and the length is hundreds of nm, the spin inductor 100 exhibits an inductance of several nH to hundreds of nH.

[0093] (Second Implementation)

[0094] Figure 8 This is a cross-sectional view of the spin inductor 101 according to the second embodiment. In the spin inductor 101 of the second embodiment, the same reference numerals are used for structures that are the same as those in the spin inductor 100 of the first embodiment, and descriptions are omitted.

[0095] The spin inductor 101 of the second embodiment includes a laminate 11, a first terminal 20, and a second terminal 30. The laminate 11 includes a wiring layer 1, a first ferromagnetic layer 2, and a second ferromagnetic layer 3. The laminate 11 differs from the laminate 10 in that it does not have a magnetic coupling layer 4 and a third ferromagnetic layer 5.

[0096] The spin inductor 101 of the second embodiment can be manufactured using the same steps as the spin inductor 100 of the first embodiment. The magnetization directions of magnetization M2 and magnetization M3 can be controlled using the coercivity difference between the second ferromagnetic layer 3 and the third ferromagnetic layer 5. For example, after applying an external magnetic field in the first direction, the magnetization directions of magnetization M2 and magnetization M3 can be controlled by applying an external magnetic field in the second direction opposite to the first direction with an intensity of magnetization reversal only in either the second ferromagnetic layer 3 or the third ferromagnetic layer 5.

[0097] The spin inductor 101 of the second embodiment utilizes both sides of the spin generated from both sides of the wiring layer 1, thus exhibiting a larger inductance compared to the case where only the spin generated from one side is used.

[0098] (Third Implementation)

[0099] Figure 9 This is a cross-sectional view of the spin inductor 102 according to the third embodiment. In the spin inductor 102 of the third embodiment, the same reference numerals are used to mark the same structures as in the spin inductor 100 of the first embodiment, and the description is omitted.

[0100] The spin inductor 102 of the third embodiment includes a laminate 12, a first terminal 20, and a second terminal 30. The laminate 12 includes a wiring layer 6, a first ferromagnetic layer 2, and a second ferromagnetic layer 3. The laminate 12 differs from the laminate 10 in that it does not have a magnetic coupling layer 4 and a third ferromagnetic layer 5, and the structure of the wiring layer 6 is different. In addition, in the initial state, the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 of the laminate 12 are oriented in the same direction.

[0101] Wiring layer 6 has a stacked structure consisting of a first layer 7 and a second layer 8. The first layer 7 is connected to the first ferromagnetic layer 2. The second layer 8 is connected to the second ferromagnetic layer 3. Wiring layer 6 may also have layers other than the first layer 7 and the second layer 8.

[0102] The first layer 7 and the second layer 8 each contain any one of the following: metal, alloy, intermetallic compound, metal boride, metal carbide, metal silicide, or metal phosphide, which has the function of generating spin current through the spin Hall effect when current flows. The first layer 7 and the second layer 8 can use the same material as the wiring layer 1.

[0103] The first layer 7 will inject spin generated by the spin Hall effect into the first ferromagnetic layer 2 within the first layer 7. The second layer 8 will inject spin generated by the spin Hall effect into the second ferromagnetic layer 3 within the second layer 8. The sign of the spin current generated in the first layer 7 is different from that generated in the second layer 8, for example.

[0104] The sign of spin current indicates which surface accumulates spins polarized in which direction when current flows along the x-direction of wiring layer 6. For example, if the sign of spin current is "positive" when spin S1 polarized in the -y direction is accumulated on the first surface and spin S2 polarized in the +y direction is accumulated on the second surface, the sign of spin current when spin S1 polarized in the +y direction is accumulated on the first surface and spin S2 polarized in the -y direction is accumulated on the second surface is "negative".

[0105] For example, the spin Hall angles of the first layer 7 and the second layer 8 have different polarities. If the "polarity of the spin Hall angle" is different, the first spin S1 will bend either in the z-direction or in the -z-direction, and the sign of the spin current will differ. The polarity of the spin Hall angles of the first layer 7 and the second layer 8 can be changed by selecting the materials constituting the first layer 7 and the second layer 8. For example, if the layer mainly contains metallic elements belonging to any one of Groups 8, 9, 10, 11, and 12, the spin Hall angle of that layer will mostly exhibit positive polarity. Conversely, if the layer mainly contains metallic elements belonging to any one of Groups 3, 4, 5, and 6, the spin Hall angle of that layer will mostly exhibit negative polarity. Furthermore, the polarity of the spin Hall angle is determined not only by the materials constituting the layers but also by factors such as the layer thickness.

[0106] Next, the function of the spin inductor 102 will be explained. Figure 10 This is a schematic diagram used to illustrate the function of the spin inductor 102.

[0107] The spin inductor 102 functions as an inductor when current flows along the wiring layer 6. If current is applied between the first terminal 20 and the second terminal 30, the current flows in the plane of the wiring layer 6.

[0108] Wiring layer 6 comprises a first layer 7 and a second layer 8. Current also flows in the x-direction within each of the first layer 7 and the second layer 8. The current flowing within the first layer 7 and the second layer 8 generates spin current through the spin Hall effect.

[0109] The signs of the spin currents generated within the first layer 7 and the second layer 8 are different. In the first layer 7, the spin S1 polarized in the -y direction bends towards the -z direction relative to the direction of travel, and the spin S2 polarized in the +y direction bends towards the +z direction relative to the direction of travel. Conversely, in the second layer 8, the spin S1 polarized in the -y direction bends towards the +z direction relative to the direction of travel, and the spin S2 polarized in the +y direction bends towards the -z direction relative to the direction of travel.

[0110] Spin S1 accumulated on the first surface 7A is injected from the first surface 7A into the adjacent first ferromagnetic layer 2. Spin S1 accumulated on the second surface 8B is injected from the second surface 8B into the adjacent second ferromagnetic layer 3. Spin S1 polarized in the same direction is injected into the first ferromagnetic layer 2 and the second ferromagnetic layer 3. Therefore, in the initial state, it is preferable that the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are oriented in the same direction.

[0111] By ensuring that the distance between the first layer 7 and the first ferromagnetic layer 2 is less than or equal to the spin diffusion length of spin S1, the spin S1 generated in the first layer 7 can be effectively injected into the first ferromagnetic layer 2. Similarly, by ensuring that the distance between the second layer 8 and the second ferromagnetic layer 3 is less than or equal to the spin diffusion length of spin S1, the spin S1 generated in the second layer 8 can be effectively injected into the second ferromagnetic layer 3.

[0112] The magnetization M2 of the first ferromagnetic layer 2 precesses by a spin S1 injected from the first layer 7. The coercivity of the magnetization M2 and the magnitude of the current flowing through the wiring layer 6 are adjusted, and the magnetization M2 is configured to precess without reversing due to the injected spin S1.

[0113] The magnetization M3 of the second ferromagnetic layer 3 precesses by the spin S1 injected from the second layer 8. The coercivity of the magnetization M3 and the magnitude of the current flowing through the wiring layer 6 are adjusted, and the magnetization M3 is configured to precess without reversing due to the injected spin S1.

[0114] If the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 precess, an energy conversion occurs between the magnetic moment and the current, and the spin inductor 102 exhibits the function of an inductor.

[0115] As described above, the spin inductor 102 of the third embodiment utilizes spin injected from both sides of the wiring layer 6 into the adjacent ferromagnetic layer, thus exhibiting a large inductance.

[0116] Furthermore, this example illustrates an initial state in which the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are oriented in the same direction, and the signs of the spin current generated in the first layer 7 and the spin current generated in the second layer 8 are different. However, the structure of the laminate 12 is not limited to this example. For instance, it is also possible that, in the initial state, the magnetization M2 of the first ferromagnetic layer 2 and the magnetization M3 of the second ferromagnetic layer 3 are oriented in opposite directions, and the signs of the spin current generated in the first layer 7 and the spin current generated in the second layer 8 are the same.

[0117] (Fourth Implementation)

[0118] Figure 11 This is a perspective view of the spin inductor 103 according to the fourth embodiment. Figure 12 This is a cross-sectional view of the spin inductor 103 according to the fourth embodiment. Figure 13 This is a top view of the spin inductor 103 according to the fourth embodiment. In the spin inductor 103 of the fourth embodiment, the same reference numerals are used to mark the same structures as in the spin inductor 100 of the first embodiment, and descriptions are omitted.

[0119] The spin inductor 103 has a laminate 10, a first terminal 20, a second terminal 30, a magnetic shield 40, an insulating layer 51, and an insulating layer 52. The spin inductor 103 differs from the spin inductor 100 in that it has a magnetic shield 40.

[0120] The magnetic shielding component 40 has, for example, a first magnetic yoke 41, a second magnetic yoke 42, and a through hole 43.

[0121] The first magnetic yoke 41 is separated from the laminate 10 in the z-direction. The first magnetic yoke 41 is separated from the first ferromagnetic layer 2, the second ferromagnetic layer 3, and the third ferromagnetic layer 5 in the z-direction.

[0122] An insulating layer 51 is provided between the laminate 10 and the first magnetic yoke 41, for example. The insulating layer 51 is an insulating layer that insulates the laminate 10 from the magnetic shield 40. The insulating layer 51 is, for example, silicon oxide (SiO2). x Silicon nitride (SiN) x Silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO2) x Magnesium oxide (MgO), aluminum nitride (AlN), etc.

[0123] The second magnetic yoke 42 is separated from the laminate 10 in the z-direction. The first magnetic yoke 41 and the second magnetic yoke 42 clamp the laminate 10 in the z-direction.

[0124] An insulating layer 52 is provided, for example, between the laminate 10 and the second magnetic yoke 42. The insulating layer 52 is an insulating layer that insulates the laminate 10 from the magnetic shield 40. The insulating layer 52 contains the same material as the insulating layer 51.

[0125] The first magnetic yoke 41 and the second magnetic yoke 42 suppress the influence of external magnetic fields on the laminate 10. Furthermore, the first magnetic yoke 41 and the second magnetic yoke 42 facilitate the magnetization of the first ferromagnetic layer 2, the second ferromagnetic layer 3, and the third ferromagnetic layer 5 in the z-direction. If the magnetization is strongly oriented in the z-direction, the precession axis of magnetizations M2 and M3 is stable, and the spin inductor 103 exhibits a large inductance.

[0126] Through-hole 43 connects the first yoke 41 and the second yoke 42. If the first yoke 41 and the second yoke 42 are connected via through-hole 43, the magnetic flux flows back along the magnetic shield 40. As a result, the magnetizations M2 and M3 are more strongly oriented in the z-direction, and the spin inductor 103 exhibits a large inductance.

[0127] The spin inductor 103 of the fourth embodiment achieves the same effect as the spin inductor 100 of the first embodiment. Furthermore, the magnetic shield 40 can reduce the influence of the external magnetic field on magnetization M2 and magnetization M3. Moreover, if the magnetic shield 40 is configured as described above, the precession of magnetization M2 and magnetization M3 is stabilized, and the spin inductor 103 exhibits a large inductance.

[0128] Magnetic shielding component 40 is not limited to Figures 11-13 The structure can be either the first magnetic yoke 41 or the second magnetic yoke 42. Additionally, the magnetic shield 40 can also be applied to the spin inductors of the second and third embodiments.

[0129] The first to fourth embodiments have been described above, illustrating the specific structure of the spin inductor. The spin inductor disclosed herein is not limited to these illustrated structures, and various modifications can be made within the scope of the main idea. Furthermore, the spin inductor disclosed herein can, for example, be assembled into a module for use. Figure 14 This is an example of the use of the spin inductor in this embodiment.

[0130] In recent years, research has been conducted on the single-chip integration of functional devices such as semiconductor circuits and memories. The technology of single-chip integration for semiconductor circuits and memories is called "die-piece" or "heterogeneous integration." By monolithizing these devices, latency, power consumption, and costs can be reduced. Even with these technologies, passive components still need to be placed around the chip to enable it to function. Therefore, even with high chip integration, passive components remain a challenge for module miniaturization. Further miniaturization of modules can be expected by assembling passive components in die-pieces or heterogeneous integration.

[0131] Figure 14 The chip C shown has a semiconductor circuit L1, a connection layer L2, a wiring layer L3, a storage layer L4, a sensor layer L5, an LCR (passive component) layer L6, and an all-solid-state thin-film battery layer L7, which are stacked sequentially. The layers are bonded together to form a monolithic structure, but... Figure 14 For ease of understanding, spaces are separated. The spin inductor disclosed herein is formed, for example, in the LCR layer L6. The LCR layer L6 can be formed not only of passive components such as inductors, capacitors, and resistors, which are existing electronic components, but also of spin inductors, spin variable capacitors, etc. The LCR layer L6 is connected to other layers via contact holes and used as a module within the overall chip C. The spin inductor disclosed herein also has, for example... Figure 14 The sensors and power supplies shown can be applied to devices capable of autonomously collecting information.

[0132] Explanation of reference numerals in the attached figures

[0133] 1, 6… Wiring layer, 1A… First side, 1B… Second side, 2… First ferromagnetic layer, 3… Second ferromagnetic layer, 4… Magnetic coupling layer, 5… Third ferromagnetic layer, 7… First layer, 8… Second layer, 10, 11, 12… Laminated structure, 10A… First side, 10B… Second side, 20… First terminal, 30… Second terminal, 40… Magnetic shield, 41… First yoke, 42… Second yoke, 43… Through hole, 51, 52… Insulating layer, 91… Conductive layer, 92, 93, 95… Ferromagnetic layer, 94… Intermediate layer, 100, 101, 102, 103… Spin inductor, M2, M3, M5… Magnetization.

Claims

1. A spin inductor, wherein, have: Wiring layer; A first ferromagnetic layer, which is in contact with the first surface of the wiring layer; and The second ferromagnetic layer is in contact with the second surface of the wiring layer opposite to the first surface.

2. The spin inductor according to claim 1, wherein, The magnetization of the first ferromagnetic layer is oriented in the opposite direction to the magnetization of the second ferromagnetic layer.

3. The spin inductor according to claim 1, wherein, It also has a third ferromagnetic layer and a magnetic coupling layer. The magnetic coupling layer is located between the second ferromagnetic layer and the third ferromagnetic layer.

4. The spin inductor according to claim 3, wherein, The magnetization of the first ferromagnetic layer is oriented in the same direction as the magnetization of the third ferromagnetic layer.

5. The spin inductor according to claim 3, wherein, The thickness of the third ferromagnetic layer is greater than that of the second ferromagnetic layer.

6. The spin inductor according to claim 1, wherein, The wiring layer has a first layer and a second layer.

7. The spin inductor according to claim 6, wherein, The sign of the spin flow generated in the first layer is different from the sign of the spin flow generated in the second layer.

8. The spin inductor according to claim 6, wherein, The magnetization of the first ferromagnetic layer is oriented in the same direction as the magnetization of the second ferromagnetic layer.

9. The spin inductor according to claim 1, wherein, It also has a magnetic shielding layer. The magnetic shielding layer is separated from the first ferromagnetic layer and the second ferromagnetic layer in the stacking direction.

10. The spin inductor according to claim 1, wherein, The wiring layer is configured to inject spins into the first ferromagnetic layer and the second ferromagnetic layer. The magnetization of the first ferromagnetic layer and the second ferromagnetic layer is configured to precess by the injected spin.

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