Spin current magnetization rotating element, magnetoresistive effect element, and magnetic memory

Abstract

A spin current magnetization rotating element includes: a first ferromagnetic layer having a variable magnetization direction; and a spin orbit moment wiring layer adjacent to the first ferromagnetic layer. At least one element in the spin-orbit moment wiring layer has a crystal structure in which when dimensions of lattice constants of the crystal structure are represented by a, b, and c: atoms occupy internal coordinates: (0, 0, 0), (0.5, 0.5, 0), (0.25, 0.75, 0.25), (0.75, 0.25, 0.25), (0, 0.5, 0.5), (0.5, 0, 0.5), (0.75, 0.75, 0.75), and (0.25, 0.25, 0.75); the ab planes are laminated to have a quadruple helix structure along the c-axis; the angle (gamma) between the a-axis and the b-axis is in the range of 60 DEG < = gamma < = 120 DEG, and the ratio of b to a (b / a) is in the range of 0.2 < = b / a < = 1.0.

Description

Technical Field

[0001] The present disclosure relates to a spin current magnetization rotation element, a magnetoresistance effect element, and a magnetic memory.This application claims priority to US Provisional Patent Application No. 63 / 439,447, the contents of which are incorporated herein by reference. Background Art

[0002] There is known a spin current magnetization rotation element provided with a ferromagnetic layer whose magnetization direction is changeable and a spin-orbit torque wiring layer adjacent to the ferromagnetic layer.

[0003] For example, the spin current magnetization rotation element taught in U.S. Patent Application Publication No. 2022 / 0,149,269 teaches a spin current magnetization rotation element (spintronics element) in which the perpendicular magnetization of the ferromagnetic layer is reversible by stacking a ferromagnetic layer and an antiferromagnetic layer (spin-orbit moment wiring layer) and changing the spin polarization direction of the spin current generated by the direction of current flowing parallel to the plane of the antiferromagnetic layer. In U.S. Patent Application Publication No. 2022 / 0,149,269, by using a canted antiferromagnetic material such as Mn3Sn as the material for the spin-orbit moment wiring layer, the spin polarization direction can be reversed to change the direction of the spin-orbit moment without using an exchange bias by reversing the direction of current flowing through the antiferromagnetic layer.

[0004] Furthermore, U.S. Patent Application Publication No. 2019 / 0,267,540 discloses another example of a spin current magnetization rotation element, a magnetoresistive element, and a magnetic memory. In U.S. Patent Application Publication No. 2019 / 0,267,540, a superparamagnetic material is incorporated into a spin-orbit moment wiring layer, enabling magnetization rotation even when the current density flowing through the spin-orbit moment wiring layer decreases.

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: U.S. Patent Application Publication No. 2022 / 0,149,269

[0008] Patent Document 2: U.S. Patent Application Publication No. 2019 / 0,267,540 Summary of the Invention

[0009] According to one aspect of the present disclosure, a spin current magnetization rotation element includes: a first ferromagnetic layer having a changeable magnetization direction; and a spin-orbit moment wiring layer adjacent to the first ferromagnetic layer. The spin-orbit moment wiring layer includes one or more elements. At least one of the one or more elements has a crystal structure, wherein when the dimensions of the lattice constant of the crystal structure are represented by a, b and c: the atoms occupy the internal coordinates of the unit cell: (0,0,0), (0.5,0.5,0), (0.25,0.75,0.25), (0.75,0.25,0.25), (0,0.5,0.5), (0.5,0,0.5), (0.75,0.75,0.75) and (0.25,0.25,0.75); the ab planes are stacked to have a quadruple helix structure along the c axis; and the angle (γ) between the a axis and the b axis is in the range of 60°≤γ≤120°, and the ratio of b to a (b / a) is in the range of 0.2≤b / a≤1.0.

[0010] According to another aspect of the present disclosure, a magnetoresistance effect element includes: the above-described spin current magnetization rotation element; a second ferromagnetic layer having a fixed magnetization direction; and a nonmagnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer.

[0011] According to still another aspect of the present disclosure, a magnetic memory includes a plurality of the above-mentioned magnetoresistive effect elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A more complete appreciation of the present disclosure and its many attendant advantages will be readily obtained as the present disclosure and its many attendant advantages will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1 is a cross-sectional view showing an embodiment of a spin current magnetization rotation element, Figure 2A is a conceptual diagram showing an ABCD stacking structure (a stacking structure having a quadruple helical axis), Figure 2B is a conceptual diagram showing an ACAC stacking structure (a stacking structure having a double helical axis). Figure 3 is a graph showing the total energy when b / a is changed in the case of an ABCD stacking structure (a stacking structure having a quadruple helical axis) and an ACAC stacking structure (a stacking structure having a double helical axis), Figure 4 is a cross-sectional view showing one embodiment of a magnetoresistive effect element, and Figure 5 is a circuit diagram of one embodiment of a magnetic memory. DETAILED DESCRIPTION

[0013] As used herein, the words "a" and "an" etc. have the meaning of "one or more". When an amount, concentration or other value or parameter is given as a range and / or its description includes a list consisting of an upper limit and a lower limit, it should be understood that all integers and fractions within the given range and all ranges formed by any paired upper and lower limits are specifically disclosed, regardless of whether a subrange is disclosed separately. Where a numerical range is cited in this article, unless otherwise stated, the range is intended to include its endpoints, as well as all integers and fractions within the range. As an example, the range 1-10 fully describes and includes independent subranges 3.4 to 7.2 and the following value list: 1, 4, 6, 10.

[0014] In the embodiments of the present disclosure, when current flows through the spin-orbit moment wiring layer of a spin-current magnetization rotation element, a relatively large spin current is generated due to the spin-orbit moment wiring layer's unique crystal structure. Therefore, when used in a magnetoresistive element or magnetic memory, the spin-current magnetization rotation element can be driven with a relatively small current.

[0015] Examples of each element will be described below.

[0016] [Spin ​​current magnetization rotation element]

[0017] Figure 1 1 is a cross-sectional view showing an embodiment of a spin current magnetization rotation element. A ferromagnetic layer (first ferromagnetic layer) 12 capable of magnetization rotation is stacked on the surface of a spin-orbit moment wiring layer 11.

[0018] In the spin current magnetization rotation element disclosed herein, a spin-orbit moment wiring layer is composed of a single element or a plurality of elements, and at least one element in the spin-orbit moment wiring layer has the following structure: in the structure, when the dimensions of the lattice constant of the crystal structure are represented by a, b, and c: atoms occupy the internal coordinates of the unit cell: (0, 0, 0), (0.5, 0.5, 0), (0.25, 0.75, 0.25), (0.75, 0.25, 0.25), (0, 0.5, 0.5), (0.5, 0, 0.5), (0.75, 0.75, 0.75), and (0.25, 0.25, 0.75); and ab planes are stacked to have a quadruple helical structure along the c-axis; and an angle (γ) between the a-axis and the b-axis is in the range of 60°≤γ≤120°, and a ratio of b to a (b / a) is in the range of 0.2≤b / a≤1.0.

[0019] The range of γ is more preferably 80°≤γ≤100°, and further preferably 85°≤γ≤95°.

[0020] Furthermore, the range of b / a is preferably 0.4≤b / a≤0.6, and further preferably 0.47≤b / a≤0.55.

[0021] In one embodiment, an element having an orthorhombic structure with an Fddd space group is included as the one or more elements included in the spin-track moment wiring layer 11 .

[0022] In one embodiment, the spin-track moment wiring layer 11 contains tungsten as the one or more elements.

[0023] In one embodiment, tungsten having an orthorhombic structure with an Fddd space group is included as the one or more elements included in the spin-track moment wiring layer 11 .

[0024] In one embodiment, the thickness of the spin-track moment wiring layer 11 is 0.1 nm to 50 nm, preferably 0.3 nm to 20 nm, and more preferably 0.5 nm to 10 nm.

[0025] The inventors of the present disclosure have discovered through performing various simulations, such as the simulation described below, that when orthorhombic tungsten has an orthorhombic structure with an Fddd space group, the resulting spin Hall conductivity is greater than that of α-W or β-W at the Fermi level, and similar phenomena are expected for heavy metal elements with atomic numbers equal to or greater than that of yttrium.

[0026] (Simulation method)

[0027] To explore crystal structures showing large spin Hall conductivity (SHC), the inventors performed an evolutionary algorithm (EA) search according to the method described by T. Ishikawa, T. Miyake, and K. Shimizu in Phys. Rev. B 100, 174506 (2019). First, (i) a population of 20 structures was randomly constructed with a fixed number of atoms (N) in the computational unit. All the structures were fully optimized using the constant pressure variable cell relaxation method and density functional theory (DFT) calculations and ranked by total energy E. Next, (ii) the next generation of 20 structures was generated and optimized by applying the evolutionary operator (EO) "mating" and "mutation" to the structures in the population. The mating operator generates a slab structure based on two structures randomly selected from the population, and averages the lattice parameters (a, b, c, α, β and γ) between them, i.e., generates a progeny with the structural characteristics of the parent. When N remains unchanged, atoms in the unit cell are randomly added or eliminated. The mutation operator changes the six lattice parameters of a structure selected from the population, i.e., the distortion of the unit cell. The rate of EO is set so that 10 structures are generated by the mating operator and another 10 structures are generated by the mutation operator. Then, (iii) four structures with very low E values ​​before applying EO are passed to the next generation. By sorting the 24 structures in the newly generated population again according to E, and removing four unstable structures with very high E values ​​from the population. By repeatedly implementing (ii) and (iii), the structures included in the population are gradually updated. By changing N from 2 to 3, 4, 5, 6, 8 and 10, several EA searches were implemented. The EA code is combined with the Quantum ESPRESSO (QE) code (see P. Giannozzi et al., J. Phys.: Condens. Matter 21, 395502 (2009)) to perform the optimization of the structures generated by EO.In the framework of the projector augmented wave (PAW) method, the generalized gradient approximation of Perdew, Burke, and Ernzerhof (PBE) is used for the exchange-correlation functional (see, for example, PE Blecher (PE. ), Phys. Rev. B 50, 17953 (1994), G. Kresse and D. Joubert, Phys. Rev. B 59, 1758 (1999). PAW potentials were obtained from the QE website (see https: / / www.quantum-espresso.org / ). The energy cutoffs for the wave function and charge density were set at 80 Ry and 640 Ry, respectively. EA search was performed using an 8×8×8 grid on the k-space integral over the Brillouin zone (BZ), and then the k-point sampling (N) was increased. k ) to more accurately compare the energies between the predicted structures. The pressure was set to zero kilobars. To check the dynamical stability of the predicted structures, phonon calculations were performed based on density functional perturbation theory, which is implemented in the QE code.

[0028] Assume that due to J c Flow along the y direction, J s is generated along the x direction and the spin polarization is along the z direction, then SHC The cleaning limit is calculated by the Kubo formula as follows:

[0029]

[0030] where f nk is the Fermi-Dirac distribution function of the n-th energy band at k, and

[0031]

[0032] is the Berry curvature of the nth band at k. |nk>(|mk>) is the Bloch state with band index n(m) and wave vector k, and ∈ nk (∈ mk ) is the eigenvalue.

[0033] and vy are the spin current operator and velocity operator, respectively. To calculate the SHC, we use the PBEsol functional (see J.P. Perdew et al., Phys. Rev. Lett. 100, 136406 (2008)) and the norm-conserving fully relativistic pseudopotential generated by the optimized norm-conserving Vanderbilt pseudopotential (ONCVP) code (see D.R. Hamann, Phys. Rev. B 88, 085117 (2013)), which is obtained from the PseudoDojo (see M.J. van Setten et al., Comput. Phys. Commun. 226, 39 (2018)). In order to deal with relativistic effects, the spin-orbit interaction is considered self-consistently. Once the QE calculation is completed self-consistently, the Bloch function is Fourier transformed into the maximally localized Wannier function (MLWF) using the Wannier90 software package (see N. Marzari et al., "Rev. Mod. Phys." 84, 1419 (2012)). The energy cutoff of the wave function is set to 100 Ry, and N k The values ​​of range from 4 × 4 × 4 to 8 × 8 × 8. The band structure obtained by MLWF fully reproduces the DFT band structure from -10 eV to 5 eV. MLWF is used to calculate the Berry curvature. A dense k-mesh of 100 × 100 × 100 is used for the Berry curvature integral over the BZ.

[0034] As a result of the EA search starting from the random generation of the structure, the bcc structure corresponding to the α phase was obtained as the most stable structure, and the Pm-3n structure corresponding to the β phase was obtained as the second most stable structure. Subsequently, other metastable structures were studied in the evolutionary population. In order to find structures different from α-W and β-W, the x-ray diffraction pattern of the structure was simulated in the population by RIETAN-2000 (see F. Izumi and T. Ikeda, Mater. Sci. Forum 321-324, 198). As a result of the comparison, 15 structures different from α-W and β-W were obtained. The space group of the structure was specified using FINDSYM (see, for example, HT Stokes and DM Hatch, J. Appl. Cryst. 38, 237 (2005)). In addition, the newly predicted 15 structures (Table 1) were calculated at the Fermi level. The absolute value of SHC under .

[0035] Table 1 shows the simulation results of the α phase, β phase, and Fddd structure among these structures.

[0036] Table 1 shows the crystal structures obtained by the structure search scheme based on first principle calculation and evolutionary algorithm. The structures of α phase and β phase correspond to Im-3m (bcc) and Pm-3n (A15), respectively. p is the number of atoms in the primitive unit cell, ΔE is the energy relative to α-W, and is the intrinsic spin Hall conductivity (SHC) at the Fermi level. ∈ max and are the position relative to the Fermi level and the SHC value of the maximum peak, respectively. and The unit is (h / e)(Ωcm) -1 .

[0037] Table 1

[0038]

[0039] Here, the unit cell parameters and atomic positions of the Fddd structure are shown in the following table (Table 2).

[0040] Table 2: Unit cell parameters and atomic positions of orthorhombic Fddd structures

[0041]

[0042] As shown in Table 1, when tungsten has an orthorhombic structure with an Fddd space group, the spin conductivity at the Fermi level is expected to be larger than that of α-W and β-W.

[0043] Since the Fddd structure is a structure in which a body-centered cubic structure is spirally deformed, the one or more elements contained in the spin-track moment wiring layer 11 are not limited to tungsten, but may be used as long as they are elements having a body-centered cubic structure.

[0044] Examples of elements other than tungsten used in the spin-track moment wiring layer 11 include tantalum and molybdenum.

[0045] The magnetization direction of the ferromagnetic layer 12 is changeable.

[0046] The magnetization may be parallel or tilted to the layer direction, but is preferably substantially perpendicular to the layer direction. In the present disclosure, "substantially perpendicular to" means having an angle of 80 to 100 degrees, preferably 85 to 95 degrees, more preferably 88 to 92 degrees.

[0047] In one embodiment, the ferromagnetic layer 12 may contain one or more metals selected from the group consisting of Co, Fe, Ni, and Gd, alloys of these metals, ferromagnets composed of Heusler alloys (e.g., Cu-Mn-Al alloy or Mn-Cu-Sn alloy), and other ferromagnets. Specific examples of other ferromagnets include oxides, such as chromium (II) oxide.

[0048] In one embodiment, the ferromagnetic layer is directly stacked on the spin-orbit moment wiring layer. In another embodiment, the first ferromagnetic layer is stacked on the spin-orbit moment wiring layer via one or more other layers. The first ferromagnetic layer can be a film that can be formed as another layer disposed between the spin-orbit moment wiring layers by a known film forming method such as sputtering or epitaxial growth (molecular beam epitaxy (MBE), metal organic chemical vapor deposition (MOCVD), and similar methods), and there is no particular limitation on this. In this case, examples of the one or more other layers include layers containing, for example, Cu, Ni, and Ru as materials.

[0049] When a current is passed through the spin-orbit moment wiring layer 11 of the spin current magnetization rotation element in a direction parallel to the layer (for example, along Figure 1When electric current flows (in the direction of the horizontal arrow in the figure), a spin current is generated in a direction orthogonal to the current due to the spin-orbit interaction (spin Hall effect), and spin accumulation is generated, which is spin-polarized perpendicularly, parallel to, or inclined to the interface between the spin-orbit moment wiring layer 11 and the ferromagnetic layer 12. The spin accumulation applies a spin-orbit torque to the magnetization of the ferromagnetic layer 12, causing magnetization rotation in the ferromagnetic layer 12.

[0050] Since a relatively large spin current is generated in the spin current magnetization rotation element of the present disclosure compared to the spin current of a conventional element, magnetization rotation can be achieved even when a current having a small current density is used.

[0051] [Method for manufacturing a spin current magnetization rotation element]

[0052] The disclosed spin current magnetization rotation element can be produced by the following procedures: (1) forming the spin orbit moment wiring layer 11, (2) laminating the ferromagnetic layer 12 on the spin orbit moment wiring layer 11, and (3) adding a voltage application mechanism. Specific descriptions will be given below.

[0053] (1) Generating the spin-orbit moment wiring layer 11

[0054] The spin-orbit moment wiring layer can be generated by forming a film composed of the material of the present disclosure on a substrate using a known film formation method such as sputtering or epitaxial growth (MBE, MOCVD, etc.).

[0055] When a spin-track moment wiring layer composed of tungsten having an orthorhombic structure with an Fddd space group is produced, for example, a method such as the methods shown in the following (a) to (d) can be employed.

[0056] (a) A GaN (1-100) substrate having an m-plane as its surface is prepared.

[0057] (b) An AlN (1-100) film is formed thereon.

[0058] (c) A Zn(1-100) film is formed thereon.

[0059] (d) A W(110) film is formed thereon.

[0060] Although it does not limit the present invention, the reason why tungsten having an orthorhombic structure with a space group of Fddd is formed by the above method can be assumed as follows.

[0061] for Figure 2A The ABCD stacking structure shown in (stacked into a quadruple helix structure) and Figure 2B For the ACAC stacking structure shown in FIG (stacked into a double helical structure), c / a is fixed to 2, and b / a is varied to perform simulation calculations of the total energy. Figure 3 This is explained using the relative value when the total energy in the ACAC stacking structure is 0. The horizontal axis is b / a, and the vertical axis is the relative value of the total energy. b / a=0.71 in the ACAC stacking structure corresponds to a body-centered cubic lattice (bcc). Figure 4 It can be understood that when b / a < 0.55, the Fddd structure (ABCD stacking structure) is more stable than the ACAC stacking structure under the same b / a. Therefore, it can be assumed that when tungsten is deformed from b / a = 0.71 corresponding to bcc (110) to close to b / a = 0.55, the ABCD stacking structure is more stable than the ACAC stacking structure, and thus the Fddd structure is generated.

[0062] For reference, the lattice constants of α-W(110), Zn(1-100), AlN(1-100), and GaN(1-100) are shown in Table 3.

[0063] Table 3

[0064] Lattice constant b A b / a α-W(110) 3.156 4.43 0.71 Zn(1-100) 2.665 4.947 0.539 AlN(1-100 3.11 4.98 0.624 GaN(1-100) 3.18 5.17 0.615

[0065] In the above method, it is conceivable that α-W(110) is formed on Zn(1-100) with approximately b / a=0.539, and the Fddd structure is generated before the α-W relaxes to the original b / a (0.71).

[0066] In the above method, the film-forming thickness of W(110) is, for example, 1 nm to 10 nm, preferably 2 nm to 9 nm, and more preferably 3 nm to 8 nm.

[0067] (2) Laminating the ferromagnetic layer 12 on the spin-track moment wiring layer 11

[0068] Next, the ferromagnetic layer 12 is formed on the spin-track moment wiring layer 11 by a known film forming method such as sputtering. When sputtering is used, for example, one or more metals selected from the group consisting of Co, Fe, and Ni, or alloys of these metals can be used as a target material.

[0069] (3) Adding a voltage application mechanism

[0070] Furthermore, a mechanism for applying voltage to the spin-orbit moment wiring layer 11 has been added. For example, a metal film can be formed on the spin-orbit moment wiring layer 11 by vapor deposition, sputtering, or the like, and a voltage can be applied to the spin-orbit moment wiring layer 11 using the metal as an electrode, with current flowing in a direction parallel to the layer. Examples of electrode materials include metals and indium tin oxide (ITO), with Cu, Au, and Al being exemplified as metals.

[0071] [Magnetoresistance effect element]

[0072] Known configurations can be used for magnetoresistive elements that use spin current to magnetize rotating elements. For example, the structures of magnetoresistive elements taught in U.S. Patent Application Publication No. 2022 / 0,149,269 and U.S. Patent Application Publication No. 2019 / 0,267,540 can be used. The description of the structures of magnetoresistive elements in U.S. Patent Application Publication No. 2022 / 0,149,269 and U.S. Patent Application Publication No. 2019 / 0,267,540 is incorporated into this specification.

[0073] Figure 4 A ferromagnetic layer (first ferromagnetic layer) 42 capable of magnetization rotation, a nonmagnetic layer 43, and a ferromagnetic layer (second ferromagnetic layer) 44 with a fixed magnetization direction are stacked on the surface of the spin-track moment wiring layer 11 in this order.

[0074] The magnetization of the second ferromagnetic layer is preferably substantially perpendicular to the ferromagnetic layer, but may also be tilted. In this magnetoresistive effect element, when the magnetization of the first ferromagnetic layer 42 and the magnetization of the second ferromagnetic layer 44 are oriented in the same direction (parallel state), a low resistance state is achieved, and when the magnetization of the first ferromagnetic layer 42 and the magnetization of the second ferromagnetic layer 44 are oriented in opposite directions (antiparallel state), a high resistance state is achieved. Therefore, by rotating the magnetization of the first ferromagnetic layer 42, which is capable of magnetization rotation, it is possible to switch between the low resistance state and the high resistance state. The magnetoresistive effect element can be used as a memory cell by using the difference in resistance value before and after switching as storage information.

[0075] Specifically, when current is passed through the spin-orbit moment wiring layer 41 of the magnetoresistive element in a direction parallel to the layer (for example, in the direction of the horizontal arrow in FIG. 2 ), a spin current is generated in a direction orthogonal to the current flow due to the spin-orbit interaction (spin Hall effect), and spins are accumulated, polarized perpendicularly, parallel to, or obliquely to the interface between the spin-orbit moment wiring layer 41 and the first ferromagnetic layer 42. This accumulated spin imparts a spin-orbit moment to the magnetization of the first ferromagnetic layer 42, causing magnetization rotation in the ferromagnetic layer 42. Therefore, switching between a low-resistance state and a high-resistance state can be achieved depending on whether a current flows in the spin-orbit moment wiring layer 41 in a direction parallel to the layer.

[0076] In one embodiment, the non-magnetic layer 43 is composed of an insulator. Examples of the material of the insulator include ceramics containing metal oxides, and the like, and as the metal oxide, magnesium oxide is exemplified.

[0077] In one embodiment, the non-magnetic layer 43 is a metal. Examples of metals include Cu and Ru.

[0078] The second ferromagnetic layer 44 has a fixed magnetization direction. This magnetization direction can be fixed using known methods. For example, the holding force of the second ferromagnetic layer 44 can be made greater than the holding force of the first ferromagnetic layer 42. Furthermore, the magnetization direction of the second ferromagnetic layer 44 can be fixed by exchange coupling with the antiferromagnetic layer.

[0079] In one embodiment, similar to the first ferromagnetic layer 42, the second ferromagnetic layer 44 may contain one or more metals selected from the group consisting of Co, Fe, Ni, and Gd, alloys of these metals, ferromagnets composed of Heusler alloys (e.g., Cu-Mn-Al alloy or Mn-Cu-Sn alloy), and other ferromagnets. Specific examples of other ferromagnets include oxides, such as chromium dioxide.

[0080] The first ferromagnetic layer 42 and the second ferromagnetic layer 44 may be formed of the same material or different materials. From the perspective of increasing the difference between the low resistance state and the high resistance state, the magnetization direction of the first ferromagnetic layer 42 and the magnetization direction of the second ferromagnetic layer 44 are preferably nearly parallel or antiparallel. That is, if the magnetization direction of the first ferromagnetic layer 42 is substantially perpendicular to the layer direction, then the magnetization direction of the second ferromagnetic layer 44 is preferably also substantially perpendicular to the layer direction. If the magnetization direction of the first ferromagnetic layer 42 is substantially parallel to the layer direction, then the magnetization direction of the second ferromagnetic layer 44 is preferably also substantially parallel to the layer direction.

[0081] The magnetoresistance effect element disclosed herein can be produced by the following procedures: (1) generating a spin-orbit moment wiring layer 41, (2) stacking a first ferromagnetic layer 42 on the spin-orbit moment wiring layer 41, (3) stacking a non-magnetic layer 43 on the first ferromagnetic layer 42, (4) stacking a second ferromagnetic layer 44 on the non-magnetic layer 43, and (5) adding a voltage applying mechanism.

[0082] Among them, (1) generating the spin-orbit moment wiring layer 41, (2) stacking the first ferromagnetic layer 42 on the spin-orbit moment wiring layer 41, and (5) adding the voltage applying mechanism are similar to the procedures described in the method for manufacturing the spin current magnetization rotation element, and therefore they will not be described in detail.

[0083] (3) The first ferromagnetic layer 42 is stacked on the non-magnetic layer 43

[0084] The non-magnetic layer 43 is formed on the first ferromagnetic layer 42 by a known film forming method such as sputtering. When sputtering is used, a material capable of forming a non-magnetic layer can be used as a target material.

[0085] (4) The second ferromagnetic layer 44 is stacked on the non-magnetic layer 43

[0086] Next, a second ferromagnetic layer 44 is formed on the non-magnetic layer 43 by a known film forming method such as sputtering. When sputtering is used, similarly to the first ferromagnetic layer, for example, one or more metals selected from the group consisting of Co, Fe, and Ni, or alloys of these metals can be used as target materials.

[0087] In the magnetoresistance effect element of the present disclosure, a relatively large spin current is generated in the spin-track moment wiring layer, and therefore, resistance can be switched at a small current.

[0088] [Magnetic Memory]

[0089] A magnetic memory can be configured using a plurality of the above-described magnetoresistive effect elements as storage cells. A known configuration can be used for a magnetic memory that uses a spin current to magnetize a rotating element. For example, the structure of a magnetic memory taught in U.S. Patent Application Publication No. 2022 / 0,149,269 and U.S. Patent Application Publication No. 2019 / 0,267,540 can be used. The description of the structure of the magnetic memory in U.S. Patent Application Publication No. 2022 / 0,149,269 and U.S. Patent Application Publication No. 2019 / 0,267,540 is incorporated into this specification.

[0090] Figure 5 1 is a circuit diagram showing one embodiment of the wiring of a memory cell constituting a portion of the magnetic memory of the present disclosure. Figure 5 The plurality of memory cells shown are arranged in a matrix form and driven.

[0091] In each memory cell, a ferromagnetic layer (first ferromagnetic layer) 52 capable of magnetization rotation, a nonmagnetic layer 53, and a ferromagnetic layer (second ferromagnetic layer) 54 with a fixed magnetization direction are stacked in this order on the surface of the spin-orbit moment wiring layer 51, thereby forming a magnetoresistive effect element. The operation of the magnetoresistive effect element in the magnetic memory is similar to the operation described above for the magnetoresistive effect element.

[0092] Two power supply electrodes 56, 56 are provided for the spin-orbit moment wiring layer 51, and the power supply electrodes 56, 56 are respectively connected to the sources of transistors 60, 60. The gates of the transistors 60, 60 are connected to a word line 58, and the drains of the two transistors 60, 60 are respectively connected to a first write bit line 59 and a second write bit line 59'. The second ferromagnetic layer 54 is connected to a read bit line 57 via an electrode 55.

[0093] Here, for example, data "1" is assigned to a high resistance state, while data "0" is assigned to a low resistance state. When data "1" is written to a memory cell to which data "0" is written, first write bit line 59 is set to an H (high voltage) level, while second write bit line 59' is set to an L (low voltage) level. Then, by setting word line 58 to an H level, current flows from first write bit line 59 to second write bit line 59' through spin-track moment wiring layer 51, inverting the magnetization of first ferromagnetic layer 52 and writing data "1."

[0094] Conversely, for example, when data "0" is written to a memory cell to which data "1" is written, first write bit line 59 is set to the L level, while second write bit line 59' is set to the H level. Then, by setting word line 58 to the H level, current flows from second write bit line 59' to first write bit line 59 through spin-track moment wiring layer 51, the magnetization of first ferromagnetic layer 52 is reversed, and data "0" is written.

[0095] When reading data stored in a memory cell, one of first write bit line 59 or second write bit line 59' is set to an H level, while the other is left open. Furthermore, by setting read bit line 57 to an L level and word line 58 to an H level, a current flows from first write bit line 59 and second write bit line 59' to read bit line 57. Therefore, by measuring the magnitude of this current, it is determined whether the memory cell is in a high resistance state or a low resistance state, and the data written to the memory cell is retrieved.

[0096] In one embodiment of a magnetic memory, by arranging the Figure 5 The memory cell shown performs predetermined write / read operations by controlling the levels of a write bit line, a read bit line, and a word line through a controller.

[0097] In the magnetic memory of the present embodiment, a relatively large spin current is generated in the spin-track moment wiring layer, and therefore, the magnetic memory can operate with a small current.

[0098] Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings, and it is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

[0099] Industrial Applicability

[0100] In the embodiments of the present disclosure, when current flows through the spin-orbit moment wiring layer of a spin-current magnetization rotation element, a relatively large spin current is generated due to the specific crystal structure of the spin-orbit moment wiring layer. Therefore, when used in a magnetoresistive element or magnetic memory, the spin-current magnetization rotation element can be driven with a relatively small current.

[0101] Explanation of Figure Numbers

[0102] 11 Spin-orbit moment wiring layer

[0103] 12 ferromagnetic layer

[0104] 41 spin-orbit moment wiring layer

[0105] 42First ferromagnetic layer

[0106] 43 non-magnetic layer

[0107] 44 Second ferromagnetic layer

[0108] 51 spin-orbit moment wiring layer

[0109] 52, 54 ferromagnetic layer

[0110] 53 non-magnetic layer

[0111] 55, 56 electrodes

[0112] 57 Read bit line

[0113] 58-character line

[0114] 59 first write bit line

[0115] 59' second write bit line

[0116] 60 transistors

Claims

1. A spin current magnetization rotation element, comprising: a first ferromagnetic layer having a changeable magnetization direction; as well as a spin-orbit moment wiring layer, adjacent to the first ferromagnetic layer, wherein the spin-orbit moment wiring layer comprises one or more elements, and at least one of the one or more elements has a crystalline structure, wherein When the dimensions of the lattice constant of the crystal structure are represented by a, b, and c: The atoms occupy the interior coordinates of the unit cell: (0,0,0), (0.5,0.5,0), (0.25,0.75,0.25), (0.75,0.25,0.25), (0,0.5,0.5), (0.5,0,0.5), (0.75,0.75,0.75), and (0.25,0.25,0.75); The ab planes are stacked to have a quadruple helical structure along the c-axis; and The angle (γ) between the a-axis and the b-axis is in the range of 60°≤γ≤120°, and the ratio of b to a (b / a) is in the range of 0.2≤b / a≤1.

0. 2 . The spin current magnetization rotation element according to claim 1 , wherein the one or more elements included in the spin orbit moment wiring layer include a heavy metal element having an atomic number equal to or greater than that of yttrium. 3 . The spin current magnetization rotation element according to claim 2 , wherein the heavy metal element is tungsten. 4 . The spin current magnetization rotation element according to claim 2 , wherein the heavy metal element is tungsten having an orthorhombic structure with an Fddd space group. 5 . The spin current magnetization rotation element according to claim 1 , wherein γ is in the range of 85°≤γ≤95°. 6 . The spin current magnetization rotation element according to claim 1 , wherein b / a is in the range of 0.4≦b / a≦0.

6. 7 . The spin current magnetization rotation element according to claim 1 , wherein b / a is in the range of 0.47≦b / a≦0.

55.

8. The spin current magnetization rotation element according to any one of claims 1 to 7, further comprising a substrate composed of a semiconductor or an insulator, wherein the spin orbit moment wiring layer is formed on the substrate directly or via an intermediate layer.

9. A magnetoresistive effect element, comprising: The spin current magnetization rotation element according to any one of claims 1 to 8; a second ferromagnetic layer having a fixed magnetization direction; as well as The non-magnetic layer is arranged between the first ferromagnetic layer and the second ferromagnetic layer.

10. A magnetic memory comprising a plurality of the magnetoresistive effect elements according to claim 9.

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