Magnetic memory element

Abstract

According to one aspect of the present invention, there is provided a magnetic memory element including a fixed layer and a memory layer. The fixed layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the fixed layer is configured to be fixed regardless of the data written into the magnetic memory element. The memory layer is stacked on the fixed layer via an electrically insulating barrier layer along the stacking direction, and includes a first ferromagnetic layer and an antiferromagnetic layer. The first ferromagnetic layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the first ferromagnetic layer is configured to be reversibly inverted according to the data written into the magnetic memory element using a tunnel current passing through the fixed layer and the memory layer. The antiferromagnetic layer includes an antiferromagnet that exhibits an anomalous Hall effect by forming a non-collinear or non-coplanar magnetic order in the ab plane defined by the a-axis and the b-axis perpendicular to the c-axis, which is the easy axis of magnetization. The antiferromagnet includes at least a domain in which the c-axis is along the stacking direction. A magnetic memory element is provided.

Description

Technical Field

[0001] The present invention relates to a magnetic memory element.

Background Art

[0002] Patent Document 1 discloses a technique for providing a magnetic memory element 1 that can operate at high speed with a small current.

[0003] The magnetic memory element 1 includes a perpendicular magnetization layer in which the direction of magnetization is perpendicular to the film surface, a nonmagnetic layer, a ferromagnetic layer having an easy axis of magnetization in the in-plane direction and the direction of magnetization being inclined at an angle of 15 degrees or more and 45 degrees or less from the direction perpendicular to the film surface, a storage layer in which the perpendicular magnetization layer and the ferromagnetic layer are laminated via the nonmagnetic layer and the perpendicular magnetization layer and the ferromagnetic layer are magnetically coupled, a magnetization fixing layer in which the direction of magnetization is fixed in the direction perpendicular to the film surface, and a nonmagnetic intermediate layer disposed between the storage layer and the magnetization fixing layer, and is configured such that information is recorded by flowing a current in the stacking direction of each layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, there is still room for improvement in the technique for efficiently writing data using such a magnetic memory element utilizing the tunneling magnetoresistance effect.

Means for Solving the Problems

[0006] According to one aspect of the present invention, there is provided a magnetic memory element including a fixed layer and a memory layer. The fixed layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the fixed layer is configured to be fixed regardless of the data written to the magnetic memory element. The memory layer is stacked on the fixed layer via an electrically insulating barrier layer along the stacking direction, and includes a first ferromagnetic layer and an antiferromagnetic layer. The first ferromagnetic layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the first ferromagnetic layer is configured to be reversibly inverted according to the data written to the magnetic memory element using the tunnel current passing through the fixed layer and the memory layer. The antiferromagnetic layer includes an antiferromagnet that exhibits an anomalous Hall effect by forming a non-collinear or non-coplanar magnetic order in the ab plane defined by the a-axis and the b-axis perpendicular to the c-axis, which is the easy axis of magnetization, and the antiferromagnet includes at least a domain whose c-axis is along the stacking direction. A magnetic memory element is provided.

[0007] According to such a configuration, a novel magnetic memory element capable of writing data more efficiently can be provided.

Brief Description of Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various characteristic matters shown in the embodiments shown below can be combined with each other.

[0010] Incidentally, the program for implementing the software appearing in one embodiment may be provided as a non-transitory computer-readable medium that can be read by a computer, may be provided so as to be downloadable from an external server, or may be provided such that the program is launched on an external computer to realize its functions on a client terminal (so-called cloud computing).

[0011] Also, in various information processes according to one embodiment, an input and an output corresponding to the input can be realized. Here, if an output is obtained as a result of the input, the form of the information (hereinafter referred to as reference information) referred to in such information processing is not limited. The reference information may be, for example, rule-based information such as a database, a lookup table, a predetermined function (including a judgment formula such as a regression formula constructed by a statistical method), a learned model in which the correlation between the input and the output has been learned in advance, or a large language model capable of outputting a desired result by inputting a prompt.

[0012] Also, in one embodiment, the “unit” may include, for example, hardware resources implemented by a circuit in a broad sense and the information processing of software that can be specifically realized by these hardware resources. Also, in one embodiment, various information is handled, and these information are represented, for example, by physical values of signal values representing voltage and current, the high and low of signal values as a set of binary bits composed of 0 or 1, or quantum superposition (so-called quantum bits), and communication and calculation can be executed on a circuit in a broad sense.

[0013] Furthermore, a circuit in a broad sense is a circuit realized by appropriately combining at least a circuit, circuitry, a processor, a memory, etc. The processor may be a general-purpose processor or a dedicated circuit. That is, it includes application specific integrated circuits (ASICs), programmable logic devices (e.g., simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs)), etc.

[0014] 1. Configuration Example of Magnetic Memory Element FIG. 1 is a diagram showing a configuration example of a magnetic memory element. As shown in FIG. 1, the magnetic memory element 1 includes a fixed layer 2, a tunnel barrier layer 3, and a storage layer 4. These layers 11 to 13 are stacked along the stacking direction D1, and a pair of electrodes (not shown) are provided at both ends of the stacked structure.

[0015] It is configured such that information can be read and written by flowing a current along the stacking direction D1 between a pair of electrodes. The magnetic memory element 1 of this embodiment is a so-called Spin Transfer Torque (STT)-RAM.

[0016] The fixed layer 2 is configured to have a spontaneous magnetization M1 along the stacking direction D1. The magnetization direction of the fixed layer 2 is configured to be fixed regardless of the data written to the magnetic memory element 1. The fixed layer 2 is, for example, a perpendicular magnetization layer forming a pin layer, and the magnetization direction of the spontaneous magnetization M1 substantially coincides with the stacking direction D1.

[0017] The tunnel barrier layer 3 is a non-magnetic insulating layer provided to exhibit giant magnetoresistance (TMR). The tunnel barrier layer 3 is not particularly limited as long as it functions as an insulating layer, such as MgO, AlO x , TiO x , etc.

[0018] The memory layer 4 is laminated on the fixed layer 2 via the tunnel barrier layer 3 having electrical insulation along the stacking direction D1. Thereby, a tunnel current can flow between the fixed layer 2 and the memory layer 4 via the tunnel barrier layer 3. The memory layer 4 includes a first ferromagnetic layer 5 and an antiferromagnetic layer 6.

[0019] The first ferromagnetic layer 5 is configured to have spontaneous magnetization M2 along the stacking direction D1. The magnetization direction of the spontaneous magnetization M2 of the first ferromagnetic layer 5 is configured to be reversible according to the data written into the magnetic memory element using the tunnel current through the fixed layer 2 and the memory layer 4. The first ferromagnetic layer 5 preferably has perpendicular magnetic anisotropy. The first ferromagnetic layer 5 may be, for example, a film formed by repeatedly laminating Co, Ni, Pd, Pt, etc., an alloy film utilizing the crystalline magnetic anisotropy derived from the L 10 -type crystal structure such as FePt and FePd, an amorphous material containing rare earths such as TbFeCo and GdFe, a material utilizing the interfacial magnetic anisotropy generated at the interface between a magnetic material such as CoFeB and FeCo and an oxide film such as MgO and Mg2AlO4, or a material utilizing the shape magnetic anisotropy generated by forming the magnetic material into the shape of a vertically long cylinder. The first ferromagnetic layer 5 may be one of those described above or a combination of a plurality of them. In particular, the first ferromagnetic layer 5 preferably contains at least Co as a magnetic element.

[0020] The spontaneous magnetization of the first ferromagnetic layer 5 can be inclined from the vertical direction with respect to the film surface (here, the stacking direction D1). The inclination of the spontaneous magnetization M1 of the first ferromagnetic layer 5 is 0.5 degrees or more and 45 degrees or less, more preferably 0.7 degrees or more and 40 degrees or less, more preferably 0.9 degrees or more and 35 degrees or less, still more preferably 1 degree or more and 30 degrees or less, from the vertical direction with respect to the film surface (for example, the stacking direction D1). In particular, when the inclination is 1 degree or more, it is possible to provide the magnetic memory element 1 in which the effect of improving the inversion characteristics in short pulses is more easily obtained. When the angle is 30 degrees or less, it is possible to provide the magnetic memory element 1 having higher holding characteristics and magnetic resistance change rate.

[0021] The antiferromagnetic layer 6 includes an antiferromagnet that exhibits an anomalous Hall effect by forming a non-collinear or non-coplanar magnetic order in the ab plane defined by the a-axis and the b-axis perpendicular to the c-axis that is the easy magnetization axis.

[0022] The antiferromagnet includes at least a domain in which the c-axis is along the stacking direction D1. The antiferromagnet can be configured to have a crystal orientation such that the c-axis extends in the stacking direction D1. Specifically, the antiferromagnet can be composed of domains in which the c-axis is along the stacking direction D1. According to such a configuration, since the internal magnetic field contributing to the first ferromagnetic layer 5 can be strengthened, it is possible to provide a magnetic memory element capable of writing data at a higher speed. That the c-axis is along the stacking direction D1 may include that the angle formed by the c-axis of the domain with respect to the stacking direction is less than 45 degrees. The angle is preferably less than 35 degrees, more preferably less than 25 degrees, more preferably less than 15 degrees, and still more preferably less than 5 degrees. The antiferromagnet is particularly preferably a single crystal in which the c-axis and the stacking direction D1 substantially coincide.

[0023] The c-axis orientation can be evaluated based on the three-dimensional orientation distribution obtained by single-crystal structure analysis methods such as transmission electron diffraction and X-ray diffraction. For example, the crystal orientation along the c-axis can be evaluated by the full width at half maximum (FWHM) of a specific reflection spot (e.g., the (002) reflection spot in Mn3Sn). Therefore, for an antiferromagnet to have a crystal orientation such that the c-axis extends in the stacking direction D1, it may mean that the FWHM of the specific reflection spot is 30 degrees or less, preferably 10 degrees or less. An antiferromagnetic layer 6 with an FWHM of 10 degrees or less is a highly oriented film, an antiferromagnetic layer 6 with an FWHM greater than 10 degrees and 30 degrees or less is a medium-oriented film, and an antiferromagnetic layer 6 with an FWHM greater than 30 degrees is a low-oriented film, which has a relatively random orientation state.

[0024] Such antiferromagnets that exhibit the anomalous Hall effect by forming non-collinear or non-coplanar magnetic orders can be configured, for example, to form a spin frustration system such as a triangular lattice or a kagome lattice in the ab-plane. For example, the antiferromagnet is a hexagonal system having a six-fold rotation axis in the c-axis direction, and particularly preferably has a space group P63 / mmc. Such antiferromagnets can be composed of one or more substances selected from the group of Mn3Sn, Mn3Pt, Mn3Ge, Mn3Ga, and Mn3Ir. For example, in the case of a hexagonal system where atoms are arranged in a triangular lattice in the ab-plane and magnetic moments are arranged, since the magnetic moments of each atom are along the ab-plane, it is preferable to form the crystal such that the c-axis of the crystal is directed in the stacking direction D1. However, the magnetic moments may have a non-aligned or random orientation in the c-axis direction. Such a triangular magnetization structure can be realized by an alloy of at least one of Mn and Ge, Ga, Sn, but the type of alloy is not limited thereto. Also, even without using the above alloy, a periodic stacking structure of magnetic and non-magnetic elements can create a triangular arrangement of magnetic moments similar to the hexagonal crystal structure.

[0025] It is preferable that the sign of the anomalous Hall coefficient of the antiferromagnet is configured not to be reversed by writing to the magnetic memory element 1. According to such a configuration, since the direction of the internal magnetic field is less likely to change significantly, the behavior of the spins of the first ferromagnetic layer 5 included in the memory layer 4 can be stabilized. Therefore, the operation of the magnetic memory element can be more easily stabilized. As an example, the sign of the anomalous Hall coefficient, in other words, the direction of the electromotive force based on the anomalous Hall effect with respect to a certain current direction, may be due to the fact that the spin chirality (for example, vector spin chirality or scalar spin chirality, etc.) takes a finite value due to non-collinear or non-coplanar magnetic order. Therefore, the non-reversal of the sign of the anomalous Hall coefficient can correspond to the non-reversal of the relative orientation of adjacent spins (especially electron spins) that define the spin chirality. Therefore, the non-reversal of the sign of the anomalous Hall coefficient is not necessarily limited to meaning that the spins at each site do not rotate independently, and may include rotating so as to maintain the relative orientation of the spins that define the spin chirality (for example, rotating by the same angle in the ab plane). Also, in the case of an antiferromagnet having a non-coplanar magnetic structure (especially an inclined ferromagnet having an easy magnetization axis in the c-axis direction), the reversal of the anomalous Hall coefficient accompanying the reversal of the spin chirality may occur due to the magnetization reversal in the c-axis direction. Therefore, it is preferable that the antiferromagnet is configured so that the magnetization in the c-axis direction (in other words, the stacking direction D1) is not reversed by writing to the magnetic memory element 1.

[0026] As an example, in such an antiferromagnet, since the magnetizations of each magnetic atom are arranged in a triangular configuration with an angle of about 120 degrees, there is almost no effective magnetization amount. However, for example, DO 19Wyckoff magnetic materials such as Mn3Sn with a specific crystal structure have a large internal magnetic field derived from their band structure and are known to exhibit a disproportionately large Hall effect and magneto-curvature effect with respect to their magnetization. These antiferromagnets are, for example, "non-collinear antiferromagnets". Also, the magnetization direction on the magnetization plane of atoms arranged in a triangle is easily changed, while it is difficult to change in the perpendicular direction. Since the antiferromagnet with this triangular magnetization has magnetic moments bound within the triangular plane, if the magnetization of the first ferromagnetic layer 5 having perpendicular magnetic anisotropy is magnetically coupled to be almost perpendicular to the atomic magnetic moment of the antiferromagnetic layer, it is considered that the magnetization direction of the first ferromagnetic layer 5 will be inclined in the in-plane direction and further rotate almost isotropically in the plane. Also, even if the antiferromagnetic layer is made thin, its magnetization does not significantly orient in the perpendicular direction, so an effect can be obtained even if the antiferromagnetic layer 6 is thinned to as thin as approximately one atomic layer of 0.3 nm. The thickness of the antiferromagnetic layer 6 is not particularly limited, but is preferably 20 nm or less, and more preferably 10 nm or less. The magnetic memory element 1 may include an intermediate layer 7 between the first ferromagnetic layer 5 and the antiferromagnetic layer 6. The intermediate layer 7 can be composed of one or more non-magnetic elements or compounds such as B, C, N, O, F, Mg, Al, Si, P, Ti, V, Cr, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au, etc. According to such a configuration, the magnitude of the magnetic coupling between the first ferromagnetic layer 5 and the antiferromagnetic layer 6 can be controlled. The intermediate layer 7 may include a layer composed of an antiferromagnet in which magnetic moments are arranged antiparallel, such as PtMn or IrMn.

[0027] Also, the intermediate layer 7 may contain magnetic elements such as Fe, Co, Ni, etc. to such an extent that the perpendicular magnetization of the first ferromagnetic layer 5 is not significantly deteriorated. According to such a configuration, a more stable interface can be formed between the first ferromagnetic layer 5 and the antiferromagnetic layer 6. Also, from another perspective, the generation of a magnetic deterioration layer at the interface between the first ferromagnetic layer 5 and the antiferromagnetic layer 6 can be suppressed.

[0028] Furthermore, for example, elements such as B, C, Fe, Co, W, Mo, Ir, Rh, etc. may be inserted between the tunnel barrier layer 3 and the memory layer 4 (specifically, the first ferromagnetic layer 5). Thereby, the magnetoresistance (MR) effect and heat resistance can be improved.

[0029] According to the above configuration, the antiferromagnetic layer 6 generates a virtual internal magnetic field inside along the c-axis direction due to the antiferromagnetic magnetic order formed in the ab plane. The internal magnetic field affects the movement of the spins responsible for the spontaneous magnetization of the first ferromagnetic layer (for example, the precession motion around the stacking direction D1) through the interaction between the first ferromagnetic layer and the antiferromagnetic layer 6. Here, the antiferromagnet generates an internal magnetic field along the stacking direction D1 by having a domain with its c-axis along the stacking direction D1. The internal magnetic field induces a precession motion around the stacking direction D1 in a state tilted from the stacking direction D1 with respect to the spins in the first ferromagnetic layer. As a result, the time for inducing the precession motion when the spins in the first ferromagnetic layer are reversed is shortened, so that the spin reversal speed can be increased compared to the prior art. Therefore, a magnetic memory element capable of writing data at a higher speed can be provided.

[0030] 2. Regarding the inclination of the spontaneous magnetization M2 of the first ferromagnetic layer 5 Next, the inclination of the spontaneous magnetization M2 of the first ferromagnetic layer 5 will be described. Here, for convenience of explanation, the inclination of the spontaneous magnetization M2 is defined by the angle θ1 formed by the direction of the magnetic moment M2 representing the spontaneous magnetization with respect to the stacking direction D1. Hereinafter, the angle θ1 will be referred to as the inclination angle θ1.

[0031] The inclination angle θ1 can be estimated by measuring the rotational hysteresis loss of the magnetic memory element 1. FIG. 2 is an example of measuring the inclination angle θ1 of the magnetization of the memory layer 3 by rotational hysteresis measurement when the magnetic moment M2 of the first ferromagnetic layer 5 is inclined with respect to the stacking direction D1. FIG. 3 is an example of measuring the inclination angle θ1 of the magnetization of the memory layer 3 by rotational hysteresis measurement when the magnetic moment M2 of the first ferromagnetic layer 5 is not inclined with respect to the stacking direction D1.

[0032] By measuring the rate of change of resistance in a rotating magnetic field, the inclination angle θ1 of magnetization can be obtained. When the inclination angle θ1 of the magnetization of the memory layer (the first ferromagnetic layer 5) is the same as the applied magnetic field angle, no resistance change occurs. For example, in resistance measurement in a rotating magnetic field, when the spin is tilted, if the applied magnetic field is changed for measurement, at the point of the inclination angle θ1, intersections occur among the resistance curves of a plurality of applied magnetic fields. On the other hand, when there is no inclination of magnetization, the respective resistance curves overlap at the point where the angle is 0 degrees, but no intersection occurs. In this way, the inclination angle θ1 of magnetization can be obtained. Thus, according to the technology of the present disclosure, a non-volatile memory capable of high-speed operation with a small current can be realized.

[0033] 3. Simulation example regarding the behavior of magnetic moment M2 Next, the procedure and results of a simulation (hereinafter referred to as this simulation) regarding the behavior of the magnetic moment M2 of the first ferromagnetic layer 5 in a system in which the above-described embodiment is further embodied will be described with reference to FIGS. 4 to 6. Note that the x direction, y direction, and z direction indicating the direction of the magnetic moment M2 in FIGS. 4 to 6 below correspond to the direction of the a axis, the direction of the b axis, and the direction of the c axis, respectively. That is, the xy plane indicates the ab plane.

[0034] The inventor of the present application first performed a simulation calculation of spin torque magnetization reversal by the Landau-Lifshitz-Gilbert (LLG) equation. As the ferromagnetic layer, calculations were performed with a magnetization amount of 1000 emu / cm 3 , a thickness of 1.5 nm, a perpendicular magnetic anisotropy of 5 kOe, a damping constant of 0.01, and a spin injection efficiency of 50%. As the antiferromagnetic layer, it was assumed that there was no effective magnetization, the magnetic moments of the antiferromagnetic atoms were arranged in a triangle and had no in-plane anisotropy, the in-plane binding magnetic field was 100 tesla, and the damping constant was 0.01.

[0035] Figure 4 shows the reversal history of magnetization M2 when the calculation is performed using only the first ferromagnetic layer 5 with a diameter of 50 nm. The reversal of magnetization M2 is defined as a reversal from positive to negative along the z-axis, and the applied pulse width is 5 ns. On the other hand, Figure 5 shows the reversal history of magnetization M2 when the antiferromagnetic layer 6 is magnetically coupled to the first ferromagnetic layer 5. The characteristics of the first ferromagnetic layer 5 are the same as those used in Figure 5. The magnetic coupling strength between the first ferromagnetic layer 5 and the antiferromagnetic layer 6 is set such that the effective magnetic field on the first ferromagnetic layer 5 is equivalent to 1 kOe. The thickness of the antiferromagnetic layer 6 is calculated to be 3 nm.

[0036] As shown in Figure 5, when the ferromagnetic layer 131 and the antiferromagnetic layer 6 are laminated and magnetically coupled, it is confirmed that the magnetization M2 of the first ferromagnetic layer 5 fluctuates while maintaining a certain angle from the z-axis direction (i.e., the lamination direction D1). This suggests that the spin torque by the antiferromagnetic layer 6 acts efficiently on tilting the magnetic moment M2 of the first ferromagnetic layer 5.

[0037] Figure 6 is a diagram showing the change history of the direction of the magnetic moment of the antiferromagnetic layer 6. Since the magnetic moment of the antiferromagnetic layer 6 rotates while remaining substantially in the ab-plane, a ring-shaped magnetization trajectory is shown. Also, this result suggests that each magnetic moment (in other words, spin) rotates in the ab-plane while maintaining a 120-degree structure, indicating that the sign of spin chirality such as vector spin chirality does not reverse in the antiferromagnetic layer 6.

[0038] Next, the results of calculating the inversion current Ic while changing the pulse width (PW) under the above conditions will be described. FIG. 7 is a diagram showing the calculation results regarding the relationship between the pulse width (PW) and the inversion current Ic. In this calculation example, calculations were performed in two cases: (a) when the memory layer 4 is composed only of the first ferromagnetic layer 5, and (b) when the memory layer 4 is composed of the first ferromagnetic layer 5 and the antiferromagnetic layer 6. As shown in FIG. 7, it is shown that the inversion current Ic when the ferromagnetic layer 131 and the antiferromagnetic layer 6 are laminated is lower than that in the case of the single layer of the first ferromagnetic layer 5. Note that the above calculation is for the case where the triangular magnetic moments are arranged in the film plane.

[0039] Next, assuming that the antiferromagnet constituting the antiferromagnetic layer 6 is a hexagonal crystal with the axis orthogonal to the triangular magnetic moment as the c-axis, and the in-plane axes as the a-axis and b-axis, for the three cases where the antiferromagnet in the antiferromagnetic layer 6 is (a) oriented along the c-axis, (b) randomly oriented polycrystalline, and (c) oriented along the a-axis or b-axis, when the magnetic coupling strength Ex acting between the ferromagnetic layer 131 and the antiferromagnetic layer 6 is changed (specifically, Ex = 0, 0.1, 0.3, 1, 2 kOe), the inversion error rate corresponding to the inversion current flowing through the magnetic memory element 1 was calculated. The pulse width is 2 ns, and other conditions are the same as the above calculation. FIG. 8 is a diagram showing the change in the error rate according to the current when the antiferromagnet in the antiferromagnetic layer 6 is oriented along the c-axis. FIG. 9 is a diagram showing the change in the error rate according to the current in the case where the antiferromagnet in the antiferromagnetic layer 6 is randomly oriented polycrystalline. FIG. 10 is a diagram showing the change in the error rate according to the current when the antiferromagnet in the antiferromagnetic layer 6 is oriented along the a-axis or b-axis. In FIGS. 8 to 10, the inversion current is shown on the horizontal axis, and the error rate is shown on the vertical axis on a logarithmic scale.

[0040] In the case of c-axis orientation and random orientation, when the magnetic coupling strength is increased, the inversion current decreases, and at the same time, the slope of the error rate becomes steep. However, in the case of a-axis or b-axis orientation, even if the magnetic coupling is strengthened, almost no decrease in the error rate is observed. Also, in c-axis orientation and random orientation, when the magnetic coupling strength is increased, the magnetization of the ferromagnetic layer tends to tilt more easily from the perpendicular direction. For example, in the case of c-axis orientation, the tilt angle θ1 is given by θ1 = tan(Hex / Hk), where Hex is the magnetic coupling magnetic field, which is the internal magnetic field generated in the first ferromagnetic layer 5 through magnetic coupling with the antiferromagnetic layer 6, and Hk is the anisotropy magnetic field of the first ferromagnetic layer 5. When the orientation is not a perfect c-axis orientation, the tilt angle θ1 is smaller compared to the perfect c-axis orientation even with the same magnetic coupling magnetic field strength.

[0041] Next, calculations are shown for the case where the thickness t of the antiferromagnetic layer 6 is changed (t = 0.3, 1, 3, 10 nm). Fig. 11 shows the calculation results of the error rate for a pulse width of 5 ns. Fig. 12 shows the calculation results of the error rate for a pulse width of 1 ns. The thinner the thickness t of the antiferromagnetic layer 6, the lower the inversion current tends to be for a pulse width of 5 ns. On the other hand, for a pulse width of 1 ns, the change in the inversion current with respect to the thickness t of the antiferromagnetic layer 6 tended to be small.

[0042] 4. Examples and Comparative Examples of the Magnetic Memory Element 1 Next, examples and comparative examples in which the above-described magnetic memory element 1 is further embodied will be described. In each example and comparative example, various layers were laminated by sputtering on a Si substrate. Note that the thicknesses of the respective layers described below are average values of the thicknesses of the respective layers.

[0043] 4.1. Preparation of Examples and Comparative Examples [Comparative Example]

[0044] Fig. 13 is a diagram showing the layer structure of the magnetic memory element 1 according to the comparative example. The magnetic memory element 1 according to the comparative example is composed of an underlayer 9, a pin layer 10, an antiferromagnetic magnetic coupling layer 11, a reference layer 12, a tunnel barrier layer 13, a ferromagnetic layer 14 constituting the memory layer, and a cap layer 15.

[0045] The underlying layer 9 was obtained by laminating a 5-nm-thick Ru layer on a 2-nm-thick Ta layer.

[0046] The pin layer 10 corresponding to the fixed layer was obtained by laminating a composite layer of Co and Pt with a thickness of about 4 nm on the Ru layer. The composite layer was configured such that a Co layer of about 0.8 nm and a Pt layer of about 0.6 nm were alternately laminated.

[0047] The antiferromagnetic magnetic coupling layer 11 is a layer for coupling the magnetizations of the pin layer 10 and the reference layer 12 in an antiparallel manner, and in this comparative example, it was composed of a 0.6-nm-thick Ru layer.

[0048] The reference layer 12 is a layer serving as a criterion for the ferromagnetic layer 14 constituting the memory layer, and in this comparative example, it was composed of a 1-nm-thick CoFeB layer having spontaneous magnetization.

[0049] The tunnel barrier layer 13 is an insulator capable of allowing a tunnel current to flow, and in this example, it was composed of 0.7-nm-thick MgO.

[0050] The ferromagnetic layer 14 constituting the memory layer was formed by laminating a 1.5-nm-thick CoFeB layer on the tunnel barrier layer 13.

[0051] The cap layer 15 was formed by sequentially laminating a 1-nm-thick Mo layer, a 0.5-nm-thick MgO layer, a 1-nm-thick Ru layer, and a 5-nm-thick Ta layer on the ferromagnetic layer 14.

[0052] Thereafter, the magnetic memory element 1 according to the comparative example was formed into a circle with a diameter of 70 nm, and electrodes were connected to both ends to obtain a measurement sample according to Example 1.

[0053] [Example 1] FIG. 14 is a diagram showing the layer structure of the magnetic memory element 1 according to Example 1. The magnetic memory element 1 according to Example 1 includes a base layer 16, a pin layer 17, an antiferromagnetic magnetic coupling layer 18, a reference layer 19, a tunnel barrier layer 20, a ferromagnetic layer 21 constituting the memory layer, an antiferromagnetic layer 22 constituting the memory layer, and a cap layer 23. The base layer 16, the pin layer 17, the antiferromagnetic magnetic coupling layer 18, the reference layer 19, and the tunnel barrier layer 20 are common to those of the magnetic memory element 1 according to the comparative example.

[0054] The ferromagnetic layer 21 according to Example 1 was obtained by sequentially laminating a CoFeB layer with a thickness of 1.3 nm, a Ta layer with a thickness of 0.2 nm, and a Co layer with a thickness of 0.5 nm on the tunnel barrier layer 20. The antiferromagnetic layer 22 was obtained by laminating Mn3Sn with a thickness of 5 nm on the Co layer of the ferromagnetic layer 21. The cap layer 23 was obtained by laminating a Ta layer with a thickness of 5 nm on the antiferromagnetic layer 22.

[0055] Thereafter, the magnetic memory element 1 according to Example 1 was formed into a circle with a diameter of 70 nm, and electrodes were connected to both ends to obtain a measurement sample according to Example 1.

[0056] [Example 2] FIG. 15 is a diagram showing the layer structure of the magnetic memory element 1 according to Example 2. The magnetic memory element 1 according to Example 2 includes a base layer 24, a pin layer 25, an antiferromagnetic magnetic coupling layer 26 for anti-parallel coupling of the magnetizations of the pin layer and the reference layer, a reference layer 27, a tunnel barrier layer 28, a ferromagnetic layer 29 constituting the memory layer, two types of antiferromagnetic layers 30 and 31 constituting the memory layer, and a cap layer 32. The base layer 24, the pin layer 25, the reference layer 27, and the tunnel barrier layer 28 are common to those of the magnetic memory element 1 according to the comparative example.

[0057] The antiferromagnetic magnetic coupling layer 26 according to Example 2 was obtained by sequentially laminating an Ir layer with a thickness of 0.6 nm and an Mo layer with a thickness of 0.3 nm on the pin layer 25.

[0058] The ferromagnetic layer 29 according to Example 2 was obtained by sequentially laminating a carbon (C) layer with a thickness of 0.3 nm and a CoFe layer with a thickness of 1.3 nm on the tunnel barrier layer 28.

[0059] The antiferromagnetic layers 30 and 31 according to Example 2 were obtained by sequentially laminating an MnIr layer 30 with a thickness of 2 nm and an Mn3Sn layer 31 with a thickness of 3 nm on the ferromagnetic layer 29.

[0060] The cap layer 32 according to Example 2 was obtained by sequentially laminating an MgO layer with a thickness of 0.5 nm and an Ru layer with a thickness of 5 nm on the Mn3Sn layer 31. Electrodes (not shown) are connected to the layers at both ends of the magnetic memory element 1 according to Example 2.

[0061] Thereafter, the magnetic memory element 1 according to Example 2 was formed into a circle with a diameter of 70 nm, and electrodes were connected to both ends to obtain a measurement sample according to Example 2.

[0062] [Example 3] FIG. 16 is a diagram showing the layer structure of the magnetic memory element 1 according to Example 3. The magnetic memory element 1 according to Example 3 includes a base layer 33, a first ferromagnetic layer 34 constituting the memory layer, an antiferromagnetic layer 35 constituting the memory layer, a first antiferromagnetic magnetic coupling layer 36 constituting the memory layer, a second ferromagnetic layer 37 constituting the memory layer, a tunnel barrier layer 38, a reference layer 39, a second antiferromagnetic magnetic coupling layer 40 for anti-parallelly coupling the magnetization of the pin layer 41 and the reference layer 39, the pin layer 41, and a cap layer 42.

[0063] The base layer 33 according to Example 3 was obtained by sequentially laminating a Ta layer with a thickness of 2 nm, an Ru layer with a thickness of 3 nm, and an MgO layer with a thickness of 0.5 nm on a Si substrate.

[0064] The first ferromagnetic layer 34 according to Example 3 was obtained by laminating a Co layer with a thickness of 0.6 nm on the MgO layer of the base layer 33.

[0065] The antiferromagnetic layer 35 according to Example 3 was obtained by laminating an Mn3Sn layer with a thickness of 1 nm on the first ferromagnetic layer 34.

[0066] The first antiferromagnetic magnetic coupling layer 36 according to Example 3 was obtained by laminating a Re layer with a thickness of 0.6 nm and a W layer with a thickness of 0.2 nm on the antiferromagnetic layer 35.

[0067] The second ferromagnetic layer 37 according to Example 3 was obtained by laminating a CoFeB layer with a thickness of 1 nm on the W layer of the first antiferromagnetic magnetic coupling layer 36.

[0068] The tunnel barrier layer 38 according to Example 3 was obtained by laminating an MgO layer with a thickness of 0.7 nm on the second ferromagnetic layer 37.

[0069] The reference layer 39 according to Example 3 was obtained by laminating a CoFeB layer with a thickness of 1 nm, a Ta layer with a thickness of 0.3 nm, and a Co layer with a thickness of 0.5 nm on the second ferromagnetic layer 37.

[0070] The second antiferromagnetic magnetic coupling layer 40 according to Example 3 was obtained by laminating an Ru layer with a thickness of 0.8 nm on the Co layer of the reference layer 39. Thus, the memory layer 4 may further include a second ferromagnetic layer. The second ferromagnetic layer may be laminated on the first ferromagnetic layer 5 via the antiferromagnetic layer 6. According to such a configuration, the spin behavior in the memory layer 4 can be further stabilized.

[0071] The pin layer 41 according to Example 3 was obtained by laminating a composite layer of Co and Pt with a thickness of 5 nm on the Ru layer. The composite layer was configured such that a Co layer of about 0.8 nm and a Pt layer of about 0.6 nm were alternately laminated. The lamination order of the Co layer and the Pt layer in the composite layer according to Example 3 was opposite to that of Examples 1, 2 and the comparative example.

[0072] The cap layer 42 was obtained by laminating an Ru layer with a thickness of 5 nm on the pin layer 41.

[0073] Thereafter, a magnetic memory element 1 according to Example 3 was formed into a circle with a diameter of 70 nm, and electrodes were connected to both ends to obtain a measurement sample according to Example 3.

[0074] 4.2. Evaluation Methods and Evaluation Results of Magnetic Memory Elements According to Examples and Comparative Examples Next, the evaluation methods and evaluation results of the magnetic memory elements according to the above-prepared examples and comparative examples will be described. The inventors of the present application applied a pulse voltage to the magnetic memory element 1 through the electrodes provided at both ends of the magnetic memory element according to each example and comparative example, and measured the current flowing through the magnetic memory element 1. The maximum voltage value of the pulse voltage was 1.2 V, and the pulse width (PW) of the pulse voltage was 10 ns or 2 ns. Based on the current-voltage measurement thus obtained, the voltage (inversion voltage) when the magnetization of the ferromagnetic layer constituting the memory layer changes between the state (P) parallel to the magnetization of the pin layer and the state (AP) antiparallel thereto was calculated. Since the resistance value of the magnetic memory element 1 differs due to the magnetoresistance effect between P and AP, the voltage value when the current value changes non-linearly was defined as the inversion voltage.

[0075] In addition, the inventors of the present application measured the M-H history in the stacking direction D1 for each magnetic memory element according to each example and comparative example using a magnetic field application probe. During the measurement, a magnetic field from -10 kOe to +10 kOe was applied along the stacking direction D1 at room temperature. Based on the M-H curve thus obtained, the coercive force of each magnetic memory element was calculated.

[0076] The following table shows the coercive force of the magnetic memory elements according to the comparative examples and examples, and the inversion voltages when inverted from parallel to antiparallel (P→AP) and from antiparallel to parallel (AP→P) with pulse widths of 10 ns and 2 ns, as experimental results of the examples and comparative examples based on the above evaluation methods.

Table 1

[0077] As shown in the above table, Examples 1 to 3 had coercive forces equivalent to those of the Comparative Example, but showed characteristics of reducing the reverse current by about 30% at a pulse width of 10 ns and reducing the reverse voltage by almost half at a pulse width of 2 ns. Since all of Examples 1 to 3 have an antiferromagnetic layer, while only the Comparative Example does not have such an antiferromagnetic layer, it is considered that the memory layer including the ferromagnetic layer and the antiferromagnetic layer contributes to the reduction of the reverse voltage in Examples 1 to 3 compared to the Comparative Example. Such results suggest that the antiferromagnetic layer 6 as described above strengthens the initial inclination angle θ1 of the magnetic moment M2 of the first ferromagnetic layer 5.

[0078] Specifically, from the above evaluation results, in the magnetic memory element 1 in which the fixed layer 2 serving as a reference for information and the memory layer 4 in which information is recorded are stacked via the tunnel barrier layer 3, the fixed layer 2 is a perpendicularly magnetized film, and the memory layer 4 is composed of a stacked film of a first ferromagnetic layer 5 having an easy axis of perpendicular magnetization and an antiferromagnet in which the magnetic moments of atoms are arranged at an angle of about 120 degrees. It was suggested that a conical easy magnetization direction in which the magnetization of the first ferromagnetic layer 5 is inclined at a certain angle from the easy magnetization axis can be formed, enabling recording with a small current and a short recording time.

[0079] [Others] The above embodiments can be implemented, for example, by appropriately combining the following aspects within a technically non - conflicting range.

[0080] The stacked structure included in the magnetic memory element 1 is not limited to the sputtering method and can be formed by any method such as the molecular beam epitaxy method.

[0081] The magnetic memory element 1 is not limited to those to which electrodes or the like are connected. In other words, as long as the memory layer 4 including the first ferromagnetic layer 5 and the antiferromagnetic layer 6 is connected to the fixed layer 2 via the tunnel barrier layer 3, its structure and current flow mode are arbitrary.

[0082] The above magnetic memory element 1 or the like may be provided in each of the following aspects.

[0083] (1) A magnetic memory element comprising a fixed layer and a memory layer, wherein the fixed layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the fixed layer is configured to be fixed regardless of the data written into the magnetic memory element; the memory layer is stacked on the fixed layer via an electrically insulating barrier layer along the stacking direction, and includes a first ferromagnetic layer and an antiferromagnetic layer; the first ferromagnetic layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the first ferromagnetic layer is configured to be reversibly inverted according to the data written into the magnetic memory element using a tunnel current passing through the fixed layer and the memory layer; the antiferromagnetic layer includes an antiferromagnet that exhibits an anomalous Hall effect by forming a non-collinear or non-coplanar magnetic order in the ab plane defined by the a-axis and the b-axis perpendicular to the c-axis that is the easy axis of magnetization, and the antiferromagnet includes at least a domain in which the c-axis is along the stacking direction.

[0084] According to such a configuration, the antiferromagnetic layer generates a virtual internal magnetic field inside along the c-axis direction due to the antiferromagnetic magnetic order formed in the ab plane. The internal magnetic field affects the movement of the spins responsible for the spontaneous magnetization of the first ferromagnetic layer (for example, the precession motion around the stacking direction axis) through the interaction between the first ferromagnetic layer and the antiferromagnetic layer. Here, since the antiferromagnet has a domain in which the c-axis is along the stacking direction, an internal magnetic field along the stacking direction is generated. The internal magnetic field induces a precession motion around the stacking direction axis in a state inclined from the stacking direction with respect to the spins in the first ferromagnetic layer. As a result, the time for inducing the precession motion when the spins in the first ferromagnetic layer are inverted is shortened, so that the inversion speed of the spins can be increased compared to the prior art. Therefore, a magnetic memory element capable of writing data at a higher speed can be provided.

[0085] (2) The magnetic memory element according to (1) above, wherein the antiferromagnet is configured such that the sign of the anomalous Hall coefficient of the antiferromagnet does not invert by writing into the magnetic memory element.

[0086] According to such a configuration, since the direction of the internal magnetic field hardly changes significantly, the behavior of the spins of the first ferromagnetic layer included in the memory layer can be stabilized. Therefore, the operation of the magnetic memory element can be more easily stabilized.

[0087] (3) The magnetic memory element according to (1) or (2) above, wherein the antiferromagnet is configured to have a crystal orientation such that the c-axis extends in the stacking direction.

[0088] (4) The magnetic memory element according to any one of (1) to (3) above, wherein the antiferromagnet is composed of domains in which the c-axis is along the stacking direction.

[0089] According to such a configuration, since the internal magnetic field contributing to the first ferromagnetic layer can be strengthened, a magnetic memory element capable of writing data at a higher speed can be provided.

[0090] (5) The magnetic memory element according to any one of (1) to (4) above, wherein the antiferromagnet is a hexagonal system having a six-fold rotation axis along the c-axis.

[0091] (6) The magnetic memory element according to any one of (1) to (5) above, wherein the antiferromagnet is composed of one or more substances selected from the group consisting of Mn3Sn, Mn3Pt, Mn3Ge, Mn3Ga, and Mn3Ir.

[0092] (7) The magnetic memory element according to any one of (1) to (6) above, wherein the first ferromagnetic layer contains at least Co element as a magnetic element.

[0093] (8) In the magnetic memory element according to any one of (1) to (7) above, the memory layer further includes a second ferromagnetic layer, and the second ferromagnetic layer is laminated on the first ferromagnetic layer via the antiferromagnetic layer. A magnetic memory element.

[0094] According to such a configuration, the behavior of spins in the memory layer can be further stabilized. Of course, this is not the case.

[0095] For example, it can be provided in the following aspects independently of or in combination with the above aspects.

[0096] (Item 1) In a magnetic memory element that records information by the direction of magnetization, it has a magnetization-fixed layer in which the magnetization is fixed in one direction and a memory layer in which the direction of magnetization changes corresponding to information, and the memory layer and the fixed layer face each other via a tunnel barrier layer. Recording is performed by flowing a current between the fixed phase and the memory layer through the tunnel barrier layer. The fixed layer is a perpendicularly magnetized film, and the memory layer is a laminated film composed of a perpendicularly magnetized ferromagnetic layer having an easy axis of perpendicular magnetization and an antiferromagnetic layer composed of a non-collinear antiferromagnet. A magnetic memory element characterized by this.

[0097] (Item 2) In the magnetic memory element of Item 1, a magnetic memory element characterized by having a magnetic interaction between the perpendicular magnetization layer and the antiferromagnetic layer of the memory layer. (Item 3) In the magnetic memory element of Item 1 or 2, a magnetic memory element characterized in that the antiferromagnetic layer is an alloy composed of at least one of Mn and Sn, Ge, and Ga.

[0098] (Item 4) In the magnetic memory element of Item 3, a magnetic memory element characterized in that the crystal structure of the antiferromagnetic layer is a hexagonal crystal structure and the c-axis is oriented in a plane perpendicular direction. (Item 5) In the magnetic memory element according to any one of Items 1 to 4, a magnetic memory element characterized in that the thickness of the antiferromagnetic layer is 0.3 nm or more and 20 nm or less.

[0099] (Item 6) The magnetic memory element according to any one of Items 1 to 5, wherein a non-magnetic layer is inserted between the perpendicular magnetization layer and the antiferromagnetic layer of the memory layer. (Item 7) The magnetic memory element according to Item 6, wherein the non-magnetic layer is at least one of B, C, N, O, F, Mg, Al, Si, P, Ti, V, Cr, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, or a compound thereof.

[0100] (Item 8) The magnetic memory element according to any one of Items 1 to 7, wherein a second antiferromagnetic layer is inserted between the perpendicular magnetization layer and the antiferromagnetic layer of the memory layer. (Item 9) The magnetic memory element according to Item 8, wherein the second antiferromagnetic layer is at least one of Mn and B, C, N, O, F, Al, Si, Cr, Ga, Ge, Ru, Rh, Pd, In, Sn, Sb, Re, Os, Ir, Pt, or a compound thereof.

[0101] (Item 10) The magnetic memory element according to any one of Items 1 to 9, wherein the magnetic moment of the magnetic atoms in the antiferromagnetic layer is substantially in-plane. (Item 11) The magnetic memory element according to any one of Items 1 to 10, wherein the direction of magnetization of the perpendicular magnetization layer is inclined by 1 degree or more and 30 degrees or less from the perpendicular direction.

[0102] (Item 12) The magnetic memory element according to any one of Items 1 to 11, having two or more perpendicular magnetization layers, and an antiferromagnetic layer is disposed in at least one of the perpendicular magnetization layers. (Item 13) In the magnetic memory element according to any one of Items 1 to 12, a magnetic memory element, characterized in that a substance composed of at least one of B, C, Fe, Co, W, Mo, Ir, Rh or a compound thereof is included between the tunnel barrier layer and the memory layer.

[0103] (Item 14) A memory device having the magnetic memory element according to any one of Items 1 to 13. Note that the problems that can be solved by the above-described magnetic memory element 1 are not limited to those described above. For example, the problems may be in the following aspects.

[0104] In information devices such as computers, dynamic random access memory (DRAM) with high speed and high density operation is widely used as random access memory (RAM). However, since DRAM is a volatile memory in which information is lost when the power is turned off, a non-volatile memory in which information is not lost is desired.

[0105] As a candidate for non-volatile memory, magnetic random access memory (MRAM) that records information by magnetization of a magnetic material has attracted attention and development has been promoted. In recent years, as a method of reversing magnetization, spin torque type MRAM (STT-MRAM) that injects spin torque to reverse magnetization by flowing a current between magnetic materials through a tunnel barrier has become mainstream. In spin torque, the spin injection efficiency depends on the angle formed by the magnetizations of the fixed layer and the memory layer, and the spin injection efficiency becomes zero when the angles are completely parallel or anti-parallel.

[0106] The interfacial magnetic anisotropy generated at the interface between a magnetic material such as CoFeB mainly used as the memory layer at present and an oxide such as MgO has excellent magnetic anisotropy in the direction perpendicular to the film surface due to its characteristics, is excellent as a perpendicular magnetic memory layer, and stable holding characteristics can be obtained. However, on the other hand, the increase in the reverse current with short pulses is large and high-speed writing is difficult.

[0107] As a solution to this problem, for example, a magnetic memory with a magnetization state that makes it easier to rotate while tilting the magnetization of the memory layer in the in-plane direction, as in Patent Document 1 described above, has been studied.

[0108] However, when attempting to stack multiple ferromagnetic materials to achieve tilted magnetization, it is difficult to control the strength of the magnetic coupling between the magnetic layers. Also, when the device is miniaturized, problems such as the expected effect not being obtained due to the influence of the magnetostatic coupling between the ferromagnetic layers arise.

[0109] This technology has been developed based on such recognition. That is, its purpose is to realize a magnetic memory device that can operate at high speed with a low current even in a fine device.

[0110] As a result of repeated studies to achieve the above object, the memory layer constituting the magnetic memory device is composed of a stacked film of a perpendicular magnetization layer having perpendicular magnetization and a triangular antiferromagnet in which each magnetic atom is arranged at 120 degrees. By doing so, the magnetization of the perpendicular magnetization layer is tilted in the plane, and a state where the angle formed by the magnetization of the fixed layer and the memory layer can be realized such that the spin torque always acts with a certain efficiency or more. As a result, for example, it is possible to shorten the inversion time and reduce the variation in the inversion time.

[0111] Finally, although various embodiments according to the present disclosure have been described, these are presented as examples and are not intended to limit the scope of the invention. The novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0112] 1: Magnetic memory element, 2: Fixed layer, 3: Tunnel barrier layer, 4: Memory layer, 5: First ferromagnetic layer, 6: Antiferromagnetic layer, 7: Intermediate layer, 9: Underlayer, 10: Pin layer, 11: Antiferromagnetic magnetic coupling layer, 12: Reference layer, 13: Tunnel barrier layer, 14: Ferromagnetic layer, 15: Cap layer, 16: Underlayer, 17: Pin layer, 18: Antiferromagnetic magnetic coupling layer, 19: Reference layer, 20: Tunnel barrier layer, 21: Ferromagnetic layer, 22: Antiferromagnetic layer, 23: Cap layer, 24: Underlayer, 25: Pin layer, 26: Antiferromagnetic magnetic coupling layer, 27: Reference layer, 28: Tunnel barrier layer, 29: Ferromagnetic layer, 30: MnIr layer, 31: Mn3Sn layer, 32: Cap layer, 33: Underlayer, 34: First ferromagnetic layer, 35: Antiferromagnetic layer, 36: First antiferromagnetic magnetic coupling layer, 37: Second ferromagnetic layer, 38: Tunnel barrier layer, 39: Reference layer, 40: Second antiferromagnetic magnetic coupling layer, 41: Pin layer, 42: Cap layer, 42: Antiferromagnetic layer, D1: Lamination direction, M1: Spontaneous magnetization, M2: Spontaneous magnetization, θ1: Tilt angle

Claims

1. A magnetic memory element, comprising: a fixed layer and a memory layer; the fixed layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the fixed layer is configured to be fixed regardless of the data written into the magnetic memory element; the memory layer is stacked on the fixed layer via an electrically insulating barrier layer along the stacking direction, and includes a first ferromagnetic layer and an antiferromagnetic layer positioned in the stacking direction with respect to the first ferromagnetic layer; the first ferromagnetic layer is configured to have spontaneous magnetization along the stacking direction, and the magnetization direction of the first ferromagnetic layer is configured to be reversibly configured according to the data written into the magnetic memory element using a tunnel current through the fixed layer and the memory layer; the antiferromagnetic layer includes an antiferromagnet that exhibits an anomalous Hall effect by forming a non-collinear or non-coplanar magnetic order in the ab plane defined by the a-axis and the b-axis perpendicular to the c-axis, which is the easy axis of magnetization; the antiferromagnet includes at least a domain in which the c-axis is along the stacking direction and has a magnetic coupling with the first ferromagnetic layer, the magnetic memory element.

2. In the magnetic memory element according to Claim 1, the antiferromagnet is configured such that the sign of the anomalous Hall coefficient of the antiferromagnet does not reverse by writing into the magnetic memory element, the magnetic memory element.

3. In the magnetic memory element according to Claim 1, the antiferromagnet is configured to have a crystal orientation such that the c-axis extends in the stacking direction, the magnetic memory element.

4. In the magnetic memory element according to Claim 1, the antiferromagnet is composed of domains in which the c-axis is along the stacking direction, the magnetic memory element.

5. In the magnetic memory element according to Claim 1, the antiferromagnet is a hexagonal system having a six-fold rotation axis along the c-axis, the magnetic memory element.

6. In the magnetic memory element according to Claim 1, The antiferromagnetic material is Mn ３ Sn, Mn ３ Pt, Mn ３ Ge, Mn ３ Ga, and Mn ３ A magnetic memory device composed of one or more substances selected from the group of Ir

7. In the magnetic memory element according to Claim 1, the first ferromagnetic layer includes at least Co element as a magnetic element, the magnetic memory element.

8. In the magnetic memory element according to any one of Claims 1 to 7, the memory layer further includes a second ferromagnetic layer, the second ferromagnetic layer is stacked on the first ferromagnetic layer via the antiferromagnetic layer, the magnetic memory element.

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