Magnetic memory devices

Abstract

The present invention provides a magnetic memory device with a simple structure, excellent ease of operation, and compatibility with semiconductor manufacturing processes, while simultaneously achieving both magnetization reversal under zero magnetic field conditions and low critical current density. [Solution] The magnetic memory device 10 comprises a channel layer 11 that generates a spin current or orbital current when an electric current is supplied, and a magnetic layer 12 disposed on one side of the channel layer 11 and whose magnetization direction can be reversed by the spin current, wherein the channel layer 12 contains maxines (MXenes) having a composition ratio represented by the following formula (1). M n+1 X n ...(1) In equation (1) above, M represents a transition metal, X represents carbon or nitrogen, and n represents an integer of 1 or more.

Description

[Technical Field]

[0001] This invention relates to a magnetic memory device. [Background technology]

[0002] In Society 5.0, which will handle big data, increasing the capacity of various storage devices installed in computer terminals is essential. However, this also presents an unavoidable problem of increased power consumption. For example, semiconductor cache memory requires power to retain recorded information, so its replacement with non-volatile magnetic random-access memory (MRAM) is being considered.

[0003] Until now, research and development has focused on electron spin transport magnetic random access memory (STT-MRAM), but in recent years, expectations for spin-orbit torque magnetic random access memory (SOT-MRAM) have been rising. SOT-MRAM comprises a channel layer that generates a flow of spin-orbit angular momentum (spin current or orbital current) without charge from the write current supplied to the SOT line, and a magnetic layer that actually stores information as the direction of orthoplane magnetization. Because SOT-MRAM uses spin current or orbital current as its recording principle, it has the advantage of not consuming power during writing in principle. In addition, since the write current is not supplied to the ferromagnetic tunnel junction element required for reading, the overall durability of the memory can be dramatically extended compared to STT-MRAM.

[0004] However, when reversing the direction of magnetization in the vertical direction using spin-orbit torque, an external magnetic field parallel to the current is usually required. Also, the critical current density (J) during writing is... c The fact that the ) is generally high is a problem that needs to be solved. In other words, zero magnetic field and low J c Research is intensifying on achieving both of these aspects, as this is a necessary technology for replacing cache memory with SOT-MRAM.

[0005] For example, in Non-Patent Document 1, writing in a zero magnetic field state was demonstrated by optimizing two systems of write current paths, pulse application timing, etc. using circuit technology. In Non-Patent Document 2, a device was shown that continuously tilts the magnetization of a magnetic layer in the film thickness direction using a Mn-Pt antiferromagnetic film as the SOT line. In Non-Patent Document 3, by laminating a ferromagnetic layer with an easy axis of magnetization in the in-plane direction on the SOT line, an effect similar to that of an in-plane DC magnetic field was shown. Numerous other attempted methods have been published as Non-Patent Document 4. Also, as a different method, in Non-Patent Document 5, a method of using a transition metal dichalcogenide (WTe2), which is a representative of two-dimensional materials, in the SOT line has been reported. This is interpreted as the generation of a spin current component convenient for reversing magnetization due to the crystal symmetry peculiar to two-dimensional materials.

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the industrialization of SOT-MRAM has not yet been in sight. This is presumably because in the technologies of Non-Patent Documents 1 to 5 above, the structure is complex, it is not a stable material, so the ease of fabrication is poor, or it deviates from the compatibility with the semiconductor manufacturing process. Also, the compatibility with a low critical current density of 10 7 A / cm 2 or less makes it even more difficult to solve the problem.

[0008] The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a magnetic memory device that has a simple structure, is excellent in workability, has compatibility with the semiconductor manufacturing process, and can achieve both magnetization direction reversal without a magnetic field and a low critical current density.

Means for Solving the Problems

[0009] [1] A magnetic memory device comprising: a channel layer that generates a spin current or orbital current when an electric current is supplied; and a magnetic layer disposed on one side of the channel layer and whose magnetization direction can be reversed by the spin current or orbital current, wherein the channel layer contains maxine having a composition ratio represented by the following formula (1). M n+1 X n (1) (In equation (1) above, M represents a transition metal, X represents carbon or nitrogen, and n represents an integer between 1 and 4.)

[0010] [2] The magnetic memory device according to [1] above, wherein the maxine is Cr2N.

[0011] [3] The magnetic memory device according to [2], further comprising a Cr layer formed between the channel layer and the magnetic layer.

[0012] [4] The magnetic memory device according to [1], wherein the channel layer comprises the maxine and a compound represented by MX.

[0013] [5] The magnetic memory device according to [4] above, wherein the maxine is Cr2N and the compound is cubic CrN.

[0014] [6] The magnetic memory device according to [5] above, wherein the volume ratio of the CrN to the Cr2N is 1 / 5 or more and 6 or less.

[0015] [7] A magnetic memory device comprising a channel layer made of cubic VN that generates a spin current or orbital current when an electric current is supplied, and a magnetic layer disposed on one side of the channel layer and whose magnetization direction can be reversed by the spin current or orbital current.

[0016] [8] The magnetic memory device according to [7] above, wherein the

[0111] crystal orientation of the VN is parallel to the thickness direction of the channel layer.

[0017] [9] The magnetic memory device according to any one of the above [1] to [8], wherein the channel layer is adjacent to the magnetic layer.

[0018]

[10] The magnetic memory device according to any one of the above [1] to [9], wherein the thickness of the channel layer is 1 nm or more and 20 nm or less.

[0019]

[11] The magnetic memory device according to any one of the above items [1] to

[10] , wherein the thickness of the magnetic layer is 0.5 nm or more and 5 nm or less. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a magnetic memory device that has a simple structure, excellent ease of operation, and compatibility with semiconductor manufacturing processes, while simultaneously achieving both reversal of the magnetization direction due to the absence of a magnetic field and a low critical current density. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a schematic diagram of a part of the magnetic memory device according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram of a part of another magnetic memory device according to the first embodiment. [Figure 3] Figure 3 shows one unit of Cr2N. [Figure 4] Figure 4A is a schematic diagram showing the spin of conduction electrons in the channel layer and the magnetization direction of the magnetic layer when current is supplied in one direction to the channel layer of the magnetic memory device according to the first embodiment, and Figure 4B is a schematic diagram showing the spin of conduction electrons in the channel layer and the magnetization direction of the magnetic layer when current is supplied in the opposite direction to the channel layer of the magnetic memory device according to the first embodiment. [Figure 5] Figure 5 shows the X-ray diffraction patterns of layers formed on a substrate by nitrogen reactive sputtering at various temperatures using a Cr target and a mixed gas of Ar and nitrogen. [Figure 6]Figure 6 is a plan view of the three-terminal test element according to Example 1. [Figure 7] Figure 7A is a graph showing the Hall resistance when an external magnetic field is swept perpendicular to the plane of the three-terminal test element according to Example 1. Figure 7B is a graph showing the Hall resistance when an external magnetic field of 290 [Oe] is applied in the in-plane direction of the three-terminal test element according to Example 1 and a pulsed current is swept across the Cr2N layer. Figure 7C is a graph showing the Hall resistance when no external magnetic field is applied in the in-plane direction of the three-terminal test element according to Example 1 (no magnetic field) and a pulsed current is swept across the Cr2N layer. [Figure 8] Figure 8A is a graph showing the Hall resistance when an external magnetic field is swept perpendicular to the plane of the three-terminal test element according to Example 2. Figure 8B is a graph showing the Hall resistance when an external magnetic field of 400 [Oe] is applied in the in-plane direction of the three-terminal test element according to Example 2 and a pulsed current is swept across the Cr2N layer. Figure 8C is a graph showing the Hall resistance when no external magnetic field is applied in the in-plane direction of the three-terminal test element according to Example 2 (no magnetic field) and a pulsed current is swept across the Cr2N layer. [Figure 9] Figure 9A is a graph showing the Hall resistance when an external magnetic field is swept perpendicular to the plane of the three-terminal test element according to Comparative Example 1. Figure 9B is a graph showing the Hall resistance when an external magnetic field of 270 [Oe] is applied in the in-plane direction of the three-terminal test element according to Comparative Example 1 and a pulsed current is swept across the Pt layer. Figure 9C is a graph showing the Hall resistance when no external magnetic field is applied in the in-plane direction of the three-terminal test element according to Comparative Example 1 (no magnetic field) and a pulsed current is swept across the Pt layer. [Figure 10] Figure 10 is a cross-sectional view of a sample according to the second embodiment. [Figure 11] Figure 11 shows the X-ray diffraction pattern of the channel in Example 6. [Figure 12] Figure 12 shows the X-ray diffraction patterns of the respective channels in Example 7 and Example 8. [Figure 13] Figure 13 shows the X-ray diffraction pattern of the channel in Comparative Example 2. [Figure 14]Figures 14A to 14C are diagrams obtained by investigating the Hall resistance of the sample according to Example 6. [Figure 15] Figures 15A to 15C are diagrams obtained by investigating the Hall resistance of the sample according to Example 7. [Figure 16] Figures 16A to 16C are diagrams obtained by investigating the Hall resistance of the sample according to Example 8. [Figure 17] Figures 17A to 17C are diagrams obtained by investigating the Hall resistance of samples related to comparative examples. [Modes for carrying out the invention]

[0022] (First Embodiment) The magnetic memory device according to this embodiment will now be described. Figure 1 is a schematic diagram of a part of the magnetic memory device according to this embodiment, Figure 2 is a schematic diagram of a part of another magnetic memory device according to this embodiment, and Figure 3 is a diagram showing one unit of Cr2N. Figure 4A is a schematic diagram showing the spin of conduction electrons in the channel layer and the magnetization direction of the magnetic layer when current is supplied in one direction to the channel layer of the magnetic memory device according to this embodiment, and Figure 4B is a schematic diagram showing the spin of conduction electrons in the channel layer and the magnetization direction of the magnetic layer when current is supplied in the opposite direction to the channel layer of the magnetic memory device according to this embodiment.

[0023] <Magnetic memory device> The magnetic memory device 10 shown in Figure 1 is capable of recording information using magnetism. Specifically, the magnetic memory device 10 is a spin-orbit torque type magnetic random access memory (SOT-MRAM) that uses the spin current or orbital current generated by spin-orbit interaction as a torque source for magnetization reversal.

[0024] The magnetic memory device 10 shown in Figure 1 comprises, in this order, a channel layer 11 that generates a spin current or orbital current when an electric current is supplied, a magnetic layer 12 whose magnetization direction can be reversed by the spin current or orbital current, an electrically insulating barrier layer 13, and a reference layer 14. Note that the magnetic memory device 10 has a substrate on the side of the channel layer 11 opposite to the side facing the magnetic layer 12, but this is omitted in the diagram. Furthermore, the magnetic memory device 10 does not necessarily need to include the barrier layer 13 and the reference layer 14, as long as it includes the channel layer 11 and the magnetic layer 12.

[0025] A first terminal T1 is connected to one end of the channel layer 11, a second terminal T2 is connected to the other end of the channel layer 11, and a third terminal T3 is connected to the reference layer 14.

[0026] <Channel Layer> The channel layer 11 is a layer that functions as an SOT line and contains maxine (MXenes) having the composition ratio shown in formula (1) below. M n+1 X n (1) In equation (1) above, M represents a transition metal, X represents carbon or nitrogen, and n represents an integer between 1 and 4.

[0027] The transition metal M is not particularly limited, but examples include Sc, Ti, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, and W. Among these, Cr, Mo, and W are preferred due to their abundant resources. n is preferably between 1 and 3, and more preferably 1 since it functions even as a single layer.

[0028] MAX phase is an inorganic compound having a crystal structure in which M atoms and X atoms are arranged in a two-dimensional layered structure. Examples of MAX phases include M2X, M3X2, M4X3, etc. (where M and X are synonymous with M and X defined in the above formula (1)). Examples of MAX phases include Sc2C, Ti2C, V2C, Cr2C, Cr2N, Zr2C, Nb2C, Hf2C, Ti3C2, Ti2C, V3C2, Ta3C2, Ta4C3, Ti4C3, V4C3, Ta4C3, or combinations thereof. Among these, Cr2N, Mo2N, and W2N are preferred because of their high stability and abundant resource amounts. The atomic arrangement of Cr2N is as shown in FIG. 3. Cr2N is a layered compound having a hexagonal hcp (hexagonal close-packed) structure belonging to the space group P-31m, and the values of lattice constants a, b, and c are a = b = 0.4805 nm and c = 0.452 nm. Also, Cr2N exhibits antiferromagnetism at room temperature. When Cr2N is adopted as the MAX phase, the

[0001] crystal orientation of Cr2N is parallel to the thickness direction d of the channel layer 11. The thickness direction d is the normal direction of the surface of the channel layer 11, and is also referred to as the plane-normal direction hereinafter.

[0029] MAX phase may be represented by the following formula (2) including terminal groups, but the MAX phase defined in this specification includes the MAX phase represented by the following formula (2). M n+1 X n T x (2) In the above formula (2), M, X, and n are synonymous with M, X, and n defined in the above formula (1), T represents a terminal group, and x represents the number of terminal groups. Examples of terminal groups include -O, -OH, -F, etc. The number of terminal groups is not particularly limited, and for example, the upper limit is not limited.

[0030] The fact that the channel layer 11 contains MAX phase can be confirmed by X-ray diffraction method.

[0031] The thickness of the channel layer 11 is preferably 1 nm or more and 20 nm or less. If the thickness of the channel layer 11 is 1 nm or more, the minimum unit of maxine consisting of three layers M and X can be formed, and if it is 20 nm or less, the maximum spin current or orbital current can be transmitted to the magnetic layer 12. The lower limit of the thickness of the channel layer 11 is more preferably 2 nm or more, or 5 nm or more, and the upper limit is more preferably 15 nm or less, or 10 nm or less. Specifically, for example, the thickness of the channel layer 11 may be 2 nm or more and 15 nm or less, or 5 nm or more and 10 nm or less. These also apply to the second embodiment described later.

[0032] The thickness of the channel layer 11 is determined by measuring the film thickness at 10 points on a cross-sectional image of the channel layer 11 taken using a transmission electron microscope (TEM) or scanning transmission electron microscope (STEM), and taking the arithmetic mean of the 10 values.

[0033] <Magnetic layer> The magnetic layer 12 is a layer whose magnetization direction can be reversed. In this specification, "reversible magnetization direction" means that the magnetization direction can be reversed before and after a writing operation. The reversible magnetization direction in the magnetic layer 12 is indicated by arrows in Figures 4A and 4B. In the embodiments shown in Figures 4A and 4B, the magnetization direction can be reversed between upward and downward in a direction perpendicular to the out-of-plane direction of the film surface.

[0034] The magnetic material constituting the magnetic layer 12 may be a ferromagnetic material. In this specification, "ferromagnetism" means the property of strongly exhibiting magnetism in the same direction as the external magnetic field when an external magnetic field is applied, and a material having ferromagnetism is referred to as a "ferromagnetic material." A ferromagnetic material has the property of retaining strong magnetism even when the external magnetic field is zero.

[0035] Examples of ferromagnetic materials include pure metals such as iron (Fe), cobalt (Co), and nickel (Ni), alloys containing at least one of these, or ferrimagnetic materials. Examples of such alloys include Fe-N, Fe-Pt, Fe-Co, Fe-Ni, Fe-Si, Fe-Dy-Tb, Fe-Ga, Fe-Si-Al, and Mn-N alloys.

[0036] The magnetic layer 12 may have a multilayer structure. A multilayer structure allows for relatively easy manifestation of perpendicular magnetic anisotropy originating from the lamination interface. When the magnetic layer 12 has a multilayer structure, it may be a multilayer structure in which Co layers and Pt layers are alternately stacked, a multilayer structure in which CoFe layers and Ni layers are alternately stacked, or a multilayer structure in which Co layers and Pd layers are alternately stacked. Among these, a multilayer structure in which Co layers and Pt layers are alternately stacked is preferred because it provides high perpendicular magnetic anisotropy, high thermal stability, and high oxidation resistance.

[0037] The thickness of the magnetic layer 12 is preferably 0.5 nm or more and 5 nm or less. If the thickness of the magnetic layer 12 is 0.5 nm or more, for example, perpendicular magnetic anisotropy can be exhibited with the smallest stacked unit of Co-Pt-Co, and if it is 5 nm or less, the perpendicular magnetic anisotropy can be further enhanced by repeating the stacking. The lower limit of the thickness of the magnetic layer 12 is more preferably 1 nm or more, 1.5 nm or more, or 2 nm or more, and the upper limit is more preferably 4 nm or less, or 3 nm or less. Specifically, for example, the thickness of the magnetic layer 12 may be 1 nm or more and 4 nm or less, or 1.5 nm or more and 3 nm or less. If the magnetic layer 12 has a stacked structure, the thickness of the magnetic layer 12 is the total thickness of the magnetic layer 12. The thickness of the magnetic layer 12 shall be measured in the same way as the thickness of the channel layer 11. These are also the same in the second embodiment described later.

[0038] <Barrier layer> The barrier layer 13 is provided adjacent to the magnetic layer 12. The barrier layer 13 is composed of an electrically insulating material. Examples of the electrically insulating material include MgO, Al-O, Mg-Al-O, and Mg-Ga-O, and it may be composed of these laminated films.

[0039] <Reference layer> The reference layer 14 is a layer with a fixed magnetization direction. In this specification, "the magnetization direction is fixed" means that the magnetization direction does not change before and after the writing operation. The reference layer 14 includes at least one ferromagnetic layer. The reference layer 14 may have a laminated structure.

[0040] The channel layer 11 shown in FIG. 1 is adjacent to the magnetic layer 12, but as shown in FIG. 2, a Cr layer 15 may be provided between the channel layer 11 and the magnetic layer 12. By providing the Cr layer 15, a lower critical current density can be achieved. This is considered to be because the spin current or orbital current generated in the channel layer 11 is amplified by the Cr layer 15, as will be described later.

[0041] <Cr layer> The thickness of the Cr layer 15 is preferably 0.3 nm or more and 3 nm or less. If the thickness of the Cr layer 15 is 0.3 nm or more, the spin current or orbital current can be amplified more, and if it is 3 nm or less, the amplification rate and the thin film growth of the magnetic layer can be maintained. The lower limit of the thickness of the Cr layer 15 is more preferably 0.5 nm or more, or 1 nm or more, and the upper limit is more preferably 2 nm or less, or 1.5 nm or less. Specifically, for example, the thickness of the Cr layer 15 may be 0.5 nm or more and 2 nm or less, or 1 nm or more and 1.5 nm or less. The thickness of the Cr layer 15 shall be measured in the same manner as the thickness of the channel layer 11.

[0042] <Substrate> The substrate is not particularly limited, but examples include single crystal substrates and glass substrates, and among these, single crystal substrates that enable epitaxial growth of the channel layer are preferred. The single crystal substrate preferably has a C-plane (0001) orientation. Examples of single crystal substrates include MgO single crystal substrates, SrTiO3 single crystal substrates, and Al2O3 single crystal substrates.

[0043] The substrate thickness is preferably, for example, 500 μm or more. If the substrate thickness is 500 μm or more, warping due to substrate heating and film formation strain can be ignored. The lower limit of the substrate thickness is more preferably 600 μm or more, or 700 μm or more, and the upper limit is more preferably 1300 μm or less, or 1000 μm or less. Specifically, for example, the substrate thickness may be 600 μm or more and 1300 μm or less, or 700 μm or more and 1000 μm or less.

[0044] The memory device according to the second embodiment, described later, also has the same structure as shown in Figure 1.

[0045] <Writing via magnetic memory device> When writing information using the magnetic memory device 10, the reversal of the magnetization direction due to spin-orbit torque is used.

[0046] Specifically, first, a writing current is supplied to the channel layer 11 in the in-plane direction via the first terminal T1 and the second terminal T2. When a writing current is supplied to the channel layer 11, the spin Hall effect causes polarization within the channel layer 11 into conduction electrons having a spin in the +z direction parallel to the perpendicular direction d (see Figure 1) and conduction electrons having a spin in the antiparallel -z direction, as shown in Figures 4A and 4B, generating a spin current or orbital current. In addition to conduction electrons with a spin in the +z direction and conduction electrons with a spin in the -z direction, the channel layer 11 also contains conduction electrons with a spin in the +y direction and conduction electrons with a spin in the -y direction.

[0047] Then, this spin current or orbital current causes conduction electrons with spin in one direction (for example, conduction electrons with spin in the +z direction or conduction electrons with spin in the -z direction) to gather at the interface between the channel layer 11 and the magnetic layer 12. As a result, an effective magnetic field is generated at this interface, and this effective magnetic field acts on the magnetization of the magnetic layer 12, reversing the magnetization direction of the magnetic layer 12. This results in a reversal of the magnetization direction due to the absence of a magnetic field, and writing is performed.

[0048] For example, when the magnetic memory device 10 stores "0", the magnetization of the magnetic layer 12 is oriented in the -z direction, and when it stores "1", the magnetization of the magnetic layer 12 is oriented in the +z direction. When writing "1" to the magnetic memory device 10, a write current is supplied from the first terminal T1 through the channel layer 11 to the second terminal T2, as shown in Figure 4A. This generates a spin current or orbital current with spin in the +z direction (upward) at the interface between the channel layer 11 and the magnetic layer 12, creating a torque that causes the magnetization of the magnetic layer 12 to point in the +z direction, thus causing the magnetization of the magnetic layer 12 to point in the +z direction. On the other hand, when writing "0" to the magnetic memory device 10, a write current is supplied from the second terminal T2 through the channel layer 11 to the first terminal T1, as shown in Figure 4B. This generates a spin current or orbital current with a spin in the -z direction (downward), and a torque is generated that causes the magnetization of the magnetic layer 12 to point in the -z direction, so the magnetization of the magnetic layer 12 points in the +z direction. This makes it possible to switch between a state where "0" is stored and a state where "1" is stored.

[0049] In the memory device according to the second embodiment described later, information is written in the same manner as in Figures 4A and 4B.

[0050] According to this embodiment, the magnetization direction can be reversed in the absence of a magnetic field with a simple structure in which a magnetic layer 12 is provided on one side of the channel layer 11 containing maxine. Furthermore, since maxine is a stable material containing carbon or nitrogen, it is easy to manufacture. In addition, the channel layer 11 can be deposited using a process similar to that used in semiconductor manufacturing, thus having compatibility with semiconductor manufacturing processes. Moreover, because maxine has high atomic layer-level flatness and phase stability, it can achieve a low critical current density J c This makes it possible to achieve both magnetization reversal without a magnetic field and low critical current density with a simple structure, excellent ease of operation, and compatibility with semiconductor manufacturing processes.

[0051] According to this embodiment, magnetization reversal can be achieved without a magnetic field, eliminating the need for external magnetic field application means such as permanent magnet thin films. This enables high integration.

[0052] To describe the present invention in detail, examples according to the first embodiment will be given below for explanation, but the present invention is not limited to these descriptions. FIG. 5 is an X-ray diffraction pattern of a layer formed by nitrogen reactive sputtering at various temperatures on a substrate using a Cr target and a mixed gas of Ar and nitrogen. FIG. 6 is a plan view of a three-terminal test element according to Example 1. FIG. 7A is a graph showing the Hall voltage when an external magnetic field is swept in the plane normal direction of the three-terminal test element according to Example 1. FIG. 7B is a graph showing the Hall resistance when an external magnetic field of 290 [Oe] is applied in the in-plane direction of the three-terminal test element according to Example 1 and a pulse current is swept through the Cr2N layer. FIG. 7C is a graph showing the Hall resistance when no external magnetic field is applied (no magnetic field) in the in-plane direction of the three-terminal test element according to Example 1 and a pulse current is swept through the Cr2N layer. FIG. 8A is a graph showing the Hall resistance when an external magnetic field is swept in the plane normal direction of the three-terminal test element according to Example 2. FIG. 8B is a graph showing the Hall resistance when an external magnetic field of 400 [Oe] is applied in the in-plane direction of the three-terminal test element according to Example 2 and a pulse current is swept through the Cr2N layer. FIG. 8C is a graph showing the Hall resistance when no external magnetic field is applied (no magnetic field) in the in-plane direction of the three-terminal test element according to Example 2 and a pulse current is swept through the Cr2N layer. FIG. 9A is a graph showing the Hall resistance when an external magnetic field is swept in the plane normal direction of the three-terminal test element according to Comparative Example 1. FIG. 9B is a graph showing the Hall resistance when an external magnetic field of 270 [Oe] is applied in the in-plane direction of the three-terminal test element according to Comparative Example 1 and a pulse current is swept through the Pt layer. FIG. 9C is a graph showing the Hall resistance when no external magnetic field is applied (no magnetic field) in the in-plane direction of the three-terminal test element according to Comparative Example 1 and a pulse current is swept through the Pt layer.

[0053] <Cr2N layer formation> On a sapphire substrate (single-crystal Al2O3 substrate) with C-plane orientation and a thickness of 500 μm, layers with a thickness of 5 nm were formed by nitrogen reactive sputtering using a Cr target (Cr purity: 99.99%) and a mixed gas of Ar and nitrogen (flow rate ratio, Ar:N2 = 95:5) at various different deposition temperatures. The X-ray diffraction patterns of the formed layers were then obtained by X-ray diffraction. From the graph shown in Figure 5, it can be understood that all formed layers are Cr2N layers, as they have peaks around 40° and 87°. In Figure 5, "T sub " indicates the substrate temperature, "*" indicates the substrate peak, and "RT" indicates room temperature (25°C). Note that the peak around 87° has a lower relative intensity than the peak around 40° due to physical reasons. Therefore, in the room temperature (RT) graph in Figure 5, the peak around 87° is not clearly visible because the substrate-derived peak base indicated by "*" is superimposed. Furthermore, the shape of the graph around 87° at room temperature is consistent with the shape when a peak exists around 87°. From this, we can conclude that a peak exists around 87° even at room temperature.

[0054] The above X-ray diffraction pattern was measured using SmartLab (manufactured by Rigaku Corporation). The measurement conditions for the X-ray diffraction pattern were as follows: ·CuKα tube used ·X-ray output: 45kV, 200mA • Divergent slit: Automatic • Detector: High-speed one-dimensional X-ray detector ("D / teX Ultra 250" (manufactured by Rigaku Corporation)) • Search range 2θ: 30~100 degrees • Loading width: 0.005 degrees

[0055] These results confirm that the Cr2N layer can be formed at a wide temperature range, from room temperature to 650°C. In particular, being able to form the Cr2N layer at room temperature helps to suppress device damage caused by the heat generated during Cr2N layer formation.

[0056] <Example 1> A 5 nm thick Cr2N layer was formed as a channel layer on a 500 μm thick sapphire substrate (single-crystal Al2O3 substrate) with C-plane orientation by nitrogen reactive sputtering using a 3-inch diameter Cr target (Cr purity: 99.99%) and a mixed gas of Ar and nitrogen (flow rate ratio, Ar:N2 = 95:5) under the following deposition conditions. (Film deposition conditions) ·Substrate temperature: 650℃ • Pressure: 1 Pa • DC Power: 30W

[0057] Next, a magnetic layer was formed on the Cr2N layer by DC magnetron sputtering, with three units of a laminated film consisting of a Co layer with a thickness of 0.3 nm to 0.4 nm and a Pt layer with a thickness of 0.3 nm to 0.4 nm stacked in that order. The Cr2N layer was in contact with the Co layer of the magnetic layer. Subsequently, a 2 nm thick MgO layer was formed on the top Pt layer of the magnetic layer by RF magnetron sputtering to act as a protective layer to suppress oxidation of the magnetic layer. Then, the Cr2N layer, magnetic layer, and MgO layer were patterned by photolithography to form a fine line section with a line width of 10 μm, having the laminated structure of the Cr2N layer, magnetic layer, and MgO layer shown in Figure 6. After the formation of the fine wire section, an electrode pad with a total thickness of 110 nm was formed by connecting it to the fine wire section using a magnetron sputtering method. This pad consists of a laminated structure of a tantalum layer with a thickness of 10 nm and a gold layer with a thickness of 100 nm, and has the shape shown in Figure 6. This yielded the three-terminal test element according to Example 1. The three-terminal element is a basic device for spin-current magnetic memory devices. The three-terminal test element has a different structure from the structure shown in Figure 1, but a simplified structure was adopted for the purpose of performing the evaluation described later.

[0058] <Example 2> In Example 2, a three-terminal test element was obtained in the same manner as in Example 1, except that the Cr2N layer was formed at a substrate temperature of 350°C.

[0059] <Example 3> In Example 3, a three-terminal test element was obtained in the same manner as in Example 1, except that the stacking order of the Co layer and Pt layer in the magnetic layer was reversed, that is, the Pt layer and Co layer were formed on the Cr2N layer in that order.

[0060] <Example 4> In Example 4, a three-terminal test element was obtained in the same manner as in Example 1, except that a Cr layer with a thickness of 1 nm was formed between the Cr2N layer and the magnetic layer.

[0061] <Example 5> In Example 5, a three-terminal test element was obtained in the same manner as in Example 1, except that the film thickness of one Cr2N layer unit was set to approximately 0.9 to 1.0 nm, and eight types of Cr2N layers, stacked in groups of 3 to 10 units, were formed using a linear shutter.

[0062] <Comparative Example 1> In Comparative Example 1, a three-terminal test element was obtained in the same manner as in Example 1, except that a Pt layer with a thickness of 5 nm was formed instead of the Cr2N layer.

[0063] <Hall resistance measurement and critical current density measurement> Hall resistance and critical current density were measured in the three-terminal test elements according to Examples 1-5 and Comparative Example 1. Specifically, Hall resistance was measured while sweeping an external magnetic field perpendicular to the plane of the three-terminal test element. In addition, Hall resistance and critical current density were measured by sweeping a pulse current with a pulse width of 10 ms and applying, or not applying, an external magnetic field of a predetermined strength in the in-plane direction of the three-terminal test element, and measuring the Hall resistance during the intermittent time of the applied pulse current for 1 s.

[0064] In the three-terminal test element according to Comparative Example 1, when an external magnetic field (270 [Oe]) was applied, a reversal of the Hall resistance was observed, indicating that a reversal of the magnetization direction due to the pulsed current was occurring (see Figure 9B). However, in the absence of a magnetic field (0 [Oe]), a reversal of the Hall resistance was not observed, confirming that a reversal of the magnetization direction due to the pulsed current was not occurring (see Figure 9C).

[0065] In contrast, in the three-terminal test element according to Example 1, a reversal of the Hall resistance was observed not only when an external magnetic field (290[Oe]) was applied, but also in a no-magnetic-field state (0[Oe]) without an external magnetic field, thus confirming that a reversal of the magnetization direction occurred (see Figures 7B and 7C). Positive Hall resistance is observed when the magnetization of the magnetic layer 12 is antiparallel to the direction d perpendicular to the surface of the channel layer 11 (see Figure 1). Negative Hall resistance is observed when the magnetization of the magnetic layer 12 is parallel to the direction d perpendicular to the surface of the channel layer 11. Furthermore, when using the change in Hall resistance measured while sweeping the external magnetic field perpendicular to the surface as a reference (see Figure 7A), the change in Hall resistance due to pulse current sweep was approximately 100% when an external magnetic field (290[Oe]) was applied (see Figure 7B), and approximately 25% in the no-magnetic-field state (0[Oe]) because the size of the fine-line pattern is large, at the micron level (see Figure 7C). It is possible to achieve 100% by reducing the size of the thin lines.

[0066] In the three-terminal test element according to Example 2, the reversal of the Hall resistance was confirmed not only when an external magnetic field (400 [Oe]) was applied, but also in a no-magnetic-field state (0 [Oe]), thus confirming that a reversal of the magnetization direction occurred (see Figures 8B and 8C). Here, in the CMOS (Complementary Metal-Oxide-Semiconductor) process, heat treatment at 400°C is performed to form the wiring pattern, but if the magnetization reversal characteristics of Cr2N are not impaired even after this heat treatment, it will be possible to move closer to mounting it in an embedded SOT-MRAM. According to Example 2, similar magnetization reversal under no-magnetic-field conditions was demonstrated in a three-terminal test element fabricated at a temperature close to 400°C.

[0067] In the three-terminal test elements of Examples 3 and 4, and in all three-terminal test elements of Example 5, similar to Example 1, a reversal of the positive and negative poles of the Hall resistance was observed not only when an external magnetic field was applied during pulse current sweep, but also in the absence of a magnetic field. This confirmed that a reversal of the magnetization direction was occurring.

[0068] Furthermore, in the three-terminal test element according to Comparative Example 1, the critical current density J c It is 60 MA / cm 2 It was to that extent. In contrast, the three-terminal test element according to Example 1 had a critical current density J c It is 20-30 MA / cm 2 Therefore, the critical current density J was lower than when using the three-terminal test element according to Comparative Example 1. c The value was low. In addition, in the three-terminal test element according to Example 2, the critical current density J c It is 60 MA / cm 2 Therefore, the critical current density J was equivalent to that obtained when using the three-terminal test element according to Comparative Example 1. c The critical current density J in the three-terminal test element according to Example 3 was... c This is the critical current density J of Example 1. c Similarly, 10 7 A / cm 2 It was a unit. The critical current density J in the three-terminal test element according to Example 4. c This is the critical current density J of Example 1. c It is about an order of magnitude lower than 10 6 A / cm 2 It was a unit. Furthermore, the critical current density J in the three-terminal test element according to Example 5 c This decreased as the number of units increased.

[0069] (Second Embodiment) In the first embodiment, Cr2N was used as the maxine constituting the channel layer. In contrast, in this embodiment, a channel layer consisting of a compound represented by MX, which is different from the maxine, will be described. However, as in the first embodiment, M represents a transition metal and X represents carbon or nitrogen. Also, M n+1 X n The channel layer containing maxine, represented by , and the compound represented by MX will also be explained. However, n is an integer between 1 and 4.

[0070] Figure 10 is a cross-sectional view of a sample according to this embodiment. As shown in Figure 10, this sample is formed by forming a channel layer 11, a magnetic layer 12, and a barrier layer 13 on a substrate 21 in that order.

[0071] The inventor of this application prepared the sample as shown in the following examples.

[0072] <Example 6> In this embodiment, non-maxine VN (vanadium nitride) was used for the channel layer 11.

[0073] First, a sapphire substrate, which is a single-crystal Al2O3 substrate, was prepared as substrate 21. The sapphire substrate 21 is C-plane oriented and has a thickness of 500 μm.

[0074] Next, a channel layer 11 consisting of a single phase of VN (vanadium) was formed on the substrate 21 to a thickness of 5 nm using reactive sputtering with a 3-inch diameter V (vanadium) target. The purity of V in the V target was 99.99%. A mixed gas of Ar gas and N2 gas with a flow rate ratio of Ar:N2 = 4:1 was used as the sputtering gas. The substrate temperature during deposition of the channel layer 11 was 350°C, and the deposition pressure was 0.3 Pa. The DC power applied between the substrate 21 and the V target was 30 W.

[0075] Next, three laminated films were formed on the channel layer 11 by stacking a Co layer with a thickness of 0.35 nm and a Pt layer with a thickness of 0.3 nm in that order, and this was designated as the magnetic layer 12.

[0076] Next, a 2 nm thick MgO layer was formed as a barrier layer 13 on the Pt layer, which is the topmost layer of the magnetic layer 12, by RF magnetron sputtering, and the oxidation of the magnetic layer 12 was suppressed by this barrier layer 13.

[0077] The channel layer 11, magnetic layer 12, and barrier layer 13 were patterned to form the fine line portion shown in Figure 6 with a line width of 10 μm.

[0078] As described later, when the channel layer 11 of the sample prepared in this way was analyzed by X-ray diffraction, it was found that the maxine V2N was not contained in the channel layer 11, and that the channel layer 11 consisted only of non-maxine VN.

[0079] <Example 7> In this embodiment, a multiphase of non-maxine CrN (chromium nitride) and Cr2N, an example of a maxine, was used in the channel layer 11.

[0080] First, a substrate 21 was prepared in the same manner as in Example 6, and a channel layer 11 consisting of a Cr2N and CrN multiphase was formed on it to a thickness of 5 nm using a reactive sputtering method with a 3-inch diameter Cr (chromium) target. The purity of Cr in the Cr target was 99.99%. A mixed gas of Ar gas and N2 gas with a flow rate ratio of Ar:N2=4:1 was used as the sputtering gas. The substrate temperature during deposition of the channel layer 11 was 350°C, and the deposition pressure was 0.3 Pa. The DC power applied between the substrate 21 and the target was 30 W.

[0081] Subsequently, a magnetic layer 12 and a barrier layer 13 were formed on the channel layer 11 in the same manner as in Example 6, and they were patterned to form a fine line portion with a line width of 10 μm (see Figure 6).

[0082] As described later, when the channel layer 11 in this embodiment was analyzed by X-ray diffraction, it was found that the volume ratio of Cr2N:CrN was 5:1, and the volume ratio of CrN to Cr2N was 1 / 5.

[0083] <Example 8> In this embodiment, a multiphase of CrN and Cr2N was formed as the channel layer 11, similar to Example 7. However, the nitrogen flow rate ratio in the sputtering gas was increased compared to Example 7 so that the ratio of CrN to Cr2N was higher than in Example 7. In this embodiment, the sputtering gas flow rate ratio was set to Ar:N2 = 3:1. All other conditions for forming the channel layer 11 were the same as in Example 7.

[0084] As described later, when the channel layer 11 in this embodiment was analyzed by X-ray diffraction, it was found that the volume ratio of Cr2N:CrN was 1:6, indicating that the volume ratio of CrN to Cr2N was 6.

[0085] <Comparative Example 2> In this comparative example, a channel layer 11 consisting solely of CrN was formed. To form the channel layer 11 using only CrN, the nitrogen flow rate ratio in the sputtering gas for the channel layer 11 should be made even larger than in Example 8. In this example, the sputtering gas flow rate ratio was set to Ar:N2 = 7:3. The other conditions for forming the channel layer 11 were the same as in Example 7.

[0086] As described later, when the channel layer 11 of the sample prepared in this way was analyzed by X-ray diffraction, it was found that the channel layer 11 did not contain maxine Cr2N, and that the channel layer 11 consisted only of non-maxine CrN.

[0087] Next, we will explain the results of the survey for each of the above samples.

[0088] X-ray diffraction pattern The X-ray diffraction patterns of the channel layer 11 in Examples 6-8 and Comparative Example 2 were measured. The measurement conditions were the same as those for the X-ray diffraction patterns in Figure 5. However, the scanning range for Examples 6 and 7 was set to 0 to 50 degrees.

[0089] Figure 11 shows the X-ray diffraction pattern of the channel layer 11 in Example 6. The horizontal axis of Figure 11 represents the X-ray diffraction angle, and the vertical axis represents the logarithmic intensity of the diffracted X-rays in arbitrary units.

[0090] As shown in this X-ray diffraction pattern, diffraction peaks originating from the 111th and 222nd planes of the fcc (face-centered cubic) structure of VN appeared. This indicates that the channel layer 11 in Example 6 contains cubic VN with an fcc structure. The lattice constants of the cubic VN are a=b=c=0.407 nm.

[0091] Furthermore, the X-ray diffraction pattern showed only diffraction peaks originating from the sapphire substrate and cubic VN, while no diffraction peaks originating from V2N appeared. This indicated that maxine V2N was not present in the channel layer 11, and that the channel layer 11 consisted only of non-maxine cubic VN. It was also found that the

[0111] crystal orientation of VN was parallel to the thickness direction d of the channel layer 11 (see Figure 10).

[0092] Figure 12 shows the X-ray diffraction patterns of the channel layer 11 in Example 7 and Example 8, respectively. The meaning of the horizontal and vertical axes in Figure 12 is the same as in Figure 11.

[0093] As shown in this X-ray diffraction pattern, in both Example 7 and Example 8, a diffraction peak originating from the 111 plane of the fcc structure CrN appeared around 37.5°. From this result, it was confirmed that the channel layer 11 in both Example 7 and Example 8 contains CrN having a cubic fcc structure. The lattice constants of the cubic CrN are a=b=c=0.415nm.

[0094] Furthermore, a diffraction peak originating from the 0001 plane of the hcp structure Cr2N appeared around 40°. This revealed that the channel layer 11 in both Example 7 and Example 8 contained not only CrN but also Maxine Cr2N with an hcp structure.

[0095] Furthermore, for each sample in Example 7 and Example 8, the volume fractions of Cr2N and CrN contained in the channel layer 11 were calculated from the integrated intensity of the X-ray diffraction peaks in Figure 12. As a result, in Example 7, the volume ratio of Cr2N:CrN was 5:1, meaning the volume ratio of CrN to Cr2N was 1 / 5. In Example 8, the volume ratio of Cr2N:CrN was 1:6, meaning the volume ratio of CrN to Cr2N was 6.

[0096] Figure 13 shows the X-ray diffraction pattern of channel layer 11 in Comparative Example 2. The meaning of the horizontal and vertical axes in Figure 13 is the same as in Figure 11.

[0097] As shown in this X-ray diffraction pattern, diffraction peaks originating from the 111 and 222 planes of the fcc structure CrN appeared. This indicates that the channel layer 11 in Comparative Example 2 contains CrN having a cubic fcc structure.

[0098] Furthermore, the X-ray diffraction pattern showed only diffraction peaks originating from the sapphire substrate and cubic CrN, while no peaks originating from Cr2N appeared. This indicated that maxine Cr2N was not present in the channel layer 11, and that the channel layer 11 consisted solely of non-maxine cubic CrN.

[0099] Hall voltage The Hall resistance of each sample from Examples 6-8 and Comparative Example 2 was measured. The measurement method for Hall resistance and the pulse width of the pulse current used for measurement were the same as those for the Hall resistance in Figures 7A-7C.

[0100] Figures 14A to 14C are diagrams obtained by investigating the Hall resistance of the sample according to Example 6. Of these, Figure 14A is a graph showing the Hall voltage when the external magnetic field is swept in the direction perpendicular to the surface of the sample, with the horizontal axis being the external magnetic field H z The vertical axis represents the Hall resistance R. xy This indicates.

[0101] As described above, in Example 6, the maxine V2N is not included in the channel layer 11, and the channel layer 11 consists only of non-maxine VN.

[0102] Figure 14B is a graph showing the Hall resistance when external magnetic fields of 520 [Oe] and -520 [Oe] are applied in the in-plane direction of the sample, and a pulsed current is swept through the channel layer 11. The horizontal axis of Figure 14B represents the current density J of the pulsed current. VN The vertical axis represents the Hall resistance R. xy This indicates.

[0103] Figure 14C is a graph showing the Hall resistance when a pulsed current is swept through the channel layer 11 in a magnetic-free state without applying an external magnetic field to the sample, and the meaning of the horizontal and vertical axes is the same as in Figure 14B.

[0104] As shown in Figure 14A, an external magnetic field H is directed perpendicular to the surface of the sample. z By sweeping, the hole resistance R xy We were able to obtain the history curve.

[0105] Furthermore, as shown in Figure 14B, the external magnetic field H in the in-plane direction is 520[Oe] and -520[Oe]. z By reversing the direction, the hysteresis curve was inverted vertically. This is due to the external magnetic field H in the in-plane direction. z This is because reversing the direction of the current reverses the direction of the spin current generated in the channel layer 11, which in turn reverses the direction of the magnetization in the magnetic layer 12.

[0106] Furthermore, as shown in Figure 14C, the external magnetic field H z Even in a magnetic-free state without a magnetic field, the Hall resistance R xy We were able to obtain a hysteresis curve. In that hysteresis curve, the current density J of the pulsed current VN Even if they are the same, there are two Hall resistors R, one positive and one negative. xy This was observed because the spin current generated in the channel layer 11 in conjunction with the pulsed current reversed the magnetization of the magnetic layer 12.

[0107] As shown in Figure 14C, it was found that even a channel layer 11 consisting only of VN can achieve magnetization reversal of the magnetic layer 12 in a zero-magnetic-field state, similar to V2N, which is the maxine. When the channel layer 11 is formed with only VN, the amount of V contained in the channel layer 11 is reduced compared to when the channel layer 11 is formed with only V2N. This makes it possible to reverse the magnetization of the magnetic layer 12 in a zero-magnetic-field state while reducing the amount of transition metals such as V used.

[0108] Figures 15A to 15C show the results obtained by investigating the Hall resistance of the sample according to Example 7. The meaning of each investigation in Figures 15A to 15C is the same as that of the investigations in Figures 14A to 14C described above, so a detailed explanation will be omitted.

[0109] In Figures 15B and 15C, the current density of the pulsed current flowing through the channel layer 11 is J. Cr2N+CrN This is represented as follows. Also, in Figure 15B, the external magnetic fields applied in the in-plane direction of the sample are 300 [Oe] and -300 [Oe].

[0110] As shown in Figure 15A, in Example 7 as well, the external magnetic field H is located perpendicular to the surface of the sample. z By sweeping, the hole resistance R xy We were able to obtain the history curve.

[0111] Furthermore, as shown in Figure 15B, the external magnetic field H in the in-plane direction is 300[Oe] and -300[Oe]. z By reversing the direction, the hysteresis curve was inverted vertically, similar to Example 6.

[0112] Furthermore, as shown in Figure 15C, the external magnetic field H z Even in a magnetic-free state without a magnetic field, the Hall resistance R xy We were able to obtain the history curve.

[0113] As mentioned above, in Example 7, the channel layer 11 includes not only maxine Cr2N but also non-maxine CrN. As shown in Figure 15C, it was found that even if the channel layer 11 is not formed solely of maxine Cr2N, but also contains non-maxine CrN, magnetization reversal of the magnetic layer 12 can be achieved in a magnetic field-free state.

[0114] This alleviates the manufacturing constraint that the channel layer 11 must be formed solely from maxine, thereby simplifying the manufacturing of magnetic memory devices. Moreover, the inclusion of CrN in the channel layer 11 reduces the Cr content in the channel layer 11 compared to the case where the channel layer 11 is composed solely of Cr2N. As a result, the amount of transition metals such as Cr used can be reduced while the magnetic layer 12 can be inverted in a magnetic field-free state.

[0115] Figures 16A to 16C show the results obtained by investigating the Hall resistance of the sample according to Example 8. The meaning of each investigation in Figures 16A to 16C is the same as that of the investigations in Figures 14A to 14C described above, so a detailed explanation is omitted. Note that in Figure 16B, the external magnetic fields applied in the in-plane direction of the sample were 300 [Oe] and -300 [Oe].

[0116] As shown in Figure 16A, in Example 8 as well, the external magnetic field H is located perpendicular to the surface of the sample. z By sweeping, the hole resistance R xy We were able to obtain the history curve.

[0117] Furthermore, as shown in Figure 16B, the external magnetic field H in the in-plane direction is 300 [Oe] and -300 [Oe]. z By reversing the direction, the hysteresis curve was inverted vertically, similar to Example 6.

[0118] Furthermore, as shown in Figure 16C, the external magnetic field H z Even in a magnetic-free state without a magnetic field, the Hall resistance R xy We were able to obtain the history curve.

[0119] Similar to Example 7, in Example 8, the channel layer 11 also contains non-maxine CrN in addition to Cr2N. As mentioned above, the volume ratio of CrN to Cr2N was 1 / 5 in Example 7 and 6 in Example 8. Therefore, it was found that by setting the volume ratio of CrN to Cr2N to between 1 / 5 and 6, magnetization reversal of the magnetic layer 12 can be achieved in a magnetic field-free state.

[0120] Figures 17A to 17C show the results obtained by investigating the Hall resistance of the sample related to Comparative Example 2. The meaning of each investigation in Figures 17A to 17C is the same as that of the investigations in Figures 14A to 14C described above, so a detailed explanation is omitted. Note that in Figure 17B, the external magnetic fields applied in the in-plane direction of the sample were 400 [Oe] and -400 [Oe].

[0121] As mentioned above, in Comparative Example 2, the maxine Cr2N is not included in the channel layer 11, and the channel layer 11 consists only of non-maxine CrN.

[0122] As shown in Figure 17A, in Comparative Example 2, the external magnetic field H is also located perpendicular to the surface of the sample. z By sweeping, the hole resistance R xy We were able to obtain the history curve.

[0123] Furthermore, as shown in Figure 17B, the external magnetic field H in the in-plane direction is 400[Oe] and -400[Oe]. z By reversing the direction, the hysteresis curve was inverted vertically, similar to Examples 6-8.

[0124] However, as shown in Figure 17C, the external magnetic field H z In a magnetic field-free state, the Hall resistance R xy We were unable to obtain a hysteresis curve. From this result, we found that, unlike Example 6 (Figure 14C) in which the channel layer 11 is composed only of non-maxine VN, if the channel layer 11 is composed only of non-maxine CrN, magnetization reversal of the magnetic layer 12 cannot be achieved in a magnetic field-free state. [Explanation of Symbols]

[0125] 10…Magnetic memory devices 11…Channel layer 12...Magnetic layer 13… Barrier layer 14...Reference layer 15...Cr layer 21… Circuit board

Claims

1. A channel layer that generates a spin current or orbital current when an electric current is supplied, The channel layer comprises a magnetic layer disposed on one side of the channel layer and whose magnetization direction can be reversed by the spin current or the orbital current, A magnetic memory device in which the channel layer contains maxine having a composition ratio represented by the following formula (1). M ｎ＋１ X ｎ (1) (In formula (1) above, M represents a transition metal, X represents carbon or nitrogen, and n represents an integer between 1 and 4.)

2. The aforementioned maxine, Cr ２ A magnetic memory device according to claim 1, wherein N.

3. The magnetic memory device according to claim 2, further comprising a Cr layer formed between the channel layer and the magnetic layer.

4. The magnetic memory device according to claim 1, wherein the channel layer comprises the maxine and a compound represented by MX.

5. The aforementioned maxine is Cr ２ The magnetic memory device according to claim 4, wherein the compound is cubic CrN.

6. The aforementioned Cr ２ The magnetic memory device according to claim 5, wherein the volume ratio of CrN to N is 1 / 5 or more and 6 or less.

7. A channel layer made of cubic VN that generates a spin current or orbital current when an electric current is supplied, A magnetic memory device comprising a magnetic layer disposed on one side of the channel layer and whose magnetization direction can be reversed by the spin current or the orbital current.

8. The magnetic memory device according to claim 7, wherein the [111] crystal orientation of the VN is parallel to the thickness direction of the channel layer.

9. The magnetic memory device according to any one of claims 1 to 8, wherein the channel layer is adjacent to the magnetic layer.

10. The magnetic memory device according to any one of claims 1 to 9, wherein the thickness of the channel layer is 1 nm or more and 20 nm or less.

11. The magnetic memory device according to any one of claims 1 to 10, wherein the thickness of the magnetic layer is 0.5 nm or more and 5 nm or less.

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