Magnetic memory device

Abstract

A magnetic memory device includes: a lower magnetic track layer extending in a first direction and including a plurality of first magnetic domains; a spacer layer on the lower magnetic track layer and extending in the first direction; an upper magnetic track layer on the spacer layer and extending in the first direction, the upper magnetic track layer including a plurality of second magnetic domains; and a plurality of reading units on the upper magnetic track layer and disposed apart from each other in a first direction, in which the plurality of first magnetic domains and the plurality of second magnetic domains have magnetization directions parallel to each other at positions overlapping each other in a second direction perpendicular to the first direction.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2023-0093343 filed in the Korean Intellectual Property Office on July 18, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The inventive concept relates to a magnetic memory device, and more particularly, to a magnetic memory device including a racetrack. Background Art

[0004] High-capacity memory devices are used for miniaturized, multifunctional, and high-performance electronic products. A racetrack including a plurality of magnetic domains that stores information according to the movement of a domain wall between magnetic domains has been proposed for providing a high-capacity memory device. In addition, a magnetic domain wall shift register type memory device including a racetrack has been developed. It is generally desired to realize a magnetic memory device having stable movement of a magnetic domain wall, high integration, and a desired long life. Summary of the invention

[0005] The inventive concept provides a magnetic memory device in which a racetrack is used to achieve high integration, which can reduce damage to a tunnel barrier in a magnetic tunnel junction structure.

[0006] The objects of the inventive concept are not limited to the foregoing, but other objects not described herein will be clearly understood by those of ordinary skill in the art from the following description.

[0007] According to one aspect of the inventive concept, a magnetic memory device is provided, comprising: a lower magnetic track layer extending in a first direction and comprising a plurality of first magnetic domains; a spacer layer on the lower magnetic track layer and extending in the first direction; an upper magnetic track layer on the spacer layer and extending in the first direction, the upper magnetic track layer comprising a plurality of second magnetic domains; and a plurality of read units arranged on the upper magnetic track layer and separated from each other in the first direction, wherein the plurality of first magnetic domains and the plurality of second magnetic domains have magnetization directions parallel to each other at positions where they overlap with each other in a second direction perpendicular to the first direction.

[0008] According to another aspect of the present invention, a magnetic memory device is provided, comprising: a spin Hall conductive layer; an operating magnetic track layer and a replica magnetic track layer stacked on the spin Hall conductive layer along a first direction; a spacer layer between the operating magnetic track layer and the replica magnetic track layer; a tunnel barrier layer on the replica magnetic track layer; and a plurality of magnetic tunnel junction sensors on the tunnel barrier layer, wherein, based on a leakage magnetic field of the operating magnetic track layer, the operating magnetic track layer and the replica magnetic track layer have magnetization directions parallel to each other at positions where they overlap with each other along the first direction.

[0009] According to another aspect of the inventive concept, a magnetic memory device is provided, comprising: a lower magnetic track layer, comprising a plurality of first magnetic domains and a plurality of first magnetic domain walls extending in a first direction and arranged alternately; a spacer layer, on the lower magnetic track layer and extending in the first direction, the spacer layer having a thickness of about 1 nm to about 5 nm; an upper magnetic track layer, comprising a plurality of second magnetic domains and a plurality of second magnetic domain walls extending in the first direction and arranged alternately, the upper magnetic track layer being on the spacer layer; and a plurality of read units on the upper magnetic track layer, the plurality of read units being configured to read a magnetization direction of the upper magnetic track layer and being arranged apart from each other in the first direction, wherein the plurality of first magnetic domain walls and the plurality of second magnetic domain walls overlap with each other in a second direction perpendicular to the first direction, and wherein the plurality of first magnetic domains and the plurality of second magnetic domains have magnetization directions parallel to each other at positions where they overlap with each other along the second direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a cross-sectional view showing elements of a magnetic memory device according to some embodiments;

[0012] Figure 2 is a diagram showing that according to some embodiments Figure 1 A cross-sectional view of an initial state (or first state) of a magnetic memory device;

[0013] Figure 3 is a diagram showing that according to some embodiments Figure 1 A cross-sectional view of a final state (or second state) of a magnetic memory device;

[0014] Figure 4 and Figure 5 is a cross-sectional view showing main elements of a magnetic memory device according to another embodiment;

[0015] Figure 6 is a flow chart illustrating a method of manufacturing a magnetic memory device according to some embodiments;

[0016] Figures 7 to 9 is a cross-sectional view illustrating a method of manufacturing a magnetic memory device in process order according to some embodiments; and

[0017] FIG. 10A to FIG. 10C is a diagram illustrating magnetic replication characteristics of a magnetic memory device according to some embodiments. DETAILED DESCRIPTION

[0018] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent the same elements, and therefore their description will be omitted. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. Note that aspects described with respect to one embodiment may be incorporated into different embodiments, although there is no specific description thereof. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination. Figure 1 is a cross-sectional view showing elements of a magnetic memory device 10 according to some embodiments, Figure 2 is a diagram showing that according to some embodiments Figure 1 A cross-sectional view of an initial state (or first state) of the magnetic memory device 10, Figure 3 is a diagram showing that according to some embodiments Figure 1 FIG. 1 is a cross-sectional view of a final state (or second state) of the magnetic memory device 10 .

[0019] Reference Figures 1 to 3 According to an embodiment, a magnetic memory device 10 may include a conductive layer 101, a lower magnetic track layer 110 disposed on the conductive layer 101, a spacer layer 103 disposed on the lower magnetic track layer 110, an upper magnetic track layer 120 disposed on the spacer layer 103, a tunnel barrier layer 105 disposed on the upper magnetic track layer 120, and a plurality of read units 130 disposed on the tunnel barrier layer 105.

[0020] In some embodiments, the conductive layer 101 may include a sensing layer that allows a spin-orbit moment (SOT) to be generated by a current flowing in the conductive layer 101. In other embodiments, the conductive layer 101 may include a material that allows a spin Hall effect or a Rashba effect to be realized by a current flowing in the conductive layer 101 along a first horizontal direction X or in a direction opposite to the first horizontal direction X. In other words, the conductive layer 101 may be referred to as a spin Hall conductive layer. In addition, a pulse injection unit and a ground (GND) unit may be connected to the conductive layer 101.

[0021] In addition, the conductive layer 101 may include a heavy metal having an atomic number of 30 or more. For example, the conductive layer 101 may include iridium (Ir), ruthenium (Ru), tantalum (Ta), platinum (Pt), palladium (Pd), bismuth (Bi), titanium (Ti), and / or tungsten (W), but the embodiment is not limited thereto.

[0022] The magnetic memory device 10 according to an embodiment may include a lower magnetic track layer 110, a spacer layer 103, and an upper magnetic track layer 120 sequentially stacked on a conductive layer 101. The lower magnetic track layer 110, the spacer layer 103, and the upper magnetic track layer 120 may be stacked on the conductive layer 101 along a vertical direction Z. Here, the lower magnetic track layer 110 may be disposed between the conductive layer 101 and the spacer layer 103, and the spacer layer 103 may be disposed between the lower magnetic track layer 110 and the upper magnetic track layer 120. In some embodiments, the length of the conductive layer 101, the length of the lower magnetic track layer 110, the length of the spacer layer 103, and the length of the upper magnetic track layer 120 may be equal to each other in the first horizontal direction X.

[0023] In some embodiments, the lower magnetic track layer 110, the spacer layer 103, and the upper magnetic track layer 120 may have a line shape having a straight line shape extending longer in a first horizontal direction X and having a certain width in a second horizontal direction Y perpendicular to the first horizontal direction X. In other embodiments, the lower magnetic track layer 110, the spacer layer 103, and the upper magnetic track layer 120 may have a line shape having a U-shape.

[0024] The lower magnetic track layer 110 may include first magnetic domains 110D and first magnetic domain walls 110W arranged along the first horizontal direction X, each of the first magnetic domain walls 110W being provided between two adjacent first magnetic domains 110D in the first magnetic domains 110D. The first magnetic domain 110D may be a region in the lower magnetic track layer 110 where magnetic moments are aligned in a certain direction. In addition, the first magnetic domain wall 110W may be a region between the first magnetic domains 110D where the direction of the magnetic moment changes. The first magnetic domains 110D and the first magnetic domain walls 110W may be alternately arranged in the first horizontal direction X.

[0025] The upper magnetic track layer 120 may include second magnetic domains 120D and second magnetic domain walls 120W arranged along the first horizontal direction X, each second magnetic domain wall 120W being provided between two adjacent second magnetic domains 120D in the second magnetic domains 120D. The second magnetic domain 120D may be a region in the upper magnetic track layer 120 where magnetic moments are aligned in a certain direction. In addition, the second magnetic domain wall 120W may be a region between the second magnetic domains 120D where the direction of the magnetic moment changes. The second magnetic domains 120D and the second magnetic domain wall 120W may be alternately arranged in the first horizontal direction X.

[0026] In some embodiments, the second magnetic domain 120D may overlap each of the first magnetic domains 110D in the vertical direction Z. In addition, as will be described below, the magnetization directions of the first magnetic domain 110D and the second magnetic domain 120D overlapping each other in the vertical direction Z may be parallel to each other. The first magnetic domain wall 110W and the second magnetic domain wall 120W may overlap each other in the vertical direction Z.

[0027] The upper magnetic track layer 120 can substantially accurately replicate the magnetization direction of the lower magnetic track layer 110 through the spacer layer 103 based on the leakage magnetic field, and thus, the magnetization direction can be set. In other words, the lower magnetic track layer 110 can be referred to as an operating magnetic track layer, and the upper magnetic track layer 120 can be referred to as a replica magnetic track layer or a link magnetic track layer. In another embodiment, based on the stacking order, the lower magnetic track layer 110 can be referred to as a first magnetic track layer, and the upper magnetic track layer 120 can be referred to as a second magnetic track layer.

[0028] In the initial state (or first state) of the magnetic memory device 10, the magnetization direction of the leftmost first magnetic domain 110D of the lower magnetic track layer 110 may be UP, and thus the magnetization direction of the corresponding second magnetic domain 120D of the upper magnetic track layer 120 may be parallel UP.

[0029] In the final state (or second state) of the magnetic memory device 10, the magnetization direction of the leftmost first magnetic domain 110D of the lower magnetic track layer 110 can be changed to downward DN, and thus the magnetization direction of the corresponding second magnetic domain 120D of the upper magnetic track layer 120 can be changed to parallel downward DN.

[0030] Each of the lower magnetic track layer 110 and the upper magnetic track layer 120 may include a magnetic element, for example, may include one or more of cobalt (Co), iron (Fe), and nickel (Ni). However, the magnetic element included in the lower magnetic track layer 110 may be different from the magnetic element included in the upper magnetic track layer 120. For example, the lower magnetic track layer 110 may include Co and Ni and may not include Fe, and the upper magnetic track layer 120 may include Co and Fe and may not include Ni.

[0031] The spacer layer 103 may include an insulating material, for example, may include one or more of hexagonal boron nitride (h-BN), aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, and graphene.

[0032] In detail, boron nitride can be a compound in which boron (B) and nitrogen (N) are mixed in the same ratio, and can have a hexagonal, cubic and / or wurtzite crystal form. Here, h-BN can be a material with high thermal conductivity, good chemical stability, robustness to thermal shock and excellent mechanical strength. In addition, h-BN can include a single-layer structure material (i.e., a two-dimensional sheet structure) including boron (B) atoms and nitrogen (N) atoms each having a hexagonal lattice structure. In this context, h-BN can have similar characteristics to graphene including carbon (C) atoms having a hexagonal lattice structure. As will be described below, the method for manufacturing a magnetic memory device 10 according to an embodiment will be described based on the characteristics of h-BN.

[0033] In some embodiments, the thickness of the spacer layer 103 may have a range of about 1 nm to about 5 nm. As will be described below, when the thickness of the spacer layer 103 is about 1 nm to about 5 nm, the magnetization direction of the lower magnetic track layer 110 may be replicated to be substantially equal to the magnetization direction of the upper magnetic track layer 120. On the other hand, when the thickness of the spacer layer 103 is greater than about 5 nm, a difference between the magnetization direction of the lower magnetic track layer 110 and the magnetization direction of the upper magnetic track layer 120 may be caused. In addition, it may be difficult to form the thickness of the spacer layer 103 to a thickness less than about 1 nm, and it may be difficult to achieve magnetic characteristics with respect to a fine thickness.

[0034] The lower magnetic track layer 110 may include a synthetic antiferromagnetic (SAF) property and / or a synthetic ferromagnetic (SF) property. The SAF and / or the SF may each be in a region where a magnetic layer (not shown) included in the lower magnetic track layer 110 and a coupling layer (not shown) disposed between the magnetic layers are coupled to each other.

[0035] The read units 130 may be disposed on the tunnel barrier layer 105 on the upper magnetic track layer 120, separated from each other in the first horizontal direction X. In the drawings, four read units (read ports 1, 2, 3, and 4) are shown, but the number of the read units 130 is not limited thereto. Here, the upper magnetic track layer 120, the tunnel barrier layer 105, and the read units 130 may be included in a magnetic tunnel junction (MTJ) structure 200. In other words, the read units 130 may be referred to as MTJ sensors.

[0036] The MTJ structure 200 may include a pinned layer 230, a free layer 220, and a tunnel barrier layer 205 therebetween. The magnetization direction of the pinned layer 230 may be fixed, and the magnetization direction of the free layer 220 may be parallel or antiparallel to the magnetization direction of the pinned layer 230 based on stored data.

[0037] The pinned layer 230 may include a ferromagnetic material. For example, the pinned layer 230 may include an alloy or a multilayer thin film of a magnetic material (e.g., CoFeB, Fe, Co, etc.) and a non-magnetic material (e.g., Pt, Ir, Ru, Ta, W, molybdenum (Mo), hafnium (Hf), etc.). In an embodiment, the pinned layer 230 may correspond to the read unit 130.

[0038] The tunnel barrier layer 205 may include an oxide of a non-magnetic material or a nitride of a non-magnetic material. For example, the tunnel barrier layer 205 may include one or more materials such as, but not limited to, MgO, TiO, AlO, MgAlO, TiN, VN, and / or BN. In an embodiment, the tunnel barrier layer 205 may correspond to the tunnel barrier layer 105.

[0039] The free layer 220 may include a ferromagnetic material, but in an embodiment, the free layer 220 may include Co and Fe and may not include Ni. In an embodiment, the free layer 220 may correspond to the upper magnetic track layer 120 .

[0040] In some embodiments, when the free layer 220 and the pinned layer 230 of the MTJ structure 200 are in a parallel state, that is, when the MTJ structure 200 has a low resistance, this can be defined as a data 0 (zero) state. On the other hand, when the free layer 220 and the pinned layer 230 of the MTJ structure 200 are in an anti-parallel state, that is, when the MTJ structure 200 has a high resistance, this can be defined as a data 1 (one) state. In other embodiments, when the free layer 220 and the pinned layer 230 of the MTJ structure 200 are in an anti-parallel state, this can be defined as a data 0 state, and when the free layer 220 and the pinned layer 230 of the MTJ structure 200 are in a parallel state, this can be defined as a data 1 state.

[0041] The read unit 130 may overlap a corresponding second magnetic domain 120D among a plurality of second magnetic domains 120D of the upper magnetic track layer 120 and a corresponding first magnetic domain 110D among a plurality of first magnetic domains 110D of the lower magnetic track layer 110 in the vertical direction Z. Therefore, in the magnetic memory device 10 according to the embodiment, the read unit 130 may read data based on the magnetization direction of the upper magnetic track layer 120 copied from the lower magnetic track layer 110.

[0042] Miniaturized, multifunctional, and high-performance electronic products may require high-capacity memory devices. A racetrack including a plurality of magnetic domains that stores information according to the movement of domain walls between magnetic domains has been proposed for providing a high-capacity memory device. In addition, a magnetic domain wall shift register type memory device including a racetrack has been developed. It is generally desired to realize a magnetic memory device having stable movement of magnetic domain walls, high integration, and a desired long life.

[0043] Generally speaking, a magnetic memory device can read the recorded magnetization direction through an MTJ structure. However, in a magnetic domain wall shift register type memory device, when a high voltage is applied to both ends of the magnetic track layer for the movement of the domain, the high voltage may be applied to the MTJ structure together, and therefore, the tunnel barrier layer may be damaged.

[0044] In order to solve or alleviate such problems, the magnetic memory device 10 according to an embodiment may have a structure in which a spacer layer 103 including an insulating material is disposed between the lower magnetic track layer 110 and the upper magnetic track layer 120 to electrically disconnect the upper magnetic track layer 120 of the MTJ structure 200 from the lower magnetic track layer 110 driven with a high voltage.

[0045] Based on the leakage magnetic field, the movement of the magnetization direction of the first magnetic domain 110D of the lower magnetic track layer 110 disposed at the relatively lower side may be copied to the second magnetic domain 120D of the upper magnetic track layer 120 disposed at the relatively upper side. The magnetic memory device 10 may operate based on a method of reading copied magnetic information through the MTJ structure 200.

[0046] As a result, in the magnetic memory device 10 according to the embodiment, since it is not necessary to apply a high voltage to the upper magnetic track layer 120, it is possible to solve the problem that a high voltage is applied to the tunnel barrier layer 105 and the tunnel barrier layer 105 is damaged due to fatigue accumulation. That is, in the magnetic memory device 10 according to the embodiment, the MTJ structure 200 can theoretically perform a read operation an unlimited number of times.

[0047] Figure 4 and Figure 5 is a cross-sectional view illustrating elements of a magnetic memory device according to another embodiment.

[0048] The material used to realize one or more of the elements of the magnetic memory devices 20 and 30 described below may be different from Figures 1 to 3 Therefore, for the convenience of description, the following will mainly describe the differences from the magnetic memory device 10 described above.

[0049] Reference Figure 4 According to an embodiment, a magnetic memory device 20 may include a conductive layer 101, a lower magnetic track layer 110 disposed on the conductive layer 101, a spacer layer 103 disposed on the lower magnetic track layer 110, an upper magnetic track layer 120 disposed on the spacer layer 103, a tunnel barrier layer 105 disposed on the upper magnetic track layer 120, and a plurality of read units 130 disposed on the tunnel barrier layer 105.

[0050] In the magnetic memory device 20 according to the embodiment, the lower magnetic track layer 110 may include 2N+1 (where N may be a natural number) number of first magnetic layers 110M and 2N number of first coupling layers 110P disposed between the first magnetic layers 110M. For example, each of the first magnetic layers 110M may include Co and Ni, and each of the first coupling layers 110P may include Ru or Ir. By adjusting the thickness of the first coupling layer 110P, the relationship between the first magnetic layers 110M may be adjusted to be ferromagnetic or antiferromagnetic.

[0051] In the magnetic memory device 20 according to an embodiment, the upper magnetic track layer 120 may include at least one second magnetic layer (not shown) including a material different from that of each of the first magnetic layers 110M included in the lower magnetic track layer 110. For example, the at least one second magnetic layer may include Co and / or Fe.

[0052] In the magnetic memory device 20 according to the embodiment configured as described above, the lower magnetic track layer 110 may be configured with an odd number of first magnetic layers 110M, and thus a stray field as a leakage magnetic field may be formed in the lower magnetic track layer 110. Such a leakage magnetic field may affect the magnetization direction of the upper magnetic track layer 120, and thus the magnetization direction of the lower magnetic track layer 110 may be parallel to the magnetization direction of the upper magnetic track layer 120.

[0053] Reference Figure 5 According to an embodiment, a magnetic memory device 30 may include a conductive layer 101, a lower magnetic track layer 110 disposed on the conductive layer 101, a spacer layer 103 disposed on the lower magnetic track layer 110, an upper magnetic track layer 120 disposed on the spacer layer 103, a tunnel barrier layer 105 disposed on the upper magnetic track layer 120, and a plurality of read units 130 disposed on the tunnel barrier layer 105.

[0054] In the magnetic memory device 30 according to the embodiment, the lower magnetic track layer 110 may include 2N+1 (where N may be a natural number) number of first magnetic layers 110M and 2N number of first coupling layers 110Q disposed between the first magnetic layers 110M. For example, each of the first magnetic layers 110M may include Co and / or Ni, and each of the first coupling layers 110Q may include Ru or Ir. Here, at least one of the first coupling layers 110Q may have a thickness different from that of each of the other first coupling layers 110Q. For example, as shown, the thickness of the first coupling layer 110Q of the upper layer may be less than the thickness of the first coupling layer 110Q of the lower layer. In detail, the thickness of the first coupling layer 110Q of the upper layer may be about 0.4 nm, and the thickness of the first coupling layer 110Q of the lower layer may be about 0.9 nm, but the embodiments of the inventive concept are not limited thereto.

[0055] In the magnetic memory device 30 according to an embodiment, the upper magnetic track layer 120 may include at least one second magnetic layer (not shown) including a material different from that of each of the first magnetic layers 110M included in the lower magnetic track layer 110. For example, the at least one second magnetic layer may include Co and / or Fe.

[0056] In the magnetic memory device 30 according to the embodiment configured as described above, the lower magnetic track layer 110 may be configured with an odd number of first magnetic layers 110M, and thus, a stray field as a leakage magnetic field may be formed in the lower magnetic track layer 110. Such a leakage magnetic field may affect the magnetization direction of the upper magnetic track layer 120, and thus, the magnetization direction of the lower magnetic track layer 110 may be parallel to the magnetization direction of the upper magnetic track layer 120.

[0057] Figure 6 is a flowchart illustrating a method S10 of manufacturing a magnetic memory device according to an embodiment.

[0058] Reference Figure 6 , the method S10 of manufacturing a magnetic memory device may include a process sequence of a first operation S110 to a sixth operation S160 .

[0059] In the case where some embodiments can be implemented differently, a certain process order can be performed, for example, differently from the described order. For example, two processes described in succession can be performed substantially simultaneously, or can be performed in an order opposite to the described order.

[0060] According to an embodiment, a method S10 of manufacturing a magnetic memory device may include: a first operation S110, forming a first fragment including a conductive layer and a lower magnetic track layer disposed on the conductive layer; a second operation S120, forming a second fragment including a spacer layer and an upper magnetic track layer disposed on the spacer layer; a third operation S130, forming a third fragment including a tunnel barrier layer and a plurality of read units disposed on the tunnel barrier layer; a fourth operation S140, attaching the second fragment to the first fragment; a fifth operation S150, attaching the third fragment to the second fragment; and a sixth operation S160, forming a magnetic memory device having first to third fragments attached to each other.

[0061] However, the method S10 of manufacturing the magnetic memory device is not limited thereto. In other embodiments, the magnetic memory device may not be formed using the first to third segments, a stacked structure may be formed, and the magnetic memory device may be manufactured by using a photolithography process and an etching process.

[0062] The following will refer to Figures 7 to 9 Example technical features of each of the first to sixth operations S110 to S160 are described in detail.

[0063] Figures 7 to 9 2 is a cross-sectional view illustrating a method of manufacturing a magnetic memory device in process order according to some embodiments.

[0064] Reference Figure 7 , a first segment F1 including a conductive layer 101 and a lower magnetic track layer 110 disposed on the conductive layer 101 may be formed.

[0065] The conductive layer 101 and the lower magnetic track layer 110 may be sequentially formed on a first base substrate (not shown). In some embodiments, a mask pattern (not shown) may be formed on the lower magnetic track layer 110, and the first segment F1 may be formed by sequentially etching the lower magnetic track layer 110 and the conductive layer 101 using the mask pattern as an etching mask.

[0066] The conductive layer 101 may include Ir, Ru, Ta, Pt, Pd, Bi, Ti, and / or W, but the embodiment is not limited thereto.

[0067] The lower magnetic track layer 110 may include first magnetic domains 110D arranged in the first horizontal direction X and first magnetic domain walls 110W each provided between two adjacent ones of the first magnetic domains 110D. In addition, the lower magnetic track layer 110 may include Co and / or Ni, and may not include Fe.

[0068] Each of the conductive layer 101 and the lower magnetic track layer 110 may be formed by using a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process, or an atomic layer deposition (ALD) process.

[0069] Reference Figure 8 , a second segment F2 including the spacer layer 103 and the upper magnetic track layer 120 disposed on the spacer layer 103 may be formed.

[0070] The spacer layer 103 and the upper magnetic track layer 120 may be sequentially formed on a second base substrate (not shown). In some embodiments, a mask pattern (not shown) may be formed on the upper magnetic track layer 120, and the second segment F2 may be formed by sequentially etching the upper magnetic track layer 120 and the spacer layer 103 using the mask pattern as an etching mask.

[0071] The spacer layer 103 may include an insulating material, and, for example, may include one or more materials such as h-BN, aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, and / or graphene.

[0072] In addition, h-BN may have a two-dimensional (2D) sheet structure including B atoms and N atoms each having a hexagonal lattice structure, and a plurality of 2D sheet structures may be stacked, whereby h-BN may be included in a three-dimensional (3D) structure. Therefore, the second fragment F2 may be formed by the spacer layer 103 including h-BN.

[0073] The upper magnetic track layer 120 may include second magnetic domains 120D and second magnetic domain walls 120W arranged along the first horizontal direction X, each second magnetic domain wall 120W being provided between two adjacent second magnetic domains 120D in the second magnetic domains 120D. In addition, the upper magnetic track layer 120 may include Co and / or Fe, and may not include Ni. That is, the magnetic element included in the lower magnetic track layer 110 may be different from the magnetic element included in the upper magnetic track layer 120.

[0074] Each of the spacer layer 103 and the upper magnetic track layer 120 may be formed by using a CVD process, a PVD process, or an ALD process.

[0075] In some embodiments, the second segment F2 may be attached to the first segment F1. In more detail, the second segment F2 may be formed, and the second segment F2 may be separated from the second base substrate by using an adhesive stamp, and the second segment F2 may be attached to the first segment F1. In other embodiments, the third segment F3 (see Fig. 9 ) after which the attachment of the second fragment F2 is performed.

[0076] Reference Fig. 9 , a third segment F3 including the tunnel barrier layer 105 and a plurality of read units 130 disposed on the tunnel barrier layer 105 may be formed.

[0077] The tunnel barrier layer 105 and the plurality of read units 130 may be sequentially formed on a third base substrate (not shown). In some embodiments, a mask pattern (not shown) may be formed on a material layer where the plurality of read units 130 are to be formed, and a third segment F3 may be formed by sequentially etching the material layer and the tunnel barrier layer 105 using the mask pattern as an etching mask.

[0078] The tunnel barrier layer 105 may include an oxide of a non-magnetic material or a nitride of a non-magnetic material. For example, the tunnel barrier layer 105 may include one or more materials such as MgO, TiO, AlO, MgAlO, TiN, VN, and / or BN.

[0079] The plurality of reading units 130 may include ferromagnetic materials. For example, the plurality of reading units 130 may include an alloy or a multilayer film of a magnetic material (e.g., CoFeB, Fe, Co, etc.) and a non-magnetic material (e.g., Pt, Ir, Ru, Ta, W, Mo, Hf, etc.).

[0080] The tunnel barrier layer 105 and each of the plurality of read units 130 may be formed by using a CVD process, a PVD process, or an ALD process.

[0081] In some embodiments, the third fragment F3 may be attached to the second fragment F2. In more detail, the third fragment F3 may be formed, and the third fragment F3 may be separated from the third base substrate by using an adhesive stamp, and the third fragment F3 may be attached to the second fragment F2.

[0082] Based on the manufacturing method described above, the magnetic memory device 10 according to the embodiment can be manufactured (see Figure 1). However, the method S10 of manufacturing the magnetic memory device is not limited thereto. In other embodiments, for example, the magnetic memory device may not be formed of the first to third segments, may form a stacked structure, and may be manufactured by using a photolithography process and an etching process.

[0083] FIG. 10A to FIG. 10C is a diagram illustrating magnetic replication characteristics of a magnetic memory device according to some embodiments.

[0084] Reference FIG. 10A to FIG. 10C , a state in which the magnetization direction of the lower magnetic track layer BL can be copied to the magnetization direction of the upper magnetic track layer TL will be described below.

[0085] A SOT layer that allows SOT to be generated when a current flows in may be disposed under the lower magnetic track layer BL. In addition, a drag layer may be disposed on the upper magnetic track layer TL.

[0086] The lower magnetic track layer BL and the upper magnetic track layer TL may be arranged to have a first gap DD therebetween. In this case, based on the size of the first gap DD, experiments have been performed on the extent to which the magnetic domain wall (DW) motion caused by SOT in the lower magnetic track layer BL affects the magnetic domain wall motion caused by the stray field in the upper magnetic track layer TL.

[0087] Here, by adjusting the above-mentioned spacer layer 103 (see Figure 1 ) is used to set the first interval DD. However, the embodiment is not limited thereto.

[0088] When the first interval DD is about 1 nm to about 5 nm, it can be seen that the movement of the magnetic domain wall of the lower magnetic track layer BL is substantially the same as the movement of the magnetic domain wall of the upper magnetic track layer TL.

[0089] In addition, when the first interval DD is configured to be about 8 nm to about 10 nm, it can be seen that a difference between the movement of the magnetic domain wall of the lower magnetic track layer BL and the movement of the magnetic domain wall of the upper magnetic track layer TL occurs.

[0090] Furthermore, when the first interval DD is configured to be about 18 nm to about 20 nm, it can be seen that a large difference between the motion of the magnetic domain wall of the lower magnetic track layer BL and the motion of the magnetic domain wall of the upper magnetic track layer TL occurs.

[0091] Furthermore, when the first interval DD is configured to be about 28 nm to about 30 nm, it can be seen that a greater difference between the motion of the magnetic domain wall of the lower magnetic track layer BL and the motion of the magnetic domain wall of the upper magnetic track layer TL occurs.

[0092] That is, when the first interval DD is about 1 nm to about 5 nm, the magnetization direction of the lower magnetic track layer BL can be copied to be substantially equal to the magnetization direction of the upper magnetic track layer TL. On the other hand, when the first interval DD is greater than about 5 nm, it has been experimentally confirmed that a difference in magnetization direction between the lower magnetic track layer BL and the upper magnetic track layer TL occurs. In addition, it may be difficult to form the first interval DD to a thickness less than about 1 nm, and it may be difficult to achieve magnetic characteristics with respect to a fine thickness.

[0093] Therefore, refer again to Figure 1 , since the thickness of the spacer layer 103 is about 1 nm to about 5 nm, the movement of the magnetization direction of the first magnetic domain 110D of the lower magnetic track layer 110 disposed at the relatively lower side may be replicated to be substantially equal to the movement of the magnetization direction of the second magnetic domain 120D of the upper magnetic track layer 120 disposed at the relatively upper side based on the leakage magnetic field. The magnetic memory device 10 may operate based on a method of reading the replicated magnetic information through the MTJ structure 200.

[0094] In the above, example embodiments have been described in the drawings and the specification. The embodiments have been described by using the terms described herein, but this is only used to describe the inventive concept and is not used to limit the meaning or the scope of the inventive concept defined in the appended claims. Therefore, it can be understood by those of ordinary skill in the art that various modifications and other equivalent embodiments can be implemented from the inventive concept. Therefore, the spirit and scope of the inventive concept can be defined based on the spirit and scope of the appended claims.

[0095] While the inventive concept has been particularly shown and described with reference to embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the appended claims.

Claims

1. A magnetic storage device, comprising: a lower magnetic track layer extending in a first direction and including a plurality of first magnetic domains; a spacer layer on the lower magnetic track layer and extending in the first direction; an upper magnetic track layer on the spacer layer and extending in the first direction, the upper magnetic track layer comprising a plurality of second magnetic domains; as well as a plurality of reading units arranged on the upper magnetic track layer and spaced apart from each other in the first direction, The plurality of first magnetic domains and the plurality of second magnetic domains have magnetization directions parallel to each other at positions where they overlap each other along a second direction perpendicular to the first direction.

2. The magnetic memory device according to claim 1, wherein: Based on a leakage magnetic field of the lower magnetic track layer, a magnetization direction of the upper magnetic track layer is equal to a magnetization direction of the lower magnetic track layer such that the magnetization directions of the upper magnetic track layer and the lower magnetic track layer are formed parallel to each other.

3. The magnetic memory device according to claim 2, wherein: Each of the plurality of read units is a pinned layer of a magnetic tunnel junction structure, Wherein, the upper magnetic track layer is the free layer of the magnetic tunnel junction structure, and Wherein, each of the plurality of reading units is configured to read the magnetization direction of the upper magnetic track layer.

4. The magnetic memory device according to claim 2, wherein: The lower magnetic track layer comprises: 2N+1 (where N is a natural number) number of first magnetic layers; and 2N coupling layers are between the 2N+1 first magnetic layers.

5. The magnetic memory device according to claim 4, wherein: Each of the 2N+1 number of first magnetic layers includes cobalt (Co) and nickel (Ni), and Wherein, each of the 2N coupling layers includes ruthenium (Ru) or iridium (Ir).

6. The magnetic memory device according to claim 5, wherein: At least one coupling layer among the 2N number of coupling layers has a thickness different from a thickness of each of the other coupling layers among the 2N number of coupling layers.

7. The magnetic memory device according to claim 4, wherein: The upper magnetic track layer includes at least one second magnetic layer including a material different from a material of each of the 2N+1 number of first magnetic layers.

8. The magnetic memory device according to claim 7, wherein: The at least one second magnetic layer includes cobalt (Co) and iron (Fe).

9. The magnetic memory device according to claim 1, wherein: The spacer layer includes hexagonal boron nitride (h-BN), and The thickness of the spacer layer is about 1 nm to about 5 nm.

10. The magnetic memory device according to claim 1, further comprising a conductive layer below the lower magnetic track layer and extending in the first direction, in, A length of the conductive layer, a length of the lower magnetic track layer, a length of the spacer layer, and a length of the upper magnetic track layer are equal to one another in the first direction.

11. A magnetic storage device comprising: Spin Hall conductive layer; An operating magnetic track layer and a replica magnetic track layer are stacked on the spin Hall conductive layer along a first direction; a spacer layer between the operating magnetic track layer and the replica magnetic track layer; a tunnel barrier layer on the replica magnetic track layer; as well as A plurality of magnetic tunnel junction sensors are provided on the tunnel barrier layer. Wherein, based on a leakage magnetic field of the operating magnetic track layer, the operating magnetic track layer and the replica magnetic track layer have magnetization directions parallel to each other at positions where they overlap each other along the first direction.

12. The magnetic memory device according to claim 11, wherein: The operating magnetic track layer includes an odd number of first magnetic layers configured to generate the leakage magnetic field.

13. The magnetic memory device according to claim 12, wherein: The replica magnetic track layer includes at least one second magnetic layer including a material different from a material of each of the first magnetic layers.

14. The magnetic memory device according to claim 11, wherein: The operating magnetic track layer includes a plurality of first magnetic domains and a plurality of first magnetic domain walls alternately arranged along a second direction perpendicular to the first direction, The replica magnetic track layer includes a plurality of second magnetic domains and a plurality of second magnetic domain walls alternately arranged along the second direction, and The plurality of first magnetic domains and the plurality of second magnetic domains have magnetization directions parallel to each other at positions where they overlap each other along the first direction.

15. The magnetic memory device according to claim 11, wherein The spin Hall conductive layer includes a spin-orbit moment (SOT) sensing layer.

16. A magnetic storage device comprising: a lower magnetic track layer including a plurality of first magnetic domains and a plurality of first magnetic domain walls extending in a first direction and arranged alternately; a spacer layer on the lower magnetic track layer and extending in the first direction, the spacer layer having a thickness of about 1 nm to about 5 nm; an upper magnetic track layer, comprising a plurality of second magnetic domains and a plurality of second magnetic domain walls extending in the first direction and arranged alternately, the upper magnetic track layer being on the spacer layer; as well as a plurality of reading units on the upper magnetic track layer, the plurality of reading units being configured to read the magnetization direction of the upper magnetic track layer and being arranged apart from each other in the first direction, wherein the plurality of first magnetic domain walls and the plurality of second magnetic domain walls overlap each other in a second direction perpendicular to the first direction, and The plurality of first magnetic domains and the plurality of second magnetic domains have magnetization directions parallel to each other at positions where they overlap each other along the second direction.

17. The magnetic memory device according to claim 16, wherein: The lower magnetic track layer and the upper magnetic track layer have magnetization directions parallel to each other at positions overlapping each other in the second direction based on a leakage magnetic field of the lower magnetic track layer.

18. The magnetic memory device according to claim 17, wherein: The lower magnetic track layer includes a plurality of first magnetic layers configured to generate the leakage magnetic field and a plurality of coupling layers between the plurality of first magnetic layers.

19. The magnetic memory device according to claim 18, wherein: The upper magnetic track layer includes at least one second magnetic layer including a material different from a material of each of the plurality of first magnetic layers.

20. The magnetic memory device according to claim 19, wherein Each of the plurality of first magnetic layers includes cobalt (Co) and nickel (Ni), and Wherein, the at least one second magnetic layer includes cobalt (Co) and iron (Fe).

Images