Magnetic memory and method for manufacturing the same

Abstract

The present application provides a magnetic memory and a preparation method thereof, which relates to the field of semiconductor technology and is used to solve the technical problem of poor flexibility in data writing. The magnetic memory at least includes a first antiferromagnetic layer, a magnetic tunnel junction arranged on the first antiferromagnetic layer, and a second antiferromagnetic layer arranged on the magnetic tunnel junction; the magnetic tunnel junction includes a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence from bottom to top; wherein, by applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer is flipped. The present application is used to improve the flexibility of data writing.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a magnetic memory and a method for preparing the same. Background Art

[0002] According to different data writing mechanisms, the development of MRAM has undergone three generations of changes. Among them, the third-generation magnetic memory, Spin-orbit Torque Magnetic Random Access Memory (SOT-MRAM), has the advantages of non-volatility, high-speed and low-power data writing, and high device durability. It is one of the key technologies that is expected to break through the power consumption bottleneck of integrated circuits in the post-Moore era.

[0003] In the related art, SOT-MRAM includes a substrate, a heavy metal layer arranged on the substrate, and a magnetic tunnel junction arranged on the heavy metal layer. The magnetic tunnel junction (MTJ) is the basic storage unit of SOT-MRAM. The magnetic tunnel junction includes a free layer, a barrier layer, and a reference layer stacked in sequence, wherein the magnetization direction of the reference layer remains unchanged, and the magnetization direction of the free layer can be changed by external excitation. When current flows through the heavy metal layer, a spin current can be generated, and the spin current can flip the magnetization direction of the free layer, thereby realizing data writing.

[0004] However, in the related art, since the spin current can only flip the magnetization direction of the free layer on one side of the barrier layer, but cannot flip the magnetization direction of the reference layer on the other side of the barrier layer, there is a technical problem of poor data writing flexibility. Summary of the invention

[0005] In view of the above problems, an embodiment of the present application provides a magnetic memory and a method for preparing the same, which can improve the flexibility of data writing.

[0006] In order to achieve the above objectives, the present application provides the following technical solutions:

[0007] A first aspect of an embodiment of the present application provides a magnetic memory, comprising at least: a first antiferromagnetic layer, a magnetic tunnel junction arranged on the first antiferromagnetic layer, and a second antiferromagnetic layer arranged on the magnetic tunnel junction; the magnetic tunnel junction comprises a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence from bottom to top; wherein, by applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer is reversed.

[0008] According to a second aspect of an embodiment of the present application, there is provided a magnetic memory, comprising at least: a first antiferromagnetic layer, at least two magnetic tunnel junctions with different required write currents arranged on the first antiferromagnetic layer, and a second antiferromagnetic layer arranged on at least two of the magnetic tunnel junctions; the magnetic tunnel junction comprises a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence from bottom to top; by applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer of at least two of the magnetic tunnel junctions is flipped jointly or individually, so as to change the resistance state of at least two magnetic tunnel junctions jointly or individually, so as to obtain multiple resistance states.

[0009] A third aspect of an embodiment of the present application provides a method for preparing a magnetic memory, which at least includes: forming a first antiferromagnetic layer; forming a magnetic tunnel junction on the first antiferromagnetic layer, the magnetic tunnel junction including a first magnetic layer, a barrier layer and a second magnetic layer stacked in sequence from bottom to top; forming a second antiferromagnetic layer on the magnetic tunnel junction; wherein, when there is one magnetic tunnel junction, a write current is applied to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer so that the magnetization direction of at least one of the first magnetic layer and the second magnetic layer is reversed; or, when there are at least two magnetic tunnel junctions, a write current is applied to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer so that the magnetization direction of at least one of the first magnetic layer and the second magnetic layer of at least two magnetic tunnel junctions is reversed jointly or individually, so as to change the resistance state of at least two magnetic tunnel junctions jointly or individually to obtain multiple resistance states.

[0010] The magnetic memory provided by the embodiment of the present application comprises at least a first antiferromagnetic layer, a magnetic tunnel junction arranged on the first antiferromagnetic layer, and a second antiferromagnetic layer arranged on the first magnetic tunnel junction; the magnetic tunnel junction comprises a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence from bottom to top; wherein the first antiferromagnetic layer and the second antiferromagnetic layer can both act as heavy metal layers (SOT layers), so that when a current is passed through the first antiferromagnetic layer, at least the magnetization direction of the first magnetic layer can be flipped and the corresponding exchange bias coupling field direction can be switched; when a current is passed through the second antiferromagnetic layer, at least the magnetization direction of the second magnetic layer can be flipped and the corresponding exchange bias coupling field direction can be switched, therefore, the first magnetic layer and the second magnetic layer on opposite sides of the barrier layer can be flipped, thereby realizing flexible data writing and improving the flexibility of data writing; in addition, since there are corresponding exchange bias coupling fields between the first antiferromagnetic layer and the first magnetic layer, and between the second antiferromagnetic layer and the second magnetic layer, the first magnetic layer and the second magnetic layer can both resist interference from the external magnetic field, thereby improving the stability of the data.

[0011] In the preparation method of the magnetic memory provided in the embodiment of the present application, one or at least two magnetic tunnel junctions are formed on the first antiferromagnetic layer, and a second antiferromagnetic layer is formed on the magnetic tunnel junction, the magnetic tunnel junction includes a first magnetic layer, a barrier layer and a second magnetic layer stacked in sequence from bottom to top. When a magnetic tunnel junction is formed on the first antiferromagnetic layer, a write current is applied to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, so that the magnetization direction of at least one of the first magnetic layer and the second magnetic layer is reversed to achieve flexible data writing; when at least two magnetic tunnel junctions are formed on the first antiferromagnetic layer, a write current is applied to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, so that the magnetization direction of at least one of the first magnetic layer and the second magnetic layer of at least two magnetic tunnel junctions is reversed jointly or individually, so as to change the resistance state of at least two magnetic tunnel junctions jointly or individually, so as to obtain multiple resistance states, thereby improving the degree of freedom of data writing.

[0012] In addition to the technical problems solved by the embodiments of the present application, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the magnetic storage device and the preparation method thereof provided by the embodiments of the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 A schematic diagram of the structure of a magnetic storage device provided in an embodiment of the present application;

[0015] Figure 2 A schematic diagram of a state in which a write current is passed through the first antiferromagnetic layer in a magnetic memory provided by an embodiment of the present application;

[0016] Figure 3 A schematic diagram of a state in which a write current is passed through the second antiferromagnetic layer of a magnetic memory provided in an embodiment of the present application;

[0017] Figure 4 A schematic diagram of a state in which a write current is applied to both the first antiferromagnetic layer and the second antiferromagnetic layer of a magnetic memory provided by an embodiment of the present application;

[0018] Figure 5 Figure (a) is another schematic diagram of the structure of the magnetic storage device provided in the embodiment of the present application;

[0019] Figure 5 Figure (b) is another structural schematic diagram of a magnetic storage device provided in an embodiment of the present application;

[0020] Figure 6 A schematic diagram of a structure of a magnetic memory having at least two parallel magnetic tunnel junctions provided in an embodiment of the present application;

[0021] Figure 7 for Figure 6 Schematic diagram of top view;

[0022] Figure 8 for Figure 6 A resistive logic diagram;

[0023] Fig. 9 for Figure 6 Another resistive logic diagram of ;

[0024] Fig.10 A schematic diagram of another structure of a magnetic storage device provided in an embodiment of the present application;

[0025] Fig.11 for Fig.10 A resistive logic diagram;

[0026] Fig.12 A schematic diagram of another structure of a magnetic storage device provided in an embodiment of the present application;

[0027] Fig.13 A schematic diagram of another structure of a magnetic storage device provided in an embodiment of the present application;

[0028] Fig.14 for Fig.12 A resistive logic diagram;

[0029] Fig.15 for Fig.12 Another resistive logic diagram of ;

[0030] Fig.16 for Fig.13 A resistive logic diagram;

[0031] Fig.17 for Fig.13 Another resistive logic diagram of .

[0032] Reference numerals:

[0033] 100- magnetic storage;

[0034] 110- a first antiferromagnetic layer;

[0035] 120-magnetic tunnel junction; 120a-first magnetic tunnel junction; 120b-second magnetic tunnel junction;

[0036] 121-first magnetic layer; 121a-first composite antiferromagnetic layer;

[0037] 122-barrier layer;

[0038] 123 - a second magnetic layer; 123a - a second composite antiferromagnetic layer;

[0039] 130 - second antiferromagnetic layer. DETAILED DESCRIPTION

[0040] In the related art, SOT-MRAM includes a substrate, a heavy metal layer (SOT layer) disposed on the substrate, and a magnetic tunnel junction disposed on the heavy metal layer. The magnetic tunnel junction includes a free layer, a barrier layer, and a reference layer stacked in sequence, wherein the magnetization direction of the reference layer remains unchanged, and the magnetization direction of the free layer can be changed by external excitation. When the magnetization direction of the free layer is parallel or antiparallel to the magnetization direction of the reference layer, the magnetic tunnel junction is in a low resistance state or a high resistance state, respectively. The two resistance states can be represented by binary data "0" and "1", respectively. When current flows through the heavy metal layer, a spin current can be generated, and the spin current can flip the magnetization direction of the free layer, thereby realizing data writing. However, since the spin current can only flip the magnetization direction of the free layer on one side of the barrier layer, and cannot flip the magnetization direction of the reference layer on the other side of the barrier layer, there is a technical problem of poor flexibility in data writing.

[0041] In order to solve the above problems, the present application provides a magnetic memory and a preparation method thereof, wherein the magnetic memory comprises at least a first antiferromagnetic layer, a magnetic tunnel junction arranged on the first antiferromagnetic layer, and a second antiferromagnetic layer arranged on the first magnetic tunnel junction; along the direction from the first antiferromagnetic layer to the second antiferromagnetic layer, the magnetic tunnel junction comprises a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence; wherein the first antiferromagnetic layer and the second antiferromagnetic layer can both act as a heavy metal layer (SOT layer), so that when a current is passed through the first antiferromagnetic layer, at least the magnetization direction of the first magnetic layer can be flipped and the corresponding cross-link can be switched. When current is passed through the second antiferromagnetic layer, at least the magnetization direction of the second magnetic layer and the corresponding exchange bias coupling field direction can be flipped. Therefore, the first magnetic layer and the second magnetic layer on opposite sides of the barrier layer can be flipped, thereby realizing flexible data writing and improving the flexibility of data writing. In addition, since there are corresponding exchange bias coupling fields between the first antiferromagnetic layer and the first magnetic layer, and between the second antiferromagnetic layer and the second magnetic layer, the first magnetic layer and the second magnetic layer can resist interference from an external magnetic field, thereby improving the stability of the data.

[0042] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0043] An embodiment of the present application provides a magnetic memory, which may include a plurality of memory cells, which may be arranged along rows and columns, or in other words, the plurality of memory cells may be arranged in a matrix form. Among them, the memory cells in the same row (or the same column) may be coupled to the same word line (word line, WL for short), and the memory cells in the same column (or the same row) may be coupled to the same group of bit lines (bit line, BL for short) and source lines (source line, SL for short). In other words, the memory cell may be a three-terminal device, and the memory cell may include a first end coupled to the word line, a second end coupled to the bit line, and a third end coupled to the source line.

[0044] In an embodiment of the present application, the memory cell includes a substrate, which can serve as a basic support structure of the memory cell, and can provide support for the structural layers stacked thereon. Exemplarily, the substrate can be a silicon substrate, a germanium substrate, a silicon carbide substrate, a silicon germanium substrate, a germanium on insulator (GOI) substrate, or a silicon on insulator (SOI) substrate, etc.

[0045] In some embodiments, please refer to Figure 1 As shown, the storage unit includes but is not limited to a first antiferromagnetic layer 110, a magnetic tunnel junction 120 disposed on the first antiferromagnetic layer 110, and a second antiferromagnetic layer 130 disposed on the magnetic tunnel junction 120. Figure 1 ), the magnetic tunnel junction 120 includes a first magnetic layer 121, a barrier layer 122 and a second magnetic layer 123 stacked in sequence.

[0046] The materials of the first magnetic layer 121 and the second magnetic layer 123 include but are not limited to at least one of cobalt (Co), iron (Fe), boron (B), nickel (Ni), ruthenium (Ru), iridium (Ir), and platinum (Pt); the material forming the barrier layer 122 may be an insulating material. For example, the material of the barrier layer 122 includes at least one of magnesium oxide (MgO), aluminum oxide (Al2O3), and silicon oxide (SiO2).

[0047] In addition, the materials of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 include but are not limited to one or more combinations of IrMn, PtMn, FeMn, PdMn, Mn3Sn, Mn3Pt, Mn3Ir, Mn3Ge, etc.

[0048] It should be noted that the “first antiferromagnetic layer”, “second antiferromagnetic layer”, “first magnetic layer” and “second magnetic layer” are merely exemplary expressions. The number of antiferromagnetic layers and magnetic layers in the storage unit includes but is not limited to two. In actual use, the number of antiferromagnetic layers and the number of magnetic layers can be adjusted and set according to actual needs, which will not be repeated here.

[0049] In the embodiment of the present application, the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 can both act as heavy metal layers (SOT layers), which can generate spin currents when current flows through them to generate torque. In this way, when current is passed through the first antiferromagnetic layer 110, the generated spin current can at least flip the magnetization direction of the first magnetic layer 121; when current is passed through the second antiferromagnetic layer 130, the generated spin current can at least flip the magnetization direction of the second magnetic layer 123. Therefore, either the first magnetic layer 121 and the second magnetic layer 123 on the opposite sides of the barrier layer 122 can be flipped or both can be flipped, thereby realizing flexible data writing and improving the flexibility of data writing.

[0050] That is to say, both the first magnetic layer 121 and the second magnetic layer 123 can act as free layers, and both the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 can act as heavy metal layers (SOT layers). In this way, when current is passed through the first antiferromagnetic layer 110, at least the magnetization direction of the first magnetic layer 121 can be reversed; when current is passed through the second antiferromagnetic layer 130, at least the magnetization direction of the second magnetic layer 123 can be reversed; when current is passed through the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 are reversed. Compared with the structure in which the side of the magnetic tunnel junction 120 that is the barrier layer 122 is the free layer, a heavy metal layer is arranged on the side of the free layer facing away from the barrier layer 122, and the other side of the barrier layer 122 facing away from the free layer is the reference layer, and compared with the structure in which no heavy metal layer is arranged on the side of the reference layer facing away from the barrier layer 122, the flexibility of data writing is improved.

[0051] In addition, due to the properties of the antiferromagnetic material, a corresponding exchange bias coupling field is generated between the first antiferromagnetic layer 110 and the first magnetic layer 121, and the exchange bias coupling field can pin the magnetization direction of the corresponding first magnetic layer 121; a corresponding exchange bias coupling field is also generated between the second antiferromagnetic layer 130 and the second magnetic layer 123, and the exchange bias coupling field can also pin the magnetization direction of the corresponding second magnetic layer 123; and when a current is passed through the first antiferromagnetic layer 110, in addition to flipping the magnetization direction of the first magnetic layer 121, it can also switch The direction of the corresponding exchange bias coupling field; when current is passed through the second antiferromagnetic layer 130, in addition to flipping the magnetization direction of the second magnetic layer 123, the direction of the corresponding exchange bias coupling field can also be switched. Since there are corresponding exchange bias coupling fields between the first antiferromagnetic layer 110 and the first magnetic layer 121, and between the second antiferromagnetic layer 130 and the second magnetic layer 123, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 can be pinned respectively, thereby resisting interference from external magnetic fields and improving data stability.

[0052] It should be noted that the exchange bias coupling field refers to the phenomenon that a unidirectional anisotropy is generated in the ferromagnetic material when a material containing a ferromagnetic or antiferromagnetic interface is cooled through the Neel temperature of the antiferromagnetic material in a magnetic field.

[0053] In some embodiments, please refer to Figure 2 As shown, the first antiferromagnetic layer 110 acts as a heavy metal layer. When a first write current is applied to the first antiferromagnetic layer 110, the spin current generated by the first antiferromagnetic layer 110 can cause the magnetization direction of the first magnetic layer 121 adjacent to the first antiferromagnetic layer 110 to flip, thereby realizing data writing.

[0054] Alternatively, please refer to Figure 3 As shown, the second antiferromagnetic layer 130 acts as a heavy metal layer. When a first write current is applied to the second antiferromagnetic layer 130, the spin current generated by the second antiferromagnetic layer 130 can cause the magnetization direction of the second magnetic layer 123 adjacent to the second antiferromagnetic layer 130 to flip, thereby realizing data writing.

[0055] Alternatively, please refer to Figure 4As shown, the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 are both used as heavy metal layers. When the first write current is applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 respectively, the spin current generated by the first antiferromagnetic layer 110 can cause the magnetization direction of the first magnetic layer 121 corresponding to the first antiferromagnetic layer 110 to be reversed. At the same time, the spin current generated by the second antiferromagnetic layer 130 can cause the magnetization direction of the second magnetic layer 123 corresponding to the second antiferromagnetic layer 130 to be synchronously reversed to achieve data writing.

[0056] It can be seen that in the embodiment of the present application, by applying the same write current to at least one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the magnetization direction of at least one of the first magnetic layer 121 and the second magnetic layer 123 can be flipped to achieve flexible data writing.

[0057] In some embodiments, the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130 is used as a heavy metal layer, and a second write current is applied to one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130. For example, the second write current is applied to the first antiferromagnetic layer 110, and the second write current is not applied to the second antiferromagnetic layer 130; or, the second write current is applied to the second antiferromagnetic layer 130, and the second write current is not applied to the first antiferromagnetic layer 110; wherein the second write current is greater than the first write current, that is, the second write current is large enough so that the generated spin current can cause the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 to be flipped at the same time, so that the other of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 can be made to flip the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 at the same time without passing the write current, thereby improving the flexibility of data writing.

[0058] In addition, by applying a second write current to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130, the generated spin current can not only simultaneously flip the magnetization direction of the first magnetic layer 121 and the second magnetic layer 123, but also flip the direction of the exchange bias coupling field between the first antiferromagnetic layer 110 and the first magnetic layer 121, and can simultaneously flip the direction of the exchange bias coupling field between the first antiferromagnetic layer 110 and the first magnetic layer 121, so as to improve the flexibility of data writing while improving the stability of data.

[0059] In some embodiments, the exchange bias coupling field between the first antiferromagnetic layer 110 and the first magnetic layer 121 is greater than the coercive field of the first magnetic layer 121. In this way, the ability of the first magnetic layer 121 to resist the interference of the external magnetic field can be improved, thereby improving the stability of the magnetization direction of the first magnetic layer 121 and further improving the stability of the data.

[0060] In addition, the exchange bias coupling field between the second antiferromagnetic layer 130 and the second magnetic layer 123 is greater than the coercive field of the second magnetic layer 123. In this way, the ability of the second magnetic layer 123 to resist the interference of the external magnetic field can be improved, thereby improving the stability of the magnetization direction of the second magnetic layer 123 and further improving the stability of the data.

[0061] In other embodiments, the exchange bias coupling field between the first antiferromagnetic layer 110 and the first magnetic layer 121 is greater than the coercive field of the first magnetic layer 121, and at the same time, the exchange bias coupling field between the second antiferromagnetic layer 130 and the second magnetic layer 123 is greater than the coercive field of the second magnetic layer 123. In this way, the ability of the first magnetic layer 121 to resist the interference of the external magnetic field can be improved, thereby improving the stability of the magnetization direction of the first magnetic layer 121. At the same time, the ability of the second magnetic layer 123 to resist the interference of the external magnetic field can also be improved, so as to improve the stability of the magnetization direction of the second magnetic layer 123 and thereby improve the stability of the data.

[0062] It should be noted that the coercive field, also known as coercive force or magnetic retention force, is one of the characteristics of magnetic materials. It refers to the magnetic field strength required to reduce the magnetization intensity of the magnetic material to zero after it has been magnetized to magnetic saturation. The coercive force represents the ability of the magnetic material to resist demagnetization and can be expressed by Hc, with units of A / m (International Standard System) or Oe (Gaussian System). The coercive force can be measured with a magnetometer or a BH analyzer.

[0063] It can be seen from the above embodiments that Figure 1 As shown in the figure, in the magnetic memory 100 provided in the embodiment of the present application, from bottom to top along the Z direction, the structure of the magnetic tunnel junction 120 is a first antiferromagnetic layer 110, a first magnetic layer 121, a barrier layer 122, a second magnetic layer 123 and a second antiferromagnetic layer 130 stacked in sequence, which makes the film layer structure simple while achieving flexible data writing and high data stability.

[0064] Of course, the magnetic tunnel junction 120 in the embodiment of the present application can also be compatible with other film layers, such as Figure 5 As shown in Figure (a), the first magnetic layer 121 is configured as a first composite antiferromagnetic layer 121a, and the exchange bias coupling field between the first antiferromagnetic layer 110 and the first composite antiferromagnetic layer 121a is greater than the coercive field of the first composite antiferromagnetic layer 121a. In this way, the first magnetic layer 121 can improve its ability to resist interference from an external magnetic field, thereby improving the stability of the magnetization direction of the first magnetic layer 121 and further improving the stability of the data.

[0065] Please continue to refer to Figure 5As shown in Figure (b), the second magnetic layer 123 is provided with a second composite antiferromagnetic layer 123a, and the exchange bias coupling field between the second antiferromagnetic layer 130 and the second composite antiferromagnetic layer 123a is greater than the coercive field of the second composite antiferromagnetic layer 123a. In this way, the resistance of the second magnetic layer 123 to the interference of the external magnetic field can be improved, thereby improving the stability of the magnetization direction of the second magnetic layer 123, and further improving the stability of the data.

[0066] At least one of the first magnetic layer 121 and the second magnetic layer 123 is configured as a composite antiferromagnetic layer. Figure 5 In the figure (a), the first magnetic layer 121 is set as the first composite antiferromagnetic layer 121a, and the second magnetic layer 123 is set as the second composite antiferromagnetic layer 123a, so that the antimagnetic properties of the first magnetic layer 121 and the second magnetic layer 123 can be improved; and Figure 5 In FIG. 1( b ), only the second magnetic layer 123 is configured as the second composite antiferromagnetic layer 123 a , which can reduce the film thickness of the magnetic tunnel junction 120 and the thin film process while satisfying the antimagnetic performance of the magnetic tunnel junction 120 .

[0067] It should be noted that the “first composite antiferromagnetic layer” and the “second composite antiferromagnetic layer” are merely exemplary expressions. The number of composite antiferromagnetic layers in the storage unit includes but is not limited to two. In actual use, the number of composite antiferromagnetic layers can be adjusted according to actual needs and will not be elaborated here.

[0068] The embodiment of the present application also provides a magnetic memory 100, which includes a plurality of storage units, each storage unit including a first antiferromagnetic layer 110, a magnetic tunnel junction 120 arranged on the first antiferromagnetic layer 110, and a second antiferromagnetic layer 130 arranged on the magnetic tunnel junction 120, wherein the structure and principle of the magnetic tunnel junction 120 are the same as the magnetic tunnel junction 120 provided in the above embodiment, and the structure and principle of the magnetic tunnel junction 120 will not be repeated here.

[0069] Among them, if the initial magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 are the same: when no write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 are not reversed, and the magnetization directions of the two are the same, and the corresponding resistance state is represented by binary data "0" (i.e., low resistance state); when the first write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130 alone, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 are opposite, and the corresponding resistance state is represented by binary data "1". When the first write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130 at the same time, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 are both reversed, and the two magnetization directions are the same, and the corresponding resistance state is represented by the binary data "0" (i.e., low resistance state); when the second write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130 alone, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 are both reversed, and the two magnetization directions are the same, and the corresponding resistance state is represented by the binary data "0" (i.e., low resistance state). Therefore, based on the examples of not applying a write current to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, applying a write current to one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, and applying a write current to both the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 with the applied currents in opposite directions, the magnetic tunnel junction 120 can realize logical operations such as 00, 01, 10, 11, so that the magnetic tunnel junction 120 is in a high resistance state or a low resistance state.

[0070] To increase storage density, refer to Figure 6 As shown, in the embodiment of the present application, the storage unit at least includes a first antiferromagnetic layer 110, at least two magnetic tunnel junctions 120 with different required write currents arranged on the first antiferromagnetic layer 110, and a second antiferromagnetic layer 130 arranged on the at least two magnetic tunnel junctions 120; Figure 6 As shown in the figure, the magnetic tunnel junction 120 includes a first magnetic layer 121, a barrier layer 122 and a second magnetic layer 123 which are stacked in sequence from bottom to top; by applying a write current to at least one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the magnetization direction of at least one of the first magnetic layer 121 and the second magnetic layer 123 of at least two magnetic tunnel junctions 120 is flipped together or individually, so as to change the resistance state of at least two magnetic tunnel junctions 120 together or individually to obtain multiple resistance states, and switching between multiple resistance states can be performed without switching the current back and forth, thereby improving the freedom of data writing.

[0071] In some embodiments, the cross-sectional dimension of one of the two magnetic tunnel junctions 120 along the horizontal direction (eg, along the vertical Z direction) is not equal to the cross-sectional dimension of one of the two magnetic tunnel junctions 120 along the horizontal direction, so that the write currents required by the two magnetic tunnel junctions 120 are different.

[0072] Exemplarily, the cross-sectional shapes of the two magnetic tunnel junctions 120 include but are not limited to a circle, an ellipse, a quadrilateral, etc., wherein the projected areas of the cross-sectional shapes of the two magnetic tunnel junctions 120 are different; for example, Figure 7 In the figure, the cross-sectional shape of the two magnetic tunnel junctions 120 is circular. For the convenience of description, the two magnetic tunnel junctions 120 are represented by the first magnetic tunnel junction 120a and the second magnetic tunnel junction 120b respectively. If the cross-sectional diameter of the first magnetic tunnel junction 120a is smaller than the cross-sectional diameter of the second magnetic tunnel junction 120b, the cross-sectional size of the first magnetic tunnel junction 120a is smaller than the cross-sectional size of the second magnetic tunnel junction 120b, so that the write current required by the first magnetic tunnel junction 120a is smaller than the write current required by the second magnetic tunnel junction 120b.

[0073] It should be noted that the “first magnetic tunnel junction 120a” and the “second magnetic tunnel junction 120b” are merely exemplary expressions. The number of magnetic tunnel junctions 120 in the storage unit includes but is not limited to two. In actual use, the number of magnetic tunnel junctions 120 in the storage unit can be adjusted according to actual needs and will not be repeated here.

[0074] As an example, if a write current is only passed through one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, without changing the direction of the current, the magnetization direction of one of the first magnetic layer 121 and the second magnetic layer 123 in the two magnetic tunnel junctions 120 can be flipped, while the other cannot be flipped, so that only the following can be achieved: Figure 8 Switching between the three resistance states shown in .

[0075] Another exemplary example is Figure 6 and Fig. 9 As shown in FIG. 1 , when the required write currents are applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 respectively, the magnetization directions of the first magnetic layer 121 and the second magnetic layer 123 in each magnetic tunnel junction 120 can be independently flipped. Therefore, the following can be achieved without changing the direction of the write current. Fig. 9 The switching between four resistance states implemented in the embodiment improves the freedom of data writing compared to switching between only two resistance states.

[0076] In some embodiments, the first antiferromagnetic layer 110 is used as a heavy metal layer, and the second antiferromagnetic layer 130 is used as a connecting layer of at least two magnetic tunnel junctions 120, that is, only the write current is passed through the first antiferromagnetic layer 110, and the write current is not passed through the second antiferromagnetic layer 130. Exemplarily, by passing a third write current through the first antiferromagnetic layer 110, the first magnetic layers 121 corresponding to the first antiferromagnetic layer 110 of at least two magnetic tunnel junctions 120 are flipped together or individually to obtain a first multi-resistance state. Exemplarily, the first multi-resistance state includes three resistance states (such as Figure 8 ), exemplarily, in combination with Figure 8 As shown, taking the case where the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b as an example, when the third write current does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a are not flipped, and the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not flipped, indicating binary data "00"; when the third write current reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, ...a are not flipped, and the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not flipped, indicating binary data "00"; The magnetization direction of the first magnetic layer of the tunnel junction 120a is reversed, and the magnetization directions of the second magnetic layer of the first magnetic tunnel junction 120a, the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "10"; when the third write current reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer of the second magnetic tunnel junction 120b are both reversed, and the magnetization directions of the second magnetic layer of the first magnetic tunnel junction 120a and the second magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11". That is, if the third write current is applied to the first antiferromagnetic layer 110, the magnetic tunnel junction 120 switches between three resistance states to achieve multiple resistance states and improve the degree of freedom of data writing.

[0077] In some other embodiments, the second antiferromagnetic layer 130 is used as a heavy metal layer, and the first antiferromagnetic layer 110 is used as a connecting layer of at least two magnetic tunnel junctions 120. By passing a third write current into the second antiferromagnetic layer 130, the second magnetic layers 123 corresponding to the second antiferromagnetic layer 130 of the at least two magnetic tunnel junctions 120 are flipped together or individually to obtain a first multi-resistance state. Exemplarily, the first multi-resistance state includes three resistance states (such as Figure 8As shown in ), taking the case where the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b as an example, when the third write current does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a are not flipped, and the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not flipped, indicating binary data "00"; when the third write current reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not flipped, indicating binary data "00"; when the third write current reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the first The magnetization direction of the second magnetic layer of the magnetic tunnel junction 120a is reversed, and the magnetization directions of the first magnetic layer of the first magnetic tunnel junction 120a, the first magnetic layer of the second magnetic tunnel junction 120b, and the second magnetic layer are not reversed, indicating binary data "10"; when the third write current reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the second magnetic layer of the first magnetic tunnel junction 120a and the second magnetic layer of the second magnetic tunnel junction 120b are both reversed, and the magnetization directions of the first magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11". That is, if the third write current is applied to the first antiferromagnetic layer 110, the magnetic tunnel junction 120 switches between three resistance states to achieve multiple resistance states and improve the degree of freedom of data writing.

[0078] In some other embodiments, the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 are both used as heavy metal layers, and a third write current is applied to both the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130. For example, a third write current (e.g., Figure 6 As shown in ), the magnetization direction of at least one of the first magnetic layer 121 and the second magnetic layer 123 of at least two magnetic tunnel junctions 120 is flipped together or individually to obtain a second multi-resistance state. Exemplarily, the second multi-resistance state includes four resistance states (such as Fig. 9 ).

[0079] Taking the example that the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b: when the third write current applied to the second antiferromagnetic layer does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, in the first case, if the third write current applied to the first antiferromagnetic layer does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, then the magnetization directions of the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a are not reversed, and the magnetization directions of the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "00"; in the second case, if the third write current applied to the first antiferromagnetic layer reaches The write current required by the first magnetic tunnel junction 120a does not reach the write current required by the second magnetic tunnel junction 120b, and the magnetization direction of the first magnetic layer of the first magnetic tunnel junction 120a is reversed, and the magnetization directions of the second magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "10"; in the third case, if the third write current applied to the first antiferromagnetic layer reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer of the second magnetic tunnel junction 120b are both reversed, and the magnetization directions of the second magnetic layer of the first magnetic tunnel junction 120a and the second magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11".

[0080] When the third write current applied to the first antiferromagnetic layer reaches the write current required by the second magnetic tunnel junction 120b, in the first case, if the third write current applied to the second antiferromagnetic layer reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer of the second magnetic tunnel junction 120b are all reversed, and the magnetization direction of the second magnetic layer of the second magnetic tunnel junction 120b is not reversed, indicating binary data "01"; in the second case, if the third write current applied to the second antiferromagnetic layer reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a are all reversed, and the magnetization directions of the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are all reversed, indicating binary data "00".

[0081] That is, when the third write current is applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 at the same time, the magnetic tunnel junction 120 switches between four resistance states to achieve multiple resistance states and improve the degree of freedom of data writing.

[0082] In some embodiments, please refer to Fig.10 As shown, one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 is used as a heavy metal layer, and the other is used as a connecting layer of at least two magnetic tunnel junctions 120, and a fourth write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130, wherein the fourth write current can simultaneously flip the first magnetic layer 121 and the second magnetic layer 123 of at least two magnetic tunnel junctions 120. In this way, the fourth write current can simultaneously flip the first magnetic layer 121 and the second magnetic layer 123 of at least two magnetic tunnel junctions 120, or flip the first magnetic layer 121 and the second magnetic layer 123 of at least two magnetic tunnel junctions 120 separately, so as to obtain a third multi-resistance state. Exemplarily, the third multi-resistance state includes four resistance states (such as Fig.11 As shown in ), taking the write current required by the first magnetic tunnel junction 120a as less than the write current required by the second magnetic tunnel junction 120b, and the fourth write current is passed to the first antiferromagnetic layer as an example:

[0083] When the fourth write current does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a are not flipped, and the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are not flipped, indicating binary data "00"; when the fourth write current reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization direction of the first magnetic layer of the first magnetic tunnel junction 120a is flipped. When the fourth write current reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer of the second magnetic tunnel junction 120b are both reversed, and the magnetization directions of the second magnetic layer of the first magnetic tunnel junction 120a and the second magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11".

[0084] When the fourth write current reaches the write current required by the second magnetic tunnel junction 120b, and reaches the magnetization direction reversal current of the second magnetic layer of the first magnetic tunnel junction 120a, but does not reach the magnetization direction reversal current of the second magnetic layer of the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer of the second magnetic tunnel junction 120b are all reversed, and the magnetization direction of the second magnetic layer of the second magnetic tunnel junction 120b is not reversed, indicating binary data "01"; when the fourth write current reaches the write current required by the second magnetic tunnel junction 120b, and reaches the magnetization direction reversal current of the second magnetic layer of the first magnetic tunnel junction 120a and the second magnetic layer of the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer and the second magnetic layer of the first magnetic tunnel junction 120a are all reversed, and the magnetization directions of the first magnetic layer and the second magnetic layer of the second magnetic tunnel junction 120b are all reversed, indicating binary data "00".

[0085] That is, by applying a sufficiently large fourth write current to one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 , the magnetic tunnel junction 120 can be switched between four resistance states to achieve multiple resistance states and improve the degree of freedom of data writing.

[0086] In some embodiments, each magnetic tunnel junction 120 of the at least two magnetic tunnel junctions 120 may also be compatible with other film layers.

[0087] Exemplarily, the first magnetic layer 121 can be set as a first composite antiferromagnetic layer 121a, and the exchange bias coupling field between the first antiferromagnetic layer 110 and the first composite antiferromagnetic layer 121a is greater than the coercive field of the first composite antiferromagnetic layer. The first composite antiferromagnetic layer 121a includes, from top to bottom, a first upper magnetic layer, an intermediate coupling layer, and a first lower magnetic layer, wherein the intermediate coupling layer is usually a metal layer, which can make the first upper magnetic layer and the first lower magnetic layer antiparallel coupled (that is, the magnetization directions of the first upper magnetic layer and the first lower magnetic layer are arranged antiparallel), so as to improve the antimagnetic performance of the first composite antiferromagnetic layer 121a.

[0088] For example, Fig.12 As shown in , the second magnetic layer 123 can be set as a second composite antiferromagnetic layer 123a, and the exchange bias coupling field between the second antiferromagnetic layer 130 and the second composite antiferromagnetic layer 123a is greater than the coercive field of the second composite antiferromagnetic layer 123a. The second composite antiferromagnetic layer 123a includes, from top to bottom, a second upper magnetic layer, an intermediate coupling layer, and a second lower magnetic layer. The intermediate coupling layer is usually a metal layer, which can make the second upper magnetic layer and the second lower magnetic layer antiparallel coupled (that is, the magnetization directions of the second upper magnetic layer and the second lower magnetic layer are arranged antiparallel), so as to improve the antimagnetic performance of the second composite antiferromagnetic layer 123a.

[0089] Based on Fig.12 The magnetic memory shown, in some embodiments, as Fig.14 As shown, taking the case where the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b, and a third write current is applied to the first antiferromagnetic layer 110 as an example:

[0090] When the third write current applied to the first antiferromagnetic layer 110 does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer of the first magnetic tunnel junction 120a are not reversed, and the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11"; when the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization direction of the first magnetic layer 121 of the first magnetic tunnel junction 120a is A reversal occurs, and the magnetization directions of the second upper magnetic layer and the second lower magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer 121, the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "01"; when the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer 121 of the first magnetic tunnel junction 120a and the first magnetic layer 121 of the second magnetic tunnel junction 120b are reversed, and the magnetization directions of the second upper magnetic layer and the second lower magnetic layer of the first magnetic tunnel junction 120a and the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "00".

[0091] In addition, the resistance logic of applying the third write current to the second antiferromagnetic layer 130 is not described in detail here.

[0092] Therefore, when the third write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130, the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer in each magnetic tunnel junction can be flipped together or individually to achieve the following operation without changing the direction of the write current. Fig.14 The switching between the three resistance states (i.e., the first multi-resistance state) is realized, thereby realizing the multi-resistance state and improving the freedom of data writing.

[0093] Based on Fig.12 The magnetic memory shown in FIG. 1 may be used in other embodiments, such as Fig.15As shown, taking the case where the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b, and a third write current is applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 as an example:

[0094] When the third write current applied to the second antiferromagnetic layer 130 does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, in the first case, if the third write current applied to the first antiferromagnetic layer 110 does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, then the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer of the first magnetic tunnel junction 120a are not reversed, and the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11"; in the second case, if the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, 0b, the magnetization direction of the first magnetic layer 121 of the first magnetic tunnel junction 120a is reversed, and the magnetization directions of the second upper magnetic layer, the second lower magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer 121, the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "01"; in the third case, if the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer 121 of the first magnetic tunnel junction 120a and the first magnetic layer 121 of the second magnetic tunnel junction 120b are reversed, and the magnetization directions of the second upper magnetic layer, the second lower magnetic layer of the first magnetic tunnel junction 120a and the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "00".

[0095] When the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, in the first case, if the third write current applied to the second antiferromagnetic layer 130 reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, the second lower magnetic layer of the first magnetic tunnel junction 120a and the first magnetic layer 121 of the second magnetic tunnel junction 120b are all reversed, and the second magnetic tunnel junction 120b In the second case, if the third write current applied to the second antiferromagnetic layer 130 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer of the first magnetic tunnel junction 120a are all reversed, and the magnetization directions of the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer of the second magnetic tunnel junction 120b are all reversed, indicating binary data "11".

[0096] Therefore, when the third write current is applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the first magnetic layer 121, the second upper magnetic layer, and the second lower magnetic layer in each magnetic tunnel junction can be flipped together or individually to achieve the following operation without changing the direction of the write current. Fig.15 The switching between the four resistance states (i.e., the second multi-resistance state) in the device can realize the multi-resistance state and improve the freedom of data writing.

[0097] For example, Fig.13 As shown in , the first magnetic layer 121 can be set as a first composite antiferromagnetic layer, and the exchange bias coupling field between the first antiferromagnetic layer and the first composite antiferromagnetic layer is greater than the coercive field of the first composite antiferromagnetic layer, and the second magnetic layer 123 can be set as a second composite antiferromagnetic layer, and the exchange bias coupling field between the second antiferromagnetic layer and the second composite antiferromagnetic layer is greater than the coercive field of the second composite antiferromagnetic layer. In this way, the antimagnetic properties of the first magnetic layer 121 and the second magnetic layer 123 can be improved, thereby improving the stability of data storage.

[0098] Based on Fig.13 The magnetic memory shown, in some embodiments, as Fig.16 As shown, taking the case where the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b, and a third write current is applied to the first antiferromagnetic layer 110 as an example:

[0099] When the third write current applied to the first antiferromagnetic layer 110 does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer of the first magnetic tunnel junction 120a are not reversed, and the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "00"; when the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer and the first lower magnetic layer of the first magnetic tunnel junction 120a are reversed. When the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer, the first lower magnetic layer of the first magnetic tunnel junction 120a and the first upper magnetic layer and the first lower magnetic layer of the second magnetic tunnel junction 120b are reversed, and the magnetization directions of the second upper magnetic layer, the second lower magnetic layer of the first magnetic tunnel junction 120a and the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11".

[0100] In addition, the resistance logic of applying the third write current to the second antiferromagnetic layer 130 is not described in detail here.

[0101] Therefore, when the third write current is applied to the first antiferromagnetic layer 110 or the second antiferromagnetic layer 130, the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer in each magnetic tunnel junction can be flipped together or individually to achieve the following operation without changing the direction of the write current. Fig.16 The switching between the three resistance states (i.e., realizing the first multi-resistance state) is realized, thereby realizing the multi-resistance state and improving the freedom of data writing.

[0102] Based on Fig.13 The magnetic memory shown in FIG. 1 may be used in other embodiments, such as Fig.17 As shown, taking the case where the write current required by the first magnetic tunnel junction 120a is less than the write current required by the second magnetic tunnel junction 120b, and a third write current is applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 as an example:

[0103] When the third write current applied to the second antiferromagnetic layer 130 does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, in the first case, if the third write current applied to the first antiferromagnetic layer 110 does not reach the write current required by the first magnetic tunnel junction 120a and does not reach the write current required by the second magnetic tunnel junction 120b, then the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer of the first magnetic tunnel junction 120a are not reversed, and the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "00"; in the second case, if the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b In the third case, if the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer and the first lower magnetic layer of the first magnetic tunnel junction 120a are reversed, and the magnetization directions of the second upper magnetic layer and the second lower magnetic layer of the first magnetic tunnel junction 120a and the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "10"; in the third case, if the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer and the first lower magnetic layer of the first magnetic tunnel junction 120a and the first upper magnetic layer and the first lower magnetic layer of the second magnetic tunnel junction 120b are reversed, and the magnetization directions of the second upper magnetic layer and the second lower magnetic layer of the first magnetic tunnel junction 120a and the second upper magnetic layer and the second lower magnetic layer of the second magnetic tunnel junction 120b are not reversed, indicating binary data "11".

[0104] When the third write current applied to the first antiferromagnetic layer 110 reaches the write current required by the second magnetic tunnel junction 120b, in the first case, if the third write current applied to the second antiferromagnetic layer 130 reaches the write current required by the first magnetic tunnel junction 120a but does not reach the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, the second lower magnetic layer of the first magnetic tunnel junction 120a and the first upper magnetic layer and the first lower magnetic layer of the second magnetic tunnel junction 120b are all reversed, and the second magnetic tunnel junction 120b The magnetization directions of the second upper magnetic layer and the second lower magnetic layer do not reverse, indicating binary data "01"; in the second case, if the third write current applied to the second antiferromagnetic layer 130 reaches the write current required by the second magnetic tunnel junction 120b, the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer of the first magnetic tunnel junction 120a are all reversed, and the magnetization directions of the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer of the second magnetic tunnel junction 120b are all reversed, indicating binary data "00".

[0105] Therefore, when a third write current is applied to the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the first upper magnetic layer, the first lower magnetic layer, the second upper magnetic layer, and the second lower magnetic layer in each magnetic tunnel junction can be flipped together or individually to achieve the following operation without changing the direction of the write current. Fig.17 The switching between the four resistance states (i.e., the second multi-resistance state) in the device can realize the multi-resistance state and improve the freedom of data writing.

[0106] It can be seen that in the embodiment of the present application, switching between multiple resistance states can be performed without switching the current back and forth, thereby improving the freedom of data writing.

[0107] An embodiment of the present application also provides a method for preparing a magnetic memory, which at least includes: forming a first antiferromagnetic layer 110; illustratively, first, providing a substrate, then forming the first antiferromagnetic layer 110 on the substrate, and after forming the first antiferromagnetic layer 110, forming a magnetic tunnel junction 120 on the first antiferromagnetic layer 110, the magnetic tunnel junction 120 including a first magnetic layer 121, a barrier layer 122 and a second magnetic layer 123 stacked in sequence from bottom to top; after forming the magnetic tunnel junction 120, forming a second antiferromagnetic layer 130 on the magnetic tunnel junction 120.

[0108] Among them, when the magnetic tunnel junction 120 between the first antiferromagnetic layer 110 and the second antiferromagnetic layer is set to one, by applying a write current to at least one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the magnetization direction of at least one of the first magnetic layer 121 and the second magnetic layer 123 is flipped to achieve flexible data writing.

[0109] When the number of magnetic tunnel junctions 120 between the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130 is set to two, by applying a write current to at least one of the first antiferromagnetic layer 110 and the second antiferromagnetic layer 130, the magnetization direction of at least one of the first magnetic layer 121 and the second magnetic layer 123 of the at least two magnetic tunnel junctions 120 is flipped jointly or individually, so as to change the resistance state of the at least two magnetic tunnel junctions 120 jointly or individually to obtain multiple resistance states, thereby improving the freedom of data writing.

[0110] The specific structure and working principle can be referred to the above embodiments and will not be described in detail here.

[0111] In summary, the magnetic memory provided by the embodiment of the present application at least includes a first antiferromagnetic layer, a magnetic tunnel junction arranged on the first antiferromagnetic layer, and a second antiferromagnetic layer arranged on the first magnetic tunnel junction; along the direction from the first antiferromagnetic layer to the second antiferromagnetic layer, the magnetic tunnel junction includes a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence; wherein the first antiferromagnetic layer and the second antiferromagnetic layer can both act as heavy metal layers (SOT layers), so that when a current is passed through the first antiferromagnetic layer, at least the corresponding exchange bias coupling field direction and the magnetization direction of the first magnetic layer can be switched. direction; when current is passed into the second antiferromagnetic layer, at least the corresponding exchange bias coupling field direction can be switched and the magnetization direction of the second magnetic layer can be flipped. Therefore, the first magnetic layer and the second magnetic layer on opposite sides of the barrier layer can be flipped, thereby realizing flexible data writing and improving the flexibility of data writing. In addition, since there are corresponding exchange bias coupling fields between the first antiferromagnetic layer and the first magnetic layer, and between the second antiferromagnetic layer and the second magnetic layer, the first magnetic layer and the second magnetic layer can resist interference from an external magnetic field, thereby improving the stability of the data.

[0112] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0113] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0114] In the description of this application, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to describe the embodiments of the present application described here; the term "and / or" is a description of the association relationship of objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A magnetic memory, characterized in that: At least: A first antiferromagnetic layer, a magnetic tunnel junction disposed on the first antiferromagnetic layer, and a second antiferromagnetic layer disposed on the magnetic tunnel junction; The magnetic tunnel junction includes a first magnetic layer, a barrier layer, and a second magnetic layer stacked in sequence from bottom to top; wherein, by applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer is reversed; By applying a write current to one of the first antiferromagnetic layer or the second antiferromagnetic layer, the magnetization directions of the first magnetic layer and the second magnetic layer are switched simultaneously.

2. The magnetic memory according to claim 1, characterized in that The first antiferromagnetic layer is a heavy metal layer, and a first write current is applied to the first antiferromagnetic layer so that the magnetization direction of the first magnetic layer corresponding to the first antiferromagnetic layer is reversed; or, The second antiferromagnetic layer is a heavy metal layer, and a first write current is applied to the second antiferromagnetic layer so that the magnetization direction of the second magnetic layer corresponding to the second antiferromagnetic layer is reversed; or, The first antiferromagnetic layer and the second antiferromagnetic layer are used as heavy metal layers. By simultaneously applying a first write current to the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of the first magnetic layer corresponding to the first antiferromagnetic layer and the magnetization direction of the second magnetic layer corresponding to the second antiferromagnetic layer are simultaneously flipped.

3. The magnetic memory according to claim 2, characterized in that: The first antiferromagnetic layer or the second antiferromagnetic layer is used as a heavy metal layer, and a second write current is applied to the first antiferromagnetic layer or the second antiferromagnetic layer so that the magnetization directions of the first magnetic layer and the second magnetic layer are simultaneously reversed; Wherein, the second write current is greater than the first write current.

4. The magnetic memory according to any one of claims 1 to 3, characterized in that: The exchange bias coupling field between the first antiferromagnetic layer and the first magnetic layer is greater than the coercive field of the first magnetic layer; and / or, An exchange bias coupling field between the second antiferromagnetic layer and the second magnetic layer is greater than a coercive field of the second magnetic layer.

5. The magnetic memory according to any one of claims 1 to 3, characterized in that: The first magnetic layer is set as a first composite antiferromagnetic layer, and the exchange bias coupling field between the first antiferromagnetic layer and the first composite antiferromagnetic layer is greater than the coercive field of the first composite antiferromagnetic layer; and / or, The second magnetic layer is configured as a second composite antiferromagnetic layer, and an exchange bias coupling field between the second composite antiferromagnetic layer and the second composite antiferromagnetic layer is greater than a coercive field of the second composite antiferromagnetic layer.

6. A magnetic memory, characterized in that: At least: A first antiferromagnetic layer, at least two magnetic tunnel junctions with different required write currents disposed on the first antiferromagnetic layer, and a second antiferromagnetic layer disposed on at least two of the magnetic tunnel junctions; The magnetic tunnel junction comprises a first magnetic layer, a barrier layer and a second magnetic layer stacked in sequence from bottom to top; Applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer so that the magnetization direction of at least one of the first magnetic layer and the second magnetic layer of at least two magnetic tunnel junctions is flipped together or individually, so as to change the resistance state of at least two magnetic tunnel junctions together or individually to obtain a multi-resistance state; By applying a write current to one of the first antiferromagnetic layer or the second antiferromagnetic layer, the magnetization directions of the first magnetic layer and the second magnetic layer are switched simultaneously.

7. The magnetic memory according to claim 6, characterized in that: The first antiferromagnetic layer is used as a heavy metal layer, the second antiferromagnetic layer is used as a connecting layer of at least two magnetic tunnel junctions, and a third write current is passed through the first antiferromagnetic layer, so that the first magnetic layers corresponding to the first antiferromagnetic layer of at least two magnetic tunnel junctions are flipped together or individually to obtain a first multi-resistance state; or The second antiferromagnetic layer is used as a heavy metal layer, the first antiferromagnetic layer is used as a connecting layer of at least two magnetic tunnel junctions, and the second magnetic layers corresponding to the second antiferromagnetic layer of at least two magnetic tunnel junctions are flipped together or individually to obtain a first multi-resistance state by passing a third write current into the second antiferromagnetic layer. or, The first antiferromagnetic layer and the second antiferromagnetic layer act as heavy metal layers. By applying a third write current to the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer of at least two magnetic tunnel junctions is flipped jointly or individually to obtain a second multi-resistance state.

8. The magnetic memory according to claim 6, characterized in that: One of the first antiferromagnetic layer and the second antiferromagnetic layer is used as a heavy metal layer, and the other is used as a connecting layer of at least two of the magnetic tunnel junctions. By applying a fourth write current to the first antiferromagnetic layer or the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer of at least two of the magnetic tunnel junctions is flipped jointly or individually to obtain a third multi-resistance state.

9. The magnetic memory according to claim 6, characterized in that: A cross-sectional size of one of the two magnetic tunnel junctions is not equal to a cross-sectional size of the other one.

10. A method for preparing a magnetic memory, characterized in that: At least: forming a first antiferromagnetic layer; forming a magnetic tunnel junction on the first antiferromagnetic layer, wherein the magnetic tunnel junction comprises a first magnetic layer, a barrier layer and a second magnetic layer stacked in sequence from bottom to top; forming a second antiferromagnetic layer on the magnetic tunnel junction; Wherein, when one magnetic tunnel junction is provided, by applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization direction of at least one of the first magnetic layer and the second magnetic layer is reversed; by applying a write current to one of the first antiferromagnetic layer or the second antiferromagnetic layer, the magnetization directions of the first magnetic layer and the second magnetic layer are reversed simultaneously; or, When at least two magnetic tunnel junctions are provided, by applying a write current to at least one of the first antiferromagnetic layer and the second antiferromagnetic layer, the magnetization directions of at least one of the first magnetic layer and the second magnetic layer of at least two magnetic tunnel junctions are flipped together or individually, so as to change the resistance state of at least two magnetic tunnel junctions together or individually to obtain a multi-resistance state; by applying a write current to one of the first antiferromagnetic layer or the second antiferromagnetic layer, the magnetization directions of the first magnetic layer and the second magnetic layer are flipped simultaneously.

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