MTJ structure and magnetic random access memory
By using the first and second coupling structures with opposite polarities in the MTJ structure to couple with the PMA material layer, the problem of the double reference layer MTJ structure requiring two magnetizations and poor safety under the external magnetic field is solved, and a simple magnetization and high safety MTJ device design is realized.
Patent Information
- Application Number
- CN202410015113.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-04
- Publication Date
- 2025-07-04
AI Technical Summary
In the prior art, the dual reference layer MTJ structure requires two magnetization processes, which have high requirements for magnetic windows, and have poor working safety in external magnetic field environments.
The coupling polarity of the first coupling structure and the second coupling structure is adopted to couple with the first and second PMA material layers through ferromagnetic and antiferromagnetic coupling methods to realize a magnetization process, and the opposite magnetization direction of the reference layer is maintained through different polarities of the PMA material layer, reducing process consistency requirements and improving working safety in an external magnetic field environment.
The simple magnetization process of the MTJ structure is realized, which reduces the process consistency requirements, and maintains high working safety in the external magnetic field environment, improving the performance and reliability of MTJ devices.
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Figure CN120265104A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of magnetic random access memories, and more particularly, to an MTJ structure and a magnetic random access memory. Background Art
[0002] MRAM (Magnetoresistive Random Access Memory) is a new type of non-volatile memory, which has the advantages of fast read and write speed, low power consumption, etc., and is compatible with the CMOS back-end process, and is considered to be a memory with great potential. The magnetic tunnel junction (abbreviated as MTJ) is the basic unit of MRAM. The MTJ is composed of dozens of ultra-thin films and is usually divided into three parts: a free layer, an insulating tunneling layer, and a reference layer. For the MTJ thin film stack, the film structure and interface characteristics have extremely important effects on the performance.
[0003] In the early stage, the industry developed a double-reference-layer MTJ structure, which includes two reference layers, namely reference layer 1, a barrier layer, a free layer, an oxide layer, and reference layer 2. By a specific magnetization method, the magnetization directions of reference layer 1 and reference layer 2 are made opposite, thereby effectively reducing the switching current and improving the write speed. Later, people further optimized this structure, and the top oxide layer adopted a metal alloy material with low resistivity and high spin transfer efficiency, improving the magnetoresistance of the double-reference-layer MTJ. However, at present, there are still some core problems to be solved in the double-reference-layer MTJ structure. First, in order to achieve the effect of reducing the switching current, the directions of the two reference layers of the double-reference-layer MTJ structure must be anti-parallel, which leads to the need for two magnetization processes in different directions for the double-reference-layer MTJ structure, and thus an additional magnetic window requirement is generated. The reference layers in the prior art often adopt a synthetic antiferromagnetic structure, and the magnetization window between the two reference layers is very limited, and the requirement for process consistency is very high. Second, when subjected to a large external magnetic field, the preset magnetization state of the double-reference-layer MTJ structure in the prior art is likely to change. For example, the magnetization directions of the two reference layers change from anti-parallel to parallel, which results in poor working safety of the double-reference-layer MTJ device in an external magnetic field environment. Summary of the Invention
[0004] The main purpose of this application is to provide an MTJ structure and a magnetic random access memory to solve the problem that the double-reference-layer MTJ structure in the prior art needs to perform two magnetization processes and has a relatively high requirement for the magnetic window.
[0005] To achieve the above object, according to one aspect of the present application, an MTJ structure is provided, including: a first coupling structure, including a first PMA (Perpendicular Magnetic Anisotropy) material layer and a first reference layer located on the first PMA material layer, the first PMA material layer is coupled with the first reference layer and the coupling method is one of ferromagnetic coupling and antiferromagnetic coupling; a second coupling structure, including a second PMA material layer and a second reference layer, the second reference layer is located on the side of the first reference layer away from the first PMA material layer, the second PMA material layer is located on the surface of the second reference layer away from the first reference layer, the second PMA material layer is coupled with the second reference layer and the coupling method is the other of the ferromagnetic coupling and the antiferromagnetic coupling; a barrier layer, located between the first reference layer and the second reference layer; a free layer, located between the barrier layer and the second reference layer; and a spacer layer, located between the free layer and the second reference layer.
[0006] Optionally, the remanent magnetization of the first coupling structure and the remanent magnetization of the second coupling structure have opposite magnetization directions.
[0007] Optionally, the first reference layer includes: a magnetic coupling providing sub-layer, in contact with the first PMA material layer, the magnetic coupling providing sub-layer is used to provide coupling magnetism; a magnetoresistance enhancing sub-layer, located between the magnetic coupling providing sub-layer and the barrier layer and in contact with the barrier layer, and the spin polarization rate of the magnetoresistance enhancing sub-layer is ≥50%.
[0008] Optionally, the projected areas of the second coupling structure, the spacer layer, and the free layer on a predetermined surface are respectively smaller than the projected area of the barrier layer on the predetermined surface, and the predetermined surface is a surface perpendicular to the stacking direction of the spacer layer and the free layer.
[0009] Optionally, the projected areas of the second coupling structure, the spacer layer, and the free layer on the predetermined surface are less than or equal to 1 / 2 of the projected area of the barrier layer on the predetermined surface.
[0010] Optionally, the ratio of the remanent magnetization of the first coupling structure to the remanent magnetization of the second coupling structure is [0.8, 1.2].
[0011] Optionally, the magnetization per unit area of the second reference layer is greater than or equal to 1.2 times the magnetization per unit area of the first reference layer.
[0012] Optionally, the materials of the first reference layer and the second reference layer are different. The materials of the first PMA material layer and the second PMA material layer are independently selected from one or more of MnGa, MnAl, FePt, FePd, and CoTb. The materials of the first reference layer and the second reference layer are independently selected from one or more of Co, Fe, Ni, CoFe, CoNi, and CoFeB.
[0013] Optionally, the material of the spacer layer includes one or more of Mg, MgO, MgAlO, MgB, Al, AlB, AlC, Cu, CuN, and CuB. The material of the barrier layer includes MgO, AlO X 、MgAlO X 、TiO X 、TaO X 、GaO X and FeO X and at least one of them. The material of the free layer includes at least one of Co, Fe, Ni, CoB, FeB, NiB, CoFe, NiFe, CoNi, CoFeNi, CoFeB, NiFeB, CoNiB, CoFeNiB, FePt, FePd, CoPt, CoPd, CoFePt, CoFePd, FePtPd, CoPtPd, and CoFePtPd.
[0014] According to another aspect of the present application, a magnetic random access memory is provided, including any one of the MTJ structures described above.
[0015] Applying the technical solution of the present application, in the MTJ structure, the first coupling structure includes a first PMA material layer and a first reference layer coupled in one of the ferromagnetic coupling mode and the antiferromagnetic coupling mode. The second coupling structure includes a second PMA material layer and a second reference layer coupled in the other of the ferromagnetic coupling mode and the antiferromagnetic coupling mode, so that the coupling polarities of the first coupling structure and the second coupling structure are opposite. In this way, only one magnetization process is required for the MTJ to magnetize the first PMA material layer and the second PMA material layer to the same direction. The first reference layer and the second reference layer show opposite magnetization directions due to coupling with their respective corresponding PMA material layers (one is ferromagnetic coupling and the other is antiferromagnetic coupling). The magnetization process is relatively simple, without the need for two magnetization processes, without additional magnetic window requirements, and reduces the requirements for the process consistency of the MTJ. Moreover, after being subjected to a large external magnetic field, the first reference layer and the second reference layer always form opposite magnetization directions due to the different polarities of coupling with their respective corresponding PMA material layers, ensuring high working safety of the MTJ structure in an external magnetic field environment. Description of the Drawings
[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:
[0017] Figure 1 A schematic diagram of an MTJ structure according to an embodiment of this application is shown;
[0018] Figure 2 A schematic diagram of another MTJ structure according to an embodiment of this application is shown;
[0019] Figure 3 A schematic diagram of still another MTJ structure according to an embodiment of this application is shown.
[0020] Wherein, the accompanying drawings include the following reference numerals:
[0021] 10. First coupling structure; 11. First PMA material layer; 12. First reference layer; 121. Magnetic coupling providing sub-layer; 122. Magnetoresistance enhancing sub-layer; 20. Second coupling structure; 21. Second PMA material layer; 22. Second reference layer; 30. Barrier layer; 40. Free layer; 50. Spacer layer; 60. Seed layer; 70. Capping layer. Detailed implementation manners
[0022] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.
[0023] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to this application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0024] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element can be directly on the other element, or there can also be an intermediate element. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element.
[0025] As introduced in the background art, the existing double-reference-layer MTJ structure requires two magnetization processes in the prior art, which has relatively high requirements for the magnetic window. To solve the above technical problems, embodiments of the present application provide an MTJ structure and a magnetic random access memory.
[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.
[0027] Embodiments of the present application provide an MTJ structure as Figure 1 shown, as Figure 1 shown, the MTJ structure of the present application includes:
[0028] A first coupling structure 10, including a first PMA material layer 11 and a first reference layer 12 located on the first PMA material layer 11, the first PMA material layer 11 is coupled with the first reference layer 12 and the coupling method is one of ferromagnetic coupling and antiferromagnetic coupling;
[0029] A second coupling structure 20, including a second PMA material layer 21 and a second reference layer 22, the second reference layer 22 is located on the side of the first reference layer 12 away from the first PMA material layer 11, the second PMA material layer 21 is located on the surface of the second reference layer 22 away from the first reference layer 12, the second PMA material layer 21 is coupled with the second reference layer 22 and the coupling method is the other one of the ferromagnetic coupling and the antiferromagnetic coupling;
[0030] Specifically, the coupling method of the first coupling structure is one of ferromagnetic coupling and antiferromagnetic coupling, and the coupling method of the second coupling structure is the other one of the ferromagnetic coupling and the antiferromagnetic coupling. That is to say, the coupling polarities of the first coupling structure and the second coupling structure are opposite.
[0031] A barrier layer 30, located between the first reference layer 12 and the second reference layer 22;
[0032] Specifically, the barrier layer may be in contact with the first reference layer; or may not be in contact with the first reference layer, that is, other film layers may be provided between the barrier layer and the first reference layer according to actual needs. In the embodiments of the present application, the barrier layer is in contact with the first reference layer.
[0033] A free layer 40, located between the barrier layer 30 and the second reference layer 22;
[0034] Specifically, the free layer may be in contact with the barrier layer; it may also not be in contact with the barrier layer, that is, other film layers may be provided between the free layer and the barrier layer according to actual needs. In the embodiments of the present application, the free layer is in contact with the barrier layer.
[0035] The spacer layer 50 is located between the free layer 40 and the second reference layer 22.
[0036] Specifically, the spacer layer may be in contact with the free layer and the second reference layer respectively, or may only be in contact with the free layer or the second reference layer, or may not be in contact with either the free layer or the second reference layer. Those skilled in the art can flexibly set it according to actual needs.
[0037] Through the above embodiments, in the MTJ structure, the first coupling structure includes a first PMA material layer and a first reference layer that are coupled in one of the ferromagnetic coupling mode and the antiferromagnetic coupling mode, and the second coupling structure includes a second PMA material layer and a second reference layer that are coupled in the other of the ferromagnetic coupling mode and the antiferromagnetic coupling mode, so that the coupling polarities of the first coupling structure and the second coupling structure are opposite. In this way, only one magnetization process is required for the MTJ, magnetizing the first PMA material layer and the second PMA material layer to the same direction. The first reference layer and the second reference layer exhibit opposite magnetization directions due to coupling with their respective corresponding PMA material layers (one is ferromagnetic coupling and the other is antiferromagnetic coupling). The magnetization process is relatively simple, without the need for two magnetization processes, without additional magnetic window requirements, and reduces the requirements for the process consistency of the MTJ. Moreover, after being subjected to a large external magnetic field, the first reference layer and the second reference layer always form opposite magnetization directions due to the different polarities of coupling with their respective corresponding PMA material layers, ensuring high working safety of the MTJ structure in an external magnetic field environment.
[0038] In addition, the MTJ structure of the present application uses PMA materials, which can ensure a high flatness of the film layer interface in the first coupling structure and the second coupling structure, resulting in better quality and uniformity of the MTJ structure.
[0039] Specifically, as Figure 2 shown, the MTJ structure further includes: a seed layer 60 located on the surface of the first PMA material layer 11 away from the first reference layer 12; a capping layer 70 located on the surface of the second PMA material layer 21 away from the second reference layer 22. The seed layer is used to regulate crystal nucleation and lattice mismatch, and the capping layer is used to protect the second coupling structure, the spacer layer, the free layer, the barrier layer, and the first coupling structure.
[0040] According to a specific embodiment of the present application, the remanent magnetization of the first coupling structure and the second coupling structure have opposite magnetization directions, which can reduce the influence of the stray fields generated by the first coupling structure and the second coupling structure on the magnetization reversal of the free layer. Furthermore, after one magnetization, the dual-reference-layer MTJ structure has a lower switching current, improving the performance of the device such as power consumption and speed.
[0041] In order to further ensure that the first reference layer and the second reference layer are coupled with their respective PMA material layers to always form opposite magnetization directions, so that after being subjected to a large external magnetic field, the relative relationship of the magnetization directions of the first reference layer and the second reference layer will not be affected, and at the same time reduce the influence of the stray fields of the first coupling structure and the second coupling structure on the magnetization reversal of the free layer, thereby further ensuring that the MTJ structure has a high working safety in an external magnetic field environment. Optionally, the ratio of the remanent magnetization of the first coupling structure to the remanent magnetization of the second coupling structure is between 0.8 and 1.2, including the end values.
[0042] In another alternative embodiment, as Figure 2 shown, the first reference layer 12 includes: a magnetic coupling providing sub-layer 121, in contact with the first PMA material layer 11, and the magnetic coupling providing sub-layer 121 is used to provide coupling magnetism; a magnetoresistance enhancing sub-layer 122, located between the magnetic coupling providing sub-layer 121 and the barrier layer 30 and in contact with the barrier layer 30, and the spin polarization rate of the magnetoresistance enhancing sub-layer is ≥50%. In this embodiment, by stacking the magnetic coupling providing sub-layer and the magnetoresistance enhancing sub-layer as the first reference layer, the coupling providing sub-layer in contact with the first PMA material layer can provide strong magnetic coupling, and the magnetoresistance enhancing sub-layer with a high spin polarization rate can enhance the tunneling magnetoresistance of the MTJ structure, thereby further enhancing the read-write performance of the MTJ structure.
[0043] In order to better balance the influence of the stray fields generated by the first and second coupling structures on the free layer, specifically, as Figure 3 shown, the projected areas of the second coupling structure 20, the spacer layer 50, and the free layer 40 on a predetermined surface are respectively smaller than the projected area of the barrier layer 30 on the predetermined surface, and the predetermined surface is a surface perpendicular to the stacking direction of the spacer layer 50 and the free layer 40. That is to say, the sizes of the second coupling structure, the spacer layer, and the free layer are smaller than the size of the barrier layer, and specifically, during the process of etching to form the second coupling structure, the spacer layer, and the free layer, the etching can be stopped at the barrier layer. On this basis, the magnetization intensity per unit area of the second reference layer is greater than or equal to 1.2 times the magnetization intensity per unit area of the first reference layer, so as to better balance the influence of the stray fields generated by the first and second coupling structures on the free layer.
[0044] The predetermined surface described in this application can specifically be the surface of the first PMA material layer, or the surface of the first reference layer, or a surface parallel to the surface of the first PMA material layer, or a surface parallel to the surface of the first reference layer. In addition, the second coupling structure, the spacer layer, and the free layer have the same size, and the barrier layer and the first coupling structure have the same size. Those skilled in the art can set the specific size values of the second coupling structure, the spacer layer, and the free layer to be smaller than that of the barrier layer according to actual design requirements. In a specific solution of this application, the projected area of the second coupling structure, the spacer layer, and the free layer on the predetermined surface is less than or equal to 1 / 2 of the projected area of the barrier layer on the predetermined surface.
[0045] In addition to the above solution, in some other embodiments, the projected areas of the second coupling structure, the spacer layer, and the free layer 40 on the predetermined surface are respectively larger than the projected area of the barrier layer on the predetermined surface, and the predetermined surface is a surface perpendicular to the stacking direction of the spacer layer and the free layer. That is to say, the sizes of the second coupling structure, the spacer layer, and the free layer are larger than the size of the barrier layer. On this basis, the magnetization intensity per unit area of the second reference layer is less than 1.2 times the magnetization intensity per unit area of the first reference layer. Such a setting method can also reduce the influence of the stray fields generated by the first and second coupling structures on the free layer.
[0046] In the above embodiment, the second coupling structure, the spacer layer, and the free layer have the same size, and the barrier layer and the first coupling structure have the same size. In a more specific embodiment, the projected area of the second coupling structure, the spacer layer, and the free layer on the predetermined surface is larger than 1 / 2 of the projected area of the barrier layer on the predetermined surface.
[0047] Optionally, the materials of the first reference layer and the second reference layer are different. Specifically, it can be manifested as different elements in the first reference layer and the second reference layer; or it can be manifested as the same elements in the first reference layer and the second reference layer, but the component ratios of each element are different.
[0048] Optionally, the materials of the first PMA material layer and the second PMA material layer can be the same or different. When the materials of the first PMA material layer and the second PMA material layer are different, specifically, it can be manifested as different elements in the first PMA material layer and the second PMA material layer, or it can be manifested as the same elements in the first PMA material layer and the second PMA material layer, but the component ratios of each element are different.
[0049] In the actual application process, those skilled in the art can flexibly select the materials of each structural layer according to the actual situation. Specifically, the materials of the first PMA material layer and the second PMA material layer are independently selected from one or more of MnGa, MnAl, FePt, FePd, and CoTb. The materials of the first reference layer and the second reference layer are independently selected from one or more of Co, Fe, Ni, CoFe, CoNi, and CoFeB. The material of the spacer layer includes one or more of Mg, MgO, MgAlO, MgB, Al, AlB, AlC, Cu, CuN, and CuB. The materials of the barrier layer include at least one of MgO, AlO X , MgAlO X , TiO X , TaO X , GaO X and FeO X . The materials of the free layer include at least one of Co, Fe, Ni, CoB, FeB, NiB, CoFe, NiFe, CoNi, CoFeNi, CoFeB, NiFeB, CoNiB, CoFeNiB, FePt, FePd, CoPt, CoPd, CoFePt, CoFePd, FePtPd, CoPtPd, and CoFePtPd.
[0050] According to another specific embodiment of the present application, the first PMA material layer is ferromagnetically coupled to the first reference layer, and the second PMA material layer is antiferromagnetically coupled to the second reference layer. The materials of the first PMA material layer and the second PMA material layer are both MnGa with an L10 structure, and the atomic percentages of Mn in the first PMA material layer and the second PMA material layer are respectively greater than or equal to 50%. The first reference layer includes a magnetic coupling providing sub-layer and a magnetoresistance enhancing sub-layer. The material of the magnetic coupling providing sub-layer is CoFe, and the material of the magnetoresistance enhancing sub-layer is CoFeB. The atomic percentage of Co in CoFe is less than or equal to 20%, so that CoFe and the MnGa of the first PMA material layer generate strong ferromagnetic coupling. The material of the second reference layer is CoFe, and the atomic percentage of Co in CoFe is greater than or equal to 30%, so that the second reference layer and the MnGa of the second PMA material layer generate strong antiferromagnetic coupling. The material of the spacer layer is CuN, which has a low resistance value and can avoid affecting the tunneling magnetoresistance and the read window. The material of the barrier layer is MgO.
[0051] On the other hand, according to the present application, a magnetic random access memory is provided, including any one of the MTJ structures described above.
[0052] The described magnetic random access memory includes any one of the described MTJ structures. In the MTJ structure, the first coupling structure includes a first PMA material layer and a first reference layer coupled in one of ferromagnetic coupling and antiferromagnetic coupling modes, and the second coupling structure includes a second PMA material layer and a second reference layer coupled in the other of ferromagnetic coupling and antiferromagnetic coupling modes, such that the coupling polarities of the first coupling structure and the second coupling structure are opposite. In this way, only one magnetization process is required for the MTJ. The first PMA material layer and the second PMA material layer are magnetized to the same direction. The first reference layer and the second reference layer exhibit opposite magnetization directions due to coupling with their respective corresponding PMA material layers (one is ferromagnetic coupling and the other is antiferromagnetic coupling). The magnetization process is relatively simple, without the need for two magnetization processes and without additional magnetic window requirements, reducing the requirements for the process consistency of the MTJ. Moreover, after being subjected to a relatively large external magnetic field, the first reference layer and the second reference layer always form opposite magnetization directions due to the different polarities of coupling with their respective corresponding PMA material layers, ensuring high working safety of the MTJ structure in an external magnetic field environment.
[0053] Specifically, the magnetic random access memory may specifically be an MRAM.
[0054] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.
Claims
1. An MTJ structure, characterized in that, Comprising: A first coupling structure, comprising a first PMA material layer and a first reference layer located on the first PMA material layer, wherein the first PMA material layer is coupled to the first reference layer in one of ferromagnetic coupling and antiferromagnetic coupling; A second coupling structure, comprising a second PMA material layer and a second reference layer, the second reference layer being located on a side of the first reference layer away from the first PMA material layer, the second PMA material layer being located on a surface of the second reference layer away from the first reference layer, and the second PMA material layer being coupled to the second reference layer in the other of the ferromagnetic coupling and the antiferromagnetic coupling; A barrier layer, located between the first reference layer and the second reference layer; A free layer, located between the barrier layer and the second reference layer; A spacer layer, located between the free layer and the second reference layer.
2. The MTJ structure according to claim 1, characterized in that, The remanent magnetization of the first coupling structure and the remanent magnetization of the second coupling structure have opposite magnetization directions.
3. The MTJ structure according to claim 1, wherein The first reference layer comprises: A magnetic coupling providing sub-layer, in contact with the first PMA material layer, for providing coupling magnetism; A magnetoresistance enhancing sub-layer, located between the magnetic coupling providing sub-layer and the barrier layer and in contact with the barrier layer, and having a spin polarization rate of ≥50%.
4. The MTJ structure according to claim 1, wherein The projected areas of the second coupling structure, the spacer layer, and the free layer on a predetermined surface are respectively smaller than the projected area of the barrier layer on the predetermined surface, and the predetermined surface is a surface perpendicular to the stacking direction of the spacer layer and the free layer.
5. The MTJ structure according to claim 4, wherein The projected areas of the second coupling structure, the spacer layer, and the free layer on the predetermined surface are less than or equal to 1 / 2 of the projected area of the barrier layer on the predetermined surface.
6. The MTJ structure according to claim 4, characterized in that, The ratio of the remanent magnetization of the first coupling structure to the remanent magnetization of the second coupling structure is [0.8, 1.2].
7. The MTJ structure according to claim 4, wherein The magnetization per unit area of the second reference layer is greater than or equal to 1.2 times the magnetization per unit area of the first reference layer.
8. The MTJ structure according to any one of claims 1 to 7, characterized in that, The materials of the first reference layer and the second reference layer are different. The materials of the first PMA material layer and the second PMA material layer are independently selected from one or more of MnGa, MnAl, FePt, FePd, and CoTb. The materials of the first reference layer and the second reference layer are independently selected from one or more of Co, Fe, Ni, CoFe, CoNi, and CoFeB.
9. The MTJ structure according to any one of claims 1 to 7, characterized in that, The material of the spacer layer includes one or more of Mg, MgO, MgAlO, MgB, Al, AlB, AlC, Cu, CuN, and CuB, and the material of the barrier layer includes MgO, AlO X , MgAlO X , TiO X , TaO X , GaO X , and FeO X and at least one of them. The material of the free layer includes at least one of Co, Fe, Ni, CoB, FeB, NiB, CoFe, NiFe, CoNi, CoFeNi, CoFeB, NiFeB, CoNiB, CoFeNiB, FePt, FePd, CoPt, CoPd, CoFePt, CoFePd, FePtPd, CoPtPd, and CoFePtPd.
10. A magnetic random access memory, characterized in that, Comprising the MTJ structure according to any one of claims 1 to 9.