Magnetic tunnel junctions and magnetic storage

Abstract

The application discloses a magnetic tunnel junction and a magnetic memory, the magnetic tunnel junction comprising a spin orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinned layer which are sequentially stacked; further comprising at least one magnetic layer, the at least one magnetic layer comprising a first spin polarization enhancement layer and / or a second spin polarization enhancement layer, the first spin polarization enhancement layer being located between the spin orbit coupling layer and the free layer, the magnetization direction of the first spin polarization enhancement layer being the same as that of the free layer; the second spin polarization enhancement layer being located between the reference layer and the pinned layer, the magnetization direction of the second spin polarization enhancement layer being the same as that of the reference layer. The magnetic tunnel junction provided by the application has improved tunneling magnetoresistance.

Description

Technical Field

[0001] This application belongs to the field of semiconductor technology, and in particular relates to a magnetic tunnel junction and a magnetic memory. Background Technology

[0002] Magnetic random access memory (MRAM), as a high-performance new type of non-volatile memory, has advantages such as high speed, high stability, and high durability. Magnetic random access memory includes a magnetic tunnel junction (MTJ), but the tunneling magnetoresistivity (TMR) of the MRAM is low, typically only 100%-150%, which seriously affects the performance of the magnetic memory. Summary of the Invention

[0003] The purpose of this application is to at least solve the problem of low tunneling magnetic resistivity in magnetic tunnel structures. This purpose is achieved through the following technical solution:

[0004] The first aspect of this application proposes a magnetic tunnel junction, which includes a spin-orbit coupling layer, a free layer, a barrier layer, a reference layer, and a pinning layer stacked sequentially; it also includes at least one magnetic layer, which comprises:

[0005] A first spin-polarized enhancement layer is located between the spin-orbit coupling layer and the free layer, and the magnetization direction of the first spin-polarized enhancement layer is the same as that of the free layer; and / or,

[0006] The second spin-polarized enhancement layer is located between the reference layer and the pinned layer, and the magnetization direction of the second spin-polarized enhancement layer is the same as that of the reference layer.

[0007] The magnetic tunnel junction provided in this application includes a spin-orbit coupling layer, a free layer, a barrier layer, a reference layer, and a pinning layer stacked sequentially, and also includes at least one magnetic layer. This magnetic layer includes a first spin polarization enhancement layer and / or a second spin polarization enhancement layer. The ferromagnetic layer can be used to further improve the performance of the magnetic tunnel junction. Specifically, when the magnetic tunnel junction includes a second spin polarization enhancement layer, this layer is located between the reference layer and the pinning layer. When electrons flow from the reference layer to the free layer, strong ferromagnetic coupling is achieved because the second spin polarization enhancement layer and the reference layer have the same magnetization direction. Electrons are first polarized by the second spin polarization enhancement layer and then injected into the reference layer for further polarization, resulting in the majority of electrons being spin-polarized, which improves the tunneling magnetic resistivity of the magnetic tunnel junction. When the magnetic tunnel junction includes a first spin polarization enhancement layer, the first spin polarization enhancement layer and the free layer have the same magnetization direction, thus achieving strong ferromagnetic coupling. When current flows through the spin-orbit coupling layer, a vertical spin current is generated due to the spin Hall effect of the spin-orbit coupling layer or the Rashba effect at the interface, causing the first spin polarization enhancement layer to flip and driving the free layer to flip as well. The magnetic tunnel junction provided in this application improves the effective polarization of the readout current by setting a first spin polarization enhancement layer and / or a second spin polarization enhancement layer, thereby increasing the tunneling magnetic resistivity of the magnetic tunnel junction.

[0008] A second aspect of this application also provides a magnetic storage device, including at least one magnetic tunnel junction of any of the types provided in the first aspect of this application. Attached Figure Description

[0009] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0010] Figure 1 This is a schematic diagram of the electronic polarization process in a magnetic tunnel junction in the prior art;

[0011] Figure 2 This is a partial structural schematic diagram of the first magnetic tunnel junction provided in the embodiments of this application;

[0012] Figure 3 This is a schematic diagram of the electronic polarization process in a magnetic tunnel junction provided in an embodiment of this application.

[0013] Figure 4 This is a partial structural schematic diagram of the second type of magnetic tunnel junction provided in the embodiments of this application;

[0014] Figure 5 This is a partial structural schematic diagram of the third type of magnetic tunnel junction provided in the embodiments of this application;

[0015] Figure 6 This is a partial structural schematic diagram of the fourth type of magnetic tunnel junction provided in the embodiments of this application;

[0016] Figure 7 This is a partial structural schematic diagram of the fifth type of magnetic tunnel junction provided in the embodiments of this application;

[0017] Figure 8 This is a partial structural schematic diagram of the sixth type of magnetic tunnel junction provided in the embodiments of this application;

[0018] Figure 9 This is a partial structural schematic diagram of the seventh type of magnetic tunnel junction provided in the embodiments of this application;

[0019] Figure 10 This is a partial structural schematic diagram of the eighth magnetic tunnel junction provided in the embodiments of this application;

[0020] Figure 11 This is a partial structural schematic diagram of the ninth type of magnetic tunnel junction provided in the embodiments of this application;

[0021] Figure 12 This is a partial structural schematic diagram of the tenth magnetic tunnel junction provided in the embodiments of this application;

[0022] Figure 13 This is a partial structural schematic diagram of the first type of magnetic storage provided in the embodiments of this application;

[0023] Figure 14 This is a partial structural schematic diagram of the second type of magnetic storage provided in the embodiments of this application;

[0024] Figure 15 This is a partial structural schematic diagram of the third type of magnetic storage provided in the embodiments of this application;

[0025] Figure 16 This is a partial structural schematic diagram of the fourth type of magnetic storage provided in the embodiments of this application;

[0026] Figure 17 This is a schematic diagram of an integrated structure of a magnetic storage device provided in an embodiment of this application.

[0027] The attached figures are labeled as follows:

[0028] 01. Barrier layer; 02. Reference layer; 1. Magnetic tunnel junction; 11. Spin-orbit coupling layer; 12. Free layer; 13. Barrier layer; 14. Reference layer; 15. Pinning layer; 16. First spin polarization enhancement layer; 17. Second spin polarization enhancement layer; 18. High data retention layer; 19. Fast-flipping ferromagnetic layer; x, First direction; y, Magnetization direction; 20. Spacer layer; 21. First spacer layer; 22. Second spacer layer; 23. Third spacer layer; 24. Fourth spacer layer; 25. Fifth spacer layer; 26. Seed layer; 27. Capping layer; 2. Magnetic memory; 3. Substrate. Detailed Implementation

[0029] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0030] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0031] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0032] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0033] Research has revealed that the magnetic tunnel junction (MTJ) in related technologies comprises a stacked spin-orbit coupling layer, a free layer, a barrier layer (01), a reference layer (02), and a pinning layer. The MTJ can be written using spin shift and read out by detecting its tunneling magnetoresistivity (TMR), and is applied in magnetic memory. However, the MTJ suffers from a relatively low tunneling magnetoresistivity (TMR). For example, ... Figure 1 As shown in the figure, the arrows indicate the direction of electron flow. When electrons flow through the reference film layer 02, they are first polarized by the reference film layer 02. Since the spin polarization of the reference film layer 02 material is low, only a small portion of the electrons are polarized, resulting in a low tunneling magnetoresistivity (TMR) of the magnetic tunnel junction (MTJ), typically only 100%-150%, which leads to a high read error rate of the magnetic memory.

[0034] Therefore, this application provides a magnetic tunnel junction and a magnetic memory, which greatly improves the tunneling magnetic resistivity (TMR) of the magnetic tunnel junction (MTJ), thereby greatly improving the performance of the magnetic memory.

[0035] like Figures 2 to 4 As shown, according to an embodiment of this application, a magnetic tunnel junction 1 is proposed. The magnetic tunnel junction 1 includes a spin-orbit coupling layer 11, a free layer 12, a barrier layer 13, a reference layer 14, and a pinning layer 15 stacked sequentially. It also includes at least one magnetic layer, which includes a first spin polarization enhancement layer 16 and / or a second spin polarization enhancement layer 17. The first spin polarization enhancement layer 16 is located between the spin-orbit coupling layer 11 and the free layer 12, and the magnetization direction of the first spin polarization enhancement layer 16 is the same as the magnetization direction of the free layer 12. The second spin polarization enhancement layer 17 is located between the reference layer 14 and the pinning layer 15, and the magnetization direction of the second spin polarization enhancement layer 17 is the same as the magnetization direction of the reference layer 14.

[0036] The magnetic tunnel junction 1 provided in this application includes a spin-orbit coupling layer 11, a free layer 12, a barrier layer 13, a reference layer 14, and a pinning layer 15 stacked sequentially. It also includes at least one magnetic layer, which comprises a first spin polarization enhancement layer 16 and / or a second spin polarization enhancement layer 17. The ferromagnetic layer can be used to further improve the performance of the magnetic tunnel junction 1. Specifically, as... Figure 2 As shown, when the magnetic tunnel junction 1 includes a second spin polarization enhancement layer 17, the second spin polarization enhancement layer 17 is located between the reference layer 14 and the pinned layer 15. When electrons flow from the reference layer 14 to the free layer 12, strong ferromagnetic coupling is achieved because the second spin polarization enhancement layer 17 and the reference layer 14 have the same magnetization direction. Figure 3 As shown in the figure, the arrows indicate the direction of electron flow. Electrons are first polarized by the second spin polarization enhancement layer 17, and then injected into the reference layer 14 for further polarization, thus ensuring that the vast majority of electrons are spin polarized, which can improve the tunneling magnetoresistivity of the magnetic tunnel junction 1. Figure 4 As shown, when the magnetic tunnel junction 1 includes a first spin polarization enhancement layer 16, the first spin polarization enhancement layer 16 and the free layer 12 have the same magnetization direction, thereby achieving strong ferromagnetic coupling. When current flows through the spin-orbit coupling layer 11, a vertical spin current is generated due to the spin Hall effect of the spin-orbit coupling layer 11 or the Rashba effect at the interface, causing the first spin polarization enhancement layer 16 to flip and driving the free layer 12 to flip as well. In the magnetic tunnel junction 1 provided in this application, the effective polarization of the read current is improved by setting the first spin polarization enhancement layer 16 and / or the second spin polarization enhancement layer 17, thereby improving the tunneling magnetic resistivity of the magnetic tunnel junction 1.

[0037] In the above embodiment, the reference layer 14 and the free layer 12 are magnetic. The magnetization of the reference layer 14 is typically fixed or pinned in a specific direction by the switching bias of the pinning layer 15. The free layer 12 has a variable magnetization direction. To switch the magnetization direction of the free layer 12, a drive current is provided along the alignment direction of the reference layer 14 and the free layer 12. When sufficient drive current is driven from the spin-orbit coupling layer 11 to the pinning layer 15, the magnetization direction of the free layer 12 can be switched to be parallel to the magnetization direction of the reference layer 14. When sufficient drive current is driven from the pinning layer 15 to the spin-orbit coupling layer 11, the magnetization direction of the free layer 12 can be switched to be antiparallel to the magnetization direction of the reference layer 14. The difference in magnetic configuration corresponds to different magnetoresistances, and thus to different logic states of the magnetic tunnel junction 1 (e.g., logic "0" and logic "1"). Therefore, the state of the magnetic tunnel junction 1 can be determined by reading the tunneling magnetoresistance of the magnetic tunnel junction 1.

[0038] Specifically, the free layer 12 is made of at least one of cobalt-iron-boron alloy (CoFeB), cobalt-iron alloy (CoFe), and cobalt-iron-aluminum alloy (CoFeAl), or comprises multiple alternating layers of cobalt and platinum, or multiple alternating layers of cobalt and palladium. The reference layer 14 is made of at least one of cobalt-iron-boron alloy (CoFeB), cobalt-iron alloy (CoFe), and cobalt-iron-aluminum alloy (CoFeAl), or comprises multiple alternating layers of cobalt and platinum, or multiple alternating layers of cobalt and palladium. The barrier layer 13 is made of at least one of magnesium oxide (MgO), aluminum oxide (Al2O3), and magnesium aluminum oxide (MgAlO). The pinning layer 15 is made of multiple alternating layers of cobalt and platinum, or comprises multiple alternating layers of cobalt and palladium, or comprises at least one of cobalt-iron-boron alloy (CoFeB), cobalt-iron alloy (CoFe), and cobalt-iron-aluminum alloy (CoFeAl). The spin-orbit coupling layer 11 comprises at least one of the following: heavy metal, heavy metal alloy, antiferromagnetic material, light metal oxide, topological insulator, oxide two-dimensional electron gas, and semi-metallic material. Specifically, heavy metals include platinum (Pt), tantalum (Ta), tungsten (W), and their alloys. Antiferromagnetic materials include manganese-iridium alloy (IrMn), manganese-iron alloy (FeMn), manganese-platinum alloy (PtMn), manganese-palladium alloy (PdMn), etc. Light metal oxides include copper oxide (CuOx), titanium oxide (TiOx), etc., where x is a positive number. Topological insulators include selenium-bismuth alloy (BiSe) and antimony-bismuth alloy (Bi). 0.9 Sb 0.1 (Bi,Sb)2Te3, etc. Oxide two-dimensional electron gases such as SrTiO3 / LaAlO3, SrTiO3 / AlOx, KTaO3 / LaAlO3, KTaO3 / LaVO3, etc., and semi-metallic materials including PtTe2, MoTe2, PtSe2, SrIrO3, etc.

[0039] In the above embodiments, the first spin polarization enhancement layer 16 or the second spin polarization enhancement layer 17 can be selected according to the direction of electron flow. Specifically, the first spin polarization enhancement layer 16 or the second spin polarization enhancement layer 17 can be set at the end of the magnetic tunnel junction 1 near the electron inflow. That is, when electrons flow in from the side of the free layer 12 away from the reference layer 14, the first spin polarization enhancement layer 16 can be set, and when electrons flow in from the side of the reference layer 14 away from the free layer 12, the second spin polarization enhancement layer 17 can be set. Selecting the first spin polarization enhancement layer 16 or the second spin polarization enhancement layer 17 according to the direction of electron flow can simplify the stacking complexity of the film layers, thereby simplifying the fabrication process and achieving a balance between improving tunneling magnetoresistivity (TMR) and fabrication cost.

[0040] In the above embodiments, such as Figure 5As shown, a first spin polarization enhancement layer 16 and a second spin polarization enhancement layer 17 can also be provided simultaneously to further improve the tunneling magnetoresistivity (TMR).

[0041] In one feasible implementation, the spin polarization susceptibility of the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 ranges from 0.8 to 1. The materials of the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 include spin half-metal materials.

[0042] In the above embodiments, the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 have high spin polarization rates. Therefore, when the magnetic tunnel junction 1 includes the second spin polarization enhancement layer 17 and electrons flow from the reference layer 14 towards the free layer 12, the electrons are first polarized by the second spin polarization enhancement layer 17. The second spin polarization enhancement layer 17 is a spin half-metal material with high spin polarization, thus allowing most electrons to be polarized. Subsequently, when electrons are injected into the reference layer 14, they are further polarized, resulting in the vast majority of electrons being spin polarized, thereby improving the tunneling magnetoresistivity of the magnetic tunnel junction 1. When the magnetic tunnel junction 1 includes a first spin polarization enhancement layer 16 and electrons flow from the free layer 12 toward the reference layer 14, the electrons are first polarized by the first spin polarization enhancement layer 16. The first spin polarization enhancement layer 16 is a spin half-metal material with high spin polarization, which allows most of the electrons to be polarized. Subsequently, when the electrons are injected into the free layer 12, they are further polarized, thus allowing the vast majority of electrons to be spin polarized, which can improve the tunneling magnetoresistivity of the magnetic tunnel junction 1.

[0043] Specifically, the spin polarization of the first spin polarization enhancement layer 16 can be 0.8, 0.9, 1.0, etc.; the spin polarization of the second spin polarization enhancement layer 17 can be 0.8, 0.9, 1.0, etc. The spin polarization of the first spin polarization enhancement layer 16 and the spin polarization of the second spin polarization enhancement layer 17 can be the same or different.

[0044] In one feasible embodiment, the materials of the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 include at least one of cobalt-iron-silicon alloy, cobalt-iron-silicon-aluminum alloy, nickel-cobalt oxide, nickel-manganese-antimony alloy, platinum-manganese-antimony alloy, nickel-chromium-silicon alloy, palladium-chromium-silicon alloy, chromium dioxide, lanthanum-manganese oxide, arsenic-manganese oxide, and chromium arsenide. A superlattice material can be formed when multiple of the above materials are included. Each of the above materials may include multiple components.

[0045] In one feasible implementation, such as Figure 6As shown, at least one magnetic layer also includes a high data retention layer 18, which is located between the free layer 12 and the spin-orbit coupling layer 11. The anisotropy of the high data retention layer 18 is greater than that of the free layer 12, and the magnetization directions of the high data retention layer 18 and the free layer 12 are opposite.

[0046] In the above embodiments, the anisotropy of the high data retention layer 18 is greater than that of the free layer 12, that is, the high data retention layer 18 has strong anisotropy. The magnetization directions of the high data retention layer 18 and the free layer 12 are opposite, thereby achieving antiferromagnetic coupling with the free layer 12, which helps to improve the data retention time, thermal stability and external field stability of the free layer 12.

[0047] In one feasible implementation, the material of the high data retention layer 18 includes at least one of a cobalt-iron-boron alloy, a cobalt-iron alloy, a cobalt-iron-aluminum alloy, multiple alternating cobalt layers and platinum layers, and multiple alternating cobalt layers and palladium layers.

[0048] In one feasible implementation, such as Figure 6 As shown, at least one magnetic layer includes a first spin polarization enhancement layer 16, and a high data retention layer 18 is located between the first spin polarization enhancement layer 16 and the spin-orbit coupling layer 11. The magnetization direction of the high data retention layer 18 is opposite to the magnetization direction of the first spin polarization enhancement layer 16.

[0049] In the above embodiment, the magnetic tunnel junction 1 includes a spin-orbit coupling layer 11, a high data retention layer 18, a first spin polarization enhancement layer 16, a free layer 12, a barrier layer 13, a reference layer 14, and a pinning layer 15 stacked together. The magnetization direction of the data retention layer is opposite to that of the first spin polarization enhancement layer 16, and the magnetization direction of the first spin polarization enhancement layer 16 is the same as that of the free layer 12. When current flows through the spin-orbit coupling layer 11, a vertical spin current is generated due to the spin Hall effect of the spin-orbit coupling layer 11 or the Rashba effect at the interface, causing the high data retention layer 18 to flip, which in turn causes the first spin polarization enhancement layer 16 to flip, and consequently the free layer 12 to flip.

[0050] In one feasible implementation, such as Figure 7 As shown, at least one magnetic layer further includes a fast-flipping ferromagnetic layer 19, which is located between the free layer 12 and the spin-orbit coupling layer 11. The anisotropy of the fast-flipping ferromagnetic layer 19 is less than that of the free layer 12, and the magnetization direction of the fast-flipping ferromagnetic layer 19 is the same as that of the free layer 12.

[0051] In the above embodiment, the fast-flipping ferromagnetic layer 19 has low anisotropy and a low damping coefficient, with a damping coefficient of less than 0.01. The fast-flipping ferromagnetic layer 19 can increase the flipping speed of the free layer 12, thereby improving the read / write speed.

[0052] In one feasible implementation, the material of the rapidly flipping ferromagnetic layer 19 includes at least one of cobalt-iron-boron alloy (CoFeB), cobalt-iron alloy (CoFe), and cobalt-iron-aluminum alloy (CoFeAl).

[0053] In one feasible implementation, such as Figure 8 As shown, at least one magnetic layer includes a high data retention layer 18 and a fast-flipping ferromagnetic layer 19. The high data retention layer 18 is located between the free layer 12 and the spin-orbit coupling layer 11, and the fast-flipping ferromagnetic layer 19 is located between the high data retention layer 18 and the spin-orbit coupling layer 11. The polarization direction of the fast-flipping ferromagnetic layer 19 is opposite to the magnetization direction of the high data retention layer 18.

[0054] In the above embodiment, the magnetic tunnel junction 1 includes a spin-orbit coupling layer 11, a fast-flipping ferromagnetic layer 19, a high data retention layer 18, a free layer 12, a barrier layer 13, a reference layer 14, and a pinning layer 15, all stacked together. The magnetization direction of the fast-flipping ferromagnetic layer 19 is opposite to that of the high data retention layer 18. When current flows through the spin-orbit coupling layer 11, a vertical spin current is generated due to the spin Hall effect of the spin-orbit coupling layer 11 or the Rashba effect at the interface, causing the fast-flipping ferromagnetic layer 19 to flip rapidly, which in turn causes the high data retention layer 18 to flip, and consequently the free layer 12 to flip.

[0055] In one feasible implementation, such as Figure 9 As shown, at least one magnetic layer includes a first spin polarization enhancement layer 16, which is located between the free layer 12 and the high data retention layer 18.

[0056] In the above embodiments, a first spin polarization enhancement layer 16 may also be included, i.e., the magnetic tunnel junction 1 includes a spin-orbit coupling layer 11, a fast-flipping ferromagnetic layer 19, a high data retention layer 18, a first spin polarization enhancement layer 16, a free layer 12, a barrier layer 13, a reference layer 14, and a pinning layer 15 stacked together. The magnetization direction of the fast-flipping ferromagnetic layer 19 is opposite to that of the high data retention layer 18, the magnetization direction of the high data retention layer 18 is opposite to that of the first spin polarization enhancement layer 16, and the magnetization direction of the first spin polarization enhancement layer 16 is the same as that of the free layer 12. When current flows through the spin-orbit coupling layer 11, a vertical spin current is generated due to the spin Hall effect of the spin-orbit coupling layer 11 or the Rashba effect at the interface, causing the fast-flipping ferromagnetic layer 19 to flip rapidly, which in turn drives the high data retention layer 18 to flip, thereby causing the first spin polarization enhancement layer 16 and the free layer 12 to flip.

[0057] In one feasible implementation, the effective thermal stability factor of the rapidly flipping ferromagnetic layer 19, the high data retention layer 18, the first spin polarization enhancement layer 16, and the free layer 12 is greater than or equal to 40.

[0058] In the above embodiments, the parameter combination of the high data retention layer and the fast-flipping ferromagnetic layer can be flexibly selected and adjusted according to the requirements of energy consumption, flipping speed and data retention time. However, the total effective thermal stability factor of the four layers, namely the fast-flipping ferromagnetic layer 19, the high data retention layer 18, the first spin polarization enhancement layer 16 and the free layer 12, should be greater than or equal to 40 in order to achieve good data retention time and reliability.

[0059] In one feasible implementation, such as Figure 10 As shown, the free layer 12 and the reference layer 14 are stacked along the first direction x, and the magnetization directions y of the free layer 12, the reference layer 14, the pinning layer 15, and each magnetic layer are all perpendicular to the first direction x. Alternatively, as... Figure 9 As shown, the free layer 12 and the reference layer 14 are stacked along the first direction x, and the magnetization directions y of the free layer 12, the reference layer 14, the pinning layer 15 and each magnetic layer are all parallel to the first direction x.

[0060] Specifically, the fast-flipping ferromagnetic layer 19 has magnetic anisotropy at an acute angle to or along the first direction x; the high data retention layer 18 has strong magnetic anisotropy along the first direction x; the free layer 12 and the reference layer 14 both have magnetic anisotropy along the first direction x; and the pinning layer 15 has strong perpendicular magnetic anisotropy along the first direction x. Here, "strong magnetic anisotropy" refers to an anisotropy significantly greater than that of the free layer 12, or a coercivity significantly greater than that of the free layer 12.

[0061] In one feasible implementation, such as Figure 10As shown, it also includes a spacer layer 20 disposed adjacent to the magnetic layer, and the material of the spacer layer 20 includes a metallic material.

[0062] Specifically, such as Figure 10 As shown, the magnetic tunnel junction 1 may include multiple spacer layers 20. When the magnetic tunnel junction 1 includes a fast-flipping ferromagnetic layer 19, the multiple spacer layers 20 may include a first spacer layer 21, which is located on the surface of the fast-flipping ferromagnetic layer 19 facing away from the spin-orbit coupling layer 11. When the magnetic tunnel junction 1 includes a high data retention layer 18, the first spacer layer 21 may be located between the fast-flipping ferromagnetic layer 19 and the high data retention layer 18, and is adjacent to both the fast-flipping ferromagnetic layer 19 and the high data retention layer 18. Alternatively, when the magnetic tunnel junction 1 does not include the high data retention layer 18 but includes a first spin polarization enhancement layer 16, the first spacer layer 21 may be located between the fast-flipping ferromagnetic layer 19 and the first spin polarization enhancement layer 16, and is adjacent to both the fast-flipping ferromagnetic layer 19 and the first spin polarization enhancement layer 16. Alternatively, when the magnetic tunnel junction 1 does not include the high data retention layer 18 and the first spin polarization enhancement layer 16, the first spacer layer 21 may be located between the fast-flipping ferromagnetic layer 19 and the free layer 12, and be disposed adjacent to the fast-flipping ferromagnetic layer 19 and the free layer 12.

[0063] like Figure 10 As shown, when the magnetic tunnel junction 1 includes a high data retention layer 18, the multilayer spacer layer 20 may include a second spacer layer 22, which is located on the surface of the high data retention layer 18 facing away from the spin-orbit coupling layer 11. When the magnetic tunnel junction 1 includes a first spin polarization enhancement layer 16, the second spacer layer 22 may be located between the high data retention layer 18 and the first spin polarization enhancement layer 16, and is adjacent to both the high data retention layer 18 and the first spin polarization enhancement layer 16. Alternatively, when the magnetic tunnel junction 1 does not include the first spin polarization enhancement layer 16, the second spacer layer 22 may be located between the high data retention layer 18 and the free layer 12, and is adjacent to both the high data retention layer 18 and the free layer 12.

[0064] like Figure 10 As shown, when the magnetic tunnel junction 1 includes a second spin polarization enhancement layer 17, the multilayer spacer layer 20 may include a third spacer layer 23, which is located on the surface of the second spin polarization enhancement layer 17 facing away from the spin-orbit coupling layer 11. Specifically, the third spacer layer 23 is located between the second spin polarization enhancement layer 17 and the pinning layer 15, and is disposed adjacent to the second spin polarization enhancement layer 17 and the pinning layer 15.

[0065] like Figure 10As shown, the multilayer spacer layer 20 may include a fourth spacer layer 24, which is located on the surface of the reference layer 14 facing away from the spin-orbit coupling layer 11. Specifically, when the magnetic tunnel junction 1 includes a second spin polarization enhancement layer 17, the fourth spacer layer 24 may be located between the reference layer 14 and the second spin polarization enhancement layer 17 and is adjacent to both the reference layer 14 and the second spin polarization enhancement layer 17. The second spin polarization enhancement layer 17 is strongly ferromagnetically coupled to the reference layer 14 through the fourth spacer layer 24. In this case, the fourth spacer layer 24 may be omitted for ease of fabrication. Alternatively, when the magnetic tunnel junction 1 does not include the second spin polarization enhancement layer 17, the fourth spacer layer 24 may be located between the reference layer 14 and the pinning layer 15 and is adjacent to both the reference layer 14 and the pinning layer 15. The reference layer 14 is antiferromagnetically coupled to the pinning layer 15 through the fourth spacer layer 24.

[0066] like Figure 10 As shown, when the magnetic tunnel junction 1 includes a first spin polarization enhancement layer 16, the multilayer spacer layer 20 may include a fifth spacer layer 25, which is located on the surface of the first spin polarization enhancement layer 16 facing away from the spin-orbit coupling layer 11. Specifically, the fifth spacer layer 25 may be located between the first spin polarization enhancement layer 16 and the free layer 12 and be adjacent to both the first spin polarization enhancement layer 16 and the free layer 12.

[0067] Specifically, when the magnetization directions of the films located on both sides of the spacer layer 20 are the same, the spacer layer 20 can be omitted to save on the fabrication process. That is, the fourth spacer layer 24 and the fifth spacer layer 25 can be omitted.

[0068] In the above embodiments, the material of the spacer layer 20 includes at least one of ruthenium (Ru), tungsten (W), copper (Cu), tantalum (Ta), platinum (Pt), chromium (Cr), molybdenum (Mo), iridium (Ir), and vanadium (V).

[0069] Specifically, ferromagnetic (two film layers with the same magnetization direction) coupling or antiferromagnetic (two film layers with opposite magnetization directions) coupling and the corresponding strength can be achieved by changing the thickness of the spacer layer 20.

[0070] In one feasible implementation, the magnetic tunnel junction 1 further includes a seed layer 26 and a capping layer 27, one of which is located on the side of the spin-orbit coupling layer 11 away from the pinning layer 15, and the other of which is located on the side of the pinning layer 15 away from the spin-orbit coupling layer 11.

[0071] Specifically, the seed layer 26 is made of at least one of platinum (Pt), tantalum (Ta), and tungsten (W). The capping layer 27 is made of at least one of ruthenium (Ru), tantalum (Ta), titanium (Ti), chromium (Cr), platinum (Pt), gold (Au), copper nitride (CuN), and titanium nitride (TiN).

[0072] Specifically, such as Figure 11 As shown, in magnetic tunnel junction 1, the spin-orbit coupling layer 11 and the pinning layer 15 are arranged along the direction from the seed layer 26 to the capping layer 27. Alternatively, as... Figure 12 As shown, in the magnetic tunnel junction 1, the spin-orbit coupling layer 11 and the pinning layer 15 are arranged along the direction from the capping layer 27 to the seed layer 26. Both of the above methods can achieve the same effect.

[0073] This application also provides a magnetic storage device 2, such as... Figure 13 As shown, it includes at least one of the magnetic tunnel junctions 1 provided in the above embodiments.

[0074] In the magnetic memory 2 provided in this application, by providing a first spin polarization enhancement layer 16 and / or a second spin polarization enhancement layer 17 in the magnetic tunnel junction 1, the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 are made of spin half-metal materials and have high spin polarization. The magnetization direction of the first spin polarization enhancement layer 16 is the same as the magnetization direction of the free layer 12, and the magnetization direction of the second spin polarization enhancement layer 17 is the same as the magnetization direction of the reference layer 14, thereby improving the effective polarization of the read current of the magnetic tunnel junction 1, increasing the tunneling magnetoresistivity of the magnetic tunnel junction 1, and thus improving the performance of the magnetic memory 2.

[0075] In the magnetic storage device 2 provided in this application, such as Figure 14 As shown, by setting a high data retention layer 18 in the magnetic tunnel junction 1, the magnetization direction of the high data retention layer 18 is opposite to that of the free layer 12, and the anisotropy of the high data retention layer 18 is greater than that of the free layer 12, thereby improving the data retention time of the free layer 12 and the magnetic memory 2, and enhancing the thermal stability and external field stability of the magnetic memory 2.

[0076] In the magnetic storage device 2 provided in this application, such as Figure 15 As shown, by setting a fast-flipping ferromagnetic layer 19 in the magnetic tunnel junction 1, which has low anisotropy and low damping coefficient, and the magnetization direction of the fast-flipping ferromagnetic layer 19 is opposite to that of the high data retention layer 18, the fast-flipping ferromagnetic layer 19 can drive the high data retention layer 18 to flip rapidly, thereby improving the read and write speed of the magnetic memory 2.

[0077] The magnetic storage device 2 provided in this application may include one or more magnetic tunnel junctions 1. Specifically, as shown in the example... Figure 15 As shown, the magnetic memory 2 includes a substrate 3 and a magnetic tunnel junction 1 located on one side of the substrate 3. The magnetic tunnel junction 1 includes a seed layer 26, which is in contact with the substrate 3.

[0078] Specifically, such as Figure 15As shown, a magnetic memory 2 includes a seed layer 26 and a spin-orbit coupling layer 11, a fast-flipping ferromagnetic layer 19, a first spacer layer 21, a high data retention layer 18, a second spacer layer 22, a first spin polarization enhancement layer 16, a fifth spacer layer 25, a free layer 12, a barrier layer 13, a reference layer 14, a fourth spacer layer 24, a second spin polarization enhancement layer 17, a third spacer layer 23, a pinning layer 15, and a capping layer 27, which are sequentially stacked on one side of the seed layer 26.

[0079] like Figure 16 As shown, another type of magnetic memory 2 includes a seed layer 26 and, in sequence, a pinning layer 15, a third spacer layer 23, a second spin polarization enhancement layer 17, a fourth spacer layer 24, a reference layer 14, a barrier layer 13, a free layer 12, a fifth spacer layer 25, a first spin polarization enhancement layer 16, a second spacer layer 22, a high data retention layer 18, a first spacer layer 21, a fast-flipping ferromagnetic layer 19, a spin-orbit coupling layer 11, and a capping layer 27, which are stacked on one side of the seed layer 26.

[0080] This application also provides a method for fabricating a magnetic storage device, comprising:

[0081] S200, providing substrate 3.

[0082] Specifically, this may include chemical mechanical grinding and cleaning.

[0083] S400, at least one magnetic tunnel junction 1 is formed on one side of the substrate 3.

[0084] Specifically, the magnetic tunnel junction 1 includes a seed layer 26 and a capping layer 27 disposed opposite to each other, and also includes a spin-orbit coupling layer 11, a free layer 12, a barrier layer 13, a reference layer 14, a pinning layer 15 and at least one magnetic layer, wherein the at least one magnetic layer includes a first spin polarization enhancement layer 16 and / or a second spin polarization enhancement layer 17, and also includes part or all of a fast-flipping ferromagnetic layer 19 and a high data retention layer 18.

[0085] When forming the magnetic tunnel junction 1, the spin-orbit coupling layer 11, the free layer 12, the barrier layer 13, the reference layer 14, and the pinning layer 15 are stacked sequentially in a direction away from the seed layer 26, or the pinning layer 15, the reference layer 14, the barrier layer 13, the free layer 12, and the spin-orbit coupling layer 11 are stacked sequentially in a direction away from the seed layer 26.

[0086] Specifically, the above-mentioned film can be prepared by magnetron sputtering or chemical vapor deposition.

[0087] This also includes: performing annealing.

[0088] Specifically, the annealing temperature range can be from 250 degrees Celsius to 400 degrees Celsius, the gas atmosphere can be a vacuum or nitrogen environment, and the annealing time can be less than 2 hours. In addition, annealing can be assisted by an external magnetic field of less than 2T, and the magnetization direction of the external magnetic field is the same as the easy axis direction of the free layer 12, the reference layer 14, the pinned layer 15, and each magnetic layer.

[0089] It also includes: patterning.

[0090] Specifically, a mask can be formed using ultraviolet / deep ultraviolet / extreme ultraviolet lithography or electron beam lithography, followed by ion beam etching / reactive ion beam etching.

[0091] It also includes: using magnetron sputtering and chemical vapor deposition processes to form passivation and isolation materials.

[0092] It also includes: forming metal electrodes or interconnect metals using electron beam evaporation, sputtering or electroplating processes.

[0093] In one feasible implementation, such as Figure 17 As shown, the top layer 27 of the magnetic memory 2 can be connected to the first transistor 4, the spin-orbit coupling layer 11 of the magnetic memory 2 can be connected to the bit line 6, and the seed layer 26 of the magnetic memory 2 can be connected to the second transistor 5. The source of the first transistor 4 and the source of the second transistor 5 are connected via a source connection line 7. The gate of the first transistor 4 is connected to the first word line 8, and the drain of the first transistor 4 is connected to the top layer 27 of the magnetic memory 2. The gate of the second transistor 5 is connected to the second word line 9, and the drain of the second transistor 5 is connected to the seed layer 26 of the magnetic memory 2.

[0094] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A magnetic tunnel junction, comprising: The magnetic layer comprises a spin orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinned layer which are sequentially stacked; further comprising at least one magnetic layer, the at least one magnetic layer comprises: a first spin polarization enhancement layer between the spin orbit coupling layer and the free layer, the magnetization direction of the first spin polarization enhancement layer is the same as that of the free layer; a second spin polarization enhancement layer between the reference layer and the pinned layer, the magnetization direction of the second spin polarization enhancement layer is the same as that of the reference layer; the material of the first spin polarization enhancement layer and the second spin polarization enhancement layer comprises at least one of cobalt iron silicon alloy, cobalt iron silicon aluminum alloy, nickel cobalt oxide, nickel manganese antimony alloy, platinum manganese antimony alloy, nickel chromium silicon alloy, palladium chromium silicon alloy, lanthanum manganese oxide, arsenic manganese oxide and chromium arsenide.

2. The magnetic tunnel junction of claim 1, wherein, The spin polarization rate of the first spin polarization enhancement layer and the second spin polarization enhancement layer ranges from 0.8 to 1.

3. The magnetic tunnel junction of claim 1, wherein, The at least one magnetic layer further comprises: a high data retention layer between the free layer and the spin orbit coupling layer, the anisotropy energy of the high data retention layer is greater than that of the free layer, and the magnetization direction of the high data retention layer is opposite to that of the free layer.

4. The magnetic tunnel junction of claim 3, wherein, The material of the high data retention layer comprises at least one of cobalt iron boron alloy, cobalt iron alloy, cobalt iron aluminum alloy, multiple layers of alternately arranged cobalt layer and platinum layer, and multiple layers of alternately arranged cobalt layer and palladium layer.

5. The magnetic tunnel junction of claim 3, wherein, The at least one magnetic layer comprises the first spin polarization enhancement layer, and the high data retention layer is between the first spin polarization enhancement layer and the spin orbit coupling layer, and the magnetization direction of the high data retention layer is opposite to that of the first spin polarization enhancement layer.

6. The magnetic tunnel junction of claim 1, wherein, The at least one magnetic layer further comprises: a fast flipping ferromagnetic layer between the free layer and the spin orbit coupling layer, the anisotropy energy of the fast flipping ferromagnetic layer is less than that of the free layer, and the magnetization direction of the fast flipping ferromagnetic layer is the same as that of the free layer.

7. The magnetic tunnel junction of claim 6, wherein, The material of the fast flipping ferromagnetic layer comprises at least one of cobalt iron boron alloy, cobalt iron alloy and cobalt iron aluminum alloy.

8. The magnetic tunnel junction of claim 7, wherein, The at least one magnetic layer comprises a high data retention layer between the free layer and the spin orbit coupling layer, the magnetization direction of the high data retention layer is opposite to that of the free layer, and the fast flipping ferromagnetic layer is between the high data retention layer and the spin orbit coupling layer.

9. The magnetic tunnel junction of claim 8, wherein, The at least one magnetic layer comprises the first spin polarization enhancement layer, and the first spin polarization enhancement layer is between the free layer and the high data retention layer.

10. The magnetic tunnel junction of claim 1, wherein, The free layer and the reference layer are stacked along a first direction, and the magnetization directions of the free layer, the reference layer, the pinned layer and each magnetic layer are perpendicular to the first direction or parallel to the first direction.

11. The magnetic tunnel junction of claim 1, wherein, Further comprising a spacer layer adjacent to the magnetic layer, and the material of the spacer layer comprises a metal single element material.

12. The magnetic tunnel junction of claim 11, wherein, The material of the spacer layer comprises at least one of ruthenium, tungsten, copper, tantalum, platinum, chromium, molybdenum, iridium and vanadium.

13. The magnetic tunnel junction of claim 11, wherein, A seed layer and a capping layer are also included, one of the seed layer and the capping layer being located on a side of the spin orbit coupling layer facing away from the pinning layer, the other of the seed layer and the capping layer being located on a side of the pinning layer facing away from the spin orbit coupling layer.

14. A magnetic memory, comprising: At least one magnetic tunnel junction as claimed in any of claims 1-13 is included.

15. The magnetic memory of claim 14 wherein, A substrate and the magnetic tunnel junction located on a side of the substrate are included, the magnetic tunnel junction including a seed layer in contact with the substrate. A substrate and the magnetic tunnel junction located on a side of the substrate are included, the magnetic tunnel junction including a seed layer in contact with the substrate.

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