Magnetic tunnel junction and magnetic memory

Abstract

The invention discloses a magnetic tunnel junction and a magnetic memory. The magnetic tunnel junction comprises a spin-orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinning layer which are sequentially stacked, the spin-orbit coupling layer comprises a free layer and at least one magnetic layer, the at least one magnetic layer comprises a first spin-polarization enhancement layer and / or a second spin-polarization enhancement layer, the first spin-polarization enhancement layer is located between the spin-orbit coupling layer and the free layer, and the magnetization direction of the first spin-polarization enhancement layer is the same as that of the free layer; the second spin polarization enhancement layer is located between the reference layer and the pinning layer, and the magnetization direction of the second spin polarization enhancement layer is the same as the magnetization direction of the reference layer. The tunneling magnetic resistivity of the magnetic tunnel junction provided by the invention is improved.

Description

Technical Field

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

[0002] Magnetic random access memory (MRAM) is one of the new high-performance non-volatile memories with advantages such as high speed, high stability and high durability. Magnetic random access memory includes magnetic tunnel junction (MTJ), but the tunnel magnetoresistance (TMR) of the magnetic tunnel junction is low, generally only 100%-150%, which seriously affects the performance of magnetic memory. Summary of the invention

[0003] The purpose of this application is to at least solve the problem of low tunnel magnetoresistance of magnetic tunnel junctions. This purpose is achieved through the following technical solutions:

[0004] The first aspect of the present application provides a magnetic tunnel junction, which includes a spin-orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinned layer stacked in sequence; and also includes at least one magnetic layer, wherein the at least one magnetic layer includes:

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

[0006] The second spin polarization enhanced layer is located between the reference layer and the pinned layer, and the magnetization direction of the second spin polarization enhanced layer is the same as the magnetization direction of the reference layer.

[0007] The magnetic tunnel junction provided by the present application includes a spin-orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinned layer stacked in sequence, and also includes at least one magnetic layer, at least one magnetic layer includes a first spin polarization enhancement layer and / or a second spin polarization enhancement layer, and 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, the second spin polarization enhancement layer is located between the reference layer and the pinned layer. When electrons flow from the reference layer to the free layer, since the second spin polarization enhancement layer has the same magnetization direction as the reference layer, strong ferromagnetic coupling is achieved. The electrons are first polarized by the second spin polarization enhancement layer, and then injected into the reference layer for further polarization, so that most of the electrons are spin polarized, which can improve the tunneling magnetoresistance of the magnetic tunnel junction. When the magnetic tunnel junction includes a first spin polarization enhancement layer, the first spin polarization enhancement layer has the same magnetization direction as the free layer, thereby 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 of the interface, causing the first spin polarization enhancement layer to flip and driving the free layer to flip. In the magnetic tunnel junction provided by the present application, the effective polarization rate of the read current is increased by setting the first spin polarization enhancement layer and / or the second spin polarization enhancement layer, thereby increasing the tunnel magnetoresistance of the magnetic tunnel junction.

[0008] The second aspect of the present application also provides a magnetic memory, comprising at least one magnetic tunnel junction of any one of the types provided in the first aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

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

[0011] Figure 2 It is a schematic diagram of the partial structure of the first magnetic tunnel junction provided in an embodiment of the present application;

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

[0013] Figure 4 is a schematic diagram of a partial structure of a second magnetic tunnel junction provided in an embodiment of the present application;

[0014] Figure 5 It is a schematic diagram of the partial structure of the third magnetic tunnel junction provided in the embodiment of the present application;

[0015] Figure 6 is a schematic diagram of a partial structure of a fourth magnetic tunnel junction provided in an embodiment of the present application;

[0016] Figure 7 is a partial structural schematic diagram of a fifth magnetic tunnel junction provided in an embodiment of the present application;

[0017] Figure 8 is a partial structural schematic diagram of a sixth magnetic tunnel junction provided in an embodiment of the present application;

[0018] Fig. 9 is a partial structural schematic diagram of a seventh magnetic tunnel junction provided in an embodiment of the present application;

[0019] Fig.10 is a schematic diagram of a partial structure of an eighth magnetic tunnel junction provided in an embodiment of the present application;

[0020] Fig.11 is a partial structural schematic diagram of a ninth magnetic tunnel junction provided in an embodiment of the present application;

[0021] Fig.12 is a schematic diagram of a partial structure of a tenth magnetic tunnel junction provided in an embodiment of the present application;

[0022] Fig.13 It is a schematic diagram of the partial structure of the first magnetic storage device provided in the embodiment of the present application;

[0023] Fig.14 is a partial structural diagram of a second magnetic storage device provided in an embodiment of the present application;

[0024] Fig.15 is a partial structural diagram of a third magnetic storage device provided in an embodiment of the present application;

[0025] Fig.16 is a partial structural diagram of a fourth magnetic storage device provided in an embodiment of the present application;

[0026] Fig.17 It is a schematic diagram of the integrated structure of a magnetic storage provided in an embodiment of the present application.

[0027] The reference numerals are as follows:

[0028] 01. Barrier film layer; 02. Reference film layer; 1. Magnetic tunnel junction; 11. Spin-orbit coupling layer; 12. Free layer; 13. Barrier layer; 14. Reference layer; 15. Pinned layer; 16. First spin polarization enhancement layer; 17. Second spin polarization enhancement layer; 18. High data retention layer; 19. Fast flip 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 DESCRIPTION

[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0030] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0031] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0032] For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will 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 can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0033] It has been found through research that the magnetic tunnel junction in the magnetic memory in the related art includes a stacked spin-orbit coupling film layer, a free film layer, a barrier film layer 01, a reference film layer 02 and a pinned film layer. The magnetic tunnel junction can be written by spin transfer and read out by detecting the tunneling magnetoresistance (TMR) of the magnetic tunnel junction and applied in the magnetic memory. However, the magnetic tunnel junction (MTJ) has the disadvantage of low tunneling magnetoresistance (TMR). For example, Figure 1 As shown in the figure, the arrow is the flow direction of electrons. When electrons flow through the reference film layer 02, they are first polarized by the reference film layer 02. Since the spin polarization rate of the reference film layer 02 material is low, only a small number of electrons are polarized, which makes the tunneling magnetoresistance (TMR) of the magnetic tunnel junction (MTJ) low, generally only 100%-150%, which makes the read error rate of the magnetic memory higher.

[0034] Therefore, the present application provides a magnetic tunnel junction and a magnetic memory, wherein the tunneling magnetoresistance (TMR) of the magnetic tunnel junction (MTJ) is greatly improved, thereby greatly improving the performance of the magnetic memory.

[0035] like Figures 2 to 4 As shown, according to an embodiment of the present application, a magnetic tunnel junction 1 is proposed, which includes a spin-orbit coupling layer 11, a free layer 12, a barrier layer 13, a reference layer 14 and a pinned layer 15 stacked in sequence; it also includes at least one magnetic layer, the at least one magnetic layer 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 pinned 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 the present application includes a spin-orbit coupling layer 11, a free layer 12, a barrier layer 13, a reference layer 14 and a pinned layer 15 stacked in sequence, and also includes at least one magnetic layer, the at least one magnetic layer includes a first spin polarization enhancement layer 16 and / or a second spin polarization enhancement layer 17, and 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 the 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, since the second spin polarization enhancement layer 17 and the reference layer 14 have the same magnetization direction, strong ferromagnetic coupling is achieved. Figure 3 As shown in the figure, the arrow is the flow direction of electrons. The electrons are first polarized by the second spin polarization enhancement layer 17, and then injected into the reference layer 14 for further polarization, so that most of the electrons are spin polarized, which can improve the tunneling magnetoresistance of the magnetic tunnel junction 1. Figure 4 As shown, when the magnetic tunnel junction 1 includes the first spin polarization enhancement layer 16, the first spin polarization enhancement layer 16 has the same magnetization direction as the free layer 12, 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 of the interface, causing the first spin polarization enhancement layer 16 to flip and drive the free layer 12 to flip. In the magnetic tunnel junction 1 provided in the present application, the effective polarization rate of the read current is increased by setting the first spin polarization enhancement layer 16 and / or the second spin polarization enhancement layer 17, thereby increasing the tunneling magnetoresistance of the magnetic tunnel junction 1.

[0037] In the above-mentioned embodiments, the reference layer 14 and the free layer 12 are magnetic, and the magnetization of the reference layer 14 is usually fixed or pinned in a specific direction by the exchange bias of the pinning layer 15. The free layer 12 has a changeable magnetization direction. In order to switch the magnetization direction of the free layer 12, a driving current is provided along the arrangement direction of the reference layer 14 and the free layer 12. When a sufficient driving 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 a sufficient driving 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 magnetic resistances, and thus corresponds to different logical states (e.g., logical "0" and logical "1") of the magnetic tunnel junction 1. Therefore, by reading the tunneling magnetic resistance of the magnetic tunnel junction 1, the state of the magnetic tunnel junction 1 can be determined.

[0038] Specifically, the material of the free layer 12 includes at least one of cobalt iron boron alloy (CoFeB), cobalt iron alloy (CoFe), and cobalt iron aluminum alloy (CoFeAl), or includes multiple layers of cobalt layers and platinum layers arranged alternately, or includes multiple layers of cobalt layers and palladium layers arranged alternately. The material of the reference layer 14 includes at least one of cobalt iron boron alloy (CoFeB), cobalt iron alloy (CoFe), and cobalt iron aluminum alloy (CoFeAl), or includes multiple layers of cobalt layers and platinum layers arranged alternately, or includes multiple layers of cobalt layers and palladium layers arranged alternately. The material of the barrier layer 13 includes magnesium oxide (MgO), aluminum oxide (Al 2 O 3 ), magnesium aluminum oxide (MgAlO). The material of the pinning layer 15 includes multiple layers of cobalt layers and platinum layers alternately arranged, or includes multiple layers of cobalt layers and palladium layers alternately arranged, or includes 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 includes at least one of heavy metals, heavy metal alloys, antiferromagnetism, light metal oxides, topological insulators, oxide two-dimensional electron gas, and semi-metal materials. Specifically, heavy metals include platinum (Pt), tantalum (Ta), tungsten (W) and their alloys. Antiferromagnets include manganese iridium alloys (IrMn), manganese iron alloys (FeMn), manganese platinum alloys (PtMn), manganese palladium alloys (PdMn), etc. Light metal oxides include copper oxide (CuOx), titanium oxide (TiOx), etc., where x is a positive number. Topological insulators include selenium bismuth alloys (BiSe), antimony bismuth alloys (Bi 0.9 Sb 0.1 )、(Bi,Sb) 2 Te 3 etc. Oxide two-dimensional electron gas SrTiO 3 / LaAlO 3 、SrTiO 3 / AlOx、KTaO 3 / LaAlO 3 , KTaO 3 / LaVO 3 etc., semi-metallic materials including PtTe 2 、MoTe 2 , PtSe 2 , SrIrO 3 wait.

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

[0040] In the above implementation mode, if Figure 5 As shown, the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 may also be provided simultaneously, which may further improve the tunneling magnetoresistance (TMR).

[0041] In a feasible implementation, the spin polarization ratio of the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 is in the range of 0.8 to 1. The material of the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 includes a spin half-metal material.

[0042] In the above embodiment, 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 the electrons flow from the reference layer 14 to the free layer 12, the electrons are first polarized by the second spin polarization enhancement layer 17, and the second spin polarization enhancement layer 17 is a spin semi-metal material with a high spin polarization rate, so that most of the electrons can be polarized, and then the electrons are further polarized when injected into the reference layer 14, so that most of the electrons are spin polarized, which can improve the tunneling magnetoresistance of the magnetic tunnel junction 1. When the magnetic tunnel junction 1 includes the first spin polarization enhancement layer 16 and electrons flow from the free layer 12 to 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 semi-metal material with a high spin polarization rate, so that most of the electrons can be polarized. Subsequently, the electrons are further polarized when injected into the free layer 12, so that most of the electrons are spin polarized, which can improve the tunneling magnetoresistance of the magnetic tunnel junction 1.

[0043] Specifically, the spin polarization rate of the first spin polarization enhanced layer 16 may be 0.8, 0.9, 1.0, etc., and the spin polarization rate of the second spin polarization enhanced layer 17 may be 0.8, 0.9, 1.0, etc. The spin polarization rate of the first spin polarization enhanced layer 16 may be the same as or different from the spin polarization rate of the second spin polarization enhanced layer 17.

[0044] In a feasible implementation, the material of the first spin polarization enhancement layer 16 and the second spin polarization enhancement layer 17 includes 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. When multiple of the above materials are included, a superlattice material can be formed. Each of the above materials may include multiple components.

[0045] In a possible implementation, Figure 6 As 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 the anisotropy 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 embodiment, the anisotropy of the high data retention layer 18 is greater than the anisotropy of the free layer 12, that is, the high data retention layer 18 has strong anisotropy, and the magnetization direction of the high data retention layer 18 is opposite to that of the free layer 12, 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 a feasible embodiment, the material of the high data retention layer 18 includes at least one of cobalt-iron-boron alloy, cobalt-iron alloy, cobalt-iron-aluminum alloy, multiple layers of cobalt and platinum layers alternately disposed, and multiple layers of cobalt and palladium layers alternately disposed.

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

[0049] In the above embodiment, the magnetic tunnel junction 1 includes a stacked 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 pinned layer 15. 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 of the interface, so that the high data retention layer 18 is flipped, and the first spin polarization enhancement layer 16 is flipped, and then the free layer 12 is flipped.

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

[0051] In the above embodiment, the fast switching ferromagnetic layer 19 has low anisotropy and low damping coefficient, and its damping coefficient is less than 0.01. The fast switching ferromagnetic layer 19 can increase the switching speed of the free layer 12, thereby improving the reading and writing speed.

[0052] In a feasible implementation, the material of the fast-switching 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 a possible implementation, Figure 8 As shown, at least one magnetic layer includes a high data retention layer 18 and a fast flip ferromagnetic layer 19, the high data retention layer 18 is located between the free layer 12 and the spin-orbit coupling layer 11, the fast flip ferromagnetic layer 19 is located between the high data retention layer 18 and the spin-orbit coupling layer 11, and the polarization direction of the fast flip 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 stacked spin-orbit coupling layer 11, a fast flip ferromagnetic layer 19, a high data retention layer 18, a free layer 12, a barrier layer 13, a reference layer 14 and a pinned layer 15. The magnetization direction of the fast flip 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 of the interface, causing the fast flip ferromagnetic layer 19 to flip quickly, and driving the high data retention layer 18 to flip, thereby causing the free layer 12 to flip.

[0055] In a possible implementation, Fig. 9 As shown, the at least one magnetic layer includes a first spin polarization enhanced layer 16 , and the first spin polarization enhanced layer 16 is located between the free layer 12 and the high data retention layer 18 .

[0056] In the above embodiment, a first spin polarization enhancement layer 16 may also be included, that is, the magnetic tunnel junction 1 includes a stacked spin-orbit coupling layer 11, a fast flip 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 pinned layer 15. The magnetization direction of the fast flip ferromagnetic layer 19 is opposite to that of the high data retention layer 18, and 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 of the interface, so that the fast flip ferromagnetic layer 19 flips quickly, and drives the high data retention layer 18 to flip, thereby flipping the first spin polarization enhancement layer 16 and the free layer 12.

[0057] In a feasible implementation manner, the effective thermal stability factors of the fast-switching ferromagnetic layer 19 , the high data retention layer 18 , the first spin polarization enhanced layer 16 , and the free layer 12 are greater than or equal to 40.

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

[0059] In a possible implementation, Fig.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 pinned layer 15 and each magnetic layer are perpendicular to the first direction x. Fig. 9 As shown, the free layer 12 and the reference layer 14 are stacked along a first direction x, and the magnetization directions y of the free layer 12 , the reference layer 14 , the pinned layer 15 and each magnetic layer are parallel to the first direction x.

[0060] Specifically, the fast flip ferromagnetic layer 19 has a magnetic anisotropy that is at an acute angle to the first direction x or along the first direction x, the high data retention layer 18 has a 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 pinned layer 15 has a strong perpendicular magnetic anisotropy along the first direction x. Here, "strong magnetic anisotropy" means that the anisotropy energy is significantly greater than the anisotropy energy of the free layer 12 or the coercive force is significantly greater than the coercive force of the free layer 12.

[0061] In a possible implementation, Fig.10As shown, the magnetic layer further includes a spacer layer 20 disposed adjacent to the magnetic layer, and the spacer layer 20 is made of a single metal material.

[0062] Specifically, Fig.10 As shown, the magnetic tunnel junction 1 may include a plurality of spacer layers 20. When the magnetic tunnel junction 1 includes a fast-switching ferromagnetic layer 19, the plurality of spacer layers 20 may include a first spacer layer 21. The first spacer layer 21 is located on the surface of the fast-switching ferromagnetic layer 19 on the side 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-switching ferromagnetic layer 19 and the high data retention layer 18, and may be disposed adjacent to the fast-switching ferromagnetic layer 19 and the high data retention layer 18. Alternatively, when the magnetic tunnel junction 1 does not include a high data retention layer 18 and includes a first spin polarization enhancement layer 16, the first spacer layer 21 may be located between the fast-switching ferromagnetic layer 19 and the first spin polarization enhancement layer 16, and may be disposed adjacent to the fast-switching 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 switching ferromagnetic layer 19 and the free layer 12 , and disposed adjacent to the fast switching ferromagnetic layer 19 and the free layer 12 .

[0063] like Fig.10 As shown, when the magnetic tunnel junction 1 includes the high data retention layer 18, the multi-layer spacer layer 20 may include a second spacer layer 22, and the second spacer layer 22 is located on the surface of the high data retention layer 18 on the side away from the spin-orbit coupling layer 11. When the magnetic tunnel junction 1 includes the 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 disposed adjacent to 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 disposed adjacent to the high data retention layer 18 and the free layer 12.

[0064] like Fig.10 As shown, when the magnetic tunnel junction 1 includes the second spin polarization enhancement layer 17, the multilayer spacer layer 20 may include a third spacer layer 23, and the third spacer layer 23 is located on the surface of the second spin polarization enhancement layer 17 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 pinned layer 15, and is disposed adjacent to the second spin polarization enhancement layer 17 and the pinned layer 15.

[0065] like Fig.10As shown, the multilayer spacer layer 20 may include a fourth spacer layer 24, and the fourth spacer layer 24 is located on the surface of the reference layer 14 on the side away from the spin-orbit coupling layer 11. Specifically, when the magnetic tunnel junction 1 includes the 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 disposed adjacent to the reference layer 14 and the second spin polarization enhancement layer 17, and 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, for ease of preparation, the fourth spacer layer 24 may be omitted. 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 pinned layer 15 and is disposed adjacent to the reference layer 14 and the pinned layer 15, and the reference layer 14 is antiferromagnetically coupled to the pinned layer 15 through the fourth spacer layer 24.

[0066] like Fig.10 As shown, when the magnetic tunnel junction 1 includes the first spin polarization enhancement layer 16, the multilayer spacer layer 20 may include a fifth spacer layer 25, and the fifth spacer layer 25 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 is disposed adjacent to the first spin polarization enhancement layer 16 and the free layer 12.

[0067] Specifically, when the magnetization directions of the film layers on both sides of the spacer layer 20 are the same, the spacer layer 20 can be omitted to save the manufacturing process, that is, the fourth spacer layer 24 and the fifth spacer layer 25 can be omitted.

[0068] In the above embodiment, 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 (the two film layers have the same magnetization direction) coupling or antiferromagnetic (the two film layers have opposite magnetization directions) coupling and the corresponding strength can be achieved by changing the thickness of the spacer layer 20 .

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

[0071] Specifically, the material of the seed layer 26 includes at least one of platinum (Pt), tantalum (Ta), and tungsten (W). The material of the capping layer 27 includes 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, Fig.11 As shown, in the magnetic tunnel junction 1, the spin-orbit coupling layer 11 and the pinning layer 15 are arranged in a direction from the seed layer 26 to the capping layer 27. Fig.12 As shown, in the magnetic tunnel junction 1, the spin-orbit coupling layer 11 and the pinning layer 15 are arranged along a direction from the capping layer 27 to the seed layer 26. Both of the above-mentioned methods can achieve the same effect.

[0073] The present application also provides a magnetic storage device 2, such as Fig.13 As shown, it includes at least one magnetic tunnel junction 1 provided in any one of the above embodiments.

[0074] In the magnetic memory 2 provided in the present application, a first spin polarization enhancement layer 16 and / or a second spin polarization enhancement layer 17 are arranged 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 semi-metal materials and have a high spin polarization rate. 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 rate of the read current of the magnetic tunnel junction 1, improving the tunneling magnetoresistance of the magnetic tunnel junction 1, and thereby improving the performance of the magnetic memory 2.

[0075] In the magnetic storage device 2 provided in the present application, Fig.14 As shown, a high data retention layer 18 can be set in the magnetic tunnel junction 1, and the magnetization direction of the high data retention layer 18 is opposite to the magnetization direction of the free layer 12, and the anisotropy of the high data retention layer 18 is greater than the anisotropy of the free layer 12, thereby increasing the data retention time of the free layer 12 and the magnetic storage device 2, and improving the thermal stability and external field stability of the magnetic storage device 2.

[0076] In the magnetic storage device 2 provided in the present application, Fig.15 As shown, a fast flip ferromagnetic layer 19 with low anisotropy and low damping coefficient can be set in the magnetic tunnel junction 1. The magnetization direction of the fast flip ferromagnetic layer 19 is opposite to that of the high data retention layer 18. The fast flip ferromagnetic layer 19 can drive the high data retention layer 18 to flip quickly, thereby improving the reading and writing speed of the magnetic storage 2.

[0077] The magnetic memory 2 provided in the present application may include one or more magnetic tunnel junctions 1. Specifically, Fig.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 , and the seed layer 26 is in contact with the substrate 3 .

[0078] Specifically, Fig.15As shown, a magnetic memory 2 includes a seed layer 26 and a spin-orbit coupling layer 11, a fast flip 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 stacked in sequence on one side of the seed layer 26.

[0079] like Fig.16 As shown, another magnetic memory 2 includes a seed layer 26 and a pinned 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 flip ferromagnetic layer 19, a spin-orbit coupling layer 11, and a capping layer 27, which are stacked in sequence on one side of the seed layer 26.

[0080] The present application also provides a method for preparing a magnetic memory, comprising:

[0081] S200 , providing a substrate 3 .

[0082] Specifically, it may include chemical mechanical polishing and cleaning.

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

[0084] Specifically, the magnetic tunnel junction 1 includes a seed layer 26 and a capping layer 27 that are relatively arranged, and also includes a stacked spin-orbit coupling layer 11, a free layer 12, a barrier layer 13, a reference layer 14, a pinned layer 15 and at least one magnetic layer, 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 flip 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 pinned layer 15 are stacked in sequence in a direction away from the seed layer 26, or the pinned layer 15, the reference layer 14, the barrier layer 13, the free layer 12, and the spin-orbit coupling layer 11 are stacked in sequence in a direction away from the seed layer 26.

[0086] Specifically, the above film layer can be prepared by a magnetron sputtering process or a chemical vapor deposition process.

[0087] The method also includes: performing annealing treatment.

[0088] Specifically, the annealing temperature range may be 250 degrees Celsius to 400 degrees Celsius, the gas atmosphere may be a vacuum or nitrogen environment, and the annealing time may be less than 2 hours. In addition, the annealing may be assisted under an external magnetic field 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] Also includes: performing patterning processing.

[0090] Specifically, ultraviolet / deep ultraviolet / extreme ultraviolet lithography or electron beam exposure technology can be used to form a mask, and then ion beam etching / reactive ion beam etching can be used.

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

[0092] The method also includes forming metal electrodes or interconnecting metals by electron beam evaporation, sputtering or electroplating process.

[0093] In a possible implementation, Fig.17 As shown, the capping 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. Among them, the source of the first transistor 4 is connected to the source of the second transistor 5 through the 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 capping 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 only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A magnetic tunnel junction, characterized in that: The invention comprises a spin-orbit coupling layer, a free layer, a barrier layer, a reference layer and a pinned layer which are stacked in sequence; and at least one magnetic layer, wherein the at least one magnetic layer comprises: a first spin polarization enhancement layer, located between the spin-orbit coupling layer and the free layer, wherein the magnetization direction of the first spin polarization enhancement layer is the same as the magnetization direction of the free layer; and / or, The second spin polarization enhanced layer is located between the reference layer and the pinned layer, and the magnetization direction of the second spin polarization enhanced layer is the same as the magnetization direction of the reference layer.

2. The magnetic tunnel junction according to claim 1, characterized in that: The spin polarization ratio of the first spin polarization enhancement layer and the second spin polarization enhancement layer is in the range of 0.8-1; The material of the first spin polarization enhancement layer and the second spin polarization enhancement layer includes a spin half-metal material.

3. The magnetic tunnel junction according to claim 2, characterized in that: The material of the first spin polarization enhanced layer and the second spin polarization enhanced layer includes 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.

4. The magnetic tunnel junction according to claim 1, characterized in that: At least one of the magnetic layers further comprises: A high data retention layer is located between the free layer and the spin-orbit coupling layer, the anisotropy of the high data retention layer is greater than the anisotropy of the free layer, and the magnetization directions of the high data retention layer and the free layer are opposite.

5. The magnetic tunnel junction according to claim 4, characterized in that: The material of the high data retention layer includes at least one of cobalt-iron-boron alloy, cobalt-iron alloy, cobalt-iron-aluminum alloy, multiple layers of cobalt layers and platinum layers alternately arranged, and multiple layers of cobalt layers and palladium layers alternately arranged.

6. The magnetic tunnel junction according to claim 4, characterized in that: At least one of the magnetic layers includes the first spin polarization enhancement layer, the high data retention layer is located 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.

7. The magnetic tunnel junction according to claim 1, characterized in that: At least one of the magnetic layers further comprises: A fast-switching ferromagnetic layer is located between the free layer and the spin-orbit coupling layer, the anisotropy energy of the fast-switching ferromagnetic layer is smaller than the anisotropy energy of the free layer, and the magnetization direction of the fast-switching ferromagnetic layer is the same as the magnetization direction of the free layer.

8. The magnetic tunnel junction according to claim 7, characterized in that: The material of the fast-switching ferromagnetic layer includes at least one of a cobalt-iron-boron alloy, a cobalt-iron alloy, and a cobalt-iron-aluminum alloy.

9. The magnetic tunnel junction according to claim 8, characterized in that: At least one of the magnetic layers includes a high data retention layer, which is located 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 flip ferromagnetic layer is located between the high data retention layer and the spin-orbit coupling layer.

10. The magnetic tunnel junction according to claim 9, characterized in that: At least one of the magnetic layers includes the first spin polarization enhanced layer, and the first spin polarization enhanced layer is located between the free layer and the high data retention layer.

11. The magnetic tunnel junction according to claim 1, characterized in that: The free layer and the reference layer are stacked along a first direction, and magnetization directions of the free layer, the reference layer, the pinned layer and each of the magnetic layers are perpendicular to the first direction or parallel to the first direction.

12. The magnetic tunnel junction according to claim 1, characterized in that: It also includes a spacing layer disposed adjacent to the magnetic layer, and the material of the spacing layer includes a metal single substance material.

13. The magnetic tunnel junction according to claim 12, characterized in that: The material of the spacer layer includes at least one of ruthenium, tungsten, copper, tantalum, platinum, chromium, molybdenum, iridium, and vanadium.

14. The magnetic tunnel junction according to claim 12, characterized in that: It also includes a seed layer and a capping layer, one of which is located on a side of the spin-orbit coupling layer away from the pinned layer, and the other of which is located on a side of the pinned layer away from the spin-orbit coupling layer.

15. A magnetic memory, characterized in that: Comprising at least one magnetic tunnel junction as claimed in any one of claims 1 to 14.

16. The magnetic memory according to claim 15, characterized in that: It comprises a substrate and the magnetic tunnel junction located at one side of the substrate, wherein the magnetic tunnel junction comprises a seed layer, and the seed layer is in contact with the substrate.

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