A magnetic storage unit and a magnetic memory

Abstract

This invention discloses a magnetic storage unit and a magnetic memory. The magnetic storage unit includes an upper electrode, a pinning layer, a coupling layer, a fixed magnetic layer, a tunneling barrier layer, a free magnetic layer, and a lower electrode. These components are stacked sequentially. The coupling layer enables antiferromagnetic coupling between the fixed magnetic layer and the pinning layer. The pinning layer eliminates stray fields from the fixed magnetic layer to the free magnetic layer, and a material-doped region is provided within the pinning layer. By providing the pinning layer, the stray field from the fixed magnetic layer to the free magnetic layer can be eliminated. The material-doped region within the pinning layer ensures that the stray field experienced by the free magnetic layer remains very small under temperature changes.

Description

Technical Field

[0001] This invention relates to the field of magnetic memory technology, and particularly to a magnetic memory cell and a magnetic memory. Background Technology

[0002] Magnetic Random Access Memory (MRAM) is considered the future of solid-state non-volatile memory, characterized by high-speed read / write, large capacity, and low power consumption. However, MRAM generates stray fields, which can negatively impact its performance. Some technologies reduce stray fields by adding multiple layers of artificial antiferromagnetic layers. However, temperature has a significant impact on stray fields, and these technologies cannot eliminate temperature-dependent stray fields in MRAM, nor can they maintain a consistently low stray field value under temperature variations. Summary of the Invention

[0003] Therefore, it is necessary to provide a magnetic storage cell and a magnetic memory that can solve the technical problems in the related art of not being able to eliminate temperature-dependent stray fields in MRAM and not being able to keep the stray fields at a very small value under temperature changes.

[0004] The present invention provides a magnetic storage cell comprising an upper electrode, a pinning layer, a coupling layer, a fixed magnetic layer, a tunneling barrier layer, a free magnetic layer, and a lower electrode. The upper electrode, the pinning layer, the coupling layer, the fixed magnetic layer, the tunneling barrier layer, the free magnetic layer, and the lower electrode are stacked sequentially. The coupling layer is used to form an antiferromagnetic coupling between the fixed magnetic layer and the pinning layer. The pinning layer is used to eliminate the stray field of the fixed magnetic layer on the free magnetic layer, and a material doping region is provided within the pinning layer.

[0005] Furthermore, the material doping region is configured as a plurality of regions, and the plurality of material doping regions are uniformly distributed within the pinning layer.

[0006] Furthermore, the doped region of the material is an alloy material.

[0007] Furthermore, the material doping region includes one or more combinations of vanadium, chromium, copper, niobium, molybdenum, ruthenium, rhodium, tantalum, tungsten, rhenium, iridium, niobium, zirconium, yttrium, iron, nickel, cobalt, boron, carbon, nitrogen, oxygen, neodymium, europium, gadolinium, terbium, dysprosium, holmium, manganese, aluminum, silicon, phosphorus, gallium, germanium, arsenic, indium, tin, and antimony.

[0008] Furthermore, the material of the pinning layer includes ferromagnetic material, antiferromagnetic material, or ferrimagnetic material.

[0009] Furthermore, the material of the fixed magnetic layer includes ferromagnetic materials, antiferromagnetic materials, or subferromagnetic materials.

[0010] Furthermore, the material of the free magnetic layer includes ferromagnetic materials, antiferromagnetic materials, or subferromagnetic materials.

[0011] Furthermore, the material of the tunneling barrier layer is a metal oxide.

[0012] Furthermore, the material of the coupling layer includes one or more combinations of vanadium, chromium, copper, niobium, molybdenum, ruthenium, rhodium, tantalum, tungsten, rhenium, and iridium.

[0013] The present invention also provides a magnetic memory, including the magnetic memory unit described above.

[0014] This invention provides a magnetic storage unit and a magnetic memory. The magnetic storage unit includes an upper electrode, a pinning layer, a coupling layer, a fixed magnetic layer, a tunneling barrier layer, a free magnetic layer, and a lower electrode arranged sequentially. The pinning layer eliminates the stray field from the fixed magnetic layer to the free magnetic layer. A material doping region is provided within the pinning layer to ensure that the stray field on the free magnetic layer remains very small under temperature changes. The magnitude of the stray field is proportional to the saturation magnetization of the fixed magnetic layer and the pinning layer. However, due to the difference in the structural materials of the fixed magnetic layer and the pinning layer, the saturation magnetization does not change synchronously with temperature, as shown in Figure 3(a). This causes the stray field to change with temperature, and the greater the temperature change, the greater the shift in the stray field. Figure 4 As shown by the dashed line, by setting a material doping region within the pinning layer, the trend of the pinning layer's saturation magnetization changing with temperature can be altered. Furthermore, by precisely controlling the amount of the preset material doping region, the saturation magnetization of the fixed magnetic layer and the pinning layer can be made to change with temperature in a consistent manner, as shown in Figure 3(b). Ultimately, the stray field can be kept at a very small value (approximately equal to 0) and remain unchanged with temperature, as... Figure 4 As shown by the solid line. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a magnetic storage unit in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the pinning layer with a material doping region in an embodiment of the present invention.

[0018] Figure 3(a) shows the relationship between the saturation magnetization of the pinned layer and the fixed magnetic layer and the temperature when the pinned layer does not have a material doping region in the embodiment of the present invention; Figure 3(b) shows the relationship between the saturation magnetization of the pinned layer and the fixed magnetic layer and the temperature when the pinned layer has a material doping region in the embodiment of the present invention.

[0019] Figure 4 This is a graph showing the relationship between the stray field and temperature of the free magnetic layer before and after the material doping region is set in the pinning layer in an embodiment of the present invention.

[0020] Figure 5 This is a comparison chart showing the change in saturation magnetization of the CoPt alloy with temperature under different tungsten doping levels in embodiments of the present invention.

[0021] Figure 6 This is a schematic diagram of the structure of a magnetic storage cell in an embodiment of the present invention, wherein the pinning layer is in-plane magnetized.

[0022] in:

[0023] 100, Upper electrode; 200, Pinning layer; 210, Material doping region; 300, Coupling layer; 400, Fixed magnetic layer; 500, Tunneling barrier layer; 600, Free magnetic layer; 700, Lower electrode.

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] like Figure 1 As shown, in some embodiments, a magnetic storage cell includes an upper electrode 100, a pinning layer 200, a coupling layer 300, a fixed magnetic layer 400, a tunneling barrier layer 500, a free magnetic layer 600, and a lower electrode 700. The upper electrode 100, pinning layer 200, coupling layer 300, fixed magnetic layer 400, tunneling barrier layer 500, free magnetic layer 600, and lower electrode 700 are stacked sequentially. The coupling layer 300 is used to form an antiferromagnetic coupling between the fixed magnetic layer 400 and the pinning layer 200. The pinning layer 200 is used to eliminate the stray field of the fixed magnetic layer 400 on the free magnetic layer 600. The pinning layer 200 is provided with a material doping region (i.e., other elements are doped in the pinning layer 200). By setting the pinning layer 200, the stray field of the fixed magnetic layer 400 on the free magnetic layer 600 can be eliminated. By setting material doping regions on the pinning layer 200, the stray field of the free magnetic layer 600 can remain very small under temperature changes, achieving full-temperature stray field compensation. The magnitude of the stray field is proportional to the saturation magnetization of the fixed magnetic layer 400 and the pinning layer 200. However, due to the difference in structural materials between the fixed magnetic layer 400 and the pinning layer 200, the saturation magnetization does not change synchronously with temperature, as shown in Figure 3(a). Therefore, the stray field changes with temperature, and the greater the temperature change, the greater the stray field compensation. Figure 4 As shown by the dashed line, by setting a material doping region within the pinning layer 200, the trend of the saturation magnetization of the pinning layer 200 changing with temperature can be altered. Furthermore, by precisely controlling the amount of the preset material doping region, the saturation magnetization of the fixed magnetic layer 400 and the pinning layer 200 can be made to change with temperature in a consistent manner, as shown in Figure 3(b). Ultimately, the stray field can be kept at a very small value (approximately equal to 0) and remain unchanged with temperature, as... Figure 4 As shown by the solid line.

[0029] Among them, the pinning layer 200 can be in-plane magnetized (e.g., Figure 6As shown), it can also be out-of-plane magnetized, with the pinning layer 200 disposed between the upper electrode 100 and the coupling layer 300. The coupling layer 300 is formed on the side of the pinning layer 200 opposite to the upper electrode 100 (i.e., Figure 1 Below the pinning layer 200). The fixed magnetization layer is formed on the side of the coupling layer 300 opposite to the pinning layer 200 (i.e., Figure 1 Below the intermediate coupling layer 300, the magnetization can be either in-plane or out-of-plane. The tunneling barrier layer 500 is formed on the side of the fixed magnetic layer 400 away from the coupling layer 300 (i.e., below the intermediate coupling layer 300). Figure 1 Below the fixed magnetic layer 400. The free magnetic layer 600 is formed on the side of the tunneling barrier layer 500 opposite to the fixed magnetic layer 400 (i.e., below the fixed magnetic layer 400). Figure 1 Below the fixed magnetic layer 400, the magnetic moment direction of the free magnetic layer 600 serves as the carrier of information; it can be either in-plane magnetized or out-of-plane magnetized.

[0030] Specifically, such as Figure 2 As shown, multiple material doping regions are set, and these multiple material doping regions are evenly distributed on the pinning layer 200, which can more efficiently eliminate the temperature dependence of stray fields.

[0031] More specifically, the doped region of the material is an alloy material or an intercalated material.

[0032] Furthermore, the doping region of the material can be a transition metal element such as vanadium (V), chromium (Cr), copper (Cu), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), tantalum (Ta), tungsten (W), rhenium (Re), iridium (Ir), niobium (Nb), zirconium (Zr), yttrium (Y), iron (Fe), nickel (Ni), or cobalt (Co). Alternatively, it can be a light element such as boron (B), carbon (C), nitrogen (N), or oxygen (O). Or, it can be a rare earth element such as neodymium (Nd), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), or holmium (Ho). Or, it can be an element such as manganese (Mn), aluminum (Al), silicon (Si), phosphorus (P), gallium (Ga), germanium (Ge), arsenic (As), indium (In), tin (Sn), or antimony (Sb).

[0033] In this embodiment, the pinning layer 200 is made of a ferromagnetic, antiferromagnetic, or ferrimagnetic material. The fixed magnetic layer 400 is made of a ferromagnetic, antiferromagnetic, or ferrimagnetic material. The free magnetic layer 600 is made of a ferromagnetic, antiferromagnetic, or ferrimagnetic material.

[0034] Specifically, the magnetic material can use any existing alloy material or multilayer film structure containing one or more of iron (Fe), nickel (Ni), and cobalt (Co). Furthermore, the magnetic material can include transition metal elements such as niobium (Nb), zirconium (Zr), and yttrium (Y); or light elements such as boron (B), carbon (C), nitrogen (N), and oxygen (O); or rare earth elements such as neodymium (Nd), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), and holmium (Ho); and any existing Hessler alloy or other alloy containing manganese (Mn), aluminum (Al), silicon (Si), phosphorus (P), gallium (Ga), germanium (Ge), arsenic (As), indium (In), tin (Sn), and antimony (Sb).

[0035] Furthermore, the tunneling barrier layer 500 is an insulating layer.

[0036] Furthermore, the tunneling barrier layer 500 is made of a metal oxide. Metal oxides can be made using aluminum oxide (Al₂O₃). x ), magnesium oxide (MgO), silicon oxide (SiO) x ), Hafnium oxide (HfO) x Materials such as magnesium aluminum oxide (MgAlO).

[0037] Specifically, the material of the coupling layer 300 includes one or more combinations of vanadium, chromium, copper, niobium, molybdenum, ruthenium, rhodium, tantalum, tungsten, rhenium, and iridium.

[0038] In another embodiment, a magnetic memory includes magnetic storage cells.

[0039] Figure 3(a) shows the relationship between the saturation magnetization of the pinned layer and the fixed magnetic layer and the temperature when the pinned layer does not have a material doping region in the embodiment of the present invention; Figure 3(b) shows the relationship between the saturation magnetization of the pinned layer and the fixed magnetic layer and the temperature when the pinned layer has a material doping region in the embodiment of the present invention.

[0040] Figure 4 This is a graph showing the relationship between the stray field and temperature of the free magnetic layer before and after the material doping region is set in the pinning layer in an embodiment of the present invention.

[0041] Figure 5 The graph shows a comparison of the saturation magnetization of CoPt alloys with different tungsten doping levels, reflecting the change in saturation magnetization with temperature. The higher the W content, the more drastic the change in saturation magnetization with temperature, demonstrating that doping can alter the trend of saturation magnetization with temperature, thereby eliminating stray field variations with temperature.

[0042] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A magnetic storage unit, characterized in that, The device includes an upper electrode, a pinning layer, a coupling layer, a fixed magnetic layer, a tunneling barrier layer, a free magnetic layer, and a lower electrode. The upper electrode, the pinning layer, the coupling layer, the fixed magnetic layer, the tunneling barrier layer, the free magnetic layer, and the lower electrode are stacked sequentially. The coupling layer is used to form an antiferromagnetic coupling between the fixed magnetic layer and the pinning layer. The pinning layer is used to eliminate the stray field of the fixed magnetic layer on the free magnetic layer, and a material doping region is provided within the pinning layer. The material doping region is configured as multiple regions, which are uniformly distributed within the pinning layer. The material doping region is an alloy material or an intercalation material, and the material of the pinning layer includes ferromagnetic material, antiferromagnetic material, or subferromagnetic material. The amount of the preset material doping region is controlled so that the saturation magnetization of the fixed magnetic layer and the pinning layer changes in a consistent manner with temperature, and the stray field does not change with temperature.

2. The magnetic storage unit according to claim 1, characterized in that, The material doping region includes one or more combinations of vanadium, chromium, copper, molybdenum, ruthenium, rhodium, tantalum, tungsten, rhenium, iridium, niobium, zirconium, yttrium, iron, nickel, cobalt, boron, carbon, nitrogen, oxygen, neodymium, europium, gadolinium, terbium, dysprosium, holmium, manganese, aluminum, silicon, phosphorus, gallium, germanium, arsenic, indium, tin, and antimony.

3. The magnetic storage unit according to claim 1, characterized in that, The material of the fixed magnetic layer includes ferromagnetic materials, antiferromagnetic materials, or ferrimagnetic materials.

4. The magnetic storage unit according to claim 1, characterized in that, The material of the free magnetic layer includes ferromagnetic materials, antiferromagnetic materials, or subferromagnetic materials.

5. The magnetic storage unit according to claim 1, characterized in that, The material of the tunneling barrier layer is a metal oxide.

6. The magnetic storage unit according to claim 1, characterized in that, The material of the coupling layer includes one or more combinations of vanadium, chromium, copper, niobium, molybdenum, ruthenium, rhodium, tantalum, tungsten, rhenium, and iridium.

7. A magnetic storage device, characterized in that, Includes the magnetic storage unit as described in any one of claims 1-6.

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