A magnetic memory cell and a magnetic memory

Abstract

The application discloses a magnetic storage unit, which comprises a first electrode, a transition combination layer, a magnetic tunnel junction and a second electrode from bottom to top; the first electrode and the second electrode are used for being connected with an external circuit and controlling a resistance state of the magnetic tunnel junction; and the transition combination layer comprises a boron providing layer and a boron adsorption buffer layer which are arranged in a laminated mode. By arranging the transition combination layer, stress problems caused by lattice structure mismatching between a metal electrode and the magnetic tunnel junction are eliminated, a better mother plate is provided for growth of the magnetic tunnel junction, and the number of defects and internal stress in the magnetic tunnel junction are reduced. In a high-temperature environment, boron element diffusion and adsorption of the boron providing layer and the boron adsorption buffer layer occur, and the process can effectively slow down interface diffusion of other film layer materials in the magnetic tunnel junction in the high-temperature environment, and the interface structure quality of the magnetic tunnel junction is improved. The application also provides a magnetic storage device with the beneficial effects.

Description

Technical Field

[0001] This invention relates to the field of magnetic storage, and in particular to a magnetic storage unit and a magnetic memory. Background Technology

[0002] Magnetic random access memory (MRAM) is composed of magnetic tunnel junction (MTJ) arrays. The core structure of an MTJ includes a free layer, a barrier layer, and a fixed layer. The free and fixed layers are magnetic layers, while the barrier layer is a very thin insulating layer, typically less than 2 nm thick. During normal operation, the magnetization direction of the fixed layer remains constant, while the magnetization direction of the free layer can be changed by an applied magnetic field or input current. The resistance of the MTJ is determined by the relative magnetization directions of the free and fixed layers. When the magnetization directions of the free and fixed layers are parallel, the MTJ exhibits a low resistance state; when they are antiparallel, it exhibits a high resistance state. The resistance state of the MTJ is controlled by the relative magnetization directions of the free and fixed layers, which is one of the physical principles underlying the operation of MTJ devices.

[0003] For MTJ thin film stacks, the film structure and interface characteristics have a crucial impact on performance. However, in the fabrication of magnetic memory cells using existing technologies, the need for multiple processes at high temperatures inevitably leads to interfacial diffusion between film layers, which degrades the performance of the magnetic tunnel junction. Furthermore, the mismatch between the metal electrodes used as the MTJ growth substrate and the MTJ's lattice structure, along with stress-induced defects in the MTJ film, ultimately results in a decline in the performance of the magnetic memory cell.

[0004] In summary, how to solve the device performance degradation caused by interface diffusion and numerous interface contact defects due to high-temperature processes in the prior art is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a magnetic storage unit and a magnetic memory to solve the problem of device performance degradation caused by interface element diffusion, large internal stress, and numerous defects due to high-temperature processes in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention provides a magnetic storage cell, which includes, from bottom to top, a first electrode, a transition layer, a magnetic tunnel junction and a second electrode.

[0007] The first electrode and the second electrode are used to connect to an external circuit and control the resistance state of the magnetic tunnel junction;

[0008] The transition composite layer includes a boron-providing layer and a boron adsorption buffer layer stacked together.

[0009] Optionally, in the magnetic storage cell, the transition combination layer includes a plurality of the boron-providing layers and / or a plurality of the boron adsorption buffer layers.

[0010] Optionally, in the magnetic storage unit, the boron providing layer and the boron adsorption buffer layer are alternately stacked.

[0011] Optionally, in the magnetic storage unit, the transition combination layer includes, from bottom to top, a first boron adsorption buffer layer, a boron providing layer, and a second boron adsorption buffer layer.

[0012] Optionally, in the magnetic storage unit, the boron adsorption buffer layer is at least one layer selected from molybdenum, chromium, hafnium, zirconium, magnesium, aluminum, zinc, titanium, vanadium, or niobium.

[0013] Optionally, in the magnetic storage cell, the boron-providing layer is at least one layer selected from cobalt boride, iron boride, nickel boride, cobalt iron boron, cobalt iron chromium boron, cobalt iron chromium boron, or tantalum boride.

[0014] Optionally, in the magnetic storage cell, the thickness of the boron adsorption buffer layer and / or the boron providing layer ranges from 0.3 nanometers to 2.0 nanometers, including endpoint values.

[0015] Optionally, in the magnetic storage cell, the magnetic tunnel junction further includes a synthetic antiferromagnetic structure layer.

[0016] Optionally, in the magnetic storage cell, the magnetic tunnel junction is disposed in contact with the boron providing layer.

[0017] A magnetic memory comprising magnetic storage cells as described in any of the above.

[0018] The magnetic storage cell provided by this invention comprises, from bottom to top, a first electrode, a transition layer, a magnetic tunnel junction, and a second electrode. The first and second electrodes are used to connect to an external circuit and control the resistance state of the magnetic tunnel junction. The transition layer includes a boron-providing layer and a boron adsorption buffer layer stacked together. By setting the transition layer, this invention eliminates the stress problem caused by the mismatch between the lattice structure of the metal electrode and the magnetic tunnel junction, providing a better substrate for the growth of the magnetic tunnel junction, reducing the number of defects and internal stress in the magnetic tunnel junction. Furthermore, under high-temperature conditions, the boron-providing layer and the boron adsorption buffer layer undergo boron diffusion and adsorption. This process effectively slows down the interfacial diffusion of other film materials in the magnetic tunnel junction under high-temperature conditions, improving the high-temperature resistance of the magnetic tunnel junction, and simultaneously improving the magnetization reversal characteristics of the magnetic storage cell, thus significantly improving the quality of the finished magnetic storage cell. This invention also provides a magnetic memory with the above-mentioned beneficial effects. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0020] Figure 1 A structural schematic diagram of one specific embodiment of the magnetic storage unit provided by the present application is shown in the figure.

[0021] Figure 2 A structural schematic diagram of another specific embodiment of the magnetic storage unit provided by the present application is shown in the figure.

[0022] Figure 3 A structural schematic diagram of another specific embodiment of the magnetic storage unit provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0023] In order to make the person in the art better understand the technical solutions of the present application, the following will further describe the present application in combination with the drawings and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0024] The core of the present application is to provide a magnetic storage unit, a structural schematic diagram of one specific embodiment of which is shown in the figure. Figure 1 From bottom to top, it includes a first electrode 100, a transition combination layer 200, a magnetic tunnel junction 300 and a second electrode 400.

[0025] The first electrode 100 and the second electrode 400 are used to be connected with external circuit and control the resistance state of the magnetic tunnel junction 300.

[0026] The transition combination layer 200 includes a boron providing layer 201 and a boron adsorption buffer layer 202 which are stacked.

[0027] Among them, the boron adsorption buffer layer 202 is a layer including at least one of metal molybdenum, chromium, hafnium, zirconium, magnesium, aluminum, zinc, titanium, vanadium or niobium, in other words, the boron adsorption buffer layer 202 is a layer of any of the above metals, or an alloy layer including any of the above metals, of course, other materials can also be selected according to actual situation. The above-mentioned metals have good adsorption to boron element, and are easy to diffuse and adsorb with the boron providing layer 201 at high temperature, which can slow down the interface diffusion of other film layer materials in the magnetic tunnel junction.

[0028] Further, the boron providing layer 201 is at least one layer including cobalt boride, iron boride, nickel boride, cobalt iron boride, cobalt iron chromium boride, cobalt iron chromium boride, or tantalum boride, and of course, other materials can be selected according to actual conditions.

[0029] In addition, the thickness of the boron adsorbing buffer layer 202 and / or the boron providing layer 201 ranges from 0.3 nm to 2.0 nm, including the end values, such as any one of 0.30 nm, 1.35 nm, or 2.00 nm.

[0030] The magnetic tunnel junction 300 includes a fixed layer, a barrier layer, and a free layer, wherein the fixed layer includes a seed layer, a reference layer, a pinning layer, etc.; the seed layer is a single layer film of Pt, Pd, Ru, NiCr, or NiFeCr, or a multi-layer film stack composed of two or more of CoFeB, TaN, Mg, Pt, Pd, Ru, NiCr, NiFeCr; the reference layer includes at least one of Co, Fe, Ni, CoB, FeB, NiB, CoFe, NiFe, CoNi, and CoFeB; the barrier layer includes MgO, or one of Al, Zn, Hf, etc. doped MgO. Of course, the same magnetic tunnel junction 300 can include multiple free layers or other structures, which are not listed one by one here.

[0031] The magnetic tunnel junction 300 also includes a synthetic antiferromagnetic structure layer. The synthetic antiferromagnetic structure layer is disposed in the fixed layer of the magnetic tunnel junction 300, which can effectively weaken the influence of the fixed layer stray field on the magnetization reversal of the free layer; the synthetic antiferromagnetic structure layer includes a magnetic multi-layer film and a coupling layer, the magnetic multi-layer film includes at least one of Co / Pt multi-layer film, Co / Pd multi-layer film, Co / Ni multi-layer film, and the coupling layer is at least one of Ru and Ir.

[0032] The boron content of the boron providing layer 201 can vary with the base material of the boron providing layer 201, such as when the base material of the boron providing layer 201 is CoFeB, the thickness is 1 nm, and the Co:Fe ratio is 1:3, the boron content is 20%; in another embodiment, the boron providing layer 201 is CoB, the thickness is 0.3 nm, and the boron content is 25%.

[0033] The magnetic storage unit comprises, from bottom to top, a first electrode 100, a transition combination layer 200, a magnetic tunnel junction 300 and a second electrode 400; the first electrode 100 and the second electrode 400 are used to be connected with an external circuit and control the resistance state of the magnetic tunnel junction 300; the transition combination layer 200 comprises a boron providing layer 201 and a boron adsorption buffer layer 202 arranged in layers. The transition combination layer 200 provides a better mother plate for the growth of the magnetic tunnel junction 300, eliminates the stress problem caused by the lattice structure mismatch between the metal electrode and the magnetic tunnel junction 300, reduces the number of defects and internal stress in the magnetic tunnel junction 300, and in addition, the boron providing layer 201 and the boron adsorption buffer layer 202 will diffuse and adsorb boron elements in a high-temperature environment, which can effectively slow down the interface diffusion of other film layer materials in the magnetic tunnel junction 300 in the production process in a high-temperature environment, improve the high-temperature resistance of the magnetic tunnel junction 300, and improve the magnetization reversal characteristics of the magnetic storage unit, so that the quality of the finished magnetic storage unit is greatly improved.

[0034] On the basis of the first embodiment, the composition of the transition combination layer 200 is further limited to obtain the second embodiment, and a structural schematic diagram thereof is shown in Figure 2 The transition combination layer 200 comprises, from bottom to top, a first electrode 100, a transition combination layer 200, a magnetic tunnel junction 300 and a second electrode 400.

[0035] The first electrode 100 and the second electrode 400 are used to be connected with an external circuit and control the resistance state of the magnetic tunnel junction 300.

[0036] The transition combination layer 200 comprises a boron providing layer 201 and a boron adsorption buffer layer 202 arranged in layers.

[0037] The transition combination layer 200 comprises a plurality of boron providing layers 201 and / or a plurality of boron adsorption buffer layers 202.

[0038] The transition combination layer 200 in the embodiment comprises three or more single layers, that is, the transition combination layer 200 in the embodiment can comprise one boron providing layer 201 and a plurality of boron adsorption buffer layers 202, or one boron adsorption buffer layer 202 and a plurality of boron providing layers 201, or a plurality of boron providing layers 201 and a plurality of boron adsorption buffer layers 202. The diffusion amount of boron can be adjusted by increasing or reducing the number of layers according to the manufacturing temperature of the device in actual production, so as to obtain a better effect of preventing interface diffusion of the magnetic tunnel junction 300.

[0039] Further, the boron providing layer 201 and the boron adsorption buffer layer 202 are alternately stacked, so that boron diffusion of the transition combination layer 200 made of the same amount of raw materials is more thorough, the effect of preventing interface diffusion of the magnetic tunnel junction 300 is better, and the cost is reduced.

[0040] Further, the transition combination layer sequentially includes a first boron adsorption buffer layer, the boron providing layer 201 and a second boron adsorption buffer layer from bottom to top, as shown in the figure. Figure 2 That is, the two boron adsorption buffer layers 202 isolate the boron providing layer 201 from other structures from both sides, so as to avoid boron entering other structures of the MTJ during high-temperature boron diffusion, causing the performance of the device to decrease, and further improving the quality of the finished magnetic storage unit.

[0041] On the basis of the second embodiment, the position of the boron providing layer 201 is further limited to obtain the third embodiment, and a structural schematic diagram thereof is shown in the figure. Figure 3 The transition combination layer 200 includes a first electrode 100, a magnetic tunnel junction 300 and a second electrode 400 from bottom to top.

[0042] The first electrode 100 and the second electrode 400 are used to be connected with an external circuit and control the resistance state of the magnetic tunnel junction 300.

[0043] The transition combination layer 200 includes a boron providing layer 201 and a boron adsorption buffer layer 202 which are stacked.

[0044] The transition combination layer 200 includes a plurality of boron providing layers 201 and / or a plurality of boron adsorption buffer layers 202.

[0045] The magnetic tunnel junction 300 is in contact with the boron providing layer 201.

[0046] In the embodiment, the magnetic tunnel junction 300 is arranged on the boron providing layer 201. Generally, the boron providing layer 201 can provide a smoother and more flat film surface, improve the interface characteristics of the magnetic tunnel junction 300, and make the uniformity of the magnetic tunnel junction 300 better, so that the performance of the interface is close to uniform.

[0047] The application further provides a magnetic storage unit, which comprises the magnetic storage unit as described in any one of the above. The magnetic storage unit provided by the application comprises, from bottom to top, a first electrode 100, a transition combination layer 200, a magnetic tunnel junction 300 and a second electrode 400; the first electrode 100 and the second electrode 400 are used to be connected with an external circuit and control the resistance state of the magnetic tunnel junction 300; the transition combination layer 200 comprises a boron providing layer 201 and a boron adsorption buffer layer 202 arranged in layers. By arranging the transition combination layer 200, the stress problem caused by the lattice structure mismatch between the metal electrode and the magnetic tunnel junction 300 is eliminated, a better mother plate is provided for the growth of the magnetic tunnel junction 300, the number of defects and internal stress in the magnetic tunnel junction 300 are reduced, in addition, the boron providing layer 201 and the boron adsorption buffer layer 202 will diffuse and adsorb boron elements under high temperature environment, which can effectively slow down the interface diffusion of other film layer materials in the magnetic tunnel junction 300 under high temperature environment in the production process, improve the high temperature resistance of the magnetic tunnel junction 300, and greatly improve the quality of the finished magnetic storage unit.

[0048] The various embodiments are described in a progressive manner in the specification, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the device disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0049] It should be noted that, in the specification, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another same element in the process, method, article or device including the element.

[0050] The magnetic storage unit and the magnetic storage provided by the present application are described in detail above. The principles and implementation manners of the present application are described by using specific examples in this paper, and the above description of the examples is only used to help understand the method of the present application and the core idea thereof. It should be pointed out that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A magnetic storage unit, characterized in that, From bottom to top, it includes a first electrode, a transition layer, a magnetic tunnel junction, and a second electrode. The first electrode and the second electrode are used to connect to an external circuit and control the resistance state of the magnetic tunnel junction; The transition composite layer includes a boron supply layer and a boron adsorption buffer layer stacked together. The transition composite layer comprises, from bottom to top, a first boron adsorption buffer layer, a boron providing layer, and a second boron adsorption buffer layer; The boron-providing layer is at least one of cobalt boride, iron boride, nickel boride, cobalt iron boron, cobalt iron chromium boron, cobalt iron chromium boron, or tantalum boride.

2. The magnetic storage unit as described in claim 1, characterized in that, The transition combination layer includes multiple boron-providing layers and / or multiple boron adsorption buffer layers.

3. The magnetic storage unit as described in claim 2, characterized in that, The boron supply layer and the boron adsorption buffer layer are alternately stacked.

4. The magnetic storage unit as described in claim 1, characterized in that, The boron adsorption buffer layer is a layer comprising at least one of the following: molybdenum, chromium, hafnium, zirconium, magnesium, aluminum, zinc, titanium, vanadium, or niobium.

5. The magnetic storage unit as described in claim 1, characterized in that, The thickness of the boron adsorption buffer layer and / or the boron providing layer ranges from 0.3 nanometers to 2.0 nanometers, including the endpoint values.

6. The magnetic storage unit as claimed in claim 1, characterized in that, The magnetic tunnel junction also includes a synthetic antiferromagnetic structure layer.

7. A magnetic storage device, characterized in that, The magnetic memory includes a magnetic storage unit as described in any one of claims 1 to 6.

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