Magnetic tunnel junction based on codeposition and preparation process thereof

Abstract

The invention belongs to the technical field of spinning electronics, and discloses a magnetic tunnel junction based on codeposition and a preparation process thereof. The preparation technology comprises the steps that a four-target magnetron sputtering coating system is obtained, wherein the four-target magnetron sputtering coating system comprises a sample table, at least four independent target guns, an electric lifting mechanism connected with the target guns and used for controlling the sputtering distance between the target guns and a sample, and a turnover mechanism used for controlling the sample table to rotate; obtaining a single crystal oxide as a substrate, cleaning and drying the substrate and placing the substrate on a sample table; a multi-layer structure is deposited on a substrate by adopting a four-target magnetron sputtering coating system to form a magnetic tunnel junction, and the multi-layer structure comprises a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulation barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer and a protective layer from bottom to top. According to the invention, the proportion of various metal materials is accurately regulated and controlled through co-deposition, the spin polarizability is improved, and the overall stability of the magnetic tunnel junction is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of spin electronics, and in particular relates to a magnetic tunnel junction based on co-deposition and a preparation process thereof. Background Art

[0002] Magnetic tunnel junction (MTJ) is one of the core components in the field of spin electronics. It consists of a sandwich structure of "magnetic layer-insulating layer-magnetic layer". Its working principle is based on the tunnel magnetoresistance (TMR) effect generated by the spin motion of electrons between magnetic layers. Specifically, when the magnetization directions of the two magnetic layers are antiparallel, the resistance to electron tunneling is the greatest; and when the magnetization directions are parallel in the same direction, the resistance to electron tunneling is the smallest. The intensity of the tunnel magnetoresistance (TMR) effect is usually measured by the TMR ratio (i.e., the difference between the antiparallel resistance and the forward parallel resistance divided by the forward parallel resistance). Magnetic tunnel junctions with a high TMR ratio have very important application value: for example, their application in data storage elements can improve the signal-to-noise ratio, thereby enhancing the stability and accuracy of data reading; for another example, their application in highly integrated and mobile devices can help reduce energy consumption; for another example, their application in magnetic sensors can significantly improve their sensitivity. In order to further improve the performance of the magnetic tunnel junction, the current technology considers the magnetic material Heusler alloy when preparing the magnetic tunnel junction. Heusler alloy is a magnetic material with a specific composition ratio. It has a high spin polarization rate and excellent magnetoresistance performance. It has been proven to significantly improve the tunnel magnetoresistance value and thermal stability. Using Heusler alloy as the metal layer material of the magnetic tunnel junction helps to improve the TMR ratio, thereby improving the overall performance of the magnetic tunnel junction. Therefore, patent application number CN202410405910.1 discloses "magnetic tunnel junction and its preparation method, tunnel magnetic device", and its solution is to use Heusler alloy Co2FeAl in the ferromagnetic layer, and add an antiferromagnetic pinning layer and a protective layer to the structure to improve the sensitivity of the magnetic tunnel junction. However, this solution has the problems of insufficient magnetic stability and insufficient spin polarization rate, and also faces the challenge of process complexity. These problems have an adverse effect on the process stability and production efficiency of the magnetic tunnel junction. Summary of the invention

[0003] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the objects of the present invention is to at least solve one or more of the above-mentioned problems in the prior art. In other words, one of the objects of the present invention is to provide a magnetic tunnel junction based on co-deposition and a preparation process thereof that meets one or more of the aforementioned needs, aiming to achieve precise control of material composition and microstructure through co-deposition, optimize the multilayer structure to enhance the spin polarization rate, and thereby improve the overall stability of the magnetic tunnel junction device.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a process for preparing a magnetic tunnel junction based on co-deposition, comprising the steps of: S1, obtaining a four-target magnetron sputtering coating system, the four-target magnetron sputtering coating system comprising a sample stage, at least four independent target guns, an electric lifting mechanism connected to the target guns for controlling the sputtering distance between the target guns and the sample, and a flipping mechanism for controlling the rotation of the sample stage; S2, obtaining a single crystal oxide as a substrate, cleaning and drying it and placing it on the sample stage; S3, using the four-target magnetron sputtering coating system to deposit a multilayer structure on the substrate to form a magnetic tunnel junction, the multilayer structure being, from bottom to top, a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulating barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer, and a protective layer, the material of the first cobalt-based Heusler alloy layer being Co2MnSi or Co2FeAl, the material of the spin separation layer being L10-MnGa, and the material of the second cobalt-based Heusler alloy layer being Co2MnSi.

[0005] As a preferred solution, the target gun is also connected to a driving motor; the electric lifting mechanism includes a target gun lifting unit and a sample lifting unit; the flipping mechanism includes a stepping motor, a primary gear set and a secondary gear set.

[0006] As a preferred solution, the buffer layer is deposited by setting the power range of the power supply to [40W, 60W] and the gas pressure range to [5×10 -4 Pa,1×10 -3 Pa], the deposition temperature range was set to [150 ℃, 250 ℃], the deposition thickness range was set to [5 nm, 10 nm], and the deposition time range was set to [15 min, 20 min].

[0007] As a preferred solution, the deposition of the first cobalt-based Heusler alloy layer is specifically as follows: the power range of the power supply is set to [25 W, 35 W], and the gas pressure range is set to [2×10 -3 Pa,5×10 -3Pa], the deposition temperature range was set to [400 °C, 500 °C], the deposition thickness range was set to [10 nm, 15 nm], and the deposition time range was set to [30 min, 45 min].

[0008] As a preferred solution, the spin separation layer is deposited by setting the power range of the power supply to [15 W, 25 W] and the gas pressure range to [1×10 -3 Pa,2×10 -3 Pa], the deposition temperature range was set to [250 ℃, 350 ℃], the deposition thickness range was set to [0.5 nm, 2 nm], and the deposition time range was set to [10 min, 15 min].

[0009] As a preferred solution, the insulating barrier layer is deposited by setting the power range of the power supply to [40 W, 60 W], and the gas pressure range to [5×10 -4 Pa,1×10 -3 Pa], the deposition temperature range is set to [150℃, 250℃], the deposition thickness range is set to [2nm, 3 nm], and the deposition time range is set to [10 min, 15min].

[0010] As a preferred solution, the deposition of the second cobalt-based Heusler alloy layer is specifically as follows: the power range of the power supply is set to [25 W, 35 W], and the gas pressure range is set to [2×10 -3 Pa,5×10 -3 Pa], the deposition temperature range is set to [300°C, 400°C], the deposition thickness range is set to [5nm, 10 nm], and the deposition time range is set to [25 min, 35 min]. The second cobalt-based Heusler alloy layer after deposition is subjected to a single annealing treatment, the annealing temperature range is [250°C, 350°C], and the annealing time range is [30 min, 60 min].

[0011] As a preferred solution, the antiferromagnetic pinning layer is deposited by setting the power range of the power supply to [10 W, 20 W] and the pressure range to [1×10 -3 Pa,3×10 -3 Pa], the deposition temperature range is set to [200℃, 300℃], the deposition thickness range is set to [5nm, 10 nm], and the deposition time range is set to [20 min, 30 min].

[0012] As a preferred solution, the protective layer is deposited by setting the power range of the power supply to [15W, 25W] and the pressure range to [1×10-3 Pa,2×10 -3 Pa], the deposition temperature range is set to [50℃, 150 ℃], the deposition thickness range is set to [2nm, 5 nm], and the deposition time range is set to [10 min, 15min].

[0013] In a second aspect, the present invention provides a magnetic tunnel junction based on the preparation process as described in the first aspect, comprising a substrate and a multilayer structure deposited on the substrate; the multilayer structure comprises, from bottom to top, a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulating barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer, and a protective layer; the material of the first cobalt-based Heusler alloy layer is Co2MnSi or Co2FeAl and has a thickness range of [10nm, 15nm]; the material of the spin separation layer is L10-MnGa and has a thickness range of [0.5nm, 2nm]; the material of the second cobalt-based Heusler alloy layer is Co2MnSi and has a thickness range of [5nm, 10nm].

[0014] Compared with the prior art, the present invention has the following technical effects: 1. The present invention realizes multi-target co-deposition technology through the four-target magnetron sputtering coating system, thereby achieving precise proportion control of metal materials such as Co, Mn, Pt, and Ir, and significantly improving the crystallization characteristics and microstructural uniformity of the film.

[0015] 2. The spin separation layer is introduced between the first cobalt-based Heusler alloy layer and the insulating barrier layer, which significantly improves the spin polarization rate of electron tunneling and achieves a higher TMR ratio compared to the traditional "magnetic layer-insulating layer-magnetic layer" sandwich structure. At the same time, the thickness of the spin separation layer is set between 0.5nm and 2nm, which further ensures the spin polarization effect, thereby obtaining the magnetic tunnel junction with higher sensitivity, better data reading performance and better magnetic stability.

[0016] 3. The second cobalt-based Heusler alloy layer is annealed after deposition to enhance its perpendicular magnetic anisotropy, thereby improving the stability of the magnetic tunnel junction.

[0017] 4. In the optimized magnetic tunnel junction structure, the stability and high efficiency of the magnetic tunnel junction are ensured by precise matching of materials and parameters, making it suitable for high-precision spin electronic devices.

[0018] Further or more detailed beneficial effects will be described in detail in conjunction with specific examples in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the process of the preparation process described in the embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of the structure of the magnetic tunnel junction described in an embodiment of the present invention.

[0022] Figure Number: 1. Substrate; 2. Buffer layer; 3. First cobalt-based Heusler alloy layer; 4. Spin separation layer; 5. Insulating barrier layer; 6. Second cobalt-based Heusler alloy layer; 7. Antiferromagnetic pinning layer; 8. Protective layer. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0024] In the following description, multiple embodiments of the present invention are provided, and different embodiments may be replaced or combined, so the present invention may also be considered to include all possible combinations of the same and / or different embodiments described. Therefore, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present invention should also be considered to include embodiments containing one or more of A, B, C, and D, all other possible combinations, even though the embodiment may not be clearly described in the following text.

[0025] The following description provides examples and does not limit the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements described without departing from the scope of the present invention. Various processes or components may be appropriately omitted, substituted or added to each example. For example, the described method may be performed in an order different from the described order, and various steps may be added, omitted or combined. In addition, the features described in some examples may be combined in other examples.

[0026] In order to facilitate a better understanding of the embodiments of the present invention, before explaining the specific implementation modes of the present invention in detail, its application scenarios are first described.

[0027] The magnetic tunnel junction described in the embodiments of this specification is applied to high-precision spin electronic devices. In these scenarios, the application of the magnetic tunnel junction and its preparation process is intended to significantly improve the spin polarization rate of electron tunneling, so that the magnetic tunnel junction has higher sensitivity, better data reading performance, better magnetic stability and higher TMR ratio, so as to provide high-quality and reliable performance.

[0028] Embodiment 1: like Figure 1 As shown, this embodiment provides a magnetic tunnel junction preparation process based on co-deposition, including the steps of: S1, obtaining a four-target magnetron sputtering coating system, the four-target magnetron sputtering coating system including a sample stage, at least four independent target guns, an electric lifting mechanism connected to the target gun for controlling the sputtering distance between the target gun and the sample, and a flipping mechanism for controlling the rotation of the sample stage; S2, obtaining a single crystal oxide as a substrate, and washing and drying it and placing it on the sample stage; S3, using the four-target magnetron sputtering coating system to deposit a multilayer structure on the substrate to form a magnetic tunnel junction, the multilayer structure from bottom to top are a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulating barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer, and a protective layer, the material of the first cobalt-based Heusler alloy layer is Co2MnSi or Co2FeAl, the material of the spin separation layer is L10-MnGa, and the material of the second cobalt-based Heusler alloy layer is Co2MnSi.

[0029] Furthermore, the target gun is also connected to a VTV15W drive motor, and is connected through a 1:50 reducer and a bellows telescopic mechanism, and is electrically lifted by a 2mm pitch screw drive; the electric lifting mechanism includes a target gun lifting unit and a sample lifting unit; the target gun lifting unit is connected to the target gun, and uses a 1:50 reducer with a 2mm pitch screw; the sample lifting unit is driven by a 57 stepper motor, and a 1:20 reducer with a 4mm pitch screw; the flipping mechanism includes a stepper motor, a primary gear set and a secondary gear set; the primary gear set consists of a 20-tooth driving gear and a 60-tooth driven gear to achieve horizontal rotation of the sample; the secondary gear set consists of a 22-tooth driving gear and an 88-tooth driven gear to achieve 0-180° flipping of the sample along the horizontal axis.

[0030] Furthermore, the buffer layer is deposited by setting the power range of the power supply to [40 W, 60 W], and the gas pressure range to [5×10 -4 Pa,1×10 -3 Pa], the deposition temperature range was set to [150 ℃, 250 ℃], the deposition thickness range was set to [5 nm, 10 nm], and the deposition time range was set to [15 min, 20 min].

[0031] Furthermore, the deposition of the first cobalt-based Heusler alloy layer is specifically as follows: the power range of the power supply is set to [25 W, 35 W], and the gas pressure range is set to [2×10 -3 Pa,5×10 -3 Pa], the deposition temperature range is set to [400℃, 500℃], the deposition thickness range is set to [10nm, 15 nm], and the deposition time range is set to [30 min, 45 min].

[0032] Furthermore, the spin separation layer is deposited by setting the power range of the power supply to [15 W, 25 W], and the gas pressure range to [1×10 -3 Pa,2×10 -3 Pa], the deposition temperature range was set to [250 ℃, 350 ℃], the deposition thickness range was set to [0.5 nm, 2 nm], and the deposition time range was set to [10 min, 15 min].

[0033] Furthermore, the insulating barrier layer is deposited by setting the power range of the power supply to [40 W, 60 W], and the gas pressure range to [5×10 -4 Pa,1×10 -3 Pa], the deposition temperature range is set to [150℃, 250℃], the deposition thickness range is set to [2nm, 3 nm], and the deposition time range is set to [10 min, 15 min].

[0034] Furthermore, the deposition of the second cobalt-based Heusler alloy layer is specifically as follows: the power range of the power supply is set to [25 W, 35 W], and the gas pressure range is set to [2×10 -3 Pa,5×10 -3 Pa], the deposition temperature range is set to [300℃, 400℃], the deposition thickness range is set to [5nm, 10 nm], and the deposition time range is set to [25 min, 35 min]. The second cobalt-based Heusler alloy layer after deposition is subjected to a single annealing treatment, the annealing temperature range is [250℃, 350℃], and the annealing time range is [30 min, 60 min].

[0035] Furthermore, the antiferromagnetic pinning layer is deposited by setting the power range of the power supply to [10 W, 20 W], and the pressure range to [1×10 -3 Pa,3×10 -3Pa], the deposition temperature range is set to [200℃, 300℃], the deposition thickness range is set to [5nm, 10 nm], and the deposition time range is set to [20 min, 30 min].

[0036] Furthermore, the protective layer is deposited by setting the power range of the power supply to [15 W, 25 W], and the gas pressure range to [1×10 -3 Pa,2×10 -3 Pa], the deposition temperature range is set to [50℃, 150 ℃], the deposition thickness range is set to [2nm, 5 nm], and the deposition time range is set to [10 min, 15min].

[0037] Embodiment 2: like Figure 2 As shown, this embodiment provides a magnetic tunnel junction based on Heusler alloy, including a substrate and a multilayer structure deposited on the substrate. The multilayer structure is respectively a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulating barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer, and a protective layer from bottom to top. Furthermore, the material of the first cobalt-based Heusler alloy layer is Co2MnSi or Co2FeAl; the material of the spin separation layer is L10-MnGa; the material of the second cobalt-based Heusler alloy layer is Co2MnSi. The thickness range of the first cobalt-based Heusler alloy layer is [10nm, 15nm]; the thickness range of the spin separation layer is [0.5nm, 2nm]; the thickness range of the second cobalt-based Heusler alloy layer is [5nm, 10nm]. Furthermore, the material of the substrate is MgO; the material of the buffer layer is MgO; the material of the insulating barrier layer is MgO or Al2O3; the material of the antiferromagnetic pinning layer is IrMn or PtMn; the material of the protective layer is Pt or Ta; the thickness range of the buffer layer is [5nm, 10nm]; the thickness range of the insulating barrier layer is [2nm, 3nm]; the thickness range of the antiferromagnetic pinning layer is [5nm, 10nm]; the thickness range of the protective layer is [2nm, 5nm].

[0038] Embodiment three: To verify the effectiveness of the preparation process described in this specification, this embodiment performs the following steps in sequence to prepare a magnetic tunnel junction according to the actual application scenario of the magnetic tunnel junction: First, the single crystal oxide substrate MgO is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence, and each solvent is treated for 10 minutes to remove organic pollutants on the surface of the single crystal oxide substrate MgO, and then it is placed in a drying oven at 110°C for 60 minutes. Next, a buffer layer MgO is deposited on the single crystal oxide substrate MgO by magnetron sputtering, the power supply is set to 50 watts, and the pressure in the deposition chamber is maintained at 7×10 -4 Pascal, the deposition temperature is 200°C, the deposition thickness is 5 nanometers, and the deposition time is 15 minutes. Subsequently, the first cobalt-based Heusler alloy layer Co2MnSi is deposited on the buffer layer MgO by magnetron sputtering, the power supply power is 30 watts, and the deposition chamber pressure is 3×10 -3 Pascal, the deposition temperature is 450°C, the deposition thickness is 12 nm, and the deposition time is 40 minutes. Then, the spin separation layer L10-MnGa is deposited on the first cobalt-based Heusler alloy layer Co2MnSi by magnetron sputtering, the power supply is 20 watts, and the deposition chamber pressure is 1.5×10 -3 Pascal, the deposition temperature is 300°C, the deposition thickness is 1 nm, and the deposition time is 12 minutes, in order to improve the spin polarization rate of the tunneling electrons. Afterwards, the insulating barrier layer MgO is deposited on the spin separation layer L10-MnGa by magnetron sputtering, the power supply is 50 watts, and the pressure of the deposition chamber is 1×10 -5 Pascal, the deposition temperature is 200°C, the deposition thickness is 2 nanometers, and the deposition time is 12 minutes. Next, a second cobalt-based Heusler alloy layer Co2MnSi is deposited on the insulating barrier layer MgO by magnetron sputtering and a single rapid annealing treatment is performed. The power supply is 30 watts and the pressure in the deposition chamber is 3.5×10 -3 Pascal, the deposition temperature is 350°C, the deposition thickness is 8 nm, the deposition time is 30 minutes, the annealing temperature is 300°C, and the annealing time is 60 minutes to achieve perpendicular magnetic anisotropy. Subsequently, the antiferromagnetic pinning layer IrMn is deposited on the second cobalt-based Heusler alloy layer Co2MnSi by magnetron sputtering, the power supply is 15 watts, and the deposition chamber pressure is 2×10 -3 Pascal, the deposition temperature is 250°C, the deposition thickness is 6 nanometers, and the deposition time is 25 minutes to enhance the structural stability. Finally, a protective layer Pt is deposited on the antiferromagnetic pinning layer IrMn by magnetron sputtering, the power supply power is 20 watts, and the deposition chamber pressure is 1.5×10 -3Pascal, the deposition temperature is 100° C., the deposition thickness is 3 nanometers, and the deposition time is 12 minutes. Based on the above steps, the present embodiment prepares a magnetic tunnel junction with a high TMR ratio, and successfully verifies the effectiveness of the preparation process proposed in this specification.

[0039] Embodiment 4: To verify the effectiveness of the preparation process described in this specification, this embodiment performs the following steps in sequence to prepare a magnetic tunnel junction according to the actual application scenario of the magnetic tunnel junction: First, the single crystal oxide substrate MgO is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence, and each solvent is treated for 10 minutes to remove organic pollutants on the surface of the single crystal oxide substrate MgO, and then placed in a drying oven at 110°C for 60 minutes. Next, a buffer layer MgO is deposited on the single crystal oxide substrate MgO by magnetron sputtering, the power supply is set to 40 watts, and the pressure in the deposition chamber is maintained at 6×10 -4 Pascal, the deposition temperature is 180°C, the deposition thickness is 6 nanometers, and the deposition time is 10 minutes. Subsequently, the first cobalt-based Heusler alloy layer Co2MnSi is deposited on the buffer layer MgO by magnetron sputtering, the power supply power is 25 watts, and the deposition chamber pressure is 2.8×10 -3 Pascal, the deposition temperature is 430°C, the deposition thickness is 10 nm, and the deposition time is 35 minutes. Then, the spin separation layer L10-MnGa is deposited on the first cobalt-based Heusler alloy layer Co2MnSi by magnetron sputtering, the power supply is 18 watts, and the deposition chamber pressure is 1.2×10 -3 Pascal, the deposition temperature is 300°C, the deposition thickness is 0.8 nanometers, and the deposition time is 8 minutes, in order to improve the spin polarization rate of the tunneling electrons. Afterwards, the insulating barrier layer MgO is deposited on the spin separation layer L10-MnGa by magnetron sputtering, the power supply is 45 watts, and the pressure of the deposition chamber is 7×10 -4 Pascal, the deposition temperature is 180°C, the deposition thickness is 2 nanometers, and the deposition time is 9 minutes. Next, a second cobalt-based Heusler alloy layer Co2MnSi is deposited on the insulating barrier layer MgO by magnetron sputtering and a single rapid annealing treatment is performed. The power supply is 28 watts, and the deposition chamber pressure is 3×10 -3 Pascal, the deposition temperature is 340 ° C, the deposition thickness is 7 nanometers, the deposition time is 20 minutes, the annealing temperature is 250 ° C, and the annealing time is 30 minutes to achieve perpendicular magnetic anisotropy. Subsequently, the antiferromagnetic pinning layer IrMn is deposited on the second cobalt-based Heusler alloy layer Co2MnSi by magnetron sputtering, the power supply power is 12 watts, and the deposition chamber pressure is 2×10 -3Pascal, the deposition temperature is 220°C, the deposition thickness is 5 nanometers, and the deposition time is 22 minutes to enhance the structural stability. Finally, a protective layer Pt is deposited on the antiferromagnetic pinning layer IrMn by magnetron sputtering, the power supply is 18 watts, and the deposition chamber pressure is 2×10 -3 Pascal, the deposition temperature is 220°C, the deposition thickness is 5 nanometers, and the deposition time is 22 minutes. Based on the above steps, the present embodiment prepares a magnetic tunnel junction with a high TMR ratio, and successfully verifies the effectiveness of the preparation process proposed in this specification.

[0040] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0041] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0042] The above is only an exemplary embodiment of the present invention and cannot be used to limit the scope of the present invention. That is, any equivalent changes and modifications made according to the teachings of the present invention are still within the scope of the present invention. After considering the specification and practicing the disclosure here, it will be easy for those skilled in the art to think of the implementation scheme of the present invention. The present invention is intended to cover any modification, use or adaptation of the present invention, which follows the general principles of the present invention and includes common knowledge or customary technical means in the art that are not recorded in the present invention. The description and examples are only regarded as exemplary, and the scope and spirit of the present invention are defined by the claims.

Claims

1. A process for preparing a magnetic tunnel junction based on co-deposition, characterized in that: Includes steps: S1. Obtain a four-target magnetron sputtering coating system, wherein the four-target magnetron sputtering coating system comprises a sample stage, at least four independent target guns, an electric lifting mechanism connected to the target guns for controlling the sputtering distance between the target guns and the sample, and a flipping mechanism for controlling the rotation of the sample stage; S2, obtaining a single crystal oxide as a substrate, cleaning, drying, and placing it on the sample stage; S3. Use the four-target magnetron sputtering coating system to deposit a multilayer structure on the substrate to form a magnetic tunnel junction. The multilayer structure is, from bottom to top, a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulating barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer, and a protective layer. The material of the first cobalt-based Heusler alloy layer is Co2MnSi or Co2FeAl, the material of the spin separation layer is L10-MnGa, and the material of the second cobalt-based Heusler alloy layer is Co2MnSi.

2. The process for preparing a magnetic tunnel junction based on co-deposition according to claim 1, characterized in that: The target gun is also connected to a driving motor; The electric lifting mechanism includes a target gun lifting unit and a sample lifting unit; The turning mechanism comprises a stepping motor, a primary gear set and a secondary gear set.

3. A process for preparing a magnetic tunnel junction based on co-deposition according to claim 2, characterized in that: Depositing the buffer layer is specifically as follows: Set the power range to [40W, 60 W] and the air pressure range to [5×10 -4 Pa,1×10 -3 Pa], the deposition temperature range was set to [150 ℃, 250 ℃], the deposition thickness range was set to [5 nm, 10 nm], and the deposition time range was set to [15 min, 20 min].

4. A process for preparing a magnetic tunnel junction based on co-deposition according to claim 3, characterized in that: Depositing the first cobalt-based Heusler alloy layer specifically comprises: Set the power range to [25W,35 W] and the air pressure range to [2×10 -3 Pa,5×10 -3 Pa], the deposition temperature range was set to [400 °C, 500 °C], the deposition thickness range was set to [10 nm, 15 nm], and the deposition time range was set to [30 min, 45 min].

5. A process for preparing a magnetic tunnel junction based on co-deposition according to claim 4, characterized in that: Depositing the spin separation layer is specifically as follows: Set the power range to [15W, 25 W] and the air pressure range to [1×10 -3 Pa,2×10 -3 Pa], the deposition temperature range was set to [250 ℃, 350 ℃], the deposition thickness range was set to [0.5 nm, 2 nm], and the deposition time range was set to [10 min, 15 min].

6. A process for preparing a magnetic tunnel junction based on co-deposition according to claim 5, characterized in that: Depositing the insulating barrier layer specifically includes: Set the power range to [40W, 60 W] and the pressure range to [5×10 -4 Pa,1×10 -3 Pa], the deposition temperature range was set to [150 ℃, 250 ℃], the deposition thickness range was set to [2 nm, 3 nm], and the deposition time range was set to [10 min, 15 min].

7. A process for preparing a magnetic tunnel junction based on co-deposition according to claim 6, characterized in that: Depositing the second cobalt-based Heusler alloy layer is specifically as follows: Set the power range to [25W,35 W] and the air pressure range to [2×10 -3 Pa,5×10 -3 Pa], the deposition temperature range is set to [300 °C, 400 °C], the deposition thickness range is set to [5 nm, 10 nm], and the deposition time range is set to [25 min, 35 min]; The deposited second cobalt-based Heusler alloy layer is subjected to a single annealing treatment, the annealing temperature range is [250° C., 350° C.], and the annealing time range is [30 min, 60 min].

8. The process for preparing a magnetic tunnel junction based on co-deposition according to claim 7, characterized in that: Depositing the antiferromagnetic pinning layer is specifically as follows: Set the power range to [10W, 20 W] and the pressure range to [1×10 -3 Pa,3×10 -3 Pa], the deposition temperature range is set to [200℃, 300℃], the deposition thickness range is set to [5nm, 10 nm], and the deposition time range is set to [20 min, 30 min].

9. A process for preparing a magnetic tunnel junction based on co-deposition according to claim 8, characterized in that: Depositing the protective layer is specifically as follows: Set the power range to [15W, 25 W] and the air pressure range to [1×10 -3 Pa,2×10 -3 Pa], the deposition temperature range is set to [50℃, 150 ℃], the deposition thickness range is set to [2nm, 5 nm], and the deposition time range is set to [10min, 15min].

10. A magnetic tunnel junction based on the preparation process according to any one of claims 1 to 8, characterized in that: A multilayer structure comprising a substrate and deposited on the substrate; The multilayer structure comprises, from bottom to top, a buffer layer, a first cobalt-based Heusler alloy layer, a spin separation layer, an insulating barrier layer, a second cobalt-based Heusler alloy layer, an antiferromagnetic pinning layer, and a protective layer; The material of the first cobalt-based Heusler alloy layer is Co2MnSi or Co2FeAl and has a thickness range of [10nm, 15nm]; The material of the spin separation layer is L10-MnGa and the thickness range is [0.5nm, 2nm]; The material of the second cobalt-based Heusler alloy layer is Co2MnSi and the thickness range is [5nm, 10nm].

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