A perpendicular magnetic multilayer film device and a preparation method and a detection method thereof

Abstract

The application discloses a vertical stack magnetic multilayer film device and a preparation method and a detection method thereof. The vertical stack magnetic multilayer film device comprises, from bottom to top, a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit and an electrode layer. The spacer layer comprises a first magnetic deconstruction layer, a spin scattering layer and a second magnetic deconstruction layer. The spin scattering layer is arranged between the first magnetic deconstruction layer and the second magnetic deconstruction layer. The bottom magnetic unit and the top magnetic unit have different coercivities. The application suppresses the giant magnetoresistance background, makes the magnetic domain mismatch in the vertical direction become the main contribution source of the inverse longitudinal resistance, realizes the layer-resolved inverse longitudinal resistance response, and can identify the magnetization reversal process of different magnetic layers through external magnetic field scanning. The application can be widely applied to the technical field of spin electronic devices.

Description

Technical Field

[0001] This application relates to the field of spintronic device technology, and in particular to a vertically stacked magnetic multilayer film device and its preparation and detection methods. Background Technology

[0002] Antisymmetric longitudinal resistance (ALR) is a unique transport response in vertically magnetized multilayer films caused by non-uniform magnetic reversal. Its core origin lies in localized anomalous Hall potential asymmetry. Optically programmable control has been achieved in planar Co / Pt multilayer films, and it has important applications in the field of multi-state spintronic devices. Existing ALR devices are all planar structures, capable only of controlling ALR induced by in-plane magnetic domain asymmetry, and cannot achieve layer-resolved ALR detection in the vertical direction.

[0003] In existing vertically stacked magnetic multilayer devices, giant magnetoresistance (GMR) exists between different magnetic layers. The GMR signal masks the layer-resolved asymmetric longitudinal signal induced by vertical magnetic domain mismatch, becoming the main contributor to resistance. Simply increasing the thickness of the spacer layer to achieve magnetic decoupling cannot effectively suppress the GMR background, and the layer-resolved asymmetric longitudinal resistance still cannot be identified. Furthermore, existing vertically stacked magnetic multilayers are difficult to reverse asynchronous magnetization, further increasing the difficulty of detecting asymmetric longitudinal resistance. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide a vertically stacked magnetic multilayer film device and its fabrication and detection methods, which can effectively suppress the giant magnetoresistance background and achieve vertically layer-resolved inverse longitudinal resistance detection.

[0005] To achieve the above objectives, one aspect of this application proposes a vertically stacked magnetic multilayer film device, which includes, from bottom to top, a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit, and an electrode layer. The spacer layer includes a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. The spin scattering layer is disposed between the first magnetic deconstruction layer and the second magnetic deconstruction layer. The bottom magnetic unit and the top magnetic unit have different coercivities.

[0006] In some embodiments, the underlying magnetic unit includes a first multilayer film structure with three cycles, each of which includes a first platinum layer and a first cobalt layer from top to bottom.

[0007] In some embodiments, the top magnetic unit includes a second multilayer film structure with two cycles, each of the second multilayer film structures including a second cobalt layer and a second platinum layer from top to bottom.

[0008] In some embodiments, the spin scattering layer is a ruthenium layer, and both the first magnetic deconstruction layer and the second magnetic deconstruction layer are copper layers.

[0009] In some embodiments, the electrode layer is a gold electrode and has an interdigitated electrode structure.

[0010] In some embodiments, the thickness of both the first platinum layer and the first cobalt layer is 1 nm.

[0011] In some embodiments, the thickness of the second cobalt layer is 0.6 nm, and the thickness of the second platinum layer is 1 nm.

[0012] In some embodiments, the thickness of the ruthenium layer is 2 nm and the thickness of the copper layer is 4 nm.

[0013] To achieve the above objectives, another aspect of this application proposes a method for fabricating a vertically stacked magnetic multilayer film device, comprising the following steps: Substrate preparation; On the upper surface of the substrate, a first platinum layer and a first cobalt layer are sequentially sputtered by magnetron sputtering, and this process is repeated three times to obtain the bottom magnetic unit. On the upper surface of the bottom magnetic unit, a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer are sequentially sputtered by magnetron sputtering to obtain a spacer layer; On the upper surface of the spacer layer, a second cobalt layer and a second platinum layer are sequentially sputtered by magnetron sputtering, and the process is repeated for two cycles to obtain the top magnetic unit. An electrode layer is fabricated on the upper surface of the top magnetic unit to obtain a vertically stacked magnetic multilayer film device. The bottom magnetic unit and the top magnetic unit have different coercivity.

[0014] To achieve the above objectives, another aspect of this application proposes a detection method for vertically stacked magnetic multilayer film devices, comprising the following steps: A constant bias current is supplied to the vertically stacked magnetic multilayer film device using an electrical transport test system; An out-of-plane external magnetic field is applied to the vertically stacked magnetic multilayer film device, and the longitudinal resistance signal of the vertically stacked magnetic multilayer film device is obtained through the electrical transport test system. The magnetization reversal process of the bottom magnetic unit and the top magnetic unit is monitored by magneto-optical Kerr effect imaging. Based on the inverse symmetric peak characteristics of the longitudinal resistance signal, the inverse symmetric longitudinal resistance signal corresponding to the magnetization reversal process of the bottom magnetic unit and the top magnetic unit is obtained.

[0015] The beneficial effects of this application are as follows: The vertically stacked magnetic multilayer film device and its fabrication and detection methods are described in this application. The vertically stacked magnetic multilayer film device includes, from bottom to top, a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit, and an electrode layer. The spacer layer includes a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. The spin scattering layer is disposed between the first and second magnetic deconstruction layers. The bottom magnetic unit and the top magnetic unit have different coercivities. This application designs a composite structure of a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. By utilizing the spin scattering effect of the spin scattering layer to disrupt the spin coherent transport across the spacer layer, this application can effectively suppress the giant magnetoresistance background. At the same time, by designing bottom and top magnetic units with different coercivities, independent magnetization reversal is achieved, making the vertical magnetic domain mismatch the main contributing source of the ansymmetric longitudinal resistance, thus achieving a layer-resolved ansymmetric longitudinal resistance response. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments of this application are described below. It should be understood that the drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic cross-sectional view of a vertically stacked magnetic multilayer film device provided in one embodiment of this application; Figure 2 This is a schematic diagram of the planar structure of the electrode layer provided in one embodiment of this application; Figure 3 This is a flowchart illustrating the steps of a method for fabricating a vertically stacked magnetic multilayer film device according to an embodiment of this application. Figure 4 This is a flowchart illustrating the steps of a detection method for a vertically stacked magnetic multilayer film device according to an embodiment of this application. Figure 5 A graph showing the change of longitudinal resistance as a function of an external magnetic field for a vertically stacked magnetic multilayer film device provided in one embodiment of this application; Figure 6 A graph showing the change in longitudinal resistance of a vertically stacked magnetic multilayer film device as a function of an external magnetic field, provided for related technologies. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0019] It is understood that the terms “first,” “second,” etc., used in this application may be used to describe various concepts herein, but unless otherwise stated, these concepts are not limited by these terms. These terms are used only to distinguish one concept from another.

[0020] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0021] Antisymmetric longitudinal resistance (ALR) is a unique transport response in vertically magnetized multilayer films caused by non-uniform magnetic reversal. Its core origin lies in localized anomalous Hall potential asymmetry. Optically programmable control has been achieved in planar Co / Pt multilayer films, and it has important applications in the field of multi-state spintronic devices. Existing ALR devices are all planar structures, capable only of controlling ALR induced by in-plane magnetic domain asymmetry, and cannot achieve layer-resolved ALR detection in the vertical direction.

[0022] In traditional vertically stacked magnetic multilayer devices, a giant magnetoresistance (GMR) effect exists between different magnetic layers. The GMR signal masks the layer-resolved asymmetric longitudinal signal induced by vertical magnetic domain mismatch, becoming the main contributor to resistance. Simply increasing the thickness of the spacer layer to achieve magnetic decoupling cannot effectively suppress the GMR background, and the layer-resolved asymmetric longitudinal resistance still cannot be identified. Furthermore, the coercivity of different magnetic layers in existing vertically stacked magnetic multilayers is similar, making asynchronous magnetization reversal difficult, further increasing the difficulty of detecting asymmetric longitudinal resistance.

[0023] In view of this, this application proposes a vertically stacked magnetic multilayer film device. The vertically stacked magnetic multilayer film device, from bottom to top, includes a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit, and an electrode layer. The spacer layer includes a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. The spin scattering layer is disposed between the first and second magnetic deconstruction layers. The bottom and top magnetic units have different coercivities. This application designs a composite structure of a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. By utilizing the spin scattering effect of the spin scattering layer to disrupt the spin coherent transport across the spacer layer, it can effectively suppress the giant magnetoresistance background. Simultaneously, by designing bottom and top magnetic units with different coercivities, independent magnetization reversal is achieved, making the vertical domain mismatch the main contributing source of the antisymmetric longitudinal resistance, thus achieving a layer-resolved antisymmetric longitudinal resistance response. This can be applied to three-dimensional multi-state spintronic memory devices, layer-resolved spin logic devices, and other fields, but is not limited thereto.

[0024] Reference Figure 1 , Figure 1 This is a cross-sectional structural diagram of a vertically stacked magnetic multilayer film device provided in one embodiment of this application. The embodiment of this application proposes a vertically stacked magnetic multilayer film device, which includes, from bottom to top, a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit, and an electrode layer. The spacer layer includes a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. The spin scattering layer is disposed between the first magnetic deconstruction layer and the second magnetic deconstruction layer. The bottom magnetic unit and the top magnetic unit have different coercivities.

[0025] Specifically, this application provides a vertically stacked magnetic multilayer film device with layer-resolution anti-symmetric longitudinal resistance, which includes, from bottom to top, a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit, and an electrode layer.

[0026] In some optional embodiments, the substrate comprises silicon (Si) and silicon dioxide (SiO2) with a thickness of 500 μm. Its surface is polished and cleaned to achieve a roughness Ra ≤ 0.5 nm, which ensures the epitaxial growth quality of the multilayer film. Exemplarily, in an embodiment of this application, the substrate roughness is 0.3 nm.

[0027] Both the bottom magnetic unit and the top magnetic unit are multilayer film structures with different coercivities, which can achieve asynchronous and independent magnetization reversal under the action of an external magnetic field.

[0028] The spacer layer is a composite structure comprising a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. It is used to suppress the traditional giant magnetoresistance (GMR) background while ensuring magnetic decoupling between the bottom magnetic unit and the top magnetic unit, thus avoiding interlayer exchange coupling.

[0029] As a further optional implementation, the bottom magnetic unit includes a first multilayer film structure with three cycles, each of which includes a first platinum layer and a first cobalt layer from top to bottom.

[0030] As a further optional implementation, the thickness of both the first platinum layer and the first cobalt layer is 1 nm.

[0031] In some optional embodiments, the bottom magnetic unit is a [Pt / Co1]3 multilayer film structure with a total thickness of 6 nm, wherein the thickness of the platinum (Pt) layer is 1 nm and the thickness of the cobalt (Co) layer is 1 nm, and the process is repeated for 3 cycles.

[0032] As a further optional implementation, the top magnetic unit includes two cycles of second multilayer film structures, each of which includes a second cobalt layer and a second platinum layer from top to bottom.

[0033] As an optional further implementation, the thickness of the second cobalt layer is 0.6 nm and the thickness of the second platinum layer is 1 nm.

[0034] In some optional embodiments, the top magnetic unit is a [Co0.6 / Pt]2 multilayer film structure with a total thickness of 3.2 nm, wherein the cobalt (Co) layer has a thickness of 0.6 nm and the platinum (Pt) layer has a thickness of 1 nm, repeating for 2 cycles.

[0035] It should be noted that, in this embodiment, the coercivity of the bottom magnetic unit is designed to be greater than that of the top magnetic unit, so as to achieve asynchronous and independent magnetization reversal of the two magnetic units under the action of an external magnetic field, providing a magnetic structural basis for layer-resolved anti-symmetrical longitudinal resistance. For example, the coercivity of the bottom magnetic unit is designed to be 50 mT and the coercivity of the top magnetic unit is designed to be 25 mT.

[0036] As a further optional implementation, the spin scattering layer is a ruthenium layer, and both the first magnetic destructuring layer and the second magnetic destructuring layer are copper layers.

[0037] As an optional implementation, the ruthenium layer has a thickness of 2 nm and the copper layer has a thickness of 4 nm.

[0038] In some optional embodiments, the spacer layer is a composite structure comprising Cu / Ru / Cu with a total thickness of 10 nm. The middle ruthenium (Ru) layer is a spin scattering layer with a thickness of 2 nm, used to disrupt spin coherent transport across the spacer layer and effectively suppress the giant magnetoresistance background, with a suppression rate of ≥90% for the giant magnetoresistance signal. The upper and lower copper (Cu) layers are magnetic deconstruction layers with a thickness of 4 nm each, used to ensure magnetic decoupling between the bottom magnetic unit and the top magnetic unit and avoid interlayer exchange coupling.

[0039] As a further optional implementation, the electrode layer is a gold electrode and has an interdigitated electrode structure.

[0040] In some alternative embodiments, such as Figure 2 The diagram shows a planar structure of the electrode layer, which is made of gold and has an interdigitated electrode structure with a thickness of 5 nm, used to acquire electrical transport signals.

[0041] The structure and working principle of the vertically stacked magnetic multilayer film device according to the embodiments of this application have been described above. It can be recognized that, compared with existing vertically stacked magnetic multilayer film devices, the embodiments of this application have the following advantages: I. A composite spacer structure of a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer was designed. The spin scattering layer is a ruthenium layer. The spin scattering effect of the ruthenium layer is used to destroy the spin coherent transport across the spacer layer, which effectively suppresses the traditional giant magnetoresistance background. This solves the technical problem of the giant magnetoresistance signal masking the antisymmetric longitudinal resistance induced by vertical magnetic domain mismatch, making the vertical magnetic domain mismatch the main contributing source of the antisymmetric longitudinal resistance.

[0042] Second, bottom magnetic units and top magnetic units with different coercivity were designed to achieve asynchronous and independent magnetization reversal of the two magnetic units.

[0043] Third, the device has a vertical stacked structure, which provides the material and device basis for extending the control of antisymmetric longitudinal resistance from the plane to three dimensions. By adjusting the degree of domain mismatch in different magnetic layers, three-dimensional multi-level antisymmetric longitudinal resistance can be controlled, which is suitable for application in three-dimensional multi-state spintronic storage and logic devices.

[0044] Reference Figure 3 , Figure 3 This is a flowchart illustrating the steps of a method for fabricating a vertically stacked magnetic multilayer film device according to one embodiment of this application. This application also provides a method for fabricating a vertically stacked magnetic multilayer film device, including the following steps S101 to S105: Step S101: Prepare a substrate; Step S102: On the upper surface of the substrate, the first platinum layer and the first cobalt layer are sputtered sequentially by magnetron sputtering, and the process is repeated for three cycles to obtain the bottom magnetic unit. Step S103: On the upper surface of the bottom magnetic unit, a first magnetic deconstruction layer, a spin scattering layer and a second magnetic deconstruction layer are sequentially sputtered by magnetron sputtering to obtain a spacer layer; Step S104: On the upper surface of the spacer layer, the second cobalt layer and the second platinum layer are sputtered sequentially by magnetron sputtering, and the process is repeated for two cycles to obtain the top magnetic unit. Step S105: An electrode layer is prepared on the upper surface of the top magnetic unit to obtain a vertically stacked magnetic multilayer film device. Among them, the bottom magnetic unit and the top magnetic unit have different coercivity.

[0045] Specifically, the preparation method of this application includes substrate pretreatment, bottom magnetic unit preparation, spacer layer preparation, top magnetic unit preparation and electrode preparation steps. Each layer is prepared by magnetron sputtering, using DC magnetron sputtering to ensure film thickness uniformity and interface adhesion.

[0046] For example, for substrate pretreatment: the Si / SiO2 substrate is sequentially ultrasonically cleaned with acetone, anhydrous ethanol, and deionized water for 15 minutes each, dried with nitrogen, and then placed in the vacuum chamber of a magnetron sputtering instrument, and evacuated to a base vacuum ≤ 5 × 10⁻⁶. -7 Pa, heated to 150℃ and held for 30 min to remove adsorbed impurities on the substrate surface; For the fabrication of the bottom magnetic unit: On the pretreated substrate, a DC magnetron sputtering method was used with a pure target of 99.99% platinum (Pt) and cobalt (Co) as the sputtering source. The sputtering power was set to 20W, the sputtering pressure was set to 6mTorr, the Ar gas flow rate was set to 20sccm, and the substrate was rotated at a speed of 10r / min to ensure the uniformity of the film thickness. A 1nm platinum layer and a 1nm cobalt layer were sputtered sequentially, and the process was repeated for 3 cycles to obtain the [Pt / Co1]3 bottom magnetic unit. For the fabrication of the spacer layer: On the upper surface of the bottom magnetic unit, a DC magnetron sputtering method was used with a pure copper (Cu) and ruthenium (Ru) target of 99.99% purity as the sputtering source. The sputtering power of the copper layer was set to 40W and the sputtering power of the ruthenium layer was set to 30W. The remaining sputtering parameters were the same as those used in the fabrication of the bottom magnetic unit. A 4nm copper layer, a 2nm ruthenium layer, and a 4nm copper layer were sputtered sequentially to obtain the composite structure spacer layer. For the preparation of the top magnetic unit: On the upper surface of the spacer layer, a 0.6 nm cobalt layer and a 1 nm platinum layer were sputtered sequentially using a DC magnetron sputtering method with a pure target of 99.99% cobalt (Co) and platinum (Pt) as the sputtering source and the same sputtering parameters as the preparation of the bottom magnetic unit. This process was repeated for 2 cycles to obtain the [Co0.6 / Pt]2 top magnetic unit. For electrode layer fabrication: On the upper surface of the top magnetic unit, an interdigitated electrode pattern is prepared by photolithography, and then a 5nm gold electrode layer is sputtered by magnetron sputtering. The excess gold electrode is removed by a lift-off process to obtain the electrode layer with the interdigitated electrode structure. The above steps are used to prepare a vertically stacked magnetic multilayer film device with layer-resolution anti-symmetric longitudinal resistance.

[0047] It should be noted that the preparation method of this application embodiment adopts traditional magnetron sputtering, photolithography and lift-off processes, which are mature and easy to operate. The film thickness and structure of each layer can be precisely controlled, making it suitable for large-scale preparation.

[0048] The contents of the above-described vertically stacked magnetic multilayer film device embodiments are all applicable to the present preparation method embodiments. The specific functions implemented by the present preparation method embodiments are the same as those of the above-described vertically stacked magnetic multilayer film device embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described vertically stacked magnetic multilayer film device embodiments.

[0049] Reference Figure 4 , Figure 4 This is a flowchart illustrating the steps of a detection method for a vertically stacked magnetic multilayer film device according to one embodiment of this application. This application also provides a detection method for a vertically stacked magnetic multilayer film device, including the following steps S111 to S113: Step S111: A constant bias current is applied to the vertically stacked magnetic multilayer film device through the electrical transport test system; Step S112: Apply an out-of-plane external magnetic field to the vertically stacked magnetic multilayer film device, and obtain the longitudinal resistance signal of the vertically stacked magnetic multilayer film device through an electrical transport test system. Monitor the magnetization reversal process of the bottom magnetic unit and the top magnetic unit through magneto-optical Kerr effect imaging. Step S113: Based on the inverse peak characteristics of the longitudinal resistance signal, obtain the inverse longitudinal resistance signal corresponding to the magnetization reversal process of the bottom magnetic unit and the top magnetic unit.

[0050] Specifically, the layer-resolved asymmetric longitudinal resistance detection method of this application, through out-of-plane magnetic field scanning, combined with electrical transport testing and magneto-optical Kerr effect (MOKE) imaging, identifies the asymmetric longitudinal resistance (ALR) signals corresponding to magnetization reversal of different magnetic layers based on the asymmetric peaks with unequal amplitudes in the longitudinal resistance signal, thereby achieving layer-resolved asymmetric longitudinal resistance detection.

[0051] For example, the electrode layer is first connected to the electrical transport test system, and a constant bias current with a current density of 1×10⁻⁶ is applied to the device. 6 A / m 2 The test system has a resolution of 10. -6 Ω. Next, an external magnetic field scan is performed. An out-of-plane external magnetic field is applied to the device, with a scanning range of -200mT to 200mT and a scanning rate of 1mT / s. Simultaneously, the longitudinal resistance signal of the device is acquired through an electrical transport test system. The magnetization reversal process of the bottom and top magnetic units is monitored using magneto-optical Kerr effect (MOKE) imaging. Finally, layer-resolved asymmetric longitudinal resistance identification is performed. Based on the asymmetric peak characteristics of the longitudinal resistance signal, the asymmetric longitudinal resistance signals corresponding to the magnetization reversal of the bottom and top magnetic units are identified. Due to the different coercivity of the bottom and top magnetic units, the magnetization reversal process is asynchronous, resulting in two asymmetric longitudinal resistance peaks with unequal amplitudes, corresponding to the domain mismatch of the top and bottom magnetic units, respectively, thus achieving layer-resolved asymmetric longitudinal resistance detection.

[0052] It should be noted that the layer-resolved asymmetric longitudinal resistance detection method of this application embodiment is simple and can be achieved by combining external magnetic field scanning with electrical transport testing. It does not require complex detection equipment. The magnetization reversal process of different magnetic layers can be monitored in real time through magneto-optical Kerr effect imaging, which further improves the accuracy of layer-resolved asymmetric longitudinal resistance identification.

[0053] Furthermore, such as Figure 5 The figure shown is a graph illustrating the variation of the longitudinal resistance of a vertically stacked magnetic multilayer film device with an external magnetic field according to an embodiment of this application. Figure 6 The figure shows the longitudinal resistance of a vertically stacked magnetic multilayer film device provided by related technologies as a function of an external magnetic field. This is an existing vertically stacked magnetic multilayer film device without a ruthenium layer. Figure 5 and Figure 6 MOKE imaging shows that when the external magnetic field is scanned to 25 mT, the top magnetic unit of the device proposed in this application undergoes magnetization reversal, corresponding to the appearance of the first antisymmetric longitudinal resistance peak in the electrical transport signal, with an amplitude of 0.07% of the substrate resistance; when the external magnetic field is scanned to 50 mT, the bottom magnetic unit undergoes magnetization reversal, corresponding to the appearance of the second antisymmetric longitudinal resistance peak in the electrical transport signal, with an amplitude of 0.18% of the substrate resistance; the amplitudes of the two antisymmetric peaks are unequal, corresponding to the vertical magnetic domain mismatch of the top and bottom magnetic units, respectively, thus successfully realizing layer-resolved antisymmetric longitudinal resistance detection.

[0054] The contents of the above-described vertically stacked magnetic multilayer film device embodiments are all applicable to the embodiments of this detection method. The specific functions implemented by the embodiments of this detection method are the same as those of the above-described vertically stacked magnetic multilayer film device embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described vertically stacked magnetic multilayer film device embodiments.

[0055] In the foregoing description of this specification, the references to terms such as "one embodiment," "another embodiment," or "some embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

[0057] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A vertically stacked magnetic multilayer film device, characterized in that, From bottom to top, it includes a substrate, a bottom magnetic unit, a spacer layer, a top magnetic unit, and an electrode layer. The spacer layer includes a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer. The spin scattering layer is disposed between the first magnetic deconstruction layer and the second magnetic deconstruction layer. The bottom magnetic unit and the top magnetic unit have different coercivities.

2. The vertically stacked magnetic multilayer film device according to claim 1, characterized in that, The underlying magnetic unit includes a first multilayer film structure with three cycles, and each of the first multilayer film structures includes a first platinum layer and a first cobalt layer from top to bottom.

3. The vertically stacked magnetic multilayer film device according to claim 1, characterized in that, The top magnetic unit includes a second multilayer film structure with two cycles, and each second multilayer film structure includes a second cobalt layer and a second platinum layer from top to bottom.

4. The vertically stacked magnetic multilayer film device according to claim 1, characterized in that, The spin scattering layer is a ruthenium layer, and both the first magnetic deconstruction layer and the second magnetic deconstruction layer are copper layers.

5. The vertically stacked magnetic multilayer film device according to claim 1, characterized in that, The electrode layer is a gold electrode and has an interdigitated electrode structure.

6. The vertically stacked magnetic multilayer film device according to claim 2, characterized in that, The thickness of the first platinum layer and the first cobalt layer is 1 nm.

7. The vertically stacked magnetic multilayer film device according to claim 3, characterized in that, The second cobalt layer has a thickness of 0.6 nm, and the second platinum layer has a thickness of 1 nm.

8. The vertically stacked magnetic multilayer film device according to claim 4, characterized in that, The thickness of the ruthenium layer is 2 nm, and the thickness of the copper layer is 4 nm.

9. A method for fabricating a vertically stacked magnetic multilayer film device, used to fabricate the vertically stacked magnetic multilayer film device as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Substrate preparation; On the upper surface of the substrate, a first platinum layer and a first cobalt layer are sequentially sputtered by magnetron sputtering, and this process is repeated three times to obtain the bottom magnetic unit. On the upper surface of the bottom magnetic unit, a first magnetic deconstruction layer, a spin scattering layer, and a second magnetic deconstruction layer are sequentially sputtered by magnetron sputtering to obtain a spacer layer; On the upper surface of the spacer layer, a second cobalt layer and a second platinum layer are sequentially sputtered by magnetron sputtering, and the process is repeated for two cycles to obtain the top magnetic unit. An electrode layer is fabricated on the upper surface of the top magnetic unit to obtain a vertically stacked magnetic multilayer film device. The bottom magnetic unit and the top magnetic unit have different coercivity.

10. A method for detecting a vertically stacked magnetic multilayer film device, implemented using a vertically stacked magnetic multilayer film device as described in any one of claims 1 to 8, characterized in that, Includes the following steps: A constant bias current is supplied to the vertically stacked magnetic multilayer film device using an electrical transport test system; An out-of-plane external magnetic field is applied to the vertically stacked magnetic multilayer film device, and the longitudinal resistance signal of the vertically stacked magnetic multilayer film device is obtained through the electrical transport test system. The magnetization reversal process of the bottom magnetic unit and the top magnetic unit is monitored by magneto-optical Kerr effect imaging. Based on the inverse symmetric peak characteristics of the longitudinal resistance signal, the inverse symmetric longitudinal resistance signal corresponding to the magnetization reversal process of the bottom magnetic unit and the top magnetic unit is obtained.

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