Track electronic device and magnetic storage device based on track Hall effect

Abstract

The invention provides a track electronic device based on a track Hall effect and a magnetic memory device. The track electronic device comprises a substrate; the ferromagnetic / non-magnetic heterojunction structure is prepared on the substrate, the ferromagnetic / non-magnetic heterojunction structure comprises a ferromagnetic layer structure and a non-ferromagnetic layer structure serving as a track source, the ferromagnetic layer structure is located on the face, away from the substrate, of the non-ferromagnetic layer structure, and the ferromagnetic layer structure has perpendicular magnetic anisotropy; wherein the non-ferromagnetic layer structure is made of a 3d-5d metal material and a two-dimensional TMD material, and the ferromagnetic layer structure is an artificially synthesized antiferromagnetic layer or an artificially synthesized ferromagnetic layer. According to the orbital electronics device and the magnetic storage device which are formed on the basis of an artificially synthesized antiferromagnetic layer or an artificially synthesized ferromagnetic layer as a ferromagnetic layer, the orbital torque efficiency can be enhanced, the critical overturning current density is reduced, and the overturning speed is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic devices, and in particular to a track electronic device and a magnetic storage device based on track Hall effect. Background Art

[0002] As we all know, effective current-induced spin torque effect is of great significance for the development of spintronic memory and logic devices. In the past few decades, the research on spin orbit torque (SOT) has received widespread attention. It uses the spin Hall effect (SHE) to realize the conversion of charge flow-spin flow. Compared with charge flow, spin flow has the great advantage of no Joule heat dissipation. The spin Hall effect has been applied in many materials, such as heavy metal materials such as tungsten, tantalum and platinum. When heavy metal materials are used as spin sources, the spin Hall effect uses the strong spin-orbit coupling (SOC) of the heavy metal materials themselves to generate spin flow and induced torque to manipulate the magnetic moment of the adjacent ferromagnetic layer (FM). However, heavy metal materials have problems in practical device applications because their high resistivity makes such devices less efficient. In addition, heavy elements are usually expensive and often not suitable for large-scale production. The use of heavy metals limits the choice of spin source materials.

[0003] Recently, based on theoretical predictions and experimental results, it has been proposed to use electric fields to generate orbital currents, namely the orbital Hall effect (OHE). Similar to the spin Hall effect, orbital currents carry angular momentum like spin currents, so injecting orbital currents into the ferromagnetic layer can produce torque on the local magnetic moment of the ferromagnetic layer. This type of torque caused by orbital current injection is called orbital torque (OT). Orbital torque provides an experimental method to detect OHE, and orbital torque OT has attracted great interest. The maximum angular momentum of each electronic state caused by spin currents is is the simplified Planck constant, while the orbital flow has no restrictions on the angular momentum of an electronic state, indicating that the efficiency of OT is more significant. Theoretical calculations show that in many materials, the orbital Hall conductivity is much larger than the spin Hall conductivity. This indicates that the spin torque caused by OHE can be larger than the spin torque caused by SHE, thereby improving the spin torque efficiency of spintronic devices. In addition, since OHE originates from the momentum space orbital texture, spin-orbit coupling (SOC) is not required, making the material selection of the orbital source very wide, rather than limited to a few heavy metals.

[0004] Currently, Ti and Zr3d-5d metal materials or two-dimensional transition metal sulfide (TMD) materials have begun to be used to prepare orbital electronic devices, but how to further optimize the orbital torque efficiency of orbital electronic devices to obtain orbital electronic devices with higher performance is a problem that is being paid attention to and studied but has not yet been broken through. Summary of the invention

[0005] In view of this, the embodiments of the present invention provide a track electronics device and a magnetic storage device based on the track Hall effect to improve the track torque efficiency, thereby ensuring that the track electronics device has excellent performance while reducing costs.

[0006] One aspect of the present invention provides a track electronics device based on track Hall effect, the track electronics device comprising:

[0007] a substrate; and

[0008] A ferromagnetic / non-magnetic heterojunction structure prepared on a substrate, wherein the ferromagnetic / non-magnetic heterojunction structure comprises a ferromagnetic layer structure and a non-ferromagnetic layer structure as a track source, wherein the ferromagnetic layer structure is located on a side of the non-ferromagnetic layer structure away from the substrate, and the ferromagnetic layer structure has perpendicular magnetic anisotropy;

[0009] The non-ferromagnetic layer structure is a 3d-5d metal material, an oxide or a two-dimensional TMD material, and the ferromagnetic layer structure is an artificial antiferromagnetic layer or an artificial ferromagnetic layer.

[0010] In some embodiments of the present invention, the artificial antiferromagnetic layer or artificial ferromagnetic layer includes a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer between the first ferromagnetic layer and the second ferromagnetic layer, and the spacer layer is a non-magnetic layer.

[0011] In some embodiments of the present invention, the orbital electronics device further includes: a non-magnetic barrier layer formed on a side of the artificial antiferromagnetic layer or the artificial ferromagnetic layer away from the substrate; and a fixed layer formed on a side of the non-magnetic barrier layer away from the artificial antiferromagnetic layer or the artificial ferromagnetic layer, the fixed layer being a ferromagnetic layer; wherein the artificial antiferromagnetic layer or the artificial ferromagnetic layer, the non-magnetic barrier layer and the fixed layer form a magnetic tunnel junction.

[0012] In some embodiments of the present invention, the track electronics device further comprises: a protective layer formed on the ferromagnetic / non-magnetic heterojunction structure.

[0013] In some embodiments of the present invention, the non-ferromagnetic layer of the track source is selected from one of the following materials: Ti, Zr, Mn, Cr, Al, Ge, Ta, W, WTe2, MoS2, WSe2, WS, TaTe2, MoTe2, NbSe2, PtTe2, TaS2; the first ferromagnetic layer and the second ferromagnetic layer are selected from metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials or ferromagnetic insulators;

[0014] In some embodiments of the present invention, the first ferromagnetic layer and the second ferromagnetic layer are selected from one of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, the [Co / Pt] double film layer and the [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1.

[0015] In some embodiments of the present invention, the material of the non-magnetic barrier layer is selected from MgO, Al2O3, NiO, TiO x , BN, WSe2 two-dimensional semiconductor; the fixed layer is selected from metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials, metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials or ferromagnetic insulators;

[0016] In some embodiments of the present invention, the fixed layer is selected from one or more of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, the [Co / Pt] double film layer and the [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1.

[0017] In some embodiments of the present invention, the first ferromagnetic layer is a ferromagnetic layer with a larger orbital-spin conversion coefficient, and the second ferromagnetic layer is a ferromagnetic layer with a smaller orbital-spin conversion coefficient and a lower damping constant than the first ferromagnetic layer.

[0018] In some embodiments of the present invention, the thickness of the non-ferromagnetic layer structure is 2-100 nanometers; the thickness of the ferromagnetic layer structure is 1-40 nanometers.

[0019] Another aspect of the present invention further provides a magnetic random access memory, the magnetic random access memory comprising a basic storage unit based on a magnetic tunnel junction, the basic storage unit comprising:

[0020] substrate;

[0021] A ferromagnetic / non-magnetic heterojunction structure prepared on a substrate, wherein the ferromagnetic / non-magnetic heterojunction structure comprises a ferromagnetic layer structure and a non-ferromagnetic layer structure as a track source, wherein the ferromagnetic layer structure is located on a side of the non-ferromagnetic layer structure away from the substrate, and the ferromagnetic layer structure has perpendicular magnetic anisotropy; wherein the non-ferromagnetic layer structure is a 3d-5d metal material, an oxide or a two-dimensional TMD material, and the ferromagnetic layer structure is an artificially synthesized antiferromagnetic layer or an artificially synthesized ferromagnetic layer;

[0022] a non-magnetic barrier layer formed on a side of the artificial antiferromagnetic layer or the artificial ferromagnetic layer away from the substrate; and

[0023] A fixed layer formed on a side of the non-magnetic barrier layer away from the artificial antiferromagnetic layer or the artificial ferromagnetic layer, wherein the fixed layer is a ferromagnetic layer;

[0024] The artificial antiferromagnetic layer or the artificial ferromagnetic layer, the nonmagnetic barrier layer and the fixed layer form a magnetic tunnel junction.

[0025] The orbital electronics device based on the orbital Hall effect and the preparation method thereof of the present invention use 3d-5d metal materials and two-dimensional TMD materials as orbital source materials, thereby removing the restrictions on the selection of material orbital sources; thus, the prepared orbital electronics device is not only low-cost but also has good performance.

[0026] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically indicated in the specification and the accompanying drawings.

[0027] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are only for illustrating the principles of the present invention. In order to facilitate the illustration and description of some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other parts in the exemplary structure actually manufactured according to the present invention. In the drawings:

[0029] Figure 1 The schematic diagram of the structure of an orbital electronic device containing synthetic antiferromagnetism (SAF) based on the orbital Hall effect in one embodiment of the present invention.

[0030] Figure 2 Schematic diagram of the structure of an artificially synthesized antiferromagnetic free layer in one embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the structure of Zr(10) / [Co(0.3) / Pt(0.8)]4 / Co(0.3)Ru(0.6) / Ta(0.3)CFB(2)MgO(2) / Ta(2) in one embodiment of the present invention.

[0032] Figure 4 It is a schematic diagram of the measurement of the track torque device in an embodiment of the present invention.

[0033] Figure 5 This is the MH diagram corresponding to the sample of Example 1 in the present invention.

[0034] Figure 6 is the R corresponding to the sample of Example 1 in the present invention AHE -H and R AHE -I loop graph.

[0035] Figure 7 FIG. 4 is a schematic diagram of the structure of a magnetic tunnel junction (MTJ) based on an artificial antiferromagnetic free layer in one embodiment of the present invention.

[0036] Figure 8 This is a schematic diagram of the structure of Zr(10) / [Co(0.3) / Pt(0.8)]4 / Ru(0.6)Ta(0.3) / CFB(1.3) / MgO(2) / CFB(1.3) / Ta(0.7) / [Co(0.3) / Pt(0.8)]3 / SiO2(2) in one embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0038] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0039] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0040] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0042] Currently, although theoretical calculations and experimental results have proved the existence of orbital torque OT, there is no research on optimizing the OT intensity by adjusting the orbital source layer material.

[0043] In some embodiments of the present invention, synthetic antiferromagnetic layers (SAF) with perpendicular magnetic anisotropy are applied to orbital electronics devices based on the orbital Hall effect. That is, in embodiments of the present invention, synthetic antiferromagnetic layers are used as ferromagnetic layer structures in ferromagnetic / non-magnetic heterojunctions of orbital electronics devices to realize orbital torque (OT) driven SAF, and orbital current is used to drive the magnetization reversal of the magnetic layer to achieve improved orbital torque efficiency.

[0044] In the embodiment of the present invention, the orbital electronics device based on the orbital Hall effect is further applied to the magnetic storage device, thereby obtaining a new type of magnetic random access memory (MRAM), namely, orbital torque magnetic random access memory (OT-MRAM).

[0045] The synthetic antiferromagnetic structure refers to a structure in which two magnetic layers generate RKKY (Ruderman-Kittel-Kasuya-Yosida) interlayer exchange coupling through a non-magnetic layer (spacer layer), and the magnetic moments of the ferromagnetic layers are arranged in antiparallel under the interlayer exchange coupling. The synthetic antiferromagnetic structure has strong antiferromagnetic interlayer exchange coupling, so the synthetic antiferromagnetic structure has the advantages of small stray magnetic field and insensitivity to external magnetic field disturbance.

[0046] Usually, people use heavy metal layers or topological materials with strong spin-orbit coupling to achieve efficient magnetization reversal caused by spin-orbit torque. In recent years, some light metals with high orbital effects have emerged. The magnetic order in crystalline antiferromagnetism is arranged alternately at the atomic scale, and the thickness of the ferromagnetic layer in SAF is usually a few nanometers. Therefore, the SAF magnetic order can be easily adjusted by the orbital torque. In an embodiment of the present invention, the orbital torque efficiency of the device is improved in an artificial synthetic antiferromagnetic layer structure with perpendicular magnetic anisotropy by using light metals with orbital effect.

[0047] Figure 1 FIG. 1 is a schematic diagram of the structure of a track electronic device containing SAF based on the track Hall effect in one embodiment of the present invention. Figure 1 As shown, the track electronic device comprises: a substrate 10; and a ferromagnetic / non-magnetic heterojunction structure 20 and a protective layer 30 prepared on the substrate 10;

[0048] Among them, the ferromagnetic / non-magnetic heterojunction structure includes a ferromagnetic layer structure 22 and a non-ferromagnetic layer structure 21 as an orbital source, the non-ferromagnetic layer 21 as an orbital source is closer to the substrate, the ferromagnetic layer structure 22 is located on the side of the non-ferromagnetic layer structure away from the substrate, and the ferromagnetic layer structure has perpendicular magnetic anisotropy; wherein the non-ferromagnetic layer structure is a light metal layer (such as a 3d-5d metal material layer) or a two-dimensional TMD material, the light metal layer or the two-dimensional TMD material is an orbital source, used as an orbital Hall channel layer, and the ferromagnetic layer structure is an artificially synthesized antiferromagnetic layer or an artificially synthesized ferromagnetic layer.

[0049] In some embodiments of the present invention, the substrate may be, for example, a Si / SiO2 substrate, an Al2O3 substrate or a MgO substrate, and the non-ferromagnetic layer as an orbital source may be selected from one of the following light metal materials: Ti, Zr, Mn, Cr, Al, Ge, Ta, W, or the non-ferromagnetic layer as an orbital source may be selected from one of the following two-dimensional TMD materials: WTe2, MoS2, WSe2, WS, TaTe2, MoTe2, NbSe2, PtTe2, TaS2, but the present invention is not limited thereto. In some alternative embodiments of the present invention, an oxide may be used instead of a light metal layer or a two-dimensional TMD material as an orbital source. Examples of oxides used as orbital sources include copper oxide, etc.

[0050] The protective layer may include at least one of the following film layers: a magnesium oxide (MgO) / tungsten (W) layer, a tantalum (Ta) layer, a SiO2 layer, etc., but the present invention is not limited thereto. The protective layer may also be omitted.

[0051] like Figure 2 As shown, the artificial antiferromagnetic layer 22 may include a first ferromagnetic layer 221, a second ferromagnetic layer 223 and a spacer layer 222 located between the first ferromagnetic layer 221 and the second ferromagnetic layer 223, wherein the spacer layer is a non-magnetic layer. The first ferromagnetic layer and the second ferromagnetic layer may be selected from one of metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials, ferromagnetic insulators or antiferromagnetic materials. More specifically, metal ferromagnetic materials include, for example, Fe, Co, Ni, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n ; Alloy ferromagnetic materials include, for example: CoCrPt, CoFeB, CoTb, FePd, FePt, CoPd, CoPt, CoNi; two-dimensional magnetic materials include, for example: MnBi2Te4, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2; oxide magnetic materials include, for example: NiCo2O4, SrRuO3, SrTiO3; ferromagnetic insulators include, for example: YIG, YAIG, TmIG; antiferromagnetic materials include, for example: IrMn, Mn3Ge, FeMn and PtMn, etc.

[0052] As an example, the first ferromagnetic layer and the second ferromagnetic layer can be selected from one of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, [Co / Pt] double film layer and [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1

[0053] Preferably, the first ferromagnetic layer is a ferromagnetic layer with a larger orbital-spin conversion coefficient, and the second ferromagnetic layer is a ferromagnetic layer with a smaller orbital-spin conversion coefficient and a lower damping constant than the first ferromagnetic layer. The thickness of the ferromagnetic layers 221 and 223 is preferably 0.5-10 nanometers.

[0054] The material of the spacer layer 222 may include one or more of Nb, Ta, Cr, Mo, W, Re, Ru, Os, Rh, Ir, Pt, Cu, Ag or Au, with a thickness of 0.1 nm to 10 nm.

[0055] In some embodiments of the present invention, the thickness of the non-ferromagnetic layer is preferably 2-20 nanometers, and the thickness of the ferromagnetic layer structure is preferably 1-20 nanometers.

[0056] By forming corresponding electrode layers on the basic structure of the electronic device as above, different types of track electronics devices can be formed.

[0057] As an example, the orbital electronic device based on the orbital Hall effect further includes: a top electrode and a lower electrode.

[0058] The top electrode may be formed on the protection layer. In the case where the protection layer is omitted, the top electrode may also be directly formed on the ferromagnetic layer structure of the ferromagnetic / non-magnetic heterojunction.

[0059] A bottom electrode (not shown) may be formed to contact the orbital Hall channel layer for generating an in-plane current flowing through the orbital Hall channel layer. The bottom electrode and the top electrode may be used to generate a perpendicular current flowing through the ferromagnetic / non-magnetic heterojunction.

[0060] In some embodiments of the present invention, the non-ferromagnetic layer can be prepared by a magnetron sputtering process; when the ferromagnetic layer is a single film layer or a multi-film layer, each film layer is prepared by a magnetron sputtering process; when the ferromagnetic layer is a two-dimensional ferromagnetic material, the two-dimensional ferromagnetic material is prepared by magnetron sputtering, CVD / CVT or mechanical stripping and other processes.

[0061] The orbital electronic device of the present invention with the above structure can be used for spin-orbit moment electronic storage logic, orbital torque magnetic tunnel junction device and orbital Hall nano-oscillator device, etc.

[0062] A magnetic tunnel junction (MTJ) usually includes a sandwich structure consisting of two magnetic metal layers and an ultra-thin insulating layer in the middle (called an intermediate layer or pinned layer), one of which is called a reference layer or a pinned layer, and its magnetization is fixed along the easy magnetization axis; the other ferromagnetic layer is called a free layer, and its magnetization has two stable orientations, parallel or anti-parallel to the reference layer, which will put the magnetic tunnel junction in a low resistance state or a high resistance state. This phenomenon is called the tunneling magnetoresistance effect. The intermediate layer is a non-magnetic barrier layer.

[0063] When the present invention applies the orbital electronics device based on the orbital Hall effect using an artificial antiferromagnetic layer to an orbital torque magnetic tunnel junction (MTJ) device, the orbital torque magnetic tunnel junction device, in addition to the structure of the orbital electronics device based on the orbital Hall effect mentioned above, also includes: a non-magnetic barrier layer and a fixed layer.

[0064] like Figure 7 As shown, the MTJ type track electronics device formed based on the artificial synthetic antiferromagnetic layer / artificial synthetic ferromagnetic layer structure includes the following structure: substrate 10, ferromagnetic / non-magnetic heterojunction structure 20, non-magnetic barrier layer 40, fixed layer 50 and protective layer 30, wherein the ferromagnetic / non-magnetic heterojunction structure 20 includes a non-ferromagnetic layer structure 21 and a ferromagnetic layer structure 22 as a track source, the ferromagnetic layer structure is located on the side of the non-ferromagnetic layer structure away from the substrate, and the ferromagnetic layer structure has perpendicular magnetic anisotropy. Figure 2 As shown, the artificial antiferromagnetic layer / artificial ferromagnetic layer 22 includes a ferromagnetic layer 221, a non-magnetic layer 222 and a ferromagnetic layer 223. The non-magnetic barrier layer 40 is formed on the side of the artificial antiferromagnetic layer / artificial ferromagnetic layer 22 away from the substrate; the fixed layer 50 is formed on the side of the non-magnetic barrier layer 40 away from the artificial antiferromagnetic layer / artificial ferromagnetic layer, and the fixed layer is a ferromagnetic layer. The artificial antiferromagnetic layer / artificial ferromagnetic layer 22, the barrier layer 40 and the fixed layer 50 form an MTJ structure, and the artificial antiferromagnetic layer / artificial ferromagnetic layer 22 serves as a free layer, that is, the embodiment of the present invention uses the orbital flow to regulate the artificial antiferromagnetic / artificial ferromagnetic structure from the antiferromagnetic state to the ferromagnetic state, so that it becomes the free layer of the MTJ. When the free layer and the fixed layer have the same tendency, it is in a low resistance state, and when it is antiparallel to the fixed layer, it is in a high resistance state. The exchange coupling in SAF is weaker than the direct exchange coupling or super exchange coupling in crystalline antiferromagnetism, so its SAF antiferromagnetic order is easier to control through OT. MTJ devices can be used in many fields, such as magnetic storage, sensors and computer chips.

[0065] One embodiment of the present invention uses the MTJ as the basic structure (basic storage unit) of magnetic random access memory (MRAM) to form a new type of magnetic random access memory, namely, orbital torque magnetic random access memory (OT-MRAM).

[0066] The SAF-based MTJ device of the present invention is used in MRAM to achieve high-speed data writing. In an embodiment of the present invention, the heterojunction formed by the orbital Hall channel layer and the artificial synthetic antiferromagnetic layer / artificial synthetic ferromagnetic layer can achieve high orbital torque efficiency. In this structure, there are two ways for the orbital Hall layer to convert spins. One is that its own spin-orbit coupling can be converted into spin current, and the other is that the orbital current generated by the orbital Hall effect can be converted into spin current in the magnetic material. Therefore, the current density during data writing is reduced. The MTJ based on the artificial synthetic antiferromagnetic / artificial synthetic ferromagnetic layer free layer for OT-MRAM data writing provided in an embodiment of the present invention can achieve high-speed data writing and reduce energy consumption.

[0067] For example, the material of the non-magnetic barrier layer in the MTJ device can be selected from MgO, Al2O3, NiO, TiO x , BN, WSe2 two-dimensional semiconductor; the fixed layer can be selected from metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials, ferromagnetic insulators or antiferromagnetic layer materials. More specifically, the metal ferromagnetic materials include, for example, Fe, Co, Ni, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n ; Alloy ferromagnetic materials include, for example: CoCrPt, CoFeB, CoTb, FePd, FePt, CoPd, CoPt, CoNi; two-dimensional magnetic materials include, for example: MnBi2Te4, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2; oxide magnetic materials include, for example: NiCo2O4, SrRuO3, SrTiO3; ferromagnetic insulators include, for example: YIG, YAIG, TmIG; antiferromagnetic materials include, for example: IrMn, Mn3Ge, FeMn and PtMn, etc.

[0068] As an example, the fixed layer can be selected from one of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n, FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, [Co / Pt] double film layer and [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1

[0069] Several examples of track electronics structures are listed below.

[0070] Example 1: Zr(10) / [Co(0.3) / Pt(0.8)]4 / Co(0.3) / Ru(0.6) / Ta(0.3) / CoFeB(1.3) / MgO(2) / Ta(2) orbital electron device

[0071] like Figure 3 As shown, the orbital electronic device provided in this embodiment includes the following film layers in sequence: substrate (Si or SiO2), non-ferromagnetic layer Ti(10), artificial antiferromagnetic layer [Co(0.3) / Pt(0.8)]4 / Co(0.3) / Ru(0.6) / Ta(0.3) / CoFeB(1.3) / MgO(2) and protective layer Ta(2). The values ​​in parentheses represent the thickness of each film layer in nanometers. The subscript 4 in the brackets represents the number of Co / Pt double film layers, that is, the subscript 4 represents 4 Co / Pt double film layers, [Co(0.3) / Pt(0.8)]4 can be abbreviated as [Co / Pt]4, and the thickness of the Co layer and the Pt layer in the Co / Pt double film layer are 0.3 nanometers and 0.8 nanometers respectively. The thickness of the protective layer Ta is 2 nanometers. Zr(10) is an orbital source and is used as an orbital Hall channel layer. The artificial synthetic antiferromagnetic layer [Co(0.3) / Pt(0.8)]4 / Co(0.3) / Ru(0.6) / Ta(0.3) / CoFeB(1.3) / MgO(2) is used as a ferromagnetic layer structure, including a ferromagnetic layer [Co(0.3) / Pt(0.8)]4, a non-magnetic layer Ru and a ferromagnetic layer Ta(0.3) / CoFeB(1.3) / MgO(2). The artificial synthetic antiferromagnetic layer has good perpendicular magnetic anisotropy (PMA) and a large orbital-spin conversion coefficient. The artificial synthetic antiferromagnetic layer [Co(0.3) / Pt(0.8)]4 / Co(0.3) / Ru(0.6) / Ta(0.3) / CoFeB(1.3) / MgO(2) and the non-ferromagnetic layer Zr(10) form a ferromagnetic / non-magnetic heterojunction structure. The Ta layer acts as a protective layer to protect the underlying film from oxidation.

[0072] The orbital electronics device based on the orbital Hall effect with the above structure in this embodiment is prepared by magnetron sputtering using the following process:

[0073] (1) Using an ultra-high vacuum multi-target sputtering system, Zr, Co, Pt, Ru and SiO2 targets are installed on multiple sputtering target heads respectively;

[0074] (2) The Si / SiO2 substrate is placed on the sample holder, and appropriate process parameters are adjusted to form films on the substrate using magnetron sputtering.

[0075] When forming a film on a substrate by magnetron sputtering, it is necessary to control the growth order of each layer. First, the Zr film is grown by controlling the sputtering of the Ti target, and the thickness of the Zr film is controlled by controlling the sputtering time according to the sputtering rate; further, the Co and Pt films are grown by controlling the sputtering of the Co target and the Pt target in turn, and the growth thickness of the Co film and the Pt film is controlled by controlling the sputtering time according to the sputtering rate, and the Co and Pt films are repeatedly grown to form four Co / Pt double film layers; after forming four Co / Pt double film layers, the Ru target is further controlled to grow the Ru film; after growing the Ru film of a predetermined thickness, the TaCFB and MgO films are repeatedly grown. Then the Ta target is used to grow the Ta protective layer. During the growth process, the thickness of the Zr, Co, Pt, Ru, Ta, CFB, and MgO films are controlled to be 10, 0.3, 0.8, 0.6, 0.3, 1.3, and 2 nanometers, respectively.

[0076] Exemplary process parameters in the sample preparation process may include: substrate temperature is room temperature; argon gas flow rate is 33sccm; sputtering pressure is 3mTorr; Ti sputtering power is 100 watts during the growth of Ti film; Co and Pt sputtering powers are 50 and 15 watts respectively during the growth of [Co(0.3) / Pt(0.8)]4 multilayer film; Ru sputtering power is 50 watts during the growth of Ru film; Ta sputtering power is 50 watts during the growth of protective layer, and Zr, Co, Pt, Ru and Ta sputtering rates are 0.194, 0.237, 0.174, 0.768 and 0.33 angstroms / second respectively; Here, the listed process parameters are only examples, and the present invention is not limited to these specific parameters, but these parameters can be appropriately adjusted and changed. The thickness of each layer structure in the ferromagnetic layer and the composition ratio are adjusted so that the ferromagnetic layer as a whole has good perpendicular magnetic anisotropy. In addition, although the thickness of the Ru layer in this embodiment is 0.6 nanometers, it is not limited thereto, and the coupling of the two ferromagnetic layers from ferromagnetism to antiferromagnetism can be achieved by adjusting its thickness.

[0077] Track torque flip test:

[0078] The samples were fabricated into Hall bars by standard photolithography and argon ion milling techniques, e.g. Figure 4 As shown, it is used to measure perpendicular magnetic anisotropy and critical switching current. Figure 4 The numbers 1, 2, 3, 4, 5, and 6 represent electrodes, and the number 7 represents Figure 1 The structure of the orbital electronics device in the circuit. A pulse current is passed along the longitudinal direction (electrode 3→4), and the anomalous Hall resistance R is measured in the transverse direction (electrode 1→5 or electrode 2→6). AHE . Figure 5 is the MH test result, and the track torque test result is as follows Figure 6 As shown. Among them, Figure 6 (a) represents the structure R prepared in this example AHE -H map, Figure 6 (b) and (c) show the R of the structure prepared in this example. AHE -Iloop diagram, more specifically, Figure 6 When (b) is Hx = +100Oe, R AHE -I test results, Figure 6 When (c) is Hx = -100Oe, R AHE -I test results. Among them, R AHE -H diagram shows abnormal Hall resistance R AHE As the external magnetic field changes, the AHE -H diagram can reflect the perpendicular magnetic anisotropy of the sample structure; R AHE -I diagram shows the abnormal Hall resistance R AHE As the applied current changes, the AHE -I diagram can reflect the critical reversal current density of the sample structure; by comparing R AHE -H and R AHE -I in R AHE The size of can reflect the extent to which the torque generated in the orbital source flips the magnetic moment of the ferromagnetic layer.

[0079] Figure 5 and Figure 6 The results of magnetic tests shown in (a) show that the artificial antiferromagnetic layer Zr / [Co(0.3) / Pt(0.8)]4 / Co(0.3)Ru(0.6) / Ta(0.3) / CFB(1.3) / MgO(2) / Ta(2) has good perpendicular magnetic anisotropy (PMA) and exhibits a double loop pattern, proving that the two ferromagnetic layers form an antiferromagnetic coupling. When Zr is used as an orbital source, its critical flipping current is low and the device has a very high orbital torque efficiency. In addition, the antiferromagnetic order of SAF has high thermal stability, ultrafast spin dynamics and strong anti-interference.

[0080] Figure 6The results of the orbital torque reversal tests shown in (b) and (c) also indicate that when Ti is used as the orbital source, the first ferromagnetic layer is a ferromagnetic layer with a larger orbital-spin conversion coefficient, and the second ferromagnetic layer is a ferromagnetic layer with a smaller orbital-spin conversion coefficient and a low damping constant. Its critical reversal current is low, and the device has a very high orbital torque efficiency.

[0081] Example 2: SAF-based MTJ type orbital electronic device (MTJ device): Zr(10) / [Co(0.3) / Pt(0.8)]4 / Co(0.3)Ru(0.6) / Ta(0.3)CFB(1.3)MgO(2)CFB(1.3)Ta(0.7)[Co(0.3) / Pt(0.8)]3 / SiO2(2) orbital electronic device Figure 7 The structure diagram of Zr(10) / [Co(0.3) / Pt(0.8)]4 / Ru(0.6) / Ta(0.3)CFB(1.3)MgO(2)CFB(1.3)Ta(0.7)[Co(0.3) / Pt(0.8)]3 / SiO2(2) in one embodiment of the present invention is shown. Figure 7 As shown, the SAF-based MTJ type track electronic device provided in this embodiment includes the following film layers in sequence: substrate (Si or SiO2), non-ferromagnetic layer Zr(10), artificial synthetic antiferromagnetic layer [Co(0.3) / Pt(0.8)]4 / Co(0.3)Ru(0.6) / Ta(0.3)CFB(1.3)MgO(2), non-magnetic barrier layer MgO(2), fixed layer MgO(2)CFB(1.3)Ta(0.7)[Co(0.3) / Pt(0.8)]3 and protective layer SiO2(2), the values ​​in the parentheses represent the thickness of each film layer in nanometers, and the subscript 4 in the brackets represents the number of Co / Pt double film layers. Zr(10) is an orbital source and is used as an orbital Hall channel layer. The artificial antiferromagnetic layer [Co(0.3) / Pt(0.8)]4 / Co(0.3)Ru(0.6) / Ta(0.3)CFB(1.3)MgO(2) is used as the free layer of the MTJ, which includes a ferromagnetic layer [Co(0.3) / Pt(0.8)]4 with a large orbital-spin conversion coefficient, a non-magnetic layer Ru, and a ferromagnetic layer Ta(0.3)CFB(1.3)MgO(2) with a small orbital-spin conversion coefficient and a low damping constant. The artificial antiferromagnetic layer has good perpendicular magnetic anisotropy (PMA) and a large orbital-spin conversion coefficient. MgO(2) is used as a barrier layer; CFB(1.3)Ta(0.7)[Co(0.3) / Pt(0.8)]4 is used as a fixed layer.

[0082] The orbital electronics device based on the orbital Hall effect with the above structure in this embodiment is prepared by magnetron sputtering using the following process:

[0083] (1) Using an ultra-high vacuum multi-target sputtering system, Zr, Co, Pt, Ru, MgO, CoFeB, Ta and SiO2 are installed on multiple sputtering target heads respectively;

[0084] (2) The Si / SiO2 substrate is placed on the sample holder, and appropriate process parameters are adjusted to form films on the substrate using magnetron sputtering.

[0085] Control the growth order of each layer. First, grow a Zr film by controlling the sputtering of the Zr target, and control the sputtering time according to the sputtering rate to control the thickness of the Zr film; further, grow Co and Pt films by controlling the sputtering of the Co target and the Pt target in turn, control the growth thickness of the Co film and the Pt film by controlling the sputtering time according to the sputtering rate, and repeatedly grow Co and Pt films to form four Co / Pt double film layers; after forming four Co / Pt double film layers, further control the Ru target to grow a Ru film; after growing a Ru film of a predetermined thickness, grow Ta, CFB and MgO films. And a fixed layer CO / Pt multilayer film and a SiO2 film as a protective layer. During the growth process, the thickness of the Zr, Co, Pt, Ru, MgO, CFB and SiO2 films are controlled to be 10, 0.3, 0.8, 0.6, 2, 1.3 and 2 nanometers respectively.

[0086] Exemplary process parameters in the sample preparation process may include: substrate temperature is room temperature; argon gas flow rate is 33sccm; sputtering pressure is 3mTorr; the sputtering power of Zr during the growth of Zr film is 100 watts; the sputtering powers of Co and Pt during the growth of [Co(0.3) / Pt(0.8)]4 multilayer film are 50 and 15 watts, respectively; the sputtering power of Ru during the growth of Ru film is 50 watts; the sputtering powers of MgO, CFB and SiO2 during the growth of MgO film, CFB film and SiO2 film as a protective layer are 150 watts, 50 watts, and 50 watts, respectively, and the sputtering rates of Zr, Co, Pt, Ru, MgO, CFB and SiO2 are 0.194, 0.237, 0.174, 0.768, 0.072, 0.147 and 0.092 angstroms / second, respectively; the process parameters listed here are only examples, the present invention is not limited to these specific parameters, but these parameters can be appropriately adjusted and changed. The thickness and composition ratio of each layer structure in the ferromagnetic layer are adjusted so that the ferromagnetic layer as a whole has good perpendicular magnetic anisotropy. In addition, although the thickness of the Ru layer in this embodiment is 0.6 nanometers, it is not limited thereto, and its thickness can be between 0.3-1.5 nanometers to make the two magnetic layers in an antiferromagnetic coupling state.

[0087] In addition, in the above embodiments of the present invention, the thickness of each film layer and the number of layers of the multi-film layer are only examples, and are not limited thereto in practical applications, but may be varied within an appropriate range.

[0088] The orbital electronics device based on the orbital Hall effect and the preparation method thereof provided by the embodiment of the present invention can enhance the orbital torque efficiency and reduce the critical flip current density by using SAF as the ferromagnetic layer structure. The MTJ device based on SAF can avoid the interference between the stray fields of the device; can effectively resist the interference of the strong external magnetic field; the spin dynamics process at the picosecond level can meet the faster reading and writing requirements.

[0089] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0090] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A track electronics device based on track Hall effect, characterized in that: The track electronics include: a substrate; and A ferromagnetic / non-magnetic heterojunction structure prepared on a substrate, wherein the ferromagnetic / non-magnetic heterojunction structure comprises a ferromagnetic layer structure and a non-ferromagnetic layer structure as a track source, wherein the ferromagnetic layer structure is located on a side of the non-ferromagnetic layer structure away from the substrate, and the ferromagnetic layer structure has perpendicular magnetic anisotropy; Wherein, the non-ferromagnetic layer structure is a 3d-5d metal material, oxide or two-dimensional TMD material, and the ferromagnetic layer structure is an artificial antiferromagnetic layer or an artificial ferromagnetic layer.

2. The rail electronics device according to claim 1, characterized in that: The artificial synthetic antiferromagnetic layer or artificial synthetic ferromagnetic layer comprises a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer located between the first ferromagnetic layer and the second ferromagnetic layer, and the spacer layer is a non-magnetic layer.

3. The rail electronics device according to claim 1, characterized in that: The track electronics device also includes: a non-magnetic barrier layer formed on a side of the artificial antiferromagnetic layer or the artificial ferromagnetic layer away from the substrate; and A fixed layer formed on a side of the non-magnetic barrier layer away from the artificial synthetic antiferromagnetic layer or the artificial synthetic ferromagnetic layer, wherein the fixed layer is a synthetic antiferromagnetic layer; The artificial antiferromagnetic layer or the artificial ferromagnetic layer, the nonmagnetic barrier layer and the fixed layer form a magnetic tunnel junction.

4. The rail electronics device according to any one of claims 1 to 3, characterized in that: The track electronics device also includes: A protective layer is formed on the ferromagnetic / non-magnetic heterojunction structure.

5. The rail electronics device according to claim 2, characterized in that: The non-ferromagnetic layer of the track source is selected from one of the following materials: Ti, Zr, Mn, Cr, Al, Ge, Ta, W, WTe2, MoS2, WSe2, WS, TaTe2, MoTe2, NbSe2, PtTe2, TaS2; The first ferromagnetic layer and the second ferromagnetic layer are selected from metallic ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials or ferromagnetic insulators.

6. The rail electronics device according to claim 2, characterized in that: The first ferromagnetic layer and the second ferromagnetic layer are selected from one of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, the [Co / Pt] double film layer and the [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1.

7. The rail electronics device according to claim 1, characterized in that: The first ferromagnetic layer is a ferromagnetic layer having a larger orbit-spin conversion coefficient, and the second ferromagnetic layer is a ferromagnetic layer having a smaller orbit-spin conversion coefficient and a lower damping constant than the first ferromagnetic layer.

8. The rail electronics device according to claim 3, characterized in that: The material of the non-magnetic barrier layer is selected from MgO, Al2O3, NiO, TiO x , BN, or one of the two-dimensional semiconductors WSe2; The fixed layer is selected from metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials, ferromagnetic insulators or antiferromagnetic materials.

9. The rail electronics device according to claim 3, characterized in that: The fixed layer is selected from one or more of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, the [Co / Pt] double film layer and the [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1.

10. The rail electronics device according to claim 1, characterized in that: The thickness of the non-ferromagnetic layer structure is 2-100 nanometers; the thickness of the ferromagnetic layer structure is 1-40 nanometers.

11. A magnetic random access memory, characterized in that: The magnetic random access memory comprises a basic storage unit based on a magnetic tunnel junction, and the basic storage unit comprises: substrate; A ferromagnetic / non-magnetic heterojunction structure prepared on a substrate, wherein the ferromagnetic / non-magnetic heterojunction structure comprises a ferromagnetic layer structure and a non-ferromagnetic layer structure as a track source, wherein the ferromagnetic layer structure is located on a side of the non-ferromagnetic layer structure away from the substrate, and the ferromagnetic layer structure has perpendicular magnetic anisotropy; wherein the non-ferromagnetic layer structure is a 3d-5d metal material, an oxide or a two-dimensional TMD material layer, and the ferromagnetic layer structure is an artificially synthesized antiferromagnetic layer or an artificially synthesized ferromagnetic layer; a non-magnetic barrier layer formed on a side of the artificial antiferromagnetic layer or the artificial ferromagnetic layer away from the substrate; and A fixed layer formed on a side of the non-magnetic barrier layer away from the artificial antiferromagnetic layer or the artificial ferromagnetic layer, wherein the fixed layer is a ferromagnetic layer; The artificial antiferromagnetic layer or the artificial ferromagnetic layer, the nonmagnetic barrier layer and the fixed layer form a magnetic tunnel junction.

12. The magnetic random access memory according to claim 11, characterized in that: The artificial synthetic antiferromagnetic layer or artificial synthetic ferromagnetic layer comprises a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer located between the first ferromagnetic layer and the second ferromagnetic layer, and the spacer layer is a non-magnetic layer.

13. The magnetic random access memory according to claim 12, characterized in that: The non-ferromagnetic layer of the track source is selected from one of the following materials: Ti, Zr, Mn, Cr, Al, Ge, Ta, W, WTe2, MoS2, WSe2, WS, TaTe2, MoTe2, NbSe2, PtTe2, TaS2; The first ferromagnetic layer and the second ferromagnetic layer are selected from metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials or ferromagnetic insulators; The material of the non-magnetic barrier layer is selected from MgO, Al2O3, NiO, TiO x , BN, or one of the two-dimensional semiconductors WSe2; The fixed layer is selected from metal ferromagnetic materials, alloy ferromagnetic materials, two-dimensional magnetic materials, oxide magnetic materials, and ferromagnetic insulators.

14. The magnetic random access memory according to claim 12, characterized in that: The first ferromagnetic layer and the second ferromagnetic layer are selected from one of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, The fixed layer is selected from one or more of the following materials: Fe, Co, CoFe, Ni, CoCrPt, CoFeB, CoTb, Mn3Ge, FePd, [Co / Ni] p 、[Co / Pd] m 、[Co / Pt] n , FePt, CoPd, CoPt, CoNi, MnBi2Te4, NiCo2O4, SrRuO3, SrTiO3, Fe3GeTe2, Cr2Ge2Te6, Fe5GeTe2, Fe3GaTe2, YIG, YAIG, TmIG or Heusler alloy, wherein m, n and p represent the number of times the [Co / Pd] double film layer, the [Co / Pt] double film layer and the [Co / Ni] double film layer are repeatedly stacked, respectively, and m, n and p are greater than 1.

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