阅读说明：本技术 多层磁性薄膜器件及其制备方法、磁存储器 (Multilayer magnetic thin film device, preparation method thereof and magnetic memory ) 是由 王开友 曹易 张晓敏 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种多层磁性薄膜器件及其制备方法、磁存储器,其中,上述多层磁性薄膜器件包括从下至上依次设置的如下结构：衬底、第一磁性层、非磁层、第二磁性层；上述第一磁性层的居里温度高于上述第二磁性层；上述非磁层用于实现上述第一磁性层与上述第二磁性层之间的层间交换磁耦合。(The invention discloses a multilayer magnetic thin film device, a preparation method thereof and a magnetic memory, wherein the multilayer magnetic thin film device comprises the following structures which are sequentially arranged from bottom to top: the magnetic sensor comprises a substrate, a first magnetic layer, a non-magnetic layer and a second magnetic layer; the Curie temperature of the first magnetic layer is higher than that of the second magnetic layer; the nonmagnetic layer is used for realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer.)

1. A multilayer magnetic thin film device comprises the following structures which are sequentially arranged from bottom to top: the magnetic sensor comprises a substrate, a first magnetic layer, a non-magnetic layer and a second magnetic layer;

the first magnetic layer has a Curie temperature higher than that of the second magnetic layer;

the nonmagnetic layer is used for realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer.

2. The multilayer magnetic thin film device of claim 1, wherein the interlayer exchange magnetic coupling comprises any one of a ferromagnetic coupling, an antiferromagnetic coupling.

3. The multilayer magnetic thin film device of claim 1, wherein the first magnetic layer comprises a three-dimensional magnetic material; the second magnetic layer includes a two-dimensional ferromagnetic van der waals material.

4. The multilayer magnetic thin film device of claim 1, wherein the material of the first magnetic layer comprises any one of Co, CoFe, CoP, FePt, CoFeB.

5. The multilayer magnetic thin film device of claim 1, wherein the material of the second magnetic layer comprises Fe₃GeTe₂、Cr₂Ge₂Te₆Any one of the above; the material of the non-magnetic layer comprises any one of metal, metal oxide and amorphous material.

6. The multilayer magnetic thin film device of claim 5, wherein the metal comprises any one of Ta, Pt, Ru, Au, Ag, Cu; the metal oxide comprises MgO and Al₂O₃Any one of the above; the amorphous material comprises NiP.

7. The multilayer magnetic thin film device of claim 1, wherein the first and second magnetic layers each comprise a thickness of 0.5 to 5 nm.

8. A method of making a multilayer magnetic thin film device as claimed in any one of claims 1 to 7, comprising:

providing a substrate;

growing a first magnetic layer on the substrate;

growing a nonmagnetic layer on the first magnetic layer;

growing or transfer stacking a second magnetic layer on the nonmagnetic layer;

and realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer through magnetic exchange interaction.

9. The method of claim 8, wherein the method of growing the first and/or second magnetic layers comprises any one of:

physical vapor deposition, magnetron sputtering, molecular beam epitaxy, chemical vapor deposition, thermal evaporation, electron beam evaporation, pulsed laser deposition, atomic layer deposition.

10. A magnetic memory comprising the multilayer magnetic thin film device of any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of magnetic memories, in particular to a multilayer magnetic thin film device, a preparation method thereof and a magnetic memory.

Background

In recent years, two-dimensional materials have been widely noticed and studied due to their excellent dimensional characteristics. From the 2004 discovery of graphene, to transition metal chalcogenides, to the more recently emerging two-dimensional ferromagnetic materials, such as CrI₃、Cr2Ge₂Te₆、Fe₃GeTe₂And the like. The new low-dimensional materials with magnetism are the material basis for constructing novel spintronics devices, and bring new hopes to the spintronics devices.

With a two-dimensional semiconductor Crl₃And a two-dimensional insulatorCr₂Ge₂Te₆In contrast, Fe₃GeTe₂(FGT) as an intrinsic ferromagnetic metal material has larger intrinsic perpendicular magnetic anisotropy, higher Curie temperature (about 220K) and relatively better stability, is a very promising material capable of realizing room-temperature ferromagnetism through an interface, and has extremely high application potential.

However, to date, the types of two-dimensional materials prepared to have intrinsic magnetic properties have remained quite limited, with known magnetic van der Waals materials, such as Fe₃GeTe₂、Cr₂Ge₂Te₆And the Curie temperature is far lower than the room temperature, and the air stability is poor, so that the future practical application of the composite material is greatly limited.

Disclosure of Invention

In view of the above, the present invention provides a multilayer magnetic thin film device, a method for manufacturing the same, and a magnetic memory, so as to at least partially solve the above technical problems.

The embodiment of the invention provides a multilayer magnetic thin film device, which comprises the following structures arranged from bottom to top in sequence: the magnetic sensor comprises a substrate, a first magnetic layer, a non-magnetic layer and a second magnetic layer; the Curie temperature of the first magnetic layer is higher than that of the second magnetic layer; the nonmagnetic layer is used for realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer.

According to an embodiment of the present invention, the interlayer exchange magnetic coupling includes any one of ferromagnetic coupling and antiferromagnetic coupling.

According to an embodiment of the present invention, the first magnetic layer includes a three-dimensional magnetic material; the second magnetic layer includes a two-dimensional ferromagnetic van der waals material.

According to an embodiment of the present invention, the material of the first magnetic layer includes any one of Co, CoFe, CoP, FePt, and CoFeB.

According to an embodiment of the present invention, the material of the second magnetic layer includes Fe₃GeTe₂、Cr₂Ge₂Te₆Any one of them.

According to an embodiment of the present invention, the material of the nonmagnetic layer includes any one of a metal, a metal oxide, and an amorphous material.

According to the embodiment of the invention, the metal comprises any one of Ta, Pt, Ru, Au, Ag and Cu; the metal oxide includes MgO and Al₂O₃Any one of the above; the amorphous material includes NiP.

According to an embodiment of the present invention, the first magnetic layer and the second magnetic layer each have a thickness of 0.5 to 5 nm.

The embodiment of the invention also provides a method for preparing the multilayer magnetic thin film device, which comprises the following steps: providing a substrate; growing a first magnetic layer on the substrate; growing a non-magnetic layer on the first magnetic layer; growing or transfer-stacking a second magnetic layer on the nonmagnetic layer; and realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer through magnetic exchange interaction.

According to an embodiment of the present invention, the method for growing the first magnetic layer and/or the second magnetic layer includes any one of: physical vapor deposition, magnetron sputtering, molecular beam epitaxy, chemical vapor deposition, thermal evaporation, electron beam evaporation, pulsed laser deposition, atomic layer deposition.

The embodiment of the invention also provides a magnetic memory which comprises the multilayer magnetic thin film device.

According to the multilayer magnetic thin film device provided by the embodiment of the invention, interlayer exchange coupling is realized between the first magnetic layer with higher Curie temperature and the second magnetic layer with lower Curie temperature through the non-magnetic layer, so that the Curie temperature of the multilayer magnetic thin film device is increased, and the multilayer magnetic thin film device has good perpendicular magnetic anisotropy.

Drawings

FIG. 1 is a schematic cross-sectional view showing a multilayer magnetic thin film device according to an embodiment of the present invention;

FIG. 2 schematically illustrates a PCP/FGT multilayer film device structure subjected to anomalous Hall testing in an embodiment of the present invention;

fig. 3 is a graph schematically showing the results of an abnormal hall test performed on a multilayer magnetic thin film device in an embodiment of the present invention.

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.

Since the curie temperature of two-dimensional magnetic van der waals materials is much lower than room temperature and air stability is poor, the range of applications is limited. In order to expand the application range of the two-dimensional magnetic van der waals material, the invention needs to ensure that the Curie temperature of the two-dimensional ferromagnetic van der waals material is higher than the room temperature and simultaneously has good perpendicular magnetic anisotropy.

The embodiment of the invention provides a multilayer magnetic thin film device, which comprises the following structures arranged from bottom to top in sequence: the magnetic sensor comprises a substrate, a first magnetic layer, a non-magnetic layer and a second magnetic layer; the Curie temperature of the first magnetic layer is higher than that of the second magnetic layer; the nonmagnetic layer is used for realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer.

Fig. 1 schematically shows a structural view of a multilayer magnetic thin film device in an embodiment of the present invention.

As shown in fig. 1, the multilayer magnetic thin film device includes a substrate 1, a first magnetic layer 2, a nonmagnetic layer 3, and a second magnetic layer 4 in this order from bottom to top.

According to the embodiment of the present invention, the curie temperature of the first magnetic layer is higher than that of the second magnetic layer, and the first magnetic layer and the second magnetic layer are both ferromagnetic materials having good perpendicular magnetic anisotropy, and have perpendicular magnetic anisotropy, which is magnetic anisotropy perpendicular to the film plane of the first magnetic layer and the second magnetic layer.

According to the embodiment of the present invention, the nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer for realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer, and the type and strength of the interlayer exchange magnetic coupling can be selected by the material type and thickness of the nonmagnetic layer.

According to the multilayer magnetic thin film device provided by the embodiment of the invention, interlayer exchange coupling is realized between the first magnetic layer with higher Curie temperature and the second magnetic layer with lower Curie temperature through the non-magnetic layer, so that the Curie temperature of the multilayer magnetic thin film device is increased, and the multilayer magnetic thin film device has good perpendicular magnetic anisotropy.

According to an embodiment of the present invention, the interlayer exchange magnetic coupling includes any one of ferromagnetic coupling and antiferromagnetic coupling.

In the embodiment of the invention, different materials are selected as the non-magnetic layer, so that the spin magnetic moment included angle of adjacent atom 3d electrons between the first magnetic layer and the second magnetic layer is zero, namely the magnetic moments are arranged in parallel in the same direction, and ferromagnetic coupling is realized. Or the spin magnetic moment included angle of adjacent atom 3d electrons between the first magnetic layer and the second magnetic layer is 180 degrees, namely the magnetic moments are arranged in an antiparallel manner, so that the antiferromagnetic coupling is realized. The person skilled in the art can realize ferromagnetic coupling or antiferromagnetic coupling by selecting the material of the nonmagnetic layer according to the actual application requirements.

According to an embodiment of the present invention, the first magnetic layer includes a three-dimensional magnetic material; the second magnetic layer includes a two-dimensional ferromagnetic van der waals material.

In the embodiment of the invention, the traditional three-dimensional magnetic metal Co is combined with the two-dimensional ferromagnetic Van der Waals material Fe3GeTe2, and the interaction between the traditional three-dimensional magnetic metal Co and the two-dimensional ferromagnetic Van der Waals material Fe3GeTe2 is utilized to achieve the aim of improving the Curie temperature of Fe3GeTe2, so that the application of a ferromagnetic 3D/2D heterostructure in the field of spintronics at room temperature becomes possible, and a new physical paradigm is provided for a heterogeneous interface theory.

According to an embodiment of the present invention, the material of the first magnetic layer includes any one of Co, CoFe, CoP, FePt, and CoFeB. According to the embodiment of the present invention, the material of the first magnetic layer includes, but is not limited to, Co, CoFe, CoP, FePt, CoFeB.

According to an embodiment of the present invention, the material of the second magnetic layer includes Fe₃GeTe₂、Cr₂Ge₂Te₆Any one of them.

In the embodiment of the invention, the first magnetic layer material is a three-dimensional magnetic material with high Curie temperature, and the material properties of the second magnetic layer are influenced by the material properties of the three-dimensional magnetic material, such as the Curie temperature higher than the room temperature and good perpendicular magnetic anisotropy, so that the Curie temperature of the two-dimensional ferromagnetic van der Waals material is increased and is higher than the room temperature.

According to an embodiment of the present invention, the material of the nonmagnetic layer includes any one of a metal, a metal oxide, and an amorphous material.

According to the embodiment of the invention, the metal comprises any one of Ta, Pt, Ru, Au, Ag and Cu; the metal oxide includes MgO and Al₂O₃Any one of the above; the amorphous material includes NiP.

In the embodiment of the invention, the function of the nonmagnetic layer is to realize ferromagnetic coupling or antiferromagnetic coupling between layers, so that the selection of the material of the nonmagnetic layer is determined according to actual conditions.

According to an embodiment of the present invention, the thicknesses of the first magnetic layer and the second magnetic layer each include 0.5 to 5nm, for example: 0.5nm, 1nm, 2nm, 3nm, 4nm, 5 nm.

In the embodiment of the invention, the first magnetic layer and the second magnetic layer both have perpendicular magnetic anisotropy, and the thinner the thickness of the magnetic layer is, the better the perpendicular magnetic anisotropy is. In order to achieve better interlayer exchange coupling, the thickness of the nonmagnetic layer is generally smaller than the thickness of the first and second magnetic layers.

The embodiment of the invention also provides a method for preparing the multilayer magnetic thin film device, which comprises the following steps: providing a substrate; growing a first magnetic layer on the substrate; growing a non-magnetic layer on the first magnetic layer; growing or transfer-stacking a second magnetic layer on the nonmagnetic layer; and realizing interlayer exchange magnetic coupling between the first magnetic layer and the second magnetic layer through magnetic exchange interaction.

In the embodiment of the invention, the first magnetic layer, the non-magnetic layer and the second magnetic layer are grown on the substrate in sequence by adopting a semiconductor process, and the process is simple. It should be noted that, during the manufacturing process, the growth of the first magnetic layer and the second magnetic layer can be interchanged, that is, the second magnetic layer is grown first, then the non-magnetic layer is grown, and finally the first magnetic layer is grown, so that the above multilayer magnetic thin film device can also be obtained.

According to an embodiment of the present invention, the method for growing the first magnetic layer and/or the second magnetic layer includes, but is not limited to, the following methods: physical vapor deposition, magnetron sputtering, molecular beam epitaxy, chemical vapor deposition, thermal evaporation, electron beam evaporation, pulsed laser deposition, atomic layer deposition.

The embodiment of the invention also provides a magnetic memory which comprises the multilayer magnetic thin film device.

The properties of the multilayer magnetic thin film device according to the embodiment of the present invention were verified by the abnormal hall test as follows.

In the embodiment of the invention, three-dimensional magnetic metal Co is used as a first magnetic layer, and two-dimensional ferromagnetic van der Waals material Fe₃GeTe₂As a second magnetic layer, the non-magnetic layer adopts metal Pt, and the metal Pt is prepared into Ta/Pt/Co/Pt/Fe₃GeTe₂(PCP/FGT) multilayer film device, FIG. 2 is a schematic diagram of the structure of the PCP/FGT multilayer film device for abnormal Hall test in the embodiment of the invention, and as shown in FIG. 2, the PCP/FGT multilayer film device is sequentially provided with Si/SiO from bottom to top₂Layer, Ta metal layer, Pt metal layer, Co metal layer, Pt metal layer, Fe₃GeTe₂And (3) a layer. In this embodiment, the metal layer is disposed in a cross shape for the convenience of performing the abnormal hall test, but it should be noted that the metal layer is generally disposed in a layered structure shown in fig. 1 of the present invention, and is not limited to the cross shape in this embodiment.

And respectively carrying out an abnormal Hall test on the PCP/FGT multilayer film device and the Ta/Pt/Co/Pt (PCP) multilayer film device at 310K. FIG. 3 is a graph schematically illustrating the results of an anomalous Hall test performed on a multilayer magnetic thin-film device according to an embodiment of the present invention, the results being shown in FIG. 3, where a typical rectangular R at 310K for a PCP/FGT sample_HThe hysteresis loop area is larger than that of the PCP sample at 310K, and the Hall resistance of the PCP/FGT sample is stabilized at 1.5 omega, while the Hall resistance of the PCP sample is stabilized at only 0.5 omega, which clearly shows that the PCP/FGT multilayer film device has sufficient perpendicular magnetic anisotropy and 100% out-of-plane remanence above room temperature.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.