Magnetic multilayer film structure and magnetic device

Abstract

The application discloses a magnetic multilayer film structure, comprising: a first multilayer structure formed on a buffer layer or a seed layer; the first multilayer structure comprises, in sequence: a reference layer, a non-magnetic intermediate layer, a free layer and a coupling layer; wherein the coupling layer and the free layer are antiferromagnetically or ferromagnetically coupled through an interface, the magnetic moment directions of the coupling layer and the free layer are antiparallel or parallel arranged, and the non-magnetic intermediate layer is used for isolation or insulation. The application utilizes the antiferromagnetic or ferromagnetic coupling of the coupling layer and the free layer through the interface, or the antiferromagnetic or ferromagnetic coupling of the coupling layer and the reference layer through the interface, the coupling effect of the interface provides strong perpendicular magnetic anisotropy, the thickness of the free layer or the reference layer can be further increased under the condition of guaranteeing the perpendicular magnetic anisotropy, thereby the TMR value is increased and the damping factor is reduced. When the coupling layer and the free layer are antiferromagnetically coupled, the magnetic moment directions form antiparallel arrangement, thereby the total saturation magnetization is reduced, and further the interference of an external magnetic field is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of storage and sensors, in particular to a magnetic multilayer film structure capable of constituting a SV (spin valve) or MTJ (magnetic tunnel junction); and a magnetic device having the magnetic multilayer film. BACKGROUND

[0002] Magnetic multilayer films, especially spin valve (SV) or magnetic tunnel junction (MTJ) structures, have been widely used in magnetic sensors and magnetic random access memory (MRAM), in which the key parameters such as giant magnetoresistance (GMR) / tunneling magnetoresistance (TMR), perpendicular magnetic anisotropy, damping factor of free layer, resistance to external magnetic field interference, etc. have a crucial influence on the performance of the device. During the operation of MRAM, the size of the GMR / TMR value determines the information reading speed of the MRAM cell, therefore, improving the TMR value is crucial to improve the read fault tolerance rate and the reading speed. At the same time, the size of the GMR / TMR value also determines the sensitivity of the magnetic sensor. Perpendicular magnetic anisotropy is an important indicator that determines the information retention time. In the case of the same device size, the stronger the perpendicular magnetic anisotropy, the stronger the thermal stability of the device, and the longer the information is retained in the medium. The damping factor of the free layer is another important parameter of MRAM. For spin transfer torque magnetic random access memory (STT-MRAM), a low damping factor can effectively reduce the write current; more broadly, for MRAM, a low damping factor can effectively reduce the write error rate (WER) and the like. It can be seen that how to improve the above several performance indicators is the key to improving the performance of magnetic sensors and MRAM.

[0003] At present, the main methods to improve TMR are to optimize the quality of the non-magnetic insulating layer MgO, improve the flatness of the interface, and reduce mutual diffusion, etc. Based on this method, the TMR can be improved to about 250%. In addition, by changing the free layer magnetic material (Heusler alloy) and the non-magnetic insulating layer material (MgAlO), etc. it is also expected to improve the TMR. However, under the condition of CMOS process, it is difficult to grow a high-ordered Heulser free layer and a MgAlO non-magnetic insulating layer with a specific crystal structure. In addition, to improve the thermal stability of the system, it is necessary to improve the perpendicular magnetic anisotropy (PMA) of the free layer. However, the perpendicular magnetic anisotropy of the Co-based alloy free layer mainly comes from the interface. A thinner free layer can improve its thermal stability, but it increases its damping factor and reduces the TMR of the system. At the same time, the anti-interference characteristic of the device is also a factor that must be considered in practical application. At present, the device resistance to external magnetic field interference mainly relies on magnetic shielding packaging technology. Therefore, there is no method that can increase the TMR value while increasing the perpendicular magnetic anisotropy of the free layer and reducing the damping factor, and has good anti-magnetic field interference ability. SUMMARY

[0004] In the part of the summary of the invention, a series of simplified concepts are introduced, which are simplified from the prior art in the field, which will be described in detail in the part of the specific embodiments. The part of the summary of the invention does not mean to try to limit the key features and necessary technical features of the claimed technical solutions, and does not mean to try to determine the protection scope of the claimed technical solutions.

[0005] The technical problem to be solved by the present application is to provide a magnetic multilayer film structure which can increase the perpendicular magnetic anisotropy of the free layer, reduce the damping factor, enhance the GMR / TMR value, and has better anti-magnetic field interference ability than the prior art.

[0006] In addition, the present application also provides a magnetic device with the magnetic multilayer film.

[0007] To solve the above technical problems, the present application provides a magnetic multilayer film structure, comprising:

[0008] A first multilayer structure formed on the buffer layer or the seed layer;

[0009] The first multilayer structure comprises, in order or in reverse order: a reference layer, a non-magnetic intermediate layer, a free layer, and a coupling layer;

[0010] That is, the first multilayer structure comprises, in order from top to bottom: a reference layer, a non-magnetic intermediate layer, a free layer, and a coupling layer;

[0011] Or, the first multilayer structure comprises, in order from top to bottom: a coupling layer, a free layer, a non-magnetic intermediate layer, and a reference layer.

[0012] Wherein, the coupling layer and the free layer are coupled by an anti-ferromagnetic or ferromagnetic coupling effect at the interface, the magnetic moment directions of the coupling layer and the free layer are anti-parallel or parallel, and the non-magnetic intermediate layer is used for isolation or insulation.

[0013] Optionally, the magnetic moment directions of the coupling layer, the free layer, and the reference layer are perpendicular magnetization, in-plane magnetization, or oblique magnetization, and the magnetic moment direction of the reference layer is not limited.

[0014] Optionally, the first multilayer structure comprises, in order or in reverse order: a reference layer, a non-magnetic intermediate layer, a free layer 1, a coupling layer, and a free layer 2;

[0015] That is, the first multilayer structure comprises, in order from top to bottom: a reference layer, a non-magnetic intermediate layer, a free layer 1, a coupling layer, and a free layer 2;

[0016] Or, the first multilayer structure comprises, in order from top to bottom: a free layer 2, a coupling layer, a free layer 1, a non-magnetic intermediate layer, and a reference layer.

[0017] The coupling layer and the free layer 1 and the free layer 2 are arranged in anti-ferromagnetic or ferromagnetic coupling through the interface, and the coupling layer is arranged in anti-parallel or parallel with the magnetic moment direction of the free layer 1 and the free layer 2, i.e. the magnetic moment directions of the free layer 1 and the free layer 2 are the same.

[0018] Optionally, the magnetic moment directions of the reference layer, the non-magnetic intermediate layer, the free layer 1, the coupling layer and the free layer 2 are perpendicular magnetization, in-plane magnetization or oblique magnetization, and the magnetic moment direction of the reference layer is not limited.

[0019] Optionally, the thickness of the free layer 1 and the free layer 2 ranges from 0.01 nm to 10 nm, and the thickness of the coupling layer ranges from 0.01 nm to 10 nm.

[0020] The first multi-layer structure comprises the reference layer 2, the coupling layer, the reference layer 1, the non-magnetic intermediate layer and the free layer arranged in sequence or in reverse sequence;

[0021] The coupling layer and the reference layer 1 and the reference layer 2 are arranged in anti-ferromagnetic or ferromagnetic coupling through the interface, and the coupling layer is arranged in anti-parallel or parallel with the magnetic moment direction of the reference layer 1 and the reference layer 2, i.e. the magnetic moment directions of the reference layer 1 and the reference layer 2 are the same.

[0022] The reference layer 2, the coupling layer, the reference layer 1, the non-magnetic intermediate layer and the free layer are arranged in perpendicular magnetization, in-plane magnetization or oblique magnetization, and the magnetic moment direction of the free layer is not limited.

[0023] Optionally, the thickness of the reference layer 1 and the reference layer 2 ranges from 0.01 nm to 10 nm, and the thickness of the coupling layer ranges from 0.01 nm to 10 nm.

[0024] Optionally, the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic metal layer or a non-magnetic insulating layer.

[0025] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic metal layer, an SV spin valve is formed.

[0026] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic insulating layer, an MTJ magnetic tunnel junction is formed.

[0027] Exemplarily, the feasible materials of each layer of the magnetic multi-layer film structure are described as follows:

[0028] Optionally, the reference layer (including reference layer 1 and reference layer 2) and the free layer (including free layer 1 and free layer 2) of the magnetic multilayer film structure (SV or MTJ) are made of magnetic materials. Exemplarily, the magnetic materials include, but are not limited to, CoFeB, Co, Fe, Ni, FeB, CoFeSi, CoFe, NiFe, CoFeAl, and at least one of the above materials.

[0029] Optionally, the non-magnetic intermediate layer of the magnetic multilayer film is made of metal materials to form an SV structure. Exemplarily, the metal materials include, but are not limited to, copper (Cu) and all metal materials known in the prior art that can be applied to SV structures.

[0030] Optionally, the non-magnetic intermediate layer of the magnetic multilayer film is a non-magnetic insulating layer, which is made of insulating materials to form an MTJ structure. Exemplarily, the insulating materials include, but are not limited to, MgO or AlO x , and all insulating materials known in the prior art that can be applied to MTJ structures.

[0031] Optionally, the coupling layer of the magnetic multilayer film structure (SV or MTJ) is made of rare earth transition group materials. Exemplarily, the coupling layer is made of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y), or an alloy or multilayer film structure containing lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y) (including but not limited to [gadolinium / cobalt] n ([Gd / Co] n ) multilayer film structure).

[0032] Further, the feasibility of the coupling layer is illustrated by taking a TbCo alloy as an example, in which the content of Tb is 10% to 50%, taking a TbFe alloy as an example, in which the content of Tb is 10% to 40%, and taking a GdFe alloy as an example, in which the content of Gd is 15% to 35%.

[0033] Further, the feasibility of the interface coupling is illustrated by taking a light rare earth neodymium (Nd) as an example, in which the interface between Nd and the magnetic layer CoFeB produces ferromagnetic coupling, and the magnetic moments of the two layers are arranged in parallel; and by taking a heavy rare earth gadolinium (Gd) as an example, in which the interface between Gd and the magnetic layer CoFeB produces antiferromagnetic coupling, and the magnetic moments of the two layers are arranged in anti-parallel.

[0034] Optionally, the magnetic multilayer film structure (SV or MTJ) can be used in a magnetic sensor or MRAM.

[0035] To solve the above technical problems, the present application provides a magnetic device, which can be a MRAM or a magnetic sensor, comprising a second multilayer structure formed between a cap layer and a buffer layer, or a cap layer and a seed layer.

[0036] The magnetic device structure, the artificial synthetic antiferromagnetic layer is located in the first layer or the last layer of the multilayer structure.

[0037] That is, the second multilayer structure comprises, from top to bottom, an artificial synthetic antiferromagnetic layer, a reference layer, a non-magnetic intermediate layer, a free layer and a coupling layer.

[0038] Or, the second multilayer structure comprises, from top to bottom, a coupling layer, a free layer, a non-magnetic intermediate layer, a reference layer and an artificial synthetic antiferromagnetic layer.

[0039] Wherein, the coupling layer and the free layer are arranged in antiparallel or parallel by the antiferromagnetic or ferromagnetic coupling effect of the interface, and the magnetic moment direction of the artificial synthetic antiferromagnetic layer and the reference layer is not limited.

[0040] Wherein, the magnetic moment direction of the coupling layer and the free layer is vertical magnetization, in-plane magnetization or oblique magnetization.

[0041] Optionally, the magnetic device, the second multilayer structure comprises, from top to bottom, an artificial synthetic antiferromagnetic layer, a reference layer, a non-magnetic intermediate layer, a free layer 1, a coupling layer and a free layer 2.

[0042] Or, the second multilayer structure comprises, from top to bottom, a free layer 2, a coupling layer, a free layer 1, a non-magnetic intermediate layer, a reference layer and an artificial synthetic antiferromagnetic layer.

[0043] Wherein, the coupling layer, the free layer 1 and the free layer 2 are arranged in antiparallel or parallel by the antiferromagnetic or ferromagnetic coupling effect of the interface, and the magnetic moment direction of the coupling layer and the free layer 1 and the free layer 2 is antiparallel or parallel, that is, the magnetic moment direction of the free layer 1 and the free layer 2 is the same. The magnetic moment direction of the artificial synthetic antiferromagnetic layer and the reference layer is not limited.

[0044] Wherein, the magnetic moment direction of the artificial synthetic antiferromagnetic layer, the reference layer, the free layer and the coupling layer is vertical magnetization, in-plane magnetization or oblique magnetization.

[0045] Optionally, the magnetic device, the second multilayer structure comprises, from top to bottom, an artificial synthetic antiferromagnetic layer, a reference layer 2, a coupling layer, a reference layer 1, a non-magnetic intermediate layer and a free layer.

[0046] or, the second multi-layer structure comprises, arranged in order from top to bottom: a free layer, a non-magnetic intermediate layer, a reference layer 1, a coupling layer, a reference layer 2, and an artificial synthetic antiferromagnetic layer.

[0047] wherein the coupling layer, the reference layer 1 and the reference layer 2 are arranged antiparallel or parallel to the magnetic moment direction of the reference layer 1 and the reference layer 2 respectively by the interface antiferromagnetic or ferromagnetic coupling, i.e. the magnetic moment direction of the reference layer 1 and the reference layer 2 is the same. The magnetic moment direction of the artificial synthetic antiferromagnetic layer and the free layer is not limited.

[0048] wherein the magnetic moment direction of the artificial synthetic antiferromagnetic layer, the reference layer 2, the coupling layer, the reference layer 1 and the free layer is perpendicular magnetization, in-plane magnetization or oblique magnetization.

[0049] Optionally, the magnetic device, the reference layer (including the reference layer 1 and the reference layer 2) and the free layer (including the free layer 1 and the free layer 2) are made of magnetic materials. Exemplarily, the magnetic materials include but are not limited to CoFeB, Co, Fe, Ni, FeB, CoFeSi, CoFe, NiFe, CoFeAl and the like.

[0050] Optionally, for the magnetic device formed with the MTJ structure, the non-magnetic intermediate layer is a non-magnetic insulating layer made of insulating materials. Exemplarily, the insulating materials include but are not limited to MgO or AlO x and all known insulating materials capable of being applied to the MTJ structure in the prior art.

[0051] Optionally, for the magnetic device formed with the SV structure, the non-magnetic intermediate layer is made of metal materials. Exemplarily, the metal materials include but are not limited to copper (Cu) and the like, and all known metal materials capable of being applied to the SV structure in the prior art.

[0052] Optionally, the magnetic device, the coupling layer is made of rare earth transition group materials. Exemplarily, the coupling layer is made of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and yttrium (Y), or an alloy or a multi-layer film structure containing lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and yttrium (Y) (including but not limited to gadolinium (Gd) / cobalt (Co) multi-layer film structure).

[0053] Further, the feasibility of the coupling layer is illustrated, taking the TbCo alloy as an example, wherein the content of Tb is 10% to 50%; taking the TbFe alloy as an example, wherein the content of Tb is 10% to 40%; and taking the GdFe alloy as an example, wherein the content of Gd is 15% to 35%.

[0054] Further, the feasibility of the interface coupling is illustrated, taking the light rare earth neodymium (Nd) as an example, wherein the interface between Nd and the magnetic layer CoFeB generates ferromagnetic coupling, and the magnetic moment directions of the two layers of materials are arranged in parallel; taking the heavy rare earth gadolinium (Gd) as an example, wherein the interface between Gd and the magnetic layer CoFeB generates antiferromagnetic coupling, and the magnetic moments of the two layers of materials are arranged in anti-parallel.

[0055] Alternatively, the two sides of the artificial antiferromagnetic layer are formed into a mutual antiferromagnetic coupling, i.e., an interlayer antiferromagnetic coupling. The artificial antiferromagnetic layer is a synthetic antiferromagnetic structure. The synthetic antiferromagnetic structure is obtained by inserting a spacer layer Ru between two ferromagnetic layers. When the thickness of the Ru layer is less than 1 nm, the ferromagnetic layers on both sides of the Ru layer have a strong antiferromagnetic coupling effect. This antiferromagnetic coupling effect effectively improves the pinning field, significantly reduces the static magnetic coupling effect of the spacer layer and the demagnetization field of the pinned layer, and also has a certain inhibitory effect on atomic diffusion.

[0056] Illustratively, the artificial antiferromagnetic layer is artificially synthesized and includes, from top to bottom, a first cobalt / platinum multilayer film layer, a ruthenium layer (i.e., a spacer layer), a second cobalt / platinum multilayer film layer, a cobalt layer, and a non-magnetic spacer layer (e.g., a tungsten layer).

[0057] Alternatively, the artificial antiferromagnetic layer includes, from top to bottom, a non-magnetic spacer layer (e.g., a tungsten layer), a cobalt layer, a first cobalt / platinum multilayer film layer, a ruthenium layer (i.e., a spacer layer), and a second cobalt / platinum multilayer film layer.

[0058] The application utilizes the antiferromagnetic or ferromagnetic coupling between the coupling layer and the free layer through the interface, or the antiferromagnetic or ferromagnetic coupling between the coupling layer and the reference layer through the interface. The coupling effect of the interface provides a strong perpendicular magnetic anisotropy. The thickness of the free layer or the reference layer can be further increased under the condition of ensuring the perpendicular magnetic anisotropy, thereby improving the GMR / TMR value and reducing the damping factor. Meanwhile, in the case of antiferromagnetic coupling, the magnetic moment directions of the coupling layer and the free layer, or the coupling layer and the reference layer are arranged in anti-parallel, thereby reducing the overall saturation magnetization and providing good anti-magnetic field interference capability. BRIEF DESCRIPTION OF DRAWINGS

[0059] The drawings accompanying the present invention are intended to illustrate the general characteristics of the methods, structures and / or materials used in certain example embodiments according to the present invention and to supplement the description in the present specification. However, the present drawings are not drawn to scale and, as such, can not accurately represent the precise structural or performance characteristics of any given embodiment, and the present drawings should not be construed as limiting or restricting the scope of the values or attributes encompassed by example embodiments according to the present invention. The present invention is further described below in connection with the appended drawings and detailed description.

[0060] Figures 1-2 is a structural schematic diagram of a first embodiment of the present invention.

[0061] Figures 3-4 is a structural schematic diagram of a second embodiment of the present invention.

[0062] Figures 5-6 is a structural schematic diagram of a third embodiment of the present invention.

[0063] Figures 7-8 is a structural schematic diagram of a fourth embodiment of the present invention.

[0064] Figures 9-10 is a structural schematic diagram of a fifth embodiment of the present invention.

[0065] Figures 11-12 is a structural schematic diagram of a sixth embodiment of the present invention.

[0066] Figures 13-14 is a structural schematic diagram of a seventh embodiment of the present invention. DETAILED DESCRIPTION

[0067] The embodiments of the present invention are described below by way of specific examples, and other advantages and technical effects of the present invention can be fully appreciated by those skilled in the art based on the disclosure herein. The present invention can also be implemented or applied in different specific embodiments, and the details in the present specification can be applied based on different perspectives, with various modifications or changes made without departing from the general design idea of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. The example embodiments of the present invention can be implemented in various forms, and should not be interpreted as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention complete and complete, and to fully convey the technical solutions of these example embodiments to those skilled in the art.

[0068] First embodiment;

[0069] The present invention provides a magnetic multilayer film structure, comprising:

[0070] a first multilayer structure formed on the buffer layer or seed layer;

[0071] Reference Figure 1 As shown in the figure, the first multi-layer structure comprises, sequentially arranged: a reference layer, a non-magnetic intermediate layer, a free layer and a coupling layer;

[0072] Or, reference Figure 2 As shown in the figure, the first multi-layer structure comprises, sequentially arranged: a coupling layer, a free layer, a non-magnetic intermediate layer and a reference layer;

[0073] Wherein, the magnetic moment direction of the reference layer, the free layer and the coupling layer is perpendicular magnetization, in-plane magnetization or oblique magnetization, Figure 1 And Figure 2 Exemplarily represent the magnetic moment direction of the coupling layer and the free layer in the case of in-plane magnetization and anti-ferromagnetic coupling.

[0074] Wherein, the coupling layer and the free layer are arranged in anti-parallel or parallel by the anti-ferromagnetic or ferromagnetic coupling of the interface, and the non-magnetic intermediate layer is used for isolation or insulation. The coupling layer and the free layer are arranged in anti-parallel or parallel by the anti-ferromagnetic or ferromagnetic coupling of the interface, and the magnetic moment direction of the two layers is arranged in anti-parallel or parallel, and the coupling of the interface provides strong vertical magnetic anisotropy, which can further improve the thickness of the free layer under the condition of ensuring the vertical magnetic anisotropy, thereby improving the GMR / TMR value and reducing the damping factor. For the anti-ferromagnetic coupling of the coupling layer and the free layer through the interface, the magnetic moment direction of the two layers is arranged in anti-parallel, thereby reducing the overall saturation magnetization, and further reducing the interference of the external magnetic field. And the magnetic moment direction of the reference layer is arbitrary, which does not affect the implementation of the application.

[0075] Further, the two kinds of magnetic multi-layer film structures provided by the above first embodiment can form SV spin valve or MTJ magnetic tunnel junction due to the different materials of the non-magnetic intermediate layer;

[0076] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic metal layer, it forms a SV spin valve.

[0077] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic insulating layer, it forms a MTJ magnetic tunnel junction.

[0078] Second embodiment

[0079] The application provides a magnetic multi-layer film structure, comprising:

[0080] A first multi-layer structure formed on a buffer layer or a seed layer;

[0081] Reference Figure 3 As shown in the figure, the first multi-layer structure comprises, sequentially arranged: a reference layer, a non-magnetic intermediate layer, a free layer 1, a coupling layer and a free layer 2;

[0082] Or, referenceFigure 4 As shown, the first multi-layer structure comprises, sequentially arranged, a free layer 2, a coupling layer, a free layer 1, a non-magnetic intermediate layer and a reference layer;

[0083] Figure 3 and Figure 4 Exemplarily, the magnetic moment directions of the free layer 1, the coupling layer and the free layer 2 are represented;

[0084] The coupling layer and the free layer 1 and the free layer 2 are in anti-ferromagnetic or ferromagnetic coupling through the interface, and the magnetic moment directions of the coupling layer and the free layer 1 and the free layer 2 are anti-parallel or parallel. The coupling through the interface provides strong perpendicular magnetic anisotropy, and the thickness of the free layer 1 and the free layer 2 can be further increased under the condition of ensuring the perpendicular magnetic anisotropy, thereby increasing the GMR / TMR value and reducing the damping factor. When the coupling layer and the free layer 1 and the free layer 2 are in anti-ferromagnetic coupling through the interface, the magnetic moment directions are anti-parallel, thereby reducing the overall saturation magnetization and further reducing the interference of the external magnetic field.

[0085] Alternatively, the magnetic moment directions of the reference layer, the free layer 1, the coupling layer and the free layer 2 are perpendicular magnetization, in-plane magnetization or oblique magnetization.

[0086] Alternatively, the reference layer is located at the first layer or the last layer of the first multi-layer structure, and the second embodiment provides the following two kinds of magnetic multi-layer film structures.

[0087] Further, the two kinds of magnetic multi-layer film structures provided by the above-mentioned second embodiment can form SV spin valve or MTJ magnetic tunnel junction due to the different materials of the non-magnetic intermediate layer.

[0088] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic metal layer, it forms an SV spin valve.

[0089] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic insulating layer, it forms an MTJ magnetic tunnel junction.

[0090] Third embodiment

[0091] The present application provides a kind of magnetic multi-layer film structure, comprising:

[0092] First multi-layer structure formed on buffer layer or seed layer;

[0093] Reference Figure 5 As shown, the first multi-layer structure comprises, sequentially arranged, a reference layer 2, a coupling layer, a reference layer 1, a non-magnetic intermediate layer and a free layer;

[0094] Or, reference Figure 6 As shown, the first multi-layer structure comprises, sequentially arranged, a free layer, a non-magnetic intermediate layer, a reference layer 1, a coupling layer and a reference layer 2.

[0095] Figure 5 and Figure 6 Exemplarily, the magnetic moment directions of the reference layer 1, the coupling layer and the reference layer 2 are shown;

[0096] The coupling layer is antiferromagnetically or ferromagnetically coupled with the reference layer 1 and the reference layer 2 through the interface, and the magnetic moment directions of the coupling layer and the reference layer 1 and the reference layer 2 are antiparallel or parallel. The coupling of the interface provides strong perpendicular magnetic anisotropy, and the thickness of the reference layer 1 and the reference layer 2 can be further increased under the condition of ensuring the perpendicular magnetic anisotropy, thereby improving the GMR / TMR value. The coupling layer and the reference layer 1 and the reference layer 2 are antiparallel arranged in the magnetic moment direction through the antiferromagnetic coupling of the interface, thereby reducing the overall saturation magnetization, and further reducing the interference of the external magnetic field. The magnetic moment direction of the free layer is arbitrary in the opposite direction, which does not affect the implementation of the application.

[0097] Further, the two kinds of magnetic multilayer films provided by the third embodiment can form SV spin valves or MTJ magnetic tunnel junctions due to the different materials of the non-magnetic intermediate layer.

[0098] When the non-magnetic intermediate layer of the magnetic multilayer film structure is a non-magnetic metal layer, it forms an SV spin valve.

[0099] When the non-magnetic intermediate layer of the magnetic multilayer film structure is a non-magnetic insulating layer, it forms an MTJ magnetic tunnel junction.

[0100] Further, the application provides the feasible manufacturing materials of each layer of the magnetic multilayer film structure according to any one of the first embodiment to the third embodiment.

[0101] Optionally, the reference layer (including the reference layer 1 and the reference layer) and the free layer (including the free layer 1 and the free layer 2) of the magnetic multilayer film structure (SV or MTJ) are made of a magnetic material. Exemplarily, the magnetic material includes but is not limited to at least one of CoFeB, Co, Fe, Ni, FeB, CoFeSi, CoFe, NiFe, CoFeAl and the like.

[0102] Optionally, when the non-magnetic intermediate layer of the magnetic multilayer film structure is made of a metal material, it forms an SV structure. Exemplarily, the metal material includes but is not limited to copper (Cu) and all known metal materials that can be applied to the SV structure in the prior art.

[0103] Optionally, the non-magnetic intermediate layer of the magnetic multilayer film structure is a non-magnetic insulating layer, and when it is made of an insulating material, it forms an MTJ structure. Exemplarily, the insulating material includes but is not limited to MgO or AlO xand all known insulating materials in the art that can be applied to MTJ structures.

[0104] Alternatively, the coupling layer of the magnetic multilayer structure (SV or MTJ) is made of a rare earth transition metal containing material. Illustratively, the coupling layer is made of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y), or an alloy or multilayer structure containing lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y) (including but not limited to a gadolinium (Gd) / cobalt (Co) multilayer structure).

[0105] Further, the feasibility of the coupling layer is illustrated by taking a TbCo alloy as an example, in which the content of Tb is 10% to 50%; taking a TbFe alloy as an example, in which the content of Tb is 10% to 40%; and taking a GdFe alloy as an example, in which the content of Gd is 15% to 35%.

[0106] Further, the feasibility of the interface coupling is illustrated by taking a light rare earth neodymium (Nd) as an example, in which the interface between Nd and the magnetic layer CoFeB produces ferromagnetic coupling, and the magnetic moments of the two layers are arranged in parallel; and taking a heavy rare earth gadolinium (Gd) as an example, in which the interface between Gd and the magnetic layer CoFeB produces antiferromagnetic coupling, and the magnetic moments of the two layers are arranged in anti-parallel.

[0107] Alternatively, the magnetic device of any one of the first embodiment to the third embodiment can be used in an MRAM or a magnetic sensor.

[0108] In addition, it should also be understood that, although the terms "first", "second" and the like can be used herein to describe various elements, parameters, components, regions, layers and / or sections, these elements, parameters, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, parameter, component, region, layer or section from another element, parameter, component, region, layer or section. Therefore, the first element, parameter, component, region, layer or section discussed below can also be called the second element, parameter, component, region, layer or section without departing from the teachings of the exemplary embodiments according to the present application.

[0109] A fourth embodiment;

[0110] This invention provides a magnetic device, which may be an MRAM or a magnetic sensor, comprising a second multilayer structure formed between a capping layer and a buffer layer; or between a capping layer and a seed layer.

[0111] refer to Figure 7 As shown, the second multilayer structure includes a synthetic antiferromagnetic layer, a reference layer, a nonmagnetic intermediate layer, a free layer, and a coupling layer arranged in sequence.

[0112] Or, refer to Figure 8 As shown, the second multilayer structure includes, in sequence: a coupling layer, a free layer, a non-magnetic intermediate layer, a reference layer, and an artificially synthesized antiferromagnetic layer;

[0113] Figure 7 and Figure 8 The magnetic moment directions of the free layer and the coupled layer are shown as an example.

[0114] In this design, the coupling layer and the free layer are antiferromagnetically or ferromagnetically coupled at their interface, with their magnetic moments arranged antiparallel or parallel. A non-magnetic intermediate layer serves as isolation or insulation. The antiferromagnetic or ferromagnetic coupling at the interface provides strong perpendicular magnetic anisotropy, allowing for further increases in the free layer thickness while maintaining perpendicular magnetic anisotropy, thereby improving the GMR / TMR value and reducing the damping factor. The antiferromagnetic coupling at the interface between the coupling layer and the free layer, with their magnetic moments arranged antiparallel, reduces the overall saturation magnetization and thus reduces interference from the external magnetic field. The magnetic moment direction of the reference layer is arbitrary and does not affect the implementation of this invention.

[0115] Furthermore, the second multilayer structures of the two magnetic devices provided in the fourth embodiment above can form SV spin valves or MTJ magnetic tunnel junctions due to the different materials of the non-magnetic intermediate layers.

[0116] When the non-magnetic intermediate layer of the magnetic multilayer film structure is a non-magnetic metal layer, it forms an SV spin valve.

[0117] When the non-magnetic intermediate layer of the magnetic multilayer film structure is a non-magnetic insulating layer, it forms an MTJ magnetic tunnel junction.

[0118] Fifth embodiment;

[0119] This invention provides a magnetic device, which may be an MRAM or a magnetic sensor, comprising a second multilayer structure formed between a capping layer and a buffer layer; or between a capping layer and a seed layer.

[0120] refer to Figure 9The second multi-layer structure includes, in sequence, an artificial synthetic anti-ferromagnetic layer, a reference layer, a non-magnetic intermediate layer, a free layer 1, a coupling layer, and a free layer 2.

[0121] Or, referring to Figure 10 The second multi-layer structure includes, in sequence, a free layer 2, a coupling layer, a free layer 1, a non-magnetic intermediate layer, a reference layer, and an artificial synthetic anti-ferromagnetic layer.

[0122] The magnetic moment directions of the coupling layer, the free layer 1, and the free layer 2 are perpendicular magnetization, in-plane magnetization, or oblique magnetization.

[0123] Figure 9 And Figure 10 Exemplarily, the magnetic moment directions of the free layer 1, the coupling layer, and the free layer 2 are represented.

[0124] The coupling layer, the free layer 1, and the free layer 2 are arranged anti-parallel or parallel to the magnetic moment directions of the free layer 1 and the free layer 2 respectively through the anti-ferromagnetic or ferromagnetic coupling effect of the interface.

[0125] Further, the second multi-layer structure of the two magnetic devices provided by the fifth embodiment can form an SV spin valve or an MTJ magnetic tunnel junction due to the different materials of the non-magnetic intermediate layer.

[0126] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic metal layer, an SV spin valve is formed.

[0127] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic insulating layer, an MTJ magnetic tunnel junction is formed.

[0128] Sixth embodiment

[0129] The present application provides a magnetic device, which can be an MRAM or a magnetic sensor, and the magnetic device includes a second multi-layer structure formed between a cap layer and a buffer layer; or, a cap layer and a seed layer.

[0130] Referring to Figure 11 The second multi-layer structure includes, in sequence, an artificial synthetic anti-ferromagnetic layer, a reference layer 2, a coupling layer, a reference layer 1, a non-magnetic intermediate layer, and a free layer.

[0131] Or, referring to Figure 12 The second multi-layer structure includes, in sequence, a free layer, a non-magnetic intermediate layer, a reference layer 1, a coupling layer, a reference layer 2, and an artificial synthetic anti-ferromagnetic layer.

[0132] Figure 11 And Figure 12 Exemplarily, the magnetic moment directions of the reference layer 1, the coupling layer, and the reference layer 2 are represented.

[0133] The coupling layer, the reference layer 1 and the reference layer 2 are arranged in anti-parallel or parallel direction of magnetic moment by the interface anti-ferromagnetic or ferromagnetic coupling effect, and the magnetic moment direction of the coupling layer, the reference layer 1 and the reference layer 2 is vertical magnetization, in-plane magnetization or oblique magnetization.

[0134] Further, the second multi-layer structure of the two magnetic devices provided by the sixth embodiment can form an SV spin valve or an MTJ magnetic tunnel junction due to the different materials of the non-magnetic intermediate layer.

[0135] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic metal layer, the SV spin valve is formed.

[0136] When the non-magnetic intermediate layer of the magnetic multi-layer film structure is a non-magnetic insulating layer, the MTJ magnetic tunnel junction is formed.

[0137] Further, the present application provides the feasible manufacturing materials of each layer of the magnetic device according to any one of the fourth embodiment to the sixth embodiment.

[0138] Optionally, the reference layer (including the reference layer 1 and the reference layer) and the free layer (including the free layer 1 and the free layer 2) are made of magnetic materials. Exemplarily, the magnetic materials include but are not limited to at least one of CoFeB, Co, Fe, Ni, FeB, CoFeSi, CoFe, NiFe, CoFeAl and the like.

[0139] Optionally, when the non-magnetic intermediate layer is made of metal materials, the SV structure is formed. Exemplarily, the metal materials include but are not limited to copper (Cu) and the like, and all known metal materials capable of being applied to the SV structure in the prior art.

[0140] Optionally, the non-magnetic intermediate layer is a non-magnetic insulating layer, and when the non-magnetic insulating layer is made of insulating materials, the MTJ structure is formed. Exemplarily, the insulating materials include but are not limited to MgO or AlO x and the like, and all known insulating materials capable of being applied to the MTJ structure in the prior art.

[0141] Alternatively, the coupling layer is made of a rare earth transition group material. Illustratively, the coupling layer is made of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y), or an alloy or multilayer film structure containing lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y) (including but not limited to a gadolinium (Gd) / cobalt (Co) multilayer film structure).

[0142] Further, the feasibility of the coupling layer is illustrated, for example, with a TbCo alloy having a Tb content of 10% to 50%, a TbFe alloy having a Tb content of 10% to 40%, and a GdFe alloy having a Gd content of 15% to 35%.

[0143] Further, the feasibility of the interface coupling is illustrated, for example, with a light rare earth neodymium (Nd) and a magnetic layer CoFeB interface producing ferromagnetic coupling, with the magnetic moments of the two layers arranged in parallel; and with a heavy rare earth gadolinium (Gd) and a magnetic layer CoFeB interface producing antiferromagnetic coupling, with the magnetic moments of the two layers arranged in anti-parallel.

[0144] A seventh embodiment;

[0145] With the magnetic device provided by the sixth embodiment, a feasible embodiment of the manufacturing material of each layer of the present application is provided.

[0146] Reference is made to Figure 13 As shown, the cap layer is a tantalum layer or a ruthenium layer Ta / Ru.

[0147] The artificial antiferromagnetic layer is artificially synthesized and includes, from top to bottom, in order: a first cobalt / platinum multilayer film layer [Co / Pt]n1, a ruthenium layer, i.e., a spacer layer Ru, a second cobalt / platinum multilayer film layer [Co / Pt]n2, a cobalt layer Co, and a tungsten layer W; n1 and n2 represent the number of repetitions.

[0148] The reference layer is a cobalt iron boron layer CoFeB.

[0149] The non-magnetic insulating layer is a magnesium oxide layer MgO.

[0150] The free layer 1 is a cobalt iron boron layer CoFeB.

[0151] The coupling layer is terbium Tb.

[0152] The coupling layer is terbium Tb.

[0153] The free layer 2 is a cobalt-iron-boron layer CoFeB;

[0154] The buffer layer or seed layer on the substrate is a tantalum layer or a tantalum nitride layer Ta / TaN.

[0155] Alternatively, as shown in FIG. 2, the cap layer is a tantalum layer or a ruthenium layer Ta / Ru; Figure 14

[0156] The free layer 2 is a cobalt-iron-boron layer CoFeB;

[0157] The coupling layer is terbium Tb;

[0158] The free layer 1 is a cobalt-iron-boron layer CoFeB;

[0159] The non-magnetic insulating layer is a magnesium oxide layer MgO;

[0160] The reference layer is a cobalt-iron-boron layer CoFeB;

[0161] The artificial synthetic antiferromagnetic layer is artificially synthesized and sequentially includes, from top to bottom, a tungsten layer, a cobalt layer Co, a second cobalt / platinum multilayer film layer [Co / Pt]n1, a ruthenium layer, i.e., a spacer layer Ru, and a first cobalt / platinum multilayer film layer [Co / Pt]n2; n1 and n2 represent the number of repetitions.

[0162] The buffer layer or seed layer on the substrate is a tantalum layer or a tantalum nitride layer Ta / TaN.

[0163] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0164] The application has been described in detail by specific implementation and examples, but these do not constitute a limitation on the application. Those skilled in the art can also make many modifications and improvements without departing from the principles of the application, and these should also be considered as falling within the scope of protection of the application.​

Claims

1. A magnetic multilayer film structure, characterized by, Comprising: a first multilayer structure formed on a buffer layer or a seed layer; the first multilayer structure comprises, in sequence or in reverse sequence: a reference layer, a non-magnetic intermediate layer, a free layer 1 and a coupling layer and a free layer 2; wherein the coupling layer and the free layer 1 and the free layer 2 are both through interface antiferromagnetic coupling or both through interface ferromagnetic coupling, the magnetic moment directions of the coupling layer and the free layer 1 and the free layer 2 are both anti-parallel or both parallel, and the non-magnetic intermediate layer is used for isolation or insulation.

2. The magnetic multilayer film structure of claim 1, wherein: The magnetic moment directions of the reference layer, the free layer 1, the coupling layer and the free layer 2 are perpendicular magnetization, in-plane magnetization or oblique magnetization.

3. The magnetic multilayer film structure of claim 1, wherein: The thickness of the free layer 1 and the free layer 2 ranges from 0.01 nm to 10 nm, and the thickness of the coupling layer ranges from 0.01 nm to 10 nm.

4. The magnetic multilayer film structure of claim 1, wherein: The first multilayer structure comprises, in sequence or in reverse sequence: a reference layer 2, a coupling layer, a reference layer 1, a non-magnetic intermediate layer and a free layer; wherein the coupling layer and the reference layer 1 and the reference layer 2 are both through interface antiferromagnetic coupling or both through interface ferromagnetic coupling, the magnetic moment directions of the coupling layer and the reference layer 1 and the reference layer 2 are both anti-parallel or both parallel.

5. The magnetic multilayer film structure of claim 4, wherein: The magnetic moment directions of the reference layer 2, the coupling layer, the reference layer 1 and the free layer are perpendicular magnetization, in-plane magnetization or oblique magnetization.

6. The magnetic multilayer film structure of claim 4, wherein: The thickness of the reference layer 1 and the reference layer 2 ranges from 0.01 nm to 10 nm, and the thickness of the coupling layer ranges from 0.01 nm to 10 nm. The coupling layer is made of rare earth transition group material.

7. The magnetic multilayer film structure of any of claims 1-6, wherein: The non-magnetic intermediate layer is a non-magnetic metal layer or a non-magnetic insulating layer.

8. The magnetic multilayer film structure of claim 7, wherein: It is MRAM or a magnetic sensor.

9. A magnetic device having the magnetic multilayer film structure of claim 8, characterized by: ​

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