Magnetic material film functional layer, preparation method thereof and magnetic film containing same

Abstract

The present invention belongs to the field of materials and specifically relates to a magnetic material thin film functional layer, a preparation method thereof, and a magnetic film containing the same. The magnetic material thin film functional layer comprises: a magnetic material layer and an oxide material layer, wherein the oxide material layer and the magnetic material layer are stacked in an up-and-down direction; wherein the magnetic material layer contains Co, Fe, B, and N, and the oxide material layer contains an oxide. In the present invention, by combining a magnetic material layer containing Co, Fe, B, and N with an oxide material layer to form an interface, the perpendicular magnetic anisotropy of the magnetic film is enhanced. The incorporation of N effectively adjusts and regulates the orbital hybridization between ferromagnetic elements and oxygen, thereby enhancing the perpendicular magnetic anisotropy.

Description

Technical Field

[0001] The present invention belongs to the field of materials, and in particular relates to a magnetic material film functional layer, a preparation method thereof, and a magnetic film containing the same. Background Art

[0002] CoFeB-based perpendicular anisotropic magnetic tunnel junctions (p-MTJs) offer advantages such as relatively high spin polarization and thermal stability, as well as low magnetic damping coefficient and critical switching current density, making them promising candidates for use in next-generation ultra-high-density magnetic random access memory (MRAM). Spintronics devices based on this structure (STT-MRAM) are also rapidly developing, with storage densities increasing from the megabit level to the gigabit level. Therefore, improving the perpendicular magnetic anisotropy of CoFeB / MgO-based multilayers is crucial for future applications.

[0003] International research on regulating the magnetic anisotropy of CoFeB-based thin film materials has focused on adjusting the perpendicular magnetic anisotropy of the film by selecting different oxide layer materials, applying stress and strain, and introducing external electric fields. These methods mainly focus on regulating the magnetic anisotropy of ferromagnetic multilayer materials using single ions and have high R&D costs. In addition, in order to maintain good perpendicular magnetic anisotropy, the ferromagnetic layer thickness often needs to be very thin, so the single ion regulation method generally only has a significant effect in thinner material systems. The ferromagnetic layer thickness window for maintaining good magnetic anisotropy in multilayer films is very narrow (the thickness of the ferromagnetic layer can even be only a few atomic layers). This is, to a certain extent, not conducive to improving the stability of storage and logic devices. Therefore, how to effectively and simply regulate the perpendicular magnetic anisotropy of CoFeB-based films is one of the key issues in the preparation of high-efficiency MRAM devices. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetic material thin film functional layer, a preparation method thereof and a magnetic film containing the same, aiming to provide a magnetic thin film material with high perpendicular magnetic anisotropy.

[0005] To achieve the above object, the present invention provides a magnetic material thin film functional layer, comprising:

[0006] a magnetic material layer; and

[0007] The oxide material layer and the magnetic material layer are stacked in an up-and-down direction;

[0008] The magnetic material layer contains Co, Fe, B and N, and the material of the oxidized material layer contains oxide.

[0009] Optionally, at least one of MgO and Al2O3; and / or,

[0010] In the magnetic material layer, the molar ratio of Co, Fe and B is (30-50): (30-50): (15-25).

[0011] Optionally, the thickness of the magnetic material layer is and / or,

[0012] The thickness of the oxide material layer is

[0013] In addition, the present invention also provides a method for preparing the above-mentioned magnetic material thin film functional layer, comprising the following steps:

[0014] Step S10: depositing the magnetic material layer in a mixed gas atmosphere by magnetron sputtering, wherein the mixed gas includes nitrogen and an inert gas;

[0015] Step S20: depositing the oxide material layer on the surface of the magnetic material layer by magnetron sputtering to obtain a pre-product;

[0016] Step S30: heat-treating the pre-product to obtain the magnetic material thin film functional layer;

[0017] Wherein, in the mixed gas, the volume ratio of the nitrogen gas to the inert gas is (1-3):17.

[0018] Optionally, the inert gas includes argon;

[0019] In the step S10, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of the mixed gas is 0.3-0.6 Pa; and / or,

[0020] In the step S20, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure is 0.3~0.6Pa; and / or,

[0021] In the step S30, the heat treatment is performed in a vacuum environment; and / or,

[0022] The heat treatment includes keeping the temperature at 200-400° C. for 30-40 minutes.

[0023] In addition, the present invention also provides a magnetic film, comprising:

[0024] The above-mentioned magnetic material thin film functional layer;

[0025] a buffer layer, the buffer layer being stacked on an upper side of the functional layer; and

[0026] A protective layer is stacked on the lower side of the functional layer.

[0027] Optionally, the material of the buffer layer includes at least one of Ta, Ru and Pt; and / or,

[0028] The material of the protective layer includes at least one of Ta, Ru and Pt; and / or,

[0029] The thickness of the buffer layer is and / or,

[0030] The thickness of the protective layer is

[0031] Optionally, the magnetic film further includes a substrate, and the substrate is stacked on the upper side of the buffer layer or stacked on the lower side of the protective layer.

[0032] Optionally, the substrate material comprises Si; and / or,

[0033] The thickness of the substrate is 0.5 to 0.7 mm.

[0034] In addition, the present invention also provides a method for preparing the above magnetic film, comprising the following steps:

[0035] providing the buffer layer;

[0036] preparing the magnetic material thin film functional layer on the surface of the buffer layer by magnetron sputtering;

[0037] Depositing the protective layer on the surface of the magnetic material thin film functional layer by magnetron sputtering to obtain a multilayer film structure;

[0038] The multilayer film structure is subjected to heat treatment to obtain the magnetic film.

[0039] In the present invention, a magnetic material layer containing Co, Fe, B, and N is combined with an oxide material layer to form an interface, thereby enhancing the perpendicular magnetic anisotropy of the magnetic film. The incorporation of N effectively regulates and controls the orbital hybridization between the ferromagnetic elements and oxygen, thereby enhancing the perpendicular magnetic anisotropy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A schematic diagram of a process for preparing a magnetic material thin film functional layer according to the present invention;

[0042] Figure 2 A structural diagram of a magnetic film according to an embodiment of the present invention;

[0043] Figure 3 A flowchart of preparing a magnetic film according to an embodiment of the present invention;

[0044] Figure 4 XPS test graphs of samples prepared in Example 1 and Comparative Example 1;

[0045] Figure 5 Magnetic hysteresis loop test diagrams of the samples prepared in Example 1 and Comparative Example 1;

[0046] Figure 6 This is the hysteresis loop test diagram of the sample prepared in Comparative Example 2.

[0047] Description of Figure Numbers:

[0048] Label name Label name 1 buffer layer 2 Magnetic material thin film functional layer 201 Magnetic material layer 202 Oxide material layer 3 protective layer 4 substrate

[0049] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0051] It should be noted that, in the embodiments, those without specifying specific conditions, are carried out according to conventional conditions or the conditions recommended by the manufacturer. Those for reagents or instruments used that do not specify the manufacturer are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes schemes A, B, or A and B that meet the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on those of ordinary skill in the art. When the combination of the technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work belong to the scope of protection of the present invention.

[0052] In view of the fact that in the prior art, methods for improving the perpendicular magnetic anisotropy of magnetic films are often limited to new materials, improving the physical form of the materials, etc., which often result in limited improvement effects, high development costs, or the need to compress the thickness of the ferromagnetic layer to a few atoms, resulting in technical defects such as high material costs. The present invention provides a magnetic material film functional layer, comprising:

[0053] a magnetic material layer;

[0054] The oxide material layer and the magnetic material layer are stacked in an up-and-down direction;

[0055] The magnetic material layer contains Co, Fe, B and N, and the material of the oxidized material layer contains oxide.

[0056] In the present invention, a magnetic material layer containing Co, Fe, B, and N is combined with an oxide material layer to form an interface, thereby enhancing the perpendicular magnetic anisotropy of the magnetic film. The incorporation of N effectively regulates and controls the orbital hybridization between the ferromagnetic elements and oxygen, thereby enhancing the perpendicular magnetic anisotropy.

[0057] It should be noted that the oxide selected in the present invention is intended to provide oxygen and ferromagnetic elements to form hybrid orbitals. Under this premise, the oxide is not limited. In some embodiments, the oxide contains at least one of MgO and Al2O3. Specifically, the oxide includes MgO, which can further increase the perpendicular magnetic anisotropy.

[0058] It should be noted that, under the premise that the magnetic material layer and the oxide material layer can be combined and can generate perpendicular magnetic anisotropy, the thickness of the oxide material layer can be flexibly adjusted. In some embodiments, the thickness of the oxide material layer is At this thickness, its perpendicular magnetic anisotropy is further enhanced.

[0059] It should be noted that the molar ratios of Co, Fe, and B in the magnetic material layer are not limited and can be adjusted according to actual conditions. In some embodiments, the molar ratio of Co, Fe, and B in the magnetic material layer is (30-50): (30-50): (15-25). Specifically, the molar ratio of Co, Fe, and B in the magnetic material layer is 40:40:20.

[0060] It should be noted that, under the premise that the magnetic material layer and the oxide material layer can be combined and can generate perpendicular magnetic anisotropy, the thickness of the magnetic material layer can be flexibly adjusted. In some embodiments, the thickness of the magnetic material layer is At this thickness, its perpendicular magnetic anisotropy is further enhanced.

[0061] In addition, see Figure 1 The present invention also provides a method for preparing the above-mentioned magnetic material thin film functional layer, comprising the following steps:

[0062] Step S10: depositing the magnetic material layer in a mixed gas atmosphere by magnetron sputtering, wherein the mixed gas includes nitrogen and an inert gas;

[0063] Step S20: depositing the oxide material layer on the surface of the magnetic material layer by magnetron sputtering to obtain a pre-product;

[0064] Step S30: heat-treating the pre-product to obtain the magnetic material thin film functional layer;

[0065] In the mixed gas, the volume ratio of the nitrogen gas to the inert gas is (1-3):17, for example, 1:17, 2:17, 3:17, and the like.

[0066] It should be noted that the "inert gas" described herein refers to a gas that is chemically inactive and incapable of participating in chemical reactions, at least in the chemical environment provided by the present invention. Under this premise, the type of inert gas is not limited. In some embodiments, the inert gas includes argon.

[0067] The above method can be used to combine a magnetic material layer with an oxidized material layer to obtain a magnetic material thin film functional layer with perpendicular magnetic anisotropy. The inventors' research team also found that when the volume ratio is less than 1:17, the degree of oxidation is too low, while when it is greater than 3:17, it is prone to excessive oxidation. Excessive or insufficient oxidation will affect the perpendicular magnetic anisotropy. Specifically, when the nitrogen flow ratio is too high or too low, perpendicular anisotropy is almost nonexistent.

[0068] Furthermore, when the volume ratio of the nitrogen gas to the inert gas is 2:17, the perpendicular magnetic anisotropy is optimal.

[0069] In some embodiments, in step S10, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of argon is 0.3~0.6Pa; ensuring a certain working pressure and vacuum degree can ensure that the raw materials are smoothly sputtered to form a magnetic material layer, so that the prepared magnetic material layer has better performance.

[0070] It should be noted that the raw materials of the magnetic material layer of the present invention are conventional alloys formed by raw materials in corresponding proportions.

[0071] In some embodiments, in step S20, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure is 0.3-0.6 Pa; ensuring the vacuum degree can ensure that the raw materials are smoothly sputtered to form an oxide material layer, so that the prepared magnetic material layer has better performance. It should be noted that in the present invention, the atmosphere of this step is nitrogen.

[0072] In some embodiments, in step S30, the heat treatment is performed in a vacuum environment. When the heat treatment is performed in a vacuum environment, oxidation of the magnetic material layer by oxygen (O 2 ) can be avoided, thereby avoiding the occurrence of oxidation transition.

[0073] In some embodiments, the heat treatment comprises a temperature of 200-400° C. and a holding time of 30-40 minutes. When the above conditions are adopted, a magnetic / oxide multilayer film material can be successfully prepared.

[0074] In addition, see Figure 2 The present invention further provides a magnetic film, comprising:

[0075] The above-mentioned magnetic material thin film functional layer 2;

[0076] a buffer layer 1, the buffer layer 1 being stacked on the upper side of the magnetic material thin film functional layer 2; and

[0077] The protective layer 3 is stacked on the lower side of the magnetic material thin film functional layer 2 .

[0078] It is understood that the primary function of protective layer 3 is to protect the magnetic material thin film functional layer from oxidation. The buffer layer 1 material ensures a relatively flat and uniform film during the preparation of the magnetic material functional layer 2. In a sense, this protects the magnetic material thin film functional layer 2 from damage during the preparation process. The buffer layer 1 and protective layer 3, while positioned on either side of the magnetic material thin film functional layer 2, can be deposited on the surface of either the magnetic material layer 201 or the oxidized material layer 202, depending on the circumstances.

[0079] In some embodiments, the buffer layer 1 contacts the magnetic material layer 201 , and the protection layer 3 contacts the oxidized material layer 202 .

[0080] It should be noted that, under the premise that the raw materials of the magnetic material layer 201 can be protected during the manufacturing process, the material and thickness of the buffer layer 1 are not limited. In some embodiments, the material of the buffer layer 1 includes at least one of Ta, Ru and Pt; specifically, the material of the buffer layer 1 includes Ta.

[0081] In some embodiments, the thickness of the buffer layer 1 is

[0082] It should be noted that, under the premise that the magnetic material thin film functional layer 2 can be protected during the manufacturing process, the material of the protective layer 3 is not limited. In some embodiments, the material of the protective layer 3 includes at least one of Ta, Ru and Pt; specifically, the material of the protective layer 3 includes Ta.

[0083] In some embodiments, the thickness of the protective layer 3 is

[0084] In some embodiments, the magnetic film further includes a substrate 4, which is stacked on the upper side of the buffer layer 1 or stacked on the lower side of the protective layer 3. The substrate 4 is used to grow the buffer layer 1 or protective layer 3 deposited on the surface thereof, and then subsequently complete the formation of the magnetic material film functional layer 2 and the protective layer 3.

[0085] In some embodiments, the material of the substrate 4 includes Si.

[0086] In some embodiments, the thickness of the substrate 4 is 0.5 to 0.7 mm. Specifically, the substrate 4 is a Si substrate with a SiO2 oxide layer having a thickness of 300 nm on its surface.

[0087] In addition, see Figure 3 The present invention also provides a method for preparing the magnetic film, comprising the following steps:

[0088] Step A10: providing the buffer layer;

[0089] Step A20: preparing the magnetic material thin film functional layer on the surface of the buffer layer by magnetron sputtering;

[0090] Step A30: depositing the protective layer on the surface of the magnetic material thin film functional layer by magnetron sputtering to obtain a multilayer film structure;

[0091] Step A40: heat-treating the multilayer film structure to obtain the magnetic film.

[0092] Through the above steps, a magnetic film with perpendicular magnetic anisotropy can be prepared.

[0093] In some embodiments, step A10 includes:

[0094] Step A101: providing a substrate;

[0095] Step A102: depositing the buffer layer on the surface of the substrate by magnetron sputtering.

[0096] By adopting the above method, a buffer layer can be grown on the substrate.

[0097] In some embodiments, step A101 includes: cleaning the raw material of the substrate to obtain the substrate. After cleaning, the cleanliness of the substrate can be ensured, thereby ensuring smooth deposition of the subsequent buffer layer.

[0098] In some embodiments, in step A102, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, ensuring a certain vacuum degree can ensure the smooth sputtering of its raw materials, thereby forming a smooth deposition of the buffer layer.

[0099] In some embodiments, step A20 includes:

[0100] Step A201: depositing the magnetic material layer on the surface of the buffer layer in a mixed gas atmosphere by magnetron sputtering, wherein the mixed gas includes nitrogen and an inert gas;

[0101] Step A202: depositing the oxide material layer on the surface of the magnetic material layer by magnetron sputtering to obtain a magnetic material thin film functional layer.

[0102] It should be noted that the "inert gas" described herein refers to a gas that is chemically inactive and incapable of participating in chemical reactions, at least in the chemical environment provided by the present invention. Under this premise, the type of inert gas is not limited. In some embodiments, the inert gas includes argon.

[0103] By using the above method, the magnetic material layer and the oxide material layer can be combined to obtain a magnetic material thin film functional layer with perpendicular magnetic anisotropy.

[0104] In some embodiments, the volume ratio of nitrogen to inert gas in the mixed gas is (1-3):17, specifically 1:17, 2:17, and 3:17. Nitrogen is doped into the magnetic material to prevent excessive oxidation, thereby increasing the degree of oxidation and enhancing perpendicular magnetic anisotropy. When the volume ratio is less than 1:17, the degree of oxidation is too low, while when it is greater than 3:17, excessive oxidation is likely. However, when the degree of oxidation is too high or too low, perpendicular anisotropy is hardly generated.

[0105] In some embodiments, in step A201, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure is 0.3 ~ 0.6Pa; ensuring a certain working pressure and vacuum degree can ensure that the raw materials are smoothly sputtered to form a magnetic material layer.

[0106] In some embodiments, in step A202, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa; ensuring the vacuum degree can ensure that its raw materials are smoothly sputtered to form an oxide material layer.

[0107] In some embodiments, in step A30, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa; ensuring the vacuum degree can ensure that its raw materials are smoothly sputtered to form a protective layer.

[0108] In some embodiments, in step A40, the heat treatment is performed in a vacuum environment. When the heat treatment is performed in a vacuum environment, oxidation of the magnetic material layer by O2 can be avoided, and oxidation transition can be avoided.

[0109] In some embodiments, the heat treatment includes maintaining the temperature at 200-400° C. for 30-40 minutes. When the above conditions are adopted, the magnetic material layer and the oxide material layer can be smoothly combined to form a multilayer film structure.

[0110] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0111] Example 1

[0112] This embodiment provides a method for preparing a magnetic thin film, and the operations are as follows:

[0113] (1) Cleaning a Si substrate having a thickness of 0.5 to 0.7 mm and a SiO2 oxide layer having a thickness of 300 nm;

[0114] (2) Using magnetron sputtering, Ta, Co, and Si are sequentially deposited on the Si substrate in step (1). 40 Fe 40 B 20 (N), MgO and Ta layers, among which Co 40 Fe 40 B 20 (N) is the N-doped CoFeB layer, and the background vacuum of the sputtering chamber is 2×10 -5 Pa, obtained by introducing nitrogen gas while DC sputtering CoFeB, the ratio of argon to nitrogen was selected to be 17:2, and the working pressure of argon gas was 0.5Pa; finally, a multilayer film structure with Ta (buffer layer) / CoFeB (N) / MgO / Ta (protective layer) was formed, and the thickness of the deposited Ta buffer layer was The thickness of the CoFeB layer is The thickness of the MgO layer is The thickness of the Ta protective layer is

[0115] (3) When the vacuum degree is 2×10 -5 Pa, the multilayer film structure obtained in step (2) is heat-treated at a temperature of 250° C. for 30 minutes, and then cooled to room temperature.

[0116] Example 2

[0117] This embodiment provides a method for preparing a magnetic thin film, and the operations are as follows:

[0118] (1) Cleaning a Si substrate, wherein the Si substrate has a thickness of 0.5 to 0.7 mm and a SiO2 oxide layer with a thickness of 300 nm;

[0119] (2) Using magnetron sputtering, Ta, Co, and Si are sequentially deposited on the Si substrate described in step (1). 30 Fe 50 B 20 (N), MgO and Ta layers, the background vacuum of the sputtering chamber is 3×10 -5 Pa, among which Co 30 Fe 50 B 20(N) is an N-doped CoFeB layer, which is obtained by DC sputtering CoFeB while introducing nitrogen. The ratio of argon to nitrogen is selected to be 17:1. Finally, a multilayer film structure with Ta (buffer layer) / CoFeB (N) / MgO / Ta (protective layer) is formed. The working pressure of argon is 0.5 Pa. The thickness of the deposited Ta buffer layer is The thickness of the CoFeB layer is The thickness of the MgO layer is The thickness of the Ta protective layer is

[0120] (3) In 3×10 -5 Under a Pa vacuum environment, the multilayer film structure obtained in step (2) is heat-treated at a temperature of 400° C. and a holding time of 30 minutes to obtain the product.

[0121] Example 3

[0122] This embodiment provides a method for preparing a magnetic thin film, and the operations are as follows:

[0123] (1) Cleaning a Si substrate, wherein the Si substrate has a thickness of 0.5 to 0.7 mm and a SiO2 oxide layer with a thickness of 300 nm;

[0124] (2) Using magnetron sputtering, Ta, Co, and Si are sequentially deposited on the Si substrate described in step (1). 50 Fe 35 B 15 (N), MgO and Ta layers, the background vacuum of the sputtering chamber is 3×10-5Pa, wherein CoFeB(N) is an N-doped CoFeB layer, which is obtained by DC sputtering CoFeB while introducing nitrogen, and the ratio of argon to nitrogen is selected as 17:3; finally, a multilayer film structure of Ta (buffer layer) / CoFeB(N) / MgO / Ta (protective layer) is formed, and the working pressure of argon is 0.5Pa; the thickness of the deposited Ta buffer layer is The thickness of the CoFeB layer is The thickness of the MgO layer is The thickness of the Ta protective layer is

[0125] (3) In 1×10 -5 Under a Pa vacuum environment, the multilayer film structure obtained in step (2) is heat-treated at a temperature of 200° C. and a holding time of 30 minutes to obtain the product.

[0126] Example 4

[0127] This embodiment provides a method for preparing a magnetic thin film, and the operations are as follows:

[0128] (1) Cleaning a Si substrate, wherein the Si substrate has a thickness of 0.5 to 0.7 mm and a SiO2 oxide layer with a thickness of 300 nm;

[0129] (2) Using magnetron sputtering, Ta, Co, and Si are sequentially deposited on the Si substrate described in step (1). 35 Fe 30 B 35 (N), MgO and Ta layers, the background vacuum of the sputtering chamber is 2×10 -5 Pa, among which Co 35 Fe 30 B 35 (N) is an N-doped CoFeB layer, which is obtained by DC sputtering CoFeB while introducing nitrogen. The ratio of argon to nitrogen is selected as 17:2. Finally, a multilayer film structure with Ta (buffer layer) / CoFeB (N) / MgO / Ta (protective layer) is formed. The working pressure of argon is 0.5 Pa. The thickness of the deposited Ta buffer layer is The thickness of the CoFeB layer is The thickness of the MgO layer is The thickness of the Ta protective layer is

[0130] (3) In 1.5×10 -5 Under a Pa vacuum environment, the multilayer film structure obtained in step (2) is heat-treated at a temperature of 350° C. and a holding time of 30 minutes to obtain the product.

[0131] Example 5

[0132] This embodiment provides a method for preparing a magnetic thin film, and the operations are as follows:

[0133] (1) Cleaning a Si substrate, wherein the Si substrate has a thickness of 0.5 to 0.7 mm and a SiO2 oxide layer with a thickness of 300 nm;

[0134] (2) Using magnetron sputtering, Ta, Co, and Si are sequentially deposited on the Si substrate described in step (1). 30 Fe 50 B 20 (N), MgO and Ta layers, the background vacuum of the sputtering chamber is 3×10 -5 Pa, among which Co 30 Fe 50 B 20(N) is an N-doped CoFeB layer, which is obtained by DC sputtering CoFeB while introducing nitrogen. The ratio of argon to nitrogen is selected to be 17:1. Finally, a multilayer film structure with Ta (buffer layer) / CoFeB (N) / MgO / Ta (protective layer) is formed. The working pressure of argon is 0.6 Pa. The thickness of the deposited Ta buffer layer is The thickness of the CoFeB layer is The thickness of the MgO layer is The thickness of the Ta protective layer is

[0135] (3) In 3×10 -5 Under a Pa vacuum environment, the multilayer film structure obtained in step (2) is heat-treated at a temperature of 400° C. and a holding time of 40 minutes to obtain the product.

[0136] Example 6

[0137] This embodiment provides a method for preparing a magnetic thin film, and the operations are as follows:

[0138] (1) Cleaning a Si substrate, wherein the Si substrate has a thickness of 0.5 to 0.7 mm and a SiO2 oxide layer with a thickness of 300 nm;

[0139] (2) Using magnetron sputtering, Ta, Co, and Si are sequentially deposited on the Si substrate described in step (1). 50 Fe 35 B 15 (N), MgO and Ta layers, the background vacuum of the sputtering chamber is 3×10 -5 Pa, wherein CoFeB(N) is an N-doped CoFeB layer, which is obtained by DC sputtering CoFeB while introducing nitrogen, and the ratio of argon to nitrogen is selected to be 17:3; finally, a multilayer film structure of Ta (buffer layer) / CoFeB(N) / MgO / Ta (protective layer) is formed, and the working pressure of argon is 0.3 Pa; the thickness of the deposited Ta buffer layer is The thickness of the CoFeB layer is The thickness of the MgO layer is The thickness of the Ta protective layer is

[0140] (3) In 1×10 -5 Under a Pa vacuum environment, the multilayer film structure obtained in step (2) is heat-treated at a temperature of 200° C. and a holding time of 35 minutes to obtain the product.

[0141] Comparative Example 1

[0142] This comparative example provides a method for preparing a magnetic thin film. The operation is substantially the same as that of Example 1, except that only argon gas is introduced during the DC sputtering of CoFeB.

[0143] Comparative Example 2

[0144] This comparative example provides a method for preparing a magnetic thin film. The operation is substantially the same as that of Example 1, except that the ratio of argon to nitrogen is selected to be 17:5.

[0145] Test Examples

[0146] 1) High-resolution XPS spectra of Examples 1 to 6 and Comparative Examples 1 to 2 were tested, and the N ion incorporation was analyzed according to the XPS manual. The XPS manual records that the peak near 706.5 eV corresponds to Fe 2p3 / 2 in the metallic element Fe, and the peak between 707 eV and 709.4 eV corresponds to FeN x The peak between 709.4 eV and 710.9 eV in Fe2p3 / 2 (x<1) corresponds to FeO y The peak of Fe 2p3 / 2 at approximately 713 eV in (y>1) corresponds to the Auger peak of Co.

[0147] The analysis shows that the magnetic material layers of the magnetic films prepared in Examples 1 to 6 and Comparative Example 2 are successfully doped with N ions. Figure 4 As shown, for the sample of Comparative Example 1 Figure 4 (a) The high-resolution XPS spectrum of Fe 2p at the interface of the magnetic material / oxidized material layer shows that no FeN x Peak; for the sample of Example 1 Figure 4 (b) The peak at 707.28 eV is FeN x This indicates that N diffuses to the CoFeB / MgO interface.

[0148] 2) Test the in-plane and out-of-plane hysteresis loops of Examples 1 to 6 and Comparative Examples 1 to 2. The hysteresis loops of the samples were measured using a vibrating sample magnetometer. A quartz glass rod with the sample to be tested adhered to one end was placed in the center of a uniform magnetic field, and the other end was connected to a vibration motor to drive the sample to generate constant amplitude vibrations. Within the induction range of the detection coil, the voltage generated by the vibration cutting the magnetic flux lines is proportional to the magnetic moment, vibration amplitude, and vibration frequency of the sample. A lock-in amplifier was used to measure the induced voltage based on a fixed amplitude and frequency. The magnetic moment of the sample to be tested was obtained by comparing it with a standard ferromagnetic sample (provided with the system and used for calibration measurements), and then the MH curve was obtained.

[0149] It can be seen from the hysteresis loop analysis that the samples of Examples 1 to 6 have perpendicular magnetic anisotropy, while the samples of Comparative Examples 1 to 2 do not have perpendicular magnetic anisotropy. The hysteresis loop test graphs of the samples of Example 1 and Comparative Example 1 are shown in FIG. Figure 5 As shown, the hysteresis loop test diagram of the sample of comparative example 2 is as follows Figure 6 As shown, Figure 5 (a) is the hysteresis loop test diagram of the sample of comparative example 1, and (b) is the hysteresis loop test diagram of the sample of embodiment 1. Further calculation shows that the magnetic anisotropy constant Keff of the sample of embodiment 1 is about 3.2*10 6 erg / cm 3 It can be seen that when N is added into the magnetic material layer and the volume ratio of nitrogen to inert gas is (1-3):17 during the preparation process, the perpendicular magnetic anisotropy is significantly improved, which is nearly 2 times higher than that of Comparative Example 1.

[0150] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. A magnetic material thin film functional layer, characterized in that: include: a magnetic material layer; as well as, an oxidation material layer stacked with the magnetic material layer in an up-down direction; Wherein, the magnetic material layer contains Co, Fe, B and N, and the material of the oxidized material layer contains oxide; The method for preparing the magnetic material thin film functional layer comprises the following steps: Step S10: depositing the magnetic material layer in a mixed gas atmosphere by magnetron sputtering, wherein the mixed gas includes nitrogen and an inert gas; Step S20: depositing the oxide material layer on the surface of the magnetic material layer by magnetron sputtering to obtain a pre-product; Step S30: heat-treating the pre-product to obtain the magnetic material thin film functional layer; Wherein, in the mixed gas, the volume ratio of the nitrogen gas to the inert gas is (1-3):17; The oxide contains at least one of MgO and Al2O3; In the magnetic material layer, the molar ratio of Co, Fe and B is (30-50): (30-50): (15-25).

2. The magnetic material thin film functional layer according to claim 1, characterized in that: The thickness of the magnetic material layer is 10 to 12 Å; and / or, The thickness of the oxide material layer is 20 to 25 Å.

3. The magnetic material thin film functional layer according to claim 1, characterized in that: The inert gas comprises argon; and / or, In the step S10, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure of the mixed gas is 0.3-0.6 Pa; and / or, In the step S20, during the magnetron sputtering process, the background vacuum degree of the sputtering chamber is 1×10 -5 ~3×10 -5 Pa, the working pressure is 0.3~0.6 Pa; and / or, In the step S30, the heat treatment is performed in a vacuum environment; and / or, The heat treatment includes keeping the temperature at 200-400° C. for 30-40 minutes.

4. A magnetic film, characterized in that include: The magnetic material thin film functional layer according to any one of claims 1 to 3; a buffer layer, the buffer layer being stacked on an upper side of the functional layer; as well as, A protective layer is stacked on the lower side of the functional layer.

5. The magnetic film according to claim 4, wherein The material of the buffer layer includes at least one of Ta, Ru and Pt; and / or, The material of the protective layer includes at least one of Ta, Ru and Pt; and / or, The thickness of the buffer layer is 40 to 50 Å; and / or, The thickness of the protective layer is 20 to 50 Å.

6. The magnetic film according to claim 4, wherein The magnetic film further includes a substrate, and the substrate is stacked on the upper side of the buffer layer or stacked on the lower side of the protection layer.

7. The magnetic film according to claim 6, wherein The material of the substrate comprises Si; and / or, The thickness of the substrate is 0.5-0.7 mm.

8. A method for preparing a magnetic film according to claim 4, characterized in that: The following steps are involved: providing the buffer layer; preparing the magnetic material thin film functional layer on the surface of the buffer layer by magnetron sputtering; Depositing the protective layer on the surface of the magnetic material thin film functional layer by magnetron sputtering to obtain a multilayer film structure; The multilayer film structure is subjected to heat treatment to obtain the magnetic film.

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