High entropy alloy and nitride multilayer soft magnetic thin film for high frequency and preparation method thereof

Abstract

The application belongs to the field of soft magnetic high-entropy alloy material and magnetron sputtering technology, and particularly relates to a high-entropy alloy and nitride multilayer soft magnetic film for high frequency and a preparation method. The high-entropy alloy soft magnetic film layer comprises Zr and / or B, Fe, Co and Ni elements; the high-entropy alloy soft magnetic nitride film layer comprises Zr and / or B, Fe, Co, Ni and N elements, the N element is nitrogen gas with a certain partial pressure introduced in the magnetron sputtering process and nitrogen atoms are deposited into the high-entropy alloy soft magnetic nitride film layer, pure Ar and argon / nitrogen mixed gas are alternately used, the high-entropy alloy soft magnetic film layer and the high-entropy alloy soft magnetic nitride film layer are alternately sputtered on the surface of the substrate to obtain the multilayer soft magnetic film, the high-entropy alloy nitride soft magnetic film has high resistivity and low coercivity, the high-entropy alloy soft magnetic film has high saturation magnetization, the multilayer soft magnetic film has higher saturation magnetization and resistivity, and is suitable for high frequency application.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of soft magnetic high-entropy alloy materials and magnetron sputtering technology, and particularly relates to a high-entropy alloy and a nitride multilayer soft magnetic film for high frequency and a preparation method. BACKGROUND

[0002] With the increasing demand for miniaturization and integration of electronic devices, magnetic thin films applied in the GHz frequency range have been extensively studied. High-frequency soft magnetic films should have high saturation magnetization Ms (to increase the initial permeability), high permeability μ, and appropriate large in-plane uniaxial magnetic anisotropy field Hk (to adjust the ferromagnetic resonance (FMR) frequency), and considering the application environment, the thin film must also have high resistivity ρ to reduce eddy current loss. Resistivity is an important performance parameter in high-frequency applications. In the prior art, to improve the performance of the multilayer film structure, a high-resistivity non-magnetic oxide layer (such as SiO2, Al2O3, etc.) is usually added to realize the alternation sputtering method to increase the overall resistivity of the thin film, which reduces the proportion of the magnetic phase and has a significant negative impact on the high-frequency magnetic properties. At the same time, the introduction of the non-magnetic phase layer increases the complexity of the preparation process and the additional cost of high-resistivity target materials, and the heterogeneous multilayer film may have problems such as lattice mismatch, out-of-sync crystal morphology, poor film layer adhesion, high processing difficulty, and easy failure.

[0003] A domestic scholar (Lu Guangduo. Electromagnetic properties and application basic research of GHz soft magnetic granular films[D]. University of Electronic Science and Technology of China, 2012. DOI:10.7666 / d.D763445.) sputtered FeCo-SiO2 multilayer thin films, and with the increase of the thickness of SiO2, the saturation magnetization decreased and the resistivity increased, and the resonance frequency of the thin film also changed, with a change range of 1.5 GHz-4.05 GHz. CN114420402A discloses a high-orientation, high-resistivity striped film and a preparation method thereof, which alternately arranges Fe x Co y B z strips and dielectric (the dielectric is one selected from solid dielectrics silicon dioxide, zinc oxide, boron oxide, aluminum oxide, silicon nitride, and boron nitride) strips to obtain a high-resistivity, high-orientation magnetic thin film. However, this method has great preparation difficulty, complex process, and high production cost, and is not conducive to industrial large-scale production, and the segmented magnetic thin film has a certain degree of decline in overall magnetic properties.

[0004] In summary, although the conventional soft magnetic metal thin film has a high saturation magnetic induction intensity, it cannot be widely applied in the GHz working range due to its low resistivity and the disadvantages of the method for improving the resistivity of the thin film, such as reduction of magnetic performance, poor adhesion, high equipment requirement, complex process, and cost increase due to addition of new target material. SUMMARY

[0005] The present application aims to overcome the disadvantages of the prior art and provide a high-entropy soft magnetic alloy and a preparation method of a multi-layer soft magnetic thin film of nitride thereof for high frequency. The high-entropy alloy target material has good soft magnetic performance and high resistivity, which is beneficial to reduce high-frequency eddy current loss. Meanwhile, a multi-layer film structure of high-entropy soft magnetic layer / high-entropy soft magnetic nitride layer is provided, which has good comprehensive performance, high adhesion, and high-frequency application characteristics.

[0006] The complete technical solution of the present application comprises:

[0007] The high-entropy alloy and the multi-layer soft magnetic thin film of nitride thereof for high frequency comprise first film layers and second film layers arranged alternately,

[0008] The first film layers are high-entropy alloy soft magnetic film layers;

[0009] The second film layers are high-entropy alloy soft magnetic nitride film layers;

[0010] The components of the first film layers comprise Fe, Co, Ni, and Zr and / or B elements;

[0011] The components of the second film layers comprise Fe, Co, Ni, N, and Zr and / or B elements;

[0012] In the second film layers, the atomic percentage content of the elements other than N element is 100%, and the atomic percentage content of the elements other than N element is the same as that of the first film layers;

[0013] In the second film layers, N element is nitrogen gas with a certain partial pressure introduced in the process of magnetron sputtering and nitrogen atoms are deposited into the high-entropy alloy soft magnetic nitride film layers.

[0014] Further, the thickness of the high-entropy alloy soft magnetic film layers is 0.2-0.4 μm, the thickness of the high-entropy alloy soft magnetic nitride film layers is 0.05-0.15 μm, and the total thickness of the multi-layer soft magnetic thin film is 1-3 μm.

[0015] Further, in the high-entropy alloy soft magnetic nitride film layers, nitrogen atoms form nitrides with the alloy elements of the film layers, and the nitrides comprise alpha phase, gamma phase and epsilon phase compounds of FeN.

[0016] Further, in the high-entropy alloy soft magnetic film layers, the content ranges of the constituent elements are:

[0017] 1) composed of Zr, Fe, Co, Ni elements, the content range of each element is: Zr: 10.5~14.2at%, Fe: 21.7~50.5 at%, Co: 16.4~53.4 at%, Ni: 12.3~22.1 at %; or

[0018] 2) composed of B, Fe, Co, Ni elements, the content range of each element is: B: 7.5~12.1at%, Fe: 20.3~54.5 at%, Co: 13.5~58.5 at%, Ni: 11.2~22.5 at %; or

[0019] 3) composed of B, Zr, Fe, Co, Ni elements, the content range of each element is: B: 4.6~8.8at%, Zr: 2.7~6.5at%, Fe: 20.3~54.5 at%, Co: 13.5~58.5 at%, Ni: 11.2~22.5 at %.

[0020] Further, the content of each component element in the high-entropy alloy soft magnetic film layer is determined by high-throughput screening according to the content range of each component element.

[0021] Further, the saturation magnetization of the high-entropy alloy and nitride multilayer soft magnetic thin film is 1237.2emu.cm -3 , the coercivity is 1.18Oe, and the resistivity is 396.8μΩ.cm.

[0022] Further, the preparation method of the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency, characterized in that, comprising the following steps:

[0023] Step (1): processing metal M, Fe, Co and Ni to obtain a high-entropy alloy target, wherein M is one or both of Zr and B;

[0024] Step (2): selecting a high-resistivity non-magnetic material as a substrate material;

[0025] Step (3): cleaning the substrate and the high-entropy alloy target;

[0026] Step (4): using the high-entropy alloy target, using pure Ar gas and argon-nitrogen mixed gas as the sputtering atmosphere, and alternately sputtering the high-entropy alloy soft magnetic film layer and the high-entropy alloy soft magnetic nitride film layer on the surface of the substrate by using the magnetron sputtering process to obtain the high-entropy alloy and nitride multilayer soft magnetic thin film.

[0027] Further, the content of each component of the high-entropy alloy target is obtained by high-throughput screening, and the high-entropy alloy target is heat treated before magnetron sputtering.

[0028] Further, in step (4), a direct current sputtering process is adopted, the sputtering temperature is 150-250 DEG C, the sputtering power is 250-350 W, and the vacuum degree is 3.0-4.0*10 -4 Pa.

[0029] Further, when sputtering the high-entropy alloy soft magnetic film layer, pure Ar gas is introduced, and the sputtering time is 10-15 min.

[0030] Further, when sputtering the high-entropy alloy soft magnetic nitride film layer, Ar-N2 mixed gas is introduced, the ratio of the argon partial pressure in the mixed gas to the total pressure of the mixed gas is 10-40%, and the sputtering time is 5-10 min.

[0031] Further, when alternately sputtering the film layers, the buffer time for atmosphere conversion is 30-45 s.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] (1) The high-entropy alloy soft magnetic thin film is designed, which has different characteristics from conventional alloy thin films and better performance, and N doping has high resistivity and magnetic properties, so that the material magnetic moment is increased, and the saturation magnetization is increased. At the same time, due to the adjustment of the anisotropy field, the soft magnetic performance is more superior, and the high-frequency application characteristics are more superior.

[0034] (2) The double magnetic layer is more conducive to improving the performance of the thin film: the introduction of the high-resistivity magnetic phase layer increases the proportion of the overall magnetic phase in the thin film, so that the thin film has more excellent performance.

[0035] (3) Better interface matching and film layer bonding force, and the film layer is not easy to fail: in the traditional method, due to the differences in lattice structure and atomic size of different materials, lattice mismatch and different crystal morphology may occur, and the stability and bonding strength of the interface are also reduced. The film layer interface prepared by the high-entropy alloy / high-entropy alloy nitride thin film has good matching and high bonding force, which reduces the probability of processing delamination failure and application failure.

[0036] (4) Low cost, simple process control, more conducive to industrial production: no new target material is needed, and single-target-site magnetron sputtering equipment can be used for preparation, which reduces the production cost. At the same time, the introduction and concentration control of nitrogen (Ar+N2) are relatively easy, and the prepared thin film has good uniformity and excellent performance, which is suitable for industrialization. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a cross-sectional organization diagram of the thin film of the present application.

[0038] Figure 2 The hysteresis loop (VSM) figure of the thin film of the present application.

[0039] Figure 3 The EDS figure of the present application. DETAILED DESCRIPTION

[0040] The present application will be described in detail below with reference to the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplarily describe the present application, and cannot constitute any limitation on the protection scope of the present application. All reasonable transformations and combinations within the inventive concept of the present application fall within the protection scope of the present application.

[0041] High-entropy alloy is a new type of alloy material developed in recent years, which has greater mixing entropy and lattice distortion effect compared with traditional one-component and two-component alloys, can increase the scattering of metal conductive phonons, thereby greatly increasing the resistivity of the material. Soft magnetic high-entropy alloy thin film (HEATFs) exhibits better resistivity than other soft magnetic thin films, has excellent magnetic properties, high thermal stability, corrosion resistance and strong mechanical properties, and good adhesion to the substrate, and is a very promising thin film with application potential.

[0042] The high-entropy soft magnetic nitride thin film presents performance with high-frequency application characteristics (high Bs, low Hc, high anisotropy and high p). The thin film is formed by N doping control to form a plurality of different structures of nitrides, so that the performance presents the performance with high-frequency application characteristics (high saturation magnetic induction Bs, low coercivity Hc, high anisotropy and high resistivity p). In addition, the high-entropy soft magnetic nitride thin film has strong adhesion to the high-entropy soft magnetic thin film, good stability, and is less likely to fail.

[0043] In order to solve the problems of magnetic performance decline caused by the introduction of non-magnetic layer, weak hetero-layer adhesion, high cost, complex production process and the like in the prior art, the present application provides a multilayer film structure of high-entropy soft magnetic layer / high-entropy soft magnetic nitride layer and a preparation method thereof. This structure combines the characteristics of high resistivity, low coercivity of high-entropy alloy nitride soft magnetic thin film and high saturation magnetization of high-entropy alloy soft magnetic thin film. Higher saturation magnetization and resistivity than ordinary single-layer soft magnetic thin film can be obtained, and a high-performance double-magnetic-phase thin film suitable for high-frequency application can be obtained. This thin film has high resistivity characteristics, which is beneficial to high-frequency application, while maintaining high saturation magnetization Ms and low coercivity Hc and other excellent soft magnetic performance characteristics. At the same time, the structure thin film has strong adhesion, good stability, small processing difficulty, no need to add new target material to reduce cost, has the characteristics of simple preparation method and easy control, and is convenient for industrialization promotion.

[0044] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0045] The application discloses a high-entropy soft magnetic alloy and a preparation method of a high-entropy soft magnetic alloy and nitride multilayer soft magnetic film.

[0046] Target material preparation: high-entropy alloy target material is prepared by processing metals M, Fe, Co and Ni, wherein M is one or both of Zr and B; substrate preparation: a high-resistivity non-magnetic material is selected as a substrate material; target material and substrate cleaning: the substrate and the high-entropy alloy target material are cleaned; soft magnetic high-entropy / high-entropy nitride multilayer film sputtering: a magnetic control sputtering process is used to control the chamber atmosphere conditions and sputter the high-entropy / high-entropy nitride multilayer film on the substrate surface. Further, the target material preparation mode in step (1) is vacuum induction melting, nitrogen, hydrogen, oxygen and carbon dissolved in steel and alloy can be removed to a level much lower than that of normal pressure smelting under vacuum, and impurity elements (copper, zinc, lead, antimony, bismuth, tin and arsenic) with a higher vapor pressure than the base metal at the smelting temperature can also be removed by volatilization. Therefore, vacuum induction melting makes the melt cleaner and the uniformity of the structure and composition better. The composition and content of the target material are consistent with those of the prepared high-entropy soft magnetic alloy, and preferably, the content of each component element is within the preset range. More preferably, the optimal component content is determined by a high-throughput screening component design method.

[0047] Preferably, the purity of all the metal blocks used for smelting is not less than 99.99%.

[0048] Further, in step (2), the substrate material is a high-resistivity silicon wafer (resistivity > 1000 Ω.cm).

[0049] Further, in step (3), the substrate cleaning sequentially adopts acetone, deionized water and anhydrous ethanol ultrasonic cleaning for 10 minutes, and is blown dry under N2 flow; the target material is sequentially cleaned by deionized water and anhydrous ethanol, and is blown dry under N2 flow.

[0050] Further, in step (4), the working gas is 99.99% Ar gas and 99.9% N2 gas. In order to realize the structure of the multilayer film, the atmosphere conditions during sputtering of different film layers need to be controlled, so as to achieve the purpose of alternately sputtering high-entropy alloy soft magnetic / high-entropy alloy nitride soft magnetic film layers.

[0051] Preferably, the high-entropy alloy target material adopts a direct current sputtering process, the sputtering temperature is 150-250 DEG C, the sputtering power is 250-350 W, and the vacuum degree is 3.0-4.0 x 10 -4 Pa.

[0052] Preferably, when the high-entropy alloy soft magnetic film layer is sputtered, pure Ar gas is introduced into the atmosphere, and the sputtering time is 10-15 minutes.

[0053] Preferably, when the high-entropy alloy soft magnetic nitride film layer is sputtered, PN2 The argon-nitrogen mixed gas has an argon content of 60% to 90% and a nitrogen content of 10% to 40%, and the sputtering time is 5 to 10 minutes.

[0054] Preferably, when the film layers are sputtered alternately, the buffer time for atmosphere conversion is 30 to 45 seconds.

[0055] In particular, the optimal composition of the high-entropy alloy is determined by a high-throughput screening composition design method. To illustrate the alloy composition optimization process of the present application, the high-throughput screening method is further described.

[0056] (1.1) Multi-component gradient thin film sputtering: using a magnetron sputtering process, controlling the chamber atmosphere conditions, sputtering and plating on the substrate surface, depositing multiple materials on the substrate, and obtaining multiple uniform thin film samples with different material component contents after plating.

[0057] First, the content of each component element determined by the present application is pre-set in the following range:

[0058] 1) Zr: 10.5 to 14.2 at%, Fe: 21.7 to 50.5 at%, Co: 16.4 to 53.4 at%, Ni: 12.3 to 22.1 at%; or

[0059] 2) B: 7.5 to 12.1 at%, Fe: 20.3 to 54.5 at%, Co: 13.5 to 58.5 at%, Ni: 11.2 to 22.5 at%; or

[0060] 3) B: 4.6 to 8.8 at%, Zr: 2.7 to 6.5 at%, Fe: 20.3 to 54.5 at%, Co: 13.5 to 58.5 at%, Ni: 11.2 to 22.5 at%.

[0061] In this process, in order to make the component content of the thin film sample within the pre-set range, and the content of each component in each sample as uniform as possible, facilitating subsequent high-throughput screening. Due to the different atomic binding forces of each target material in the sputtering process, resulting in different atomic detachment speeds of each target material, the present application analyzes the spatial distribution rule of the atomic detachment of each target material (the concentration of target element atoms in space gradually decreases with the increase of the distance from the target material), analyzes the main influencing factors (the total number of samples, the horizontal and vertical spacing of each sample), and selects the following experimental method:

[0062] The high-purity Fe, high-purity Co, high-purity Ni and high-purity M target materials are uniformly placed in four positions in the chamber, wherein the M target material is a Zr target material, or a B target material, or a mixed Zr and B target material, the angles of the four target positions are adjusted to be 45° with the horizontal, the sample holder is placed in the middle of the four target materials, and a plurality of high-resistivity non-magnetic material substrates are placed on the sample holder.

[0063] First, a fixed sputtering time t0 and the same sample at a fixed distance d0 from the target material are selected, and the deposition thickness of each target material element on the sample surface is measured at different powers to characterize the desorption speed at different powers. Then, taking the Fe component as the reference, the reference sputtering power (250 W) of the Fe target material and the desorption speed of Fe at this power are determined, and then the corresponding power is selected for other components so that the desorption speed at the corresponding sputtering power meets:

[0064]

[0065] In the formula: is the component the desorption speed at the selected corresponding power, is the desorption speed of the Fe component at the reference sputtering power, is the component the minimum atomic percentage content in the preset range, is the component the maximum atomic percentage content in the preset range, is the minimum atomic percentage content of Fe in the preset range, is the maximum atomic percentage content of Fe in the preset range.

[0066] When M is a Zr target material or a B target material, the maximum and minimum atomic percentage contents of the M component are the maximum and minimum atomic percentage contents of Zr and B elements, respectively, and when M is a Zr / B mixed target material, the maximum atomic percentage content of the M component is the sum of the maximum atomic percentage contents of Zr and B elements, and the minimum atomic percentage content of the M component is the sum of the minimum atomic percentage contents of Zr and B elements.

[0067] Then, the placement parameters (horizontal distance, vertical distance and number) of the sample are determined. The Fe target material and the M target material are selected, and the deposition rate (the ratio of the deposition thickness to the deposition time on the substrate surface) of the sample closest to the target material and the deposition rate of the sample farthest from the target material are measured under different sample distances (horizontal distance, vertical distance) and sample numbers, and the degree of attenuation is counted. The relationship between the degree of attenuation and the sample horizontal distance, vertical distance and sample number is obtained by multiple linear regression, wherein when M is a Zr target material and a B target material, the deposition rates of Zr and B elements are counted and analyzed respectively, and when M is a Zr / B mixed target material, the total deposition rate of the two elements is counted and analyzed.

[0068] According to the obtained relationship, the corresponding sample spacing and quantity are selected to make:

[0069]

[0070]

[0071] wherein, is the maximum value of the atomic percentage ratio of the Fe component to the M component in the preset range, is the maximum value of the atomic percentage ratio of the M component to the Fe component in the preset range in the high-throughput test. Similarly, when M is a Zr target and a B target, the maximum and minimum values of the atomic percentage of the M component are the maximum and minimum values of the atomic percentage of the Zr and B elements, and when it is a Zr / B mixed target, the maximum value of the atomic percentage of the M component is the sum of the maximum values of the atomic percentages of the Zr and B elements, and the minimum value of the atomic percentage of the M component is the sum of the minimum values of the atomic percentages of the Zr and B elements. is the deposition rate of Fe atoms on the sample closest to the Fe target, is the deposition rate of Fe atoms on the sample farthest from the Fe target; is the deposition rate of M atoms on the sample closest to the M target, is the deposition rate of M atoms on the sample farthest from the M target.

[0072] The finally selected parameters are: horizontal spacing 2.5 cm, vertical spacing 1.3 cm, and quantity 60.

[0073] (1.2) Sample testing and target component design: test the obtained multiple thin film samples, screen the specific content of each constituent element of the high-entropy alloy according to the performance requirements of saturation magnetization, coercive force and resistivity, and use the specific content of each constituent element as the content of the constituent elements of the high-entropy alloy target in the foregoing step (1) to obtain the high-entropy alloy target.

[0074] After the high-entropy alloy target is prepared, the target is cut and processed and then heat treated. In terms of target cutting and processing size and heat treatment process, a response surface model is constructed for experimental design, and an optimized parameter combination is obtained according to the experimental results. The controllable variables selected include: target cutting thickness X1, with a value range of 10-20 mm; target cutting diameter X2, with a value range of 100-150 mm; heat treatment times X3, with a value range of 1-3 times; heat treatment temperature X4, with a value range of 700-1000℃; and heat treatment time X5, with a value range of 1-15 hours.

[0075] The component content deviation degree Y is selected as a response variable. Factor level coding is performed, actual experimental parameters are constructed according to the coding values of each experiment in the design, designs not meeting the actual requirements are removed, central composite experimental design is performed, multiple experiments are conducted, and the component content deviation degree Y of each experiment is measured and calculated. A second-order polynomial regression model based on the component content deviation degree and the controllable variables is established, the least square method is used to fit the coefficient estimates of the regression model, the predicted component content deviation degree Y obtained by the regression model is taken as the objective function, and the target is to minimize Y. Set the initial solution and perform iterative optimization, and when the set maximum number of iterations is reached, the current solution at this time is the optimized parameter combination. Specifically, the target material cutting diameter is 142 mm, the cutting thickness is 16 mm, a two-stage heat treatment process is adopted, wherein the first-stage heat treatment temperature is 820 ℃, the heat treatment holding time is 10 h; the second-stage heat treatment temperature is 980 ℃, and the heat treatment holding time is 1.5 h.

[0076] Example 1

[0077] (1) Target material preparation: according to the alloy components and contents of the high-entropy alloy target material, the corresponding metal powder is selected. Vacuum melting is performed, in order to ensure the uniformity of the target material components, high-entropy alloy ingots are obtained by melting four times, and high-entropy alloy target materials with a thickness of 2 mm are prepared by wire cutting.

[0078] (2) Substrate preparation: the substrate is a high-resistance Si sheet with a size of 10x10 mm and 3x3 mm.

[0079] (3) Target and substrate cleaning: the substrate is cleaned with acetone, deionized water, and anhydrous ethanol in sequence for 10 min, and is blown dry under N2 flow; the target is cleaned with deionized water and anhydrous ethanol in sequence, and is blown dry under N2 flow.

[0080] (4) Thin film sputtering: the sputtering temperature is room temperature, and the vacuum degree is 3.0-4.0x10-4 Pa. The high-entropy alloy target material is sputtered by direct current, and the sputtering power is 200 W. The specific process includes:

[0081] a. High-entropy alloy soft magnetic film layer sputtering: the working atmosphere is pure Ar gas, and the sputtering time is 10-15 min;

[0082] b. Atmosphere buffer: 30-45 s;

[0083] c. High-entropy alloy soft magnetic nitride film layer sputtering: the working atmosphere is nitrogen-argon mixed gas, the nitrogen partial pressure (the ratio of nitrogen pressure to total working gas pressure) P N2 (N2 / (Ar+N2)) is 10-40%, and the sputtering time is 5-10 min;

[0084] d. Atmosphere buffer: 30-45 s;

[0085] Repeat the ad process steps in step (4) for a total of 3 times to prepare a high-entropy soft magnetic / high-entropy soft magnetic nitride multilayer film.

[0086] Its cross-sectional structure is as follows Figure 1 As shown, it can be seen that it is a typical columnar crystal structure, and the magnetization intensity is as follows Figure 2 As shown, the N content distribution trend from the surface to the inner layer is as follows Figure 3 As shown, Figure 3 (a) is the cross section of the specimen, and the white line in (a) is Figure 3 The horizontal axis in (b) corresponds to the distribution of N element, which reaches its peak value near 0.5μm, 1.2μm and 2μm. Among the film properties, the saturation magnetization Ms is 1237.2 emu.cm -3 , the coercivity is 1.18 Oe, and the resistivity is 396.8 μΩ.cm.

[0087] Those skilled in the art will readily recognize other embodiments of the present disclosure after considering the disclosure in the specification and examples. The present invention is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims.

Claims

1. A method for fabricating high-entropy alloy and nitride multilayer soft magnetic thin films for high frequencies, characterized in that, The high-entropy alloy and nitride multilayer soft magnetic film for high frequency includes first film layers and second film layers arranged alternately, the first film layers are high-entropy alloy soft magnetic film layers, the second film layers are high-entropy alloy soft magnetic nitride film layers, the first film layers include Fe, Co, Ni, and Zr and / or B elements, and the second film layers include Fe, Co, Ni, N, and Zr and / or B elements; In the second film layer, the atomic percentage of the elements other than N is 100%, and the atomic percentage of the elements other than N is the same as that of the first film layer; in the second film layer, N is nitrogen gas with a certain partial pressure introduced in the magnetron sputtering process, and nitrogen atoms are deposited into the high-entropy alloy soft magnetic nitride film layer; The optimal composition of the high-entropy alloy is determined by a high-throughput screening composition design method, including: Multi-component gradient film sputtering: using a magnetron sputtering process, controlling the chamber atmosphere conditions, sputtering and plating on the substrate surface, depositing multiple materials on the substrate, and obtaining multiple uniform film samples with different material composition contents after plating; Firstly, the determined content range of each component element is: 1) composed of Zr, Fe, Co, and Ni elements, and the content range of each element is: Zr: 10.5~14.2at%, Fe: 21.7~50.5at%, Co: 16.4~53.4 at%, and Ni: 12.3~22.1 at%; or 2) composed of B, Fe, Co, and Ni elements, and the content range of each element is: B: 7.5~12.1at%, Fe: 20.3~54.5 at%, Co: 13.5~58.5 at%, and Ni: 11.2~22.5 at%; or 3) composed of B, Zr, Fe, Co, and Ni elements, and the content range of each element is: B: 4.6~8.8at%, Zr: 2.7~6.5at%, Fe: 20.3~54.5 at%, Co: 13.5~58.5 at%, and Ni: 11.2~22.5 at%; High-purity Fe, high-purity Co, high-purity Ni, and high-purity M target materials are used and uniformly placed in four positions of the chamber, and the M target material is a Zr target material, or a B target material, or a mixed target material of Zr and B; According to the desorption speed of each element under different sputtering powers and the content range of each component element, the sputtering power of each target material and the film sample placement parameters are determined to make the composition content of multiple film samples meet the content range of each component element; the sputtering power of each target material is selected as follows: the sputtering power of the Fe target material and the desorption speed of Fe under the power are determined, and then the corresponding power is selected for other components to make the desorption speed under the corresponding sputtering power meet: wherein: is the composition is the desorption rate at the selected corresponding power, is the desorption rate of the Fe composition at the reference sputter power, is the composition is the minimum atomic percentage content of is the composition is the maximum atomic percentage content of is the minimum atomic percentage content of Fe, is the maximum atomic percentage content of Fe; The obtained multiple film samples are tested, and the optimal composition of the high-entropy alloy target material is screened according to the required performance requirements.

2. The method of claim 1, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. The thickness of the high-entropy alloy soft magnetic film layer is 0.2~0.4μm, the thickness of the high-entropy alloy soft magnetic nitride film layer is 0.05~0.15μm, and the total thickness of the multilayer soft magnetic film is 1~3μm.

3. The method of claim 2, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. In the high-entropy alloy soft magnetic nitride film layer, nitrogen atoms form nitrides with alloy elements of the film layer, and the nitrides include alpha phase, gamma phase and epsilon phase compounds of FeN.

4. The method of claim 3, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. The method for determining the sample placement parameters comprises the following steps: selecting Fe target material and M target material, respectively, under different horizontal spacing, vertical spacing and sample quantity conditions, measuring the deposition rate of the sample closest to the target and the deposition rate of the sample farthest from the target, and statistically analyzing the attenuation degree, using multiple linear regression to obtain the relationship between the attenuation degree and the sample horizontal spacing, vertical spacing and sample quantity, wherein, when M is Zr target material and B target material, the deposition rates of Zr and B elements are respectively statistically analyzed and correspondingly analyzed, and when it is a Zr / B mixed target material, the total deposition rate of the two elements is statistically analyzed; according to the obtained relationship, the corresponding sample spacing and quantity are selected to make: wherein, is the maximum value of the atomic percentage ratio of the Fe component to the M component within the preset range, is the maximum value of the atomic percentage ratio of the M component to the Fe component within the preset range in the high flux test; is the deposition rate of Fe atoms on the sample closest to the Fe target, is the deposition rate of Fe atoms on the sample farthest from the Fe target; is the deposition rate of M atoms on the sample closest to the M target, is the deposition rate of M atoms on the sample farthest from the M target.

5. The method of claim 4, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. Specifically, the method comprises the following steps: Step (1): processing metal M, Fe, Co and Ni to obtain a high-entropy alloy target material, wherein M is one or both of Zr and B; Step (2): selecting a high-resistivity non-magnetic material as a substrate; Step (3): cleaning the substrate and the high-entropy alloy target material; Step (4): using the high-entropy alloy target material, using pure Ar gas and argon-nitrogen mixed gas as the sputtering atmosphere alternately, sputtering high-entropy alloy soft magnetic film layers and high-entropy alloy soft magnetic nitride film layers on the surface of the substrate alternately by using a magnetron sputtering process to obtain a high-entropy alloy and nitride multilayer soft magnetic thin film.

6. The method of claim 5, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. The high-entropy alloy target material is heat treated after preparation and before magnetron sputtering.

7. The method of claim 6, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. In step (4), a direct current sputtering process is used, with a sputtering temperature of 150-250°C, a sputtering power of 250-350W, and a vacuum degree of 3.0-4.0x10 -4 Pa.

8. The method of claim 7, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by the steps of: depositing a high-entropy alloy thin film on a substrate by a sputtering method; and depositing a nitride thin film on the high-entropy alloy thin film by a sputtering method. When sputtering the high-entropy alloy soft magnetic film layer, pure Ar gas is used as the atmosphere, and the sputtering time is 10-15 min.

9. The method of claim 8, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by a method comprising: depositing a high-entropy alloy thin film on a substrate by a physical vapor deposition method; and depositing a nitride thin film on the high-entropy alloy thin film by a physical vapor deposition method. When sputtering the high-entropy alloy soft magnetic nitride film layer, argon-nitrogen mixed gas is used as the atmosphere, the ratio of the argon partial pressure in the mixed gas to the total pressure of the mixed gas is 10-40%, and the sputtering time is 5-10 min.

10. The method of claim 9, wherein the high-entropy alloy and nitride multilayer soft magnetic thin film for high frequency is prepared by a method comprising: depositing a high-entropy alloy thin film on a substrate; and depositing a nitride thin film on the high-entropy alloy thin film. When sputtering the film layers alternately, the buffer time for atmosphere conversion is 30 s-45 s.

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