Nitrogen-doped high-entropy alloy film inductance material and preparation method thereof

Abstract

The invention belongs to the technical field of soft magnetic high-entropy alloy materials and magnetron sputtering, and particularly relates to a nitrogen-doped high-entropy alloy film inductance material and a preparation method thereof.The high-entropy alloy components comprise B and / or Zr, Fe, Co and Ni elements, and the nitrogen-doped high-entropy alloy film inductance material is obtained through a magnetron sputtering method. The method specifically comprises the steps that in the sputtering process of the high-entropy alloy film, nitrogen with certain partial pressure is introduced, and the nitrogen element is deposited into the high-entropy alloy film and forms nitride with a high-entropy alloy element; the high resistivity characteristic of the material is improved, magnetic performance deterioration caused by introduction of a non-magnetic phase is weakened, meanwhile, the material has excellent magnetic performance, the performance of the film is regulated and controlled by controlling nitrogen partial pressure, nitrides of various different structures are formed, the regulation and control mode is more accurate, the nitrogen doping effect is more uniform, cost is reduced, and the preparation method is suitable for industrial production. The method is suitable for large-scale industrial production.

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 nitrogen-doped high-entropy alloy thin film inductor material and a preparation method thereof. BACKGROUND

[0002] With the development of electronic devices towards high frequency, miniaturization, lightness and thinness and integration, inductor devices gradually transit to thin film inductors. The application of soft magnetic thin films in thin film inductors is conducive to increasing the unit inductance and enhancing the performance of inductors. Metal soft magnetic thin films have high saturation magnetization, high initial permeability and high cutoff frequency. However, the low resistivity of soft magnetic thin films leads to large eddy current loss at high frequency, which affects the performance of inductors. At present, the relatively low resistivity is still an important problem affecting the performance of inductors and the application of thin films in other fields.

[0003] Soft magnetic metal thin films, such as FeCo, FeNi, FeSi and FeAl soft magnetic thin films, are most suitable for compatibility with semiconductor processes. However, the resistivity of metal materials is usually low (10 -7 ~10 -6 Ω.m), and the high frequency loss is large, so it is usually necessary to add a high resistivity non-magnetic phase or to pattern the thin film to improve the overall resistivity of the thin film. However, the introduction of a non-magnetic phase or the patterning of the thin film will cause the magnetic properties of the thin film to deteriorate, such as saturation magnetization, permeability and other properties, increasing the complexity of the preparation process. In addition, the high resistivity target material required for sputtering, such as a SiO2 target, will also bring additional costs. Foreign scholar G. Suran (G. Suran, H. Ouahmane, M. Rivoire, J. Sztern; Static and dynamic magnetic properties of (CoZr) 100−x (RE) x amorphous thin films. J.Appl. Phys. 15 May 1993; 73 (10): 5721–5723.) found that the resistivity can be increased by 10 times by adding an appropriate amount of rare earth elements (RE) to the magnetic thin film. However, due to the low saturation magnetization of the material, the practical application effect is poor. CN116397193A discloses a preparation method of a high-resistivity high-cutoff-frequency soft magnetic thin film, which uses a high-resistivity SiO2 target and Fe 40 Co 40 B 20Target co-sputtering, by adjusting the sputtering power of the SiO2 target to achieve the control of the film resistivity. However, the introduction of non-magnetic phase SiO2 leads to the decrease of material saturation magnetization 4πMs (Gs) from 19235 to 12330. CN114420402A discloses a high-orientation, high-resistivity stripe-shaped thin film and a preparation method thereof. By designing the pattern of the magnetic thin film stripes, Fe x Co y B z The stripes of the magnetic thin film and the dielectric (the dielectric is one selected from solid dielectric silicon dioxide, zinc oxide, boron oxide, aluminum oxide, silicon nitride and boron nitride) stripes are alternately arranged to obtain a high-resistivity, high-orientation magnetic thin film. However, this method is difficult to prepare, the process is complex, the production cost is high, and it is not conducive to industrial large-scale production. The fragmented magnetic thin film shows a certain degree of decline in overall magnetic performance.

[0004] Therefore, although the conventional soft magnetic metal thin film has a high saturation magnetic induction intensity, it cannot be widely used in the GHz working range due to its low resistivity and the method for improving the resistivity of the thin film which will reduce the magnetic performance. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and provide a high-entropy soft magnetic target material composition and a preparation method for optimizing the performance of a magnetic thin film by nitrogen doping. The high-entropy alloy target composition has good soft magnetic properties and high resistivity characteristics, which is beneficial to reduce high-frequency eddy current loss. At the same time, a preparation method for optimizing the performance of a magnetic thin film by nitrogen doping is provided, which further enhances the resistivity of the thin film while maintaining good soft magnetic properties. The core content of the present application includes: (1) In view of the problem of low resistivity of conventional soft magnetic alloy, a high-entropy soft magnetic alloy target composition is designed. Compared with conventional soft magnetic metal thin film, the high-entropy alloy thin film shows different characteristics from traditional alloy due to the influence of entropy value regulation, and shows better performance than other metal soft magnetic thin film. By utilizing the high-entropy effect, lattice distortion effect, slow diffusion effect and cocktail effect of high-entropy alloy, the scattering of metal conduction phonon is increased, thereby greatly increasing the resistivity of the material. This method improves the high-resistivity characteristics of the material itself to a certain extent, and weakens the deterioration of the magnetic performance caused by the introduction of non-magnetic phase, and the material itself has excellent magnetic properties, which means that the material has more excellent comprehensive performance.

[0006] (2) N2 is introduced in sputtering. By controlling P N2The performance of the thin film is regulated, and the nitride formed is also a magnetic phase due to various different structures. Therefore, this method is different from the traditional method of improving the resistivity of the thin film by sacrificing part of the magnetic performance of the SiO2 / Al2O3 target and the like. This method improves the resistivity of the thin film while maintaining excellent magnetic properties. In addition, the regulation of the gas ratio is more accurate, and the nitrogen doping effect is more uniform. This method does not require additional target materials, reduces costs, and is suitable for large-scale industrial production.

[0007] The complete technical solution of the present application comprises: A nitrogen-doped high-entropy alloy thin film inductor material, the component elements of the high-entropy alloy are: 1) composed of Zr, Fe, Co, and Ni elements; or 2) composed of B, Fe, Co, and Ni elements; or 3) composed of B, Zr, Fe, Co, and Ni elements; The nitrogen-doped high-entropy alloy thin film inductor material is obtained by a magnetron sputtering method, specifically, during the sputtering process, a mixed gas of nitrogen and argon is used as the working gas, the flow rate of the working gas and the nitrogen partial pressure in the working gas are controlled to allow the nitrogen element to be deposited into the high-entropy alloy thin film and form a nitride with the high-entropy alloy elements, and the nitrogen partial pressure in the working gas is 10-40%.

[0008] Further, the nitride is a FeN compound.

[0009] Further, the FeN compound includes α-FeN, γ-FeN, and ε-FeN compounds.

[0010] Further, the content range of each component element of the high-entropy alloy is: 1) Zr: 10.5-14.2 at%, Fe: 21.7-50.5 at%, Co: 16.4-53.4 at%, and Ni: 12.3-22.1 at%; or 2) B: 7.5-12.1 at%, Fe: 20.3-54.5 at%, Co: 13.5-58.5 at%, and Ni: 11.2-22.5 at%; or 3) B: 4.6-8.8 at%, Zr: 2.7-6.5 at%, Fe: 20.3-54.5 at%, Co: 13.5-58.5 at%, and Ni: 11.2-22.5 at%.

[0011] Further, according to the content range of each component element of the high-entropy alloy, the specific content of each component element of the high-entropy alloy is determined by a high-throughput screening component design method. Further, according to the content range of each component element of the high-entropy alloy, the specific content of each component element of the high-entropy alloy is determined by a high-throughput screening component design method.

[0012] Further, in the high-throughput screening, each target material uses an independent target gun, and a magnetron sputtering is used to sputter and deposit films on the surface of the substrate to obtain multiple film samples with a component content gradient; in the magnetron sputtering process, the desorption speed of each element under different sputtering powers is obtained through experiments first, and then the sputtering power of each target material and the film sample placement parameters are determined according to the desorption speed of each element under different sputtering powers and the content range of each component element of the high-entropy alloy, so that the component content of the film sample is within the content range of each component element of the high-entropy alloy; subsequently, the multiple film samples obtained are tested, and the specific content of each component element of the high-entropy alloy is screened according to the required performance requirements.

[0013] Further, in the magnetron sputtering process of the high-entropy alloy film, an M, Fe, Co and Ni alloy target material is used, the M is one or both of Zr and B, and the component content of the alloy target material is the specific content of each component element of the high-entropy alloy obtained through the high-throughput screening.

[0014] Further, the alloy target material is subjected to heat treatment before the magnetron sputtering.

[0015] Further, the gas flow rate is 50-80 sccm.

[0016] Further, the vacuum degree of the magnetron sputtering is 3.0-4.0×10 -4 Pa, the sputtering time is 15-20 min, the alloy target material uses direct current sputtering, and the sputtering power is 200-350 W.

[0017] Further, the saturation magnetization of the nitrogen-doped high-entropy alloy film inductive material is 981.6-1688.4 emu / cm 3 , the coercive force is 26.8-63.5 Oe, and the resistivity is 83.9-135.1 mu Omega.cm.

[0018] Further, the preparation method of the nitrogen-doped high-entropy alloy film inductive material comprises the following steps: Step (1): processing a metal M, Fe, Co and Ni to obtain an alloy target material, the M is one or both of Zr and B; Step (2): selecting a high-resistivity non-magnetic material as a substrate material, and cleaning the alloy target material and the substrate; Step (3): using a magnetron sputtering process, a mixed gas of nitrogen and argon as working gas, controlling the flow rate of the working gas and the nitrogen partial pressure, and sputtering a nitrogen-doped high-entropy alloy soft magnetic film on the surface of the substrate.

[0019] Compared with the prior art, the beneficial effects of the present application are: (1) The composition elements of the high-entropy alloy soft magnetic film are designed, and the high-entropy alloy soft magnetic film is a new type of alloy film compared with a conventional soft magnetic metal film. Influenced by the entropy value regulation, the high-entropy alloy film presents different characteristics from traditional alloys, and shows better performance than other metal soft magnetic films. It is very meaningful and has application prospect to study the high-entropy alloy film. On the basis of the existing high-entropy alloy Fe, Co and Ni composition elements, Zr and / or B elements are added according to the performance requirements of the inductor material, which is beneficial to form an amorphous structure. At the same time, N element is introduced in the magnetron sputtering process, and nitrogen doping has high resistivity and magnetic performance. Different from the conventional method of increasing resistivity, the introduction of N atoms in the application not only increases the magnetic moment of the material and the saturation magnetization. At the same time, the anisotropy field is also adjusted, so that the soft magnetic performance is more superior, and the high-frequency application characteristics are more superior.

[0020] (3) High controllability of organization and performance: when the film is deposited in Ar+N2 atmosphere, nitrogen atoms occupy the interstitial position, resulting in the generation of FeN alpha, gamma and epsilon phase compounds, and the soft magnetic performance of the film is regulated by controlling the gas partial pressure and flow rate.

[0021] (4) High control precision and simple process, which is more conducive to industrial production. The traditional method of increasing resistivity by co-sputtering high-resistivity materials such as SiO2 needs to add SiO2 target, and the distribution uniformity of SiO2 after sputtering is relatively poor, and the equipment and process requirements are high. At the same time, the introduction of non-magnetic phase will have a negative impact on the performance of the film. The introduction of nitrogen and the control of partial pressure (adjusting the ratio of Ar / N2) are relatively easy, and the uniformity of the film is good, the performance of the film is excellent, and it is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the surface organization chart of the nitrogen-doped high-entropy alloy film inductor material prepared by the application.

[0023] Figure 2 It is the magnetic hysteresis loop (VSM) chart of the nitrogen-doped high-entropy alloy film inductor material under different nitrogen partial pressures.

[0024] Figure 3 It is the XRD chart of the nitrogen-doped high-entropy alloy film inductor material under different nitrogen partial pressures.

[0025] Figure 4 It is the cross-sectional organization chart of the nitrogen-doped high-entropy alloy film inductor material. DETAILED DESCRIPTION

[0026] 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 to the protection scope of the present application. All reasonable variations and combinations within the scope of the inventive concept of the present application fall within the protection scope of the present application.

[0027] In order to obtain a high-performance soft magnetic high-entropy alloy to obtain a high-quality soft magnetic thin film, the present application first designs the component types of the high-entropy alloy. The elements selected for the high-entropy alloy components are B and / or Zr, Fe, Co, and Ni atoms. Fe, Co, and Ni atoms tend to form simple cubic and body-centered cubic, and are base elements. Fe has the characteristics of high magnetic moment and high Curie temperature, and has low magnetic crystal anisotropy. Co has a moderate magnetic moment, and FeCo alloy has a higher saturation magnetization than pure Fe and pure Co, and has a high Curie temperature, but FeCo alloy has a positive magnetostriction coefficient λs, which will cause a large coercivity. The magnetic moment of Ni is the lowest, and the saturation magnetic induction of pure Ni is very low, and has a negative magnetostriction coefficient. Adding Ni can neutralize the magnetostriction coefficient of FeCo alloy, and can have high magnetic permeability and lower coercivity. The mixing enthalpy between Zr and Fe, Co, and Ni elements is very low, and due to the "large atomic size effect", it causes serious lattice distortion, destroys the long-range ordered arrangement of atoms, and the atomic mobility is low, which inhibits the formation and growth of crystal nucleus and surface diffusion. Zr-Fe / Co / Ni forms a short-range ordered cluster (similar to a topologically dense packing phase) with high mixing enthalpy, which becomes the core skeleton of the amorphous structure, enhances the scattering effect of free electrons, and thus enhances the resistivity of the thin film and optimizes the soft magnetic properties. B as a metalloid forms a strong covalent bond with Fe / Co / Ni (such as Fe-B), breaks the continuity of the metal bond, forces the atomic arrangement to be disordered, and is segregated at the potential grain boundary position, pinning the grain boundary migration, so that the grain size tends to be nanoscale or even completely amorphous. At the same time, B significantly reduces the melting point of the alloy, so that the sputtering particles are more easily maintained in an amorphous state in a low-temperature environment of the substrate.

[0028] In the application, the high-entropy alloy is composed of Zr, Fe, Co and Ni, and the content ranges of the elements are as follows: Zr: 10.5-14.2 at%, Fe: 21.7-50.5 at%, Co: 16.4-53.4 at%, and Ni: 12.3-22.1 at%; the high-entropy alloy is composed of B, Fe, Co and Ni, and the content ranges of the elements are as follows: B: 7.5-12.1 at%, Fe: 20.3-54.5 at%, Co: 13.5-58.5 at%, and Ni: 11.2-22.5 at%; and the high-entropy alloy is composed of B, Zr, Fe, Co and Ni, and the content ranges of the elements are as follows: B: 4.6-8.8 at%, Zr: 2.7-6.5 at%, Fe: 20.3-54.5 at%, Co: 13.5-58.5 at%, and Ni: 11.2-22.5 at%.

[0029] In the application, the optimal component content of the high-entropy alloy is determined by a high-throughput screening component design method. To illustrate the alloy component optimization process of the application, the high-throughput screening method is further described.

[0030] (1) First, multi-component content gradient thin film sputtering is performed: by using a magnetron sputtering process, the chamber atmosphere conditions are controlled, the surface of the substrate is sputtered and plated, a plurality of materials are deposited on the substrate, and a plurality of uniform thin film samples with different material component contents are obtained after plating.

[0031] In order to ensure that the surface thin film components in the samples are within the preset range, and the component content of each component in each sample is as uniform as possible, facilitating subsequent high-throughput screening. According to the different atomic detachment speeds of each target material caused by the different atomic binding forces of each target material in the sputtering process, the spatial distribution law of the atomic detachment of each target material is analyzed (the concentration of target element atoms in space gradually decreases with the increase of the distance from the target material), the influencing factors (the total number of samples, the horizontal and vertical spacing of each sample) are analyzed, and the following experimental method is selected: High-purity Fe, high-purity Co, high-purity Ni and high-purity M target materials are used, and 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 target material of Zr and B, a sample holder is placed in the middle of the four target materials, the sample holder includes a plurality of platforms with different heights, and a plurality of high-resistivity non-magnetic material substrates are placed on each platform.

[0032] First, select a fixed sputtering time t0, and the same sample at a fixed distance d0 from the target material, by measuring the deposition thickness of each target element on the sample surface at different powers to characterize the desorption speed at different powers. Then, taking the Fe component as the reference, determine the sputtering power of the Fe target (250 W) and the desorption speed of Fe at this power, and then select the corresponding power for other components so that the desorption speed at the corresponding sputtering power meets:

[0033] 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 of is the component the maximum atomic percentage content of is the minimum atomic percentage content of Fe, is the maximum atomic percentage content of Fe. When M is a Zr target or a B target, the maximum and minimum atomic percentage content of the M component are the maximum and minimum atomic percentage content of Zr and B elements, respectively. When M is a Zr / B mixed target, the maximum atomic percentage content of the M component is the sum of the maximum atomic percentage content of Zr and B elements, and the minimum atomic percentage content of the M component is the sum of the minimum atomic percentage content of Zr and B elements.

[0034] Then determine the placement parameters of the samples (horizontal spacing, vertical spacing, and number). Select the Fe target and the M target, and measure their deposition rates at the nearest sample and the farthest sample at different sample spacings (horizontal spacing, vertical spacing) and sample numbers, and calculate their attenuation degrees. Use multiple linear regression to obtain the relationship between the attenuation degree and the sample horizontal spacing, vertical spacing, and sample number. When M is a Zr target and a B target, respectively, calculate the deposition speed of Zr and B elements and perform corresponding analysis, and when M is a Zr / B mixed target, calculate the sum of the deposition speeds of the two elements and perform analysis.

[0035] According to the obtained relationship, select the corresponding sample spacing and number so that:

[0036]

[0037] In the formula, is the maximum value of the content ratio of the Fe component to the M component in high-throughput testing, is the maximum value of the content ratio of the M component to the Fe component in high-throughput testing. The deposition rate of Fe atoms on the sample closest to the Fe target. The deposition rate of Fe atoms on the sample furthest from the Fe target; The deposition rate of M atoms on the sample closest to the M target. The deposition rate of M atoms on the sample furthest from the M target is denoted as M.

[0038] Similarly, calculation and When M is a Zr target and a B target, the maximum and minimum atomic percentages of component M are the maximum and minimum atomic percentages of Zr and B, respectively. When it is a Zr / B mixed target, the maximum atomic percentage of component M is the sum of the maximum atomic percentages of Zr and B, and the minimum atomic percentage of component M is the sum of the minimum atomic percentages of Zr and B.

[0039] The final selected parameters are: horizontal spacing 2.5cm, vertical spacing 1.3cm, and quantity 60.

[0040] (2) Subsequently, sample testing and target material composition design were carried out: multiple thin film samples were tested, and the specific composition content of high-entropy alloy target material was selected based on the performance requirements such as saturation magnetization, coercivity, and resistivity.

[0041] Furthermore, to address the problem of rapid deterioration of magnetic properties caused by non-magnetic dopants increasing thin film resistivity, this invention provides a method for controlling thin film properties through nitrogen doping, resulting in thin films exhibiting properties more suited for high-frequency applications (high saturation magnetic induction Bs, low coercivity Hc, high anisotropy, and high resistivity ρ). This method differs from conventional processing methods; the key lies in the introduction of nitrogen gas during sputtering, which forms various nitride structures in the thin film. These nitrides are also magnetic phases. For example, α-Fe... 16 N2 material has the highest known efficiency of 2320 emu / cm². 3 Its saturation magnetization is higher than that of ordinary FeCo alloys, and it is called a giant magnetization material; ε-Fe3N material has good mechanical, corrosion resistance and soft magnetic properties, and its saturation magnetization can reach 1100 emu / cm. 3 γ-Fe4N has the second highest saturation magnetization among FeN materials, second only to α-Fe. 16 N2, up to 1440 emu / cm 3 Nitrogen compounds possess high Curie temperature, high hardness, wear resistance, and corrosion resistance, as well as excellent thermal stability and low coercivity. Therefore, through nitrogen doping, the soft magnetic properties of materials can be improved by controlling the nitride phase, while also achieving high resistivity, reducing eddy current losses, and increasing the resonant frequency.

[0042] Therefore, the application provides a high-entropy soft magnetic thin film inductor material and a preparation method thereof. By introducing nitrogen gas with a suitable partial pressure during sputtering of the high-entropy thin film, the phase of the high-entropy soft magnetic thin film is controlled, and a soft magnetic thin film with excellent comprehensive performance is obtained. The thin film has high resistivity, which is beneficial to high-frequency application, while maintaining excellent soft magnetic performance characteristics such as high saturation magnetization Ms and low coercivity Hc. The preparation method is simple, easy to control, and convenient for industrialization and popularization.

[0043] In order to achieve the above-mentioned purpose, the application adopts the following technical solutions: The application designs a nitrogen-doped optimized high-entropy alloy thin film inductor material and a preparation method thereof. The preparation steps of the application include: (1) Target material preparation: process metals M, Fe, Co and Ni to obtain an alloy target material, M is one or both of Zr and B. The target material is prepared by vacuum induction melting, the target material composition is the optimal composition obtained by the aforementioned high-throughput screening, and the purity of all metal blocks for melting is not less than 99.99%; melting under vacuum can more easily remove nitrogen, hydrogen, oxygen and carbon dissolved in steel and alloy to a level much lower than that of normal pressure melting, and impurity elements (copper, zinc, lead, antimony, bismuth, tin and arsenic, etc.) with higher vapor pressure than the base metal at the melting temperature can also be removed by volatilization. Therefore, vacuum induction melting makes the melt cleaner and the organization and composition more uniform. After the target material preparation is completed, the target material is cut and processed for heat treatment.

[0044] (2) Substrate preparation: a high-resistivity non-magnetic material is selected as the substrate material; preferably, the substrate material is a high-resistivity silicon wafer (resistivity > 1000 Ω.cm).

[0045] (3) Target and substrate cleaning: the substrate is cleaned with acetone, deionized water and anhydrous ethanol in sequence for 10 min, and then dried under N2 flow; the target is cleaned with deionized water and anhydrous ethanol in sequence, and then dried under N2 flow.

[0046] (4) Thin film sputtering: a nitrogen-doped high-entropy alloy soft magnetic thin film is sputtered on the surface of the substrate by using a magnetron sputtering process and controlling the chamber atmosphere conditions; the sputtering temperature is room temperature, the working gas is a mixture of nitrogen and argon gas, and the working gas is 99.99% argon and 99.9% nitrogen. The nitrogen partial pressure (nitrogen pressure to total working gas pressure) P N2 (N2 / (Ar+N2)) is 10-40%, the gas flow rate is 50-80 sccm; the magnetron sputtering vacuum degree is 3.0-4.0 x 10 -4 Pa, and the sputtering time is 15-20 min; the high-entropy alloy target material is sputtered by direct current, and the sputtering power is 200 W-350 W.

[0047] The surface morphology of the obtained nitrogen-doped high-entropy alloy thin film inductor material is as follows: Figure 1 As shown, the magnetization intensity is as follows Figure 2 As shown, under an applied magnetic field strength, the magnetization of the thin-film inductor material exhibits different variations with varying nitrogen partial pressures in nitrogen-doped high-entropy thin-film materials. Figure 3 The image shows the XRD pattern of a nitrogen-doped high-entropy thin film material. The vertical axis represents the diffraction intensity (au), and the horizontal axis represents the angle θ (Theta) between the X-rays and the sample surface. It can be seen that different nitride phases are exhibited under different nitrogen partial pressures. The cross-sectional morphology is as follows: Figure 4 As shown in the figure, it exhibits a distinct columnar crystalline structure. The properties of the nitrogen-doped high-entropy alloy thin-film inductor are shown in Table 1.

[0048] Table 1. Properties of nitrogen-doped high-entropy alloy thin film inductors

[0049] Example 1 (1) Target preparation: Metal powders of Zr, Fe, Co and Ni were selected according to the alloy composition content of the high-entropy alloy target. Vacuum melting was carried out. In order to ensure the uniformity of the target composition, the high-entropy alloy ingot was obtained by melting four times. After cutting, it was subjected to a two-stage heat treatment to homogenize it. Then, wire cutting was used to prepare a high-entropy alloy target with a thickness of 2 mm for sputtering.

[0050] (2) Substrate preparation: The substrate is a 10×10mm and a 3×3mm high-resistivity Si wafer.

[0051] (3) Cleaning of target and substrate: The substrate was cleaned by ultrasonic cleaning with acetone, deionized water and anhydrous ethanol for 10 min in sequence, and then dried under N2 airflow; the target was cleaned by deionized water and anhydrous ethanol in sequence, and then dried under N2 airflow.

[0052] (4) Thin film sputtering: The sputtering temperature is room temperature, and the working gas is P. N2 (N2 / (Ar+N2)) is a nitrogen-argon mixture of 10-40%, and the working gas is 99.99% argon and 99.9% nitrogen. The vacuum level is 3.0-4.0 × 10⁻⁶. -3 Pa, sputtering time is 15~20min; high-entropy alloy target material is sputtered by DC with a sputtering power of 200W.

[0053] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments as described herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A nitrogen-doped high-entropy alloy thin-film inductor material, characterized in that, The high-entropy alloy components are: 1) Composed of Zr, Fe, Co, and Ni elements; or 2) Composed of elements B, Fe, Co, and Ni; or 3) Composed of the elements B, Zr, Fe, Co, and Ni; The nitrogen-doped high-entropy alloy thin film inductor material is obtained by magnetron sputtering. Specifically, during the sputtering process, a mixture of nitrogen and argon is used as the working gas. By controlling the flow rate and nitrogen partial pressure in the working gas, nitrogen is deposited into the high-entropy alloy thin film and forms nitrides with the high-entropy alloy elements. The nitrogen partial pressure in the working gas is 10~40%.

2. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 1, characterized in that, The nitride is a FeN compound.

3. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 2, characterized in that, The FeN compounds include α-FeN, γ-FeN, and ε-FeN compounds.

4. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 3, characterized in that, The content range of each component element in the high-entropy alloy is as follows: 1) Zr: 10.5~14.2at%, Fe: 21.7~50.5at%, Co: 16.4~53.4at%, Ni: 12.3~22.1at%; or 2) B: 7.5~12.1at%, Fe: 20.3~54.5at%, Co: 13.5~58.5at%, Ni: 11.2~22.5at%; or 3) B: 4.6~8.8at%, Zr: 2.7~6.5at%, Fe: 20.3~54.5at%, Co: 13.5~58.5at%, Ni: 11.2~22.5at%.

5. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 4, characterized in that, Based on the content range of each component element in the high-entropy alloy, the specific content of the high-entropy alloy is determined by a high-throughput screening component design method.

6. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 5, characterized in that, In the high-entropy alloy thin film magnetron sputtering process, an M, Fe, Co, Ni alloy target is used, wherein M is one or both of Zr and B, and the content of each component of the alloy target is determined by a high-throughput screening component design method.

7. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 6, characterized in that, The alloy target is heat-treated before magnetron sputtering.

8. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 7, characterized in that, The working gas flow rate is 50~80 sccm.

9. The nitrogen-doped high-entropy alloy thin-film inductor material according to claim 8, characterized in that, The saturation magnetization of the nitrogen-doped high-entropy alloy thin-film inductor material is 981.6~1688.4 emu / cm. 3 The coercivity is 26.8~63.5 Oe, and the resistivity is 83.9~135.1 Ω·cm.

10. The method for preparing nitrogen-doped high-entropy alloy thin-film inductor material according to any one of claims 1-9, characterized in that, Includes the following steps: Step (1): The metals M, Fe, Co and Ni are processed to obtain an alloy target material, wherein M is one or two of Zr and B; Step (2): Select a non-magnetic material with high resistivity as the substrate material, and clean the alloy target and the substrate; Step (3): Using magnetron sputtering, the working gas is a mixture of nitrogen and argon. The flow rate of the working gas and the partial pressure of nitrogen are controlled to sputter nitrogen-doped high-entropy alloy soft magnetic thin film on the substrate surface to obtain nitrogen-doped high-entropy alloy thin film inductor material.

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