High-frequency magnetic foils, methods for their manufacture and their use

Abstract

A multi-layered magnetic film, comprising: a substrate; a first magnetic layer arranged on the substrate, wherein the first magnetic layer is Fe (50-80) N (10-20 )B (1-20) M (0-10) includes, where M is Si, Ta, Zr, Ti, Co or a combination thereof; and a second magnetic layer arranged on top of the first magnetic layer, where the second magnetic layer is Fe (50-90) N (10-50) or Fe (60-90) N (1-10 )Ta (5-30) includes; the multilayer magnetic foil exhibits a frequency range of 1 to 5 GHz, a magnetic permeability of greater than or equal to 1800, preferably greater than or equal to 2000, particularly preferably greater than or equal to 3000 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz; a magnetic loss tangent of less than or equal to 0.3, preferably less than or equal to 0.1, over a selected frequency band in the frequency range, preferably over a frequency band from 1 to 10 GHz; and a cutoff frequency greater than or equal to 1 GHz, or greater than or equal to 2 GHz, preferably greater than or equal to 5 GHz.

Description

BACKGROUND CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] This application makes use of the benefits of the preliminary US patent application Serial No. 62 / 767,553 filed on November 15, 2018.

[0002] This disclosure relates generally to high-frequency magnetic foils, methods for their manufacture and their use, e.g. in integrated circuits, power supply systems, antennas and the like.

[0003] Recent designs and manufacturing techniques have led to increasingly smaller dimensions and higher frequencies for electronic components. One approach to reducing the size of electronic components is the use of magnetic materials. In particular, ferrites, ferroelectrics, and multiferroics have been extensively studied as functional materials with improved microwave properties. While the high permeability of magnetic materials increases the DC value of the inductance, extending this magnetic permeability and the corresponding increase in inductance to the high frequencies (e.g., 1 to 5 gigahertz (GHz)) desired for various mobile applications remains a challenge. The magnetic permeability at these frequencies is significantly degraded by the Snoek limit of the materials.At the intrinsic ferromagnetic resonance (FMR) frequency of magnetic materials (typically 1-2 GHz for large, planar films), the relative magnetic permeability drops to one and the magnetic loss tangent reaches a peak value, such that the increase in inductance due to the material is negligible and the losses are dominant. It is possible to improve the frequency response of the magnetic permeability through various methods of defining and structuring the materials, but there remains a need in the prior art for materials and methods that can offer high magnetic permeability and high resonance frequency over high bandwidths. EP 0 60 571 A2 relates to a soft magnetic multilayer unit for a magnetic head or core material of a magnetic recording and playback device, such as a videocassette recorder (VCR).US 2007 / 0183923A1 discusses a magnetic thin film, and Ohnuma et al. have written an article on the magnetic properties of FeN / FeBN in the article "Soft magnetic properties of FeN / FeBN Multilayers", IEEE Translation Journal on magnetics in Japan, Vol. 7, No. 11, Nov. 1992, page 897 ff. SHORT DESCRIPTION

[0004] This document discloses a multilayer magnetic foil (or film) and a method for producing it.

[0005] In one embodiment, a multilayer film comprises a substrate; a first magnetic layer arranged on the substrate; and a second magnetic layer arranged on top of the first magnetic layer. The first magnetic layer contains Fe (50-80) N (10-20) B (1-20) M (0-10) , where M is Si, Ta, Zr, Ti, Co or a combination thereof. The second magnetic layer comprises Fe (50-90 )N (10-50) or Fe (60-90) N(1-10) Ta (5-30) The multilayer magnetic film (or magnetic foil) has, over a frequency range according to the invention of 1 to 5 GHz, a magnetic permeability of greater than or equal to 1800, preferably greater than or equal to 2000, particularly preferably greater than or equal to 3000 to 5000 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz; a magnetic loss tangent of less than or equal to 0.3, preferably less than or equal to 0.1, more preferably 0.01 to 0.1 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz; and a cutoff frequency of greater than or equal to 1 GHz, or greater than or equal to 2 GHz, preferably greater than or equal to 5 GHz, or 1 to 8 GHz.

[0006] In one embodiment, a method for forming the multilayer film comprises depositing the first magnetic layer on one side of the substrate; and depositing the second magnetic layer on a side of the first magnetic layer opposite the substrate.

[0007] Articles containing multilayer magnetic foils are described further below. The article is preferably a filter, transformer, inductor, antenna, electronic integrated circuit chip, or electromagnetic shielding device.

[0008] The above and other features and advantages are readily apparent from the following detailed description, examples, and claims when viewed in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Referring to the exemplary, non-restrictive figures in which identical elements are numbered the same: Fig. Figure 1 is a cross-sectional view of an embodiment of a multilayer magnetic foil; Fig. Figure 2 is a cross-sectional view of another embodiment of a multilayer magnetic foil; Fig. Figure 3 is a diagram showing the high-frequency characteristics of comparable Co- and Fe-based thin and multi-films, measured at room temperature; Fig. 4 is a surface profile of an FeN film using profilometry and atomic force microscopy (AFM); Fig. Figure 5 shows the magnetic hysteresis of FeN films along easily and difficult-to-magnetize directions in a plane of the film; Fig. Figure 6 is a magnetic permeability spectrum of an FeN film with a thickness of 60 nanometers (nm); Fig.7 is a surface profile of an FeN film using profilometry and AFM; Fig. 8 is a magnetic permeability spectrum of an Fe 66 N 18 B 16 -Films with a thickness of 50 nm; Fig. Figure 9 shows the relationship between effective resistance and magnetic permeability of an iron. 83-x N 17 B x -layer with varying boron content; Fig. 10 shows magnetic spectra of Fe 74 N 26 / Fe 66 N 18 B 16 -Double-layer films of varying thicknesses of FeNB; Fig. Figure 11 shows the magnetic permeability for Fe 74 N 26 / Fe 72 N 18 B 10 -Double layer films with different thicknesses of Fe 72 N 18 B 10 ; Fig. Figure 12 shows the relationship between the effective resistance and the magnetic permeability of an Fes2N 18 / Fe72 N 18 B 10 / Glass films with different thicknesses of an FeNB layer; Fig. 13 is a magnetic hysteresis of a FeTaN film with a thickness of 80 nm along the x and y directions in a plane of the film; Fig. Figure 14 is a magnetic permeability spectrum of an 80 nm thick Fe 74 Ta6N 20 -Films on a glass substrate; Fig. 15 shows magnetic spectra for Fe 74 Ta6N 20 / Fe 66 N 18 B 16 - Double layers; Fig. Figure 16 shows the relationship between effective resistance and magnetic permeability of an Fe 83 Ta6N 11 / Fe 72 N 18 B 10 / Glass layer with varying thicknesses of an FeNB layer; Fig. 17 shows magnetic spectra for Fe 74 Ta e N 20 / Fe 72 N 18 B 10 -Double-layer films; Fig. Figure 18 shows the relationship between the effective resistance and the total thickness of the three-layer films made of Fe. 72 N 18 B 10 / Fe 82 N 18 / Fe 72 N 18 B 10 ; Fig. 19 shows magnetic spectra of Fe 72 N 18 B 10 / Fe 82 N 18 / Fe 72 N 18 B 10 -Three-layer films; Fig. Figure 20 shows the relationship between the effective resistance and the total thickness of the three-layer layer of an Fe 72 N 18 B 10 / Fe 83 Ta6N 11 / Fe 72 N 18 B 10 -Three-layer structure; Fig. 21 shows magnetic spectra of an Fe 72 N 18 B 10 / Fe 72 Ta 18 N 10 / Fe 72 N 18 B 10 -Three-layer structure; Fig. 22 shows magnetic spectra for Fe82 N 18 / Ta 88 N 12 -Double-layer films; Fig. 23 shows magnetic spectra for Fe 72 N 18 B 10 / Ta 88 N 12 -Double-layer films; Fig. 24 shows magnetic spectra for Fe 83 Ta6N 11 / Ta 88 N 12 -Double-layer films; Fig. Figure 25 shows the magnetic permeability at 0.5 GHz for a single-layer, double-layer and triple-layer FeN-based film; Fig. Figure 26 is a Snoek product diagram at 0.5 GHz for a single-layer, double-layer and triple-layer FeN-based multilayer structure; Fig. Figure 27 shows the magnetic permeability at 0.5 GHz for a single-layer, double-layer, and triple-layer FeTaN-based multilayer structure; and Fig. Figure 28 is a Snoek product diagram at 0.5 GHz for a single-layer, double-layer and triple-layer FeTaN-based multilayer structure. DETAILED DESCRIPTION

[0010] The inventors have developed multilayer magnetic films with a combination of high magnetic permeability, low loss, and excellent inductance over a wide frequency range. These thin magnetic films, integrated with complementary metal-oxide semiconductors (CMOS), enable high-quality, high-density, flat inductive components on the chip / in the package.

[0011] The multilayer films are arranged on a substrate and comprise a first magnetic layer, the first magnetic layer being Fe (50-80 )N (10-20) B (1-20) M (0-10) comprising, wherein M is Si, Ta, Zr, Ti, Co, Nb or a combination thereof (hereafter referred to as FeNB); and a second magnetic layer, wherein the second magnetic layer is Fe (50-90) N (10-50) (hereinafter referred to as FeN) or Fe (60-90) N (1-10) Ta (5-30) (hereinafter referred to as FeNTa). The multilayer magnetic films can operate over a frequency range from 50 MHz to 10 GHz and can have a magnetic constant (also known as magnetic permeability) of greater than or equal to 1800 and a magnetic loss tangent of less than or equal to 0.3, measured over a selected frequency band.

[0012] An illustration of a cross-sectional view of a multilayer magnetic foil 10 is shown in Fig.Figure 1 shows the substrate 12 having a first side, i.e., a first planar surface, and a second side, i.e., an opposing second planar surface. The substrate 12 can be made of any suitable material, such as a glass, an organic polymer, or a ceramic. In one aspect, the substrate is a ceramic, such as at least one of MgO, SiC, Si3N4, aluminum oxide, silicon dioxide, or the like. The substrate can be amorphous, monocrystalline, or polycrystalline. The substrate 12 can have any suitable thickness, depending on its support properties and the intended application. For example, the substrate can have a thickness ranging from 100 micrometers to 1 millimeter.

[0013] The first magnetic layer 14 is arranged on the first side of the first planar surface. As stated above, the first magnetic layer comprises Fe (50-80) N (10-20) B (1-20) M (0-10), where M is Si, Ta, Zr, Ti, Co, Nb or a combination thereof. In a preferred aspect, the first magnetic layer comprises Fe (50-80) N (10-20) B (1-20) , where the amount of M is 0. The first magnetic layer can have a thickness of 10 to 100 nanometers, for example 10 to 50 nanometers or 20 to 80 nanometers.

[0014] A second magnetic layer 16 is arranged on a side of the first magnetic layer opposite the substrate. The second magnetic layer comprises Fe (50-90) N (10-50) or Fe (60-90) N (1-10) Ta (5-30) The second magnetic layer can have a thickness of 10 to 400 nanometers, e.g. 10 to 300 nanometers or 50 to 400 nanometers.

[0015] The multi-layered magnetic foil can contain additional layers, in particular additional alternating first and second layers. As in Fig. 2 shown, is an additional first magnetic layer 16, which is Fe(50-80) N (10-20 )B (1-20 ) comprises, arranged on the second magnetic layer 14. An additional second magnetic layer 18, consisting of Fe (50-90) N (10-50) or Fe (60-90) N (1-10) Ta (5-30) , is arranged on the additional first magnetic layer 16. Further additional first and second magnetic layers can be arranged alternately on the additional second magnetic layer (not shown).

[0016] The first magnetic layer 14 and the second magnetic layer 16 can have a combined thickness of 20 to 500 nanometers. In one embodiment, the first magnetic layer 14 has a thickness of 10 to 200 nm, and the second magnetic layer can have a thickness of 10 to 400 nm. In a particularly advantageous embodiment, the thickness of each of the magnetic layers, the ratio of the thicknesses, or both can be adjusted to obtain a desired magnetic loss tangent of the magnetic multilayer film, a desired magnetic anisotropy of the magnetic multilayer film, or both.

[0017] One method for producing the multilayer magnetic film involves depositing the first magnetic layer on one side of the substrate; and depositing the second magnetic layer on the opposite side of the first magnetic layer. Deposition of the alternating layers is continued until the entire film is produced. Deposition can be carried out by RF / DC sputtering, electron beam deposition, or a combination thereof.

[0018] According to the invention, the magnetic multilayer films are used over a frequency range of 1 to 5 GHz.

[0019] The multilayer magnetic films can have a magnetic permeability of greater than or equal to 1800, preferably greater than or equal to 2000, particularly preferably greater than or equal to 3000, or 1800 to 5000 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz. As used herein, this terminology refers to the multilayer magnetic films having at least one instance of magnetic permeability that is greater than or equal to 1800 over the frequency band of 1 to 5 GHz or 1 to 10 GHz.

[0020] The multilayer magnetic films can have a magnetic loss tangent of less than or equal to 0.3, or less than 0.3, preferably less than or equal to 0.1, or less than 0.1, or 0.01 to 0.3 over a selected frequency band in the frequency domain, preferably over a frequency band of 1 to 10 GHz. As used herein, this terminology refers to the multilayer magnetic films that have at least one instance of the magnetic loss tangent that is less than or equal to 0.3 over the frequency band of 1 to 5 GHz or 1 to 10 GHz.

[0021] The multilayer magnetic foils can have a cutoff frequency of greater than or equal to 1 GHz or greater than or equal to 2 GHz, preferably greater than or equal to 5 GHz, or 1 to 8 GHz.

[0022] The multilayer magnetic sheets can contain additional layers, such as a top layer. The top layer can contain Al₂O₃. The top layer can include an insulating cap.

[0023] Multilayer magnetic sheets can be used in electronic devices such as filters or inductors on integrated circuit chips for a wide variety of applications, including electrical power applications, data storage, and microwave communication. These sheets can be used in low-frequency applications, such as 50 MHz to 1 GHz, or in high-frequency applications, such as 1 to 10 GHz. Multilayer magnetic sheets can be used in antennas and in electronic devices such as mobile internet devices, mobile phones, tablets, desktop computers, laptops, notebooks, and the like. In one aspect, the device is a portable electronic device. Multilayer magnetic sheets can also be used in power supply systems and antennas.The multi-layered magnetic sheets can be advantageously used in integrated electronic devices.

[0024] The following examples serve to illustrate the present disclosure. These examples are for illustrative purposes only and are not intended to limit the devices manufactured according to the disclosure to the materials, conditions, or process parameters specified therein. EXAMPLES

[0025] Fig. Figure 3 is a diagram showing the initial magnetic permeability versus the resonance frequency / gigahertz (GHz) of various reference foils, reproduced from Chin. Phys. B Vol. 24, No. 5 (2015) 05750.

[0026] Example 1: FeN / FeNB / glass double layer film structure Parameters for RF magnetron sputtering: RF power = 80 to 120 watts (W) Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Argon; Reactive gas: Nitrogen Goal: Iron (99.9%), 2-inch disc (5.08 cm); 2 pieces of boron (99.9%) chip measuring 2.5x2.5 square millimeters (mm) 2 Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass Single-layer FeN film on glass substrate (reference example)

[0027] With reference to Fig. 4-6 had an FeN film, a composition of Fe 74 N 26and a thickness of 60 nanometers (nm) on a glass substrate, measured by energy-dispersive X-ray spectroscopy (EDXS) and profilometry, respectively. In the figures, the abbreviation Gl stands for glass. The 60 nm thick FeN film exhibited a fine grain size of 11 nm as determined by atomic force microscopy (AFM). The FeN film displayed magnetic anisotropy in the plane of the film, as shown in magnetic hysteresis loops. The FeN film had a magnetic permeability (µ') of 510 at 0.5 gigahertz (GHz) and a magnetic loss tangent (tanδ) of 0.3, maintaining a resonant frequency of 1.71 GHz. The FeN film had a Snoek product of 0.87 x 10¹². A summary of the magnetic properties for the 60 nm thick FeN film on a glass substrate is shown in Table 1. (1 kG = 0.1 T and 1 Oe = 79.577 A / m). Fig. 5 and Fig.Figure 13 indicates a slight (solid lines) or heavy (dashed lines) magnetization direction, indicating an energetically favorable or unfavorable direction of spontaneous magnetization. Table 1 Foil thickness (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) 4πMs(kG) Hc(Oe) µ' tanδ u' Tanδ u' tanδ Single-layer FeNB film on glass substrate (reference example)

[0028] With reference to Fig. 7 and Fig. 8. The FeNB foil (or film) on a glass substrate had a composition of Fe 66 N 18 B 16 and a thickness of 50 nm and an average grain size of 6.7 nm, measured by EDXS and profilometry, respectively. The FeNB film on glass exhibited a magnetic permeability of 864 at 1 GHz and a Snoek product of 1.26 x 10¹². A summary of the magnetic measurements for the Fe 66 N 18 B 16 -Slide is shown in Table 2. Table 2 Foil thickness (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) µ' tanδ u' Tanδ u' tanδ 50 730 0.19 864 0.18 1547 0.80 1.73 1.26

[0029] With reference to Fig.9. The effective resistance of the FeNB film increased with an increase in the boron content (x = 0, 13, 14, 16, 19). The magnetic permeability at 0.5 GHz was increased in the resistance range of 400 to 450 microohmmeters (µΩm). FeN / FeNB bilayer on a glass substrate

[0030] A Fe 66 N 18 B 16 -Film was deposited onto a glass substrate, followed by the deposition of an Fe 74 N 26 -Film with a constant thickness of 50 nm. The thickness of the Fe 66 N 18 B 16 The film had a range of 10-35 nm and varied with the deposition time. Fig. Figure 10 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of Fe. 66 N 18 B 16 -Foil in nm, as shown in the figure.

[0031] With reference to Fig.10. A FeN (50 nm) / FeNB (23 nm) bilayer film showed a high magnetic permeability of 1832 at 0.5 60 510 0.31 539 0.22 788 0.84 1.71 0.87 12.43 1.9 GHz, or a Snoek product of 3.72 x 10¹². The FeN (50 nm) / FeNB (23 nm) bilayer film exhibited a high magnetic permeability of 23¹³ at 1.5 GHz. The composition of the FeNB film was determined by EDXS to be Fe66N18B16. A summary of the magnetic measurements for the FeN / FeNB bilayer film with different FeNB layer thicknesses is shown in Table 3. Table 3 Foil thickness (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) µ' tanδ u' tanδ u' tanδ 10 899 0.44 1103 0.44 853 1.98 1.62 1.46 20 1062 0.53 1366 0.30 3221 0.41 1.83 1.94 23 1832 0.21 1679 0.27 2313 0.33 2.03 3.72 30 1042 0.02 1275 0.01 2069 0.29 2.01 2.09 35 853 0.09 1375 0.01 2201 0.23 2.01 1.71

[0032] Example 2: FeN / FeNB / glass double-layer foil structure with low boron content Parameters for RF magnetron sputtering: RF power = 80 to 120 W Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Ar; Reactive gas: Nitrogen. Goal: Iron (99.5%), 2-inch disc 2 pieces of boron (99.5%) shavings, 2.5 x 2.5 mm 2 Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass

[0033] In this example, an FeNB film was deposited onto a glass substrate, followed by a 50 nm thick FeN film deposited onto the FeNB film at ambient temperature. The thickness of the FeNB film varied with the deposition time, while maintaining a constant thickness of 50 nm for the FeN film. Magnetic permeability spectra for FeN / FeNB films with low boron content

[0034] With reference to Fig. 11 the FeNB film had a composition of Fe 72 N 18 B 10 , and the FeN had a composition of Fe 74 N 26 , measured by EDXS. Fig.Figure 11 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the Fe. 66 N 18 B 10 -Foil in nm, as shown in the figure. The two-layer foil structure showed an increased magnetic permeability from 1207 to 1741 with an increased thickness of the FeNB seed layer from 15 nm to 25 nm. The Snoek product of the FeN / FeNB foil increased by 60% with an increase in the thickness of the FeNB seed layer from 15 nm to 25 nm. A summary of the magnetic spectrum measurements for the Fe 74 N 26 / Fe 72 N 18 B 10 -The double-layer film is shown in Table 4. Table 4 FeNB thickness in FeN (50nm) / FeNB / glass (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) µ' tanδ u' tanδ u' tanδ 15 895 0.08 1207 0.04 2023 0.31 2.08 1.86 20 1248 0.18 1707 0.15 2951 0.58 1.81 2.26 22 1427 0.11 1599 0.05 2690 0.45 1.96 2.80 25 1561 0.18 1741 0.06 3094 0.27 1.91 2.98 30 1297 0.16 1657 0.13 2972 0.38 1.91 2.48 Resistance versus magnetic permeability (at 0.5 GHz) for a FeN / FeNB / glass structure

[0035] With reference to Fig.12. The effective resistance of the FeN / FeNB / glass foil was influenced by the thickness of the FeNB seed layer. The resistivity increased with increasing FeNB thickness. The magnetic permeability at 0.5 GHz was increased in the resistance range of 460 to 490 µΩm.

[0036] Example 3: FeTaN / FeNB / glass bilayer structure Parameters for RF magnetron sputtering: RF power = 80 to 120 W Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Ar (99.5%); Reactive gas: Nitrogen (99.0%) Goal: Iron (99.5%), 2-inch disc 2 pieces of boron (99.5%) chip measuring 5x5 mm 2 Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass

[0037] Magnetic properties and magnetic permeability of a single FeTaN foil on a glass substrate

[0038] With reference to Fig. 13 and Fig. Table 5 contains a summary of the magnetic spectrum measurements for an Fe (item 14). 74 Ta6N 20 -To find a single layer. (1 kG = 0.1 T and 1 Oe = 79.577 A / m) Table 5 Foil thickness (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) 4πMs(kG) Hc(Oe) µ' tanδ u' Tanδ u' tanδ 80 539 0.85 752 0.41 876 1.78 1.63 0.88 12.9 1.88

[0039] Magnetic permeability of two-layer FeTaN / FeNB films on the glass substrate

[0040] With reference to Fig. 15 comprised the two-layer foil structure Fe 74 Ta6N 20 and Fe 66 N 18 B 16 Films deposited on a glass substrate. A summary of magnetic spectrum measurements for Fe. 74 Ta6N 20 / Fe 66 N 18 B 16 -Double-layer films are included in Table 6. Table 6 FeNB thickness inFeTaN(50nm) / FeNB / Glass (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) µ' tanδ u' tanδ u' tanδ 15 913 0.10 814 0.14 1621 0.55 1.70 1.55 20 1167 0.03 953 0.24 1882 0.78 1.61 1.88 22 1130 0.11 1168 0.13 2044 1.02 1.88 1.88 Resistance versus magnetic permeability (at 0.5 GHz) for a FeTaN / FeNB / glass structure

[0041] With reference to Fig. In 16, the effective resistance of the FeNB / FeTaN foil was influenced by the thickness of the FeNB layer. The effective resistance increased from 438 µΩm to 489 µΩm with an increase in FeNB thickness from 60 nm to 75 nm. High magnetic permeability was observed in a resistance range of 430 to 460 µΩm.

[0042] Example 4: FeTaN / FeNB / glass two-layer foil structure with low boron content. Parameters for RF magnetron sputtering: RF power = 80 to 120 W Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Ar (99.5%); Reactive gas: Nitrogen (99.0%) Goal: Iron (99.5%), 2-inch disc 2 pieces of boron (99.5%) chip measuring 5x5 mm 2 1 piece for tantalum (99.99%) (5x5 mm 2 ) Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass

[0043] Magnetic permeability spectrum of a FeTaN / FeNB film with low B concentration

[0044] With reference to Fig. In 17, the FeTaN film had a composition of Fe 74 Ta6N 20 , measured by EDXS, and FeNB had a composition of Fe 72 N 18 B 10 . Fig. Figure 17 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the Fe. 72 N 18 B 10 -Foil in nm, as shown in the figure. A summary of the magnetic spectrum measurements for Fe 74 Ta6N 20 / Fe 72 N 18 B 10 -The double-layer film on a glass substrate is shown in Table 7. Table 7 FeNB thickness in FeTaN (50 nm) / FeNB / glass (nm) 0.5 GHz 1 GHz 1.5 GHz f r (GHz) Snoek product (×1012) µ' tanδ u' tanδ u' tanδ 15 985 0.52 1716 0.18 2850 0.54 1.90 1.87 20 1386 0.18 1602 0.12 2680 0.51 1.87 2.59 22 1416 0.27 1796 0.16 2351 0.47 1.83 2.59

[0045] Example 5: Three-layer FeNB / FeN / FeNB / glass structure Parameters for RF magnetron sputtering: RF power = 80 to 120 W Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Ar (99.5%); Reactive gas: Nitrogen (99.0%) Goal: Iron (99.5%), 2-inch disc 2 pieces of boron (99.5%) chip measuring 5x5 mm 2 1 piece for tantalum (99.99%) (5x5 mm 2 ) Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass Resistance value of the FeNB / FeN / FeNB structure

[0046] With reference to Fig.In 18, the effective resistivity of a three-layer film was measured using the VD Pauw method with four probes. The resistivity increased from 291 to 485 µΩm for the total thickness of the three-layer film from 55 to 125 nm. Details on the layer thickness and resistivity for Fe 72 N 18 B 10 / Fe 82 N 18 / Fe 72 N 18 B 10 Three-layer films can be found in Table 8. Table 8 Top layer FeNB (nm) Middle layer FeN(nm) Lower layer FeNB (nm) Total thickness (nm) Resistance value (µΩm) 15 20 20 55 291 15 30 30 75 351 15 35 35 85 386 20 50 25 95 455 25 50 50 125 485 Magnetic permeability for FeNB / FeN / FeNB / glass structure

[0047] With reference to Fig. In 19, the thickness of 50 nm for the FeN middle layer was set and the thicknesses of the upper and lower FeNB layers were changed. Fig.Figure 19 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the upper and lower FeNB foils in nm, as indicated in the figure. The increased magnetic permeability (at 0.5 GHz) and the Snoek product are 995 and 2.16, respectively, for the FeNB(20 nm) / FeN(50 nm) / FeNB(25 nm) structures. The magnetic permeability of the FeNB(20 nm) / FeN(50 nm) / FeNB(25 nm) structure was approximately 50% higher than that of the FeNB(25 nm) / FeTaN(50 nm) / FeNB(25 nm) structure. A summary of the magnetic spectrum measurements for Fe 72 N 18 B 10 / Fe 82 N 18 / Fe 72 N 18 B 10 The three-layer films are shown in Table 9. The last row contains details about the reference sample. Table 9 Top layer FeNB(nm) Medium Layer FeN (nm) Lower layer FeN B(nm) µ' at 0.5GHz µ' at 1.0GHz µ' at 1.5GHz fr(GHz) Snoek product (×1012) µ' tanδ µ' tanδ µ' tanδ 20 50 25 995 0.28 1339 0.27 1478 0.58 2.17 2.16 25 50 25 773 0.33 1096 0.25 1444 0.53 2.21 1.71 25 50 50 530 0.43 559 0.31 692 0.46 2.25 1.19 25 50(FeTaN) 25 382 0.41 457 0.16 464 0.96 1.79 0.68

[0048] Example 6: Three-layer FeNB / FeTaN / FeNB / glass structure Parameters for RF magnetron sputtering: RF power = 80 to 120 W Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Ar (99.5%); Reactive gas: Nitrogen (99.0%) Goal: Iron (99.5%), 2-inch disc 2 pieces of boron (99.5%) shavings, 2.5 x 2.5 mm 2 1 piece for tantalum (99.99%) (5x5 mm 2 ) Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass Specific resistivity of the FeNB / FeTaN / FeNB structure

[0049] With reference to Fig. The effective resistance increased with increasing total thickness of the three-layer FeNB / FeTaN / FeNB film. The effective resistance increased from 391 to 496 µΩm for total thicknesses from 70 to 125 nm. The effective resistance of the FeNB / FeTaN / FeNB film was approximately 5% higher than that of the FeNB / FeN / FeNB film. Details on the layer thickness and resistivity for the Fe 72 N18 B 10 / Fe 83 Ta6N 11 / Fe 72 N 18 B 10 Three-layer films are listed in Table 10. Table 10 Top layer FeNB (nm) Middle layer FeTaN (nm) Lower layer FeNB (nm) Total thickness (nm) Resistance value (µΩm) 20 25 25 70 396 20 50 25 95 437 25 50 25 100 468 25 50 50 125 496 Magnetic permeability for FeNB / FeTaN / FeNB / glass structure

[0050] With reference to Fig. 21 The thickness of the FeNB and FeTaN layer varied from 20 nm to 50 nm. Fig. Figure 21 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the top, middle, and bottom FeNB sheets in nm, as indicated in the figure. The elevated magnetic permeability (at 0.5 GHz) and the Snoek product were 545 and 1.14, respectively, for the FeNB(20 nm) / FeTaN(25 nm) / FeNB(25 nm) structures. The magnetic permeability of the FeNB(20 nm) / FeTaN(25 nm) / FeNB(25 nm) structure was approximately 45% lower than that of the FeNB(20 nm) / FeN(50 nm) / FeNB(25 nm) structure (i.e., 995). A summary of the magnetic spectrum measurements for Fe 72 N18 B 10 / Fe 72 Ta 18 N 10 / Fe 72 N 18 B 10 The three-layer films are shown in Table 11. The last row contains details about the reference sample. Table 11 Deck layer FeNB(nm) Medium layer FeN (nm) Lower layer FeNB(nm) µ' at 0.5 GHz µ' at 1.0 GHz µ' at 1.5 GHz fr (GHz) Snoek product (×1012) µ' tanδ µ' tanδ µ' tanδ 20 25 25 545 0.31 504 0.11 712 0.35 2.09 1.14 25 25 25 511 0.41 599 0.07 747 0.49 2.08 1.06 20 50 25 319 0.62 429 0.23 425 0.83 1.86 0.59 25 50 25 382 0.41 457 0.16 464 0.96 1.79 0.68 25 50 50 292 0.02 397 0.04 382 0.91 1.76 0.52 20* 50 (FeN) 25 995 0.28 1366 0.27 1478 0.58 2.17 2.16 *Reference example

[0051] Example 7: FeN, FeNB, FeTaN / TaN / glass two-layer structure Parameters for RF magnetron sputtering: RF power = 80 to 120 W Deposition pressure = 0.3 to 0.6 Pascals (Pa) Distance between target and substrate = 8 centimeters (cm) Working gas: Ar (99.5%); Reactive gas: Nitrogen (99.0%) Goal: Iron (99.5%), 2-inch disc 2 pieces of boron (99.5%) shavings, 2.5 x 2.5 mm 2 1 piece for tantalum (99.99%) (5x5 mm 2 ) Deposition time: 5 to 30 minutes Separation temperature: Ambient temperature Substrate: Optical glass Magnetic permeability for FeN / TaN / glass structure

[0052] With reference to Fig. 22. A non-magnetic TaN film was a seed layer for the deposition of a 50 nm FeN film. Fig. Figure 22 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the TaN foils in nm, as indicated in the figure. The thickness of the non-magnetic TaN seed layer varied from 15 to 30 nm. The increased magnetic permeability and the Snoek product were 716 at 0.5 GHz and 1.53 when the thickness of the TaN layer was approximately 20 nm. The magnetic permeability of the FeN(50 nm) / TaN(20 nm) / glass structure was about 20% lower than that of the FeN(50 nm) / FeTaN(10 nm) / glass structure (i.e., 892). The magnetic seed layer resulted in a higher frequency permeability than that of the non-magnetic seed layer (e.g., TaN). A summary of the magnetic spectrum measurements for Fe 82 N 18 / Ta 88 N 12The double-layer film is shown in Table 12. The last row contains details about the reference sample. Table 12 Top layer FeN(nm) Lower layer TaN(nm) µ' at 0.5GHz µ' at 1.0GHz µ' at 1.5GHz fr(GHz) Snoek product (×1012) µ' tanδ µ' tanδ µ' tanδ 50 15 507 0.22 558 0.05 1220 0.17 2.12 1.07 50 20 716 0.20 901 0.14 1939 0.17 2.13 1.53 50 25 646 0.34 778 0.05 1494 0.15 2.16 1.39 50 30 478 0.04 786 0.01 1648 0.09 2.09 1.00 50* 20 (FeTaN) 892 0.08 1145 0.13 1709 0.89 1.76 1.57 *Reference example Magnetic permeability for FeNB / TaN / glass structure

[0053] With reference to Fig. 23 The thickness of the non-magnetic TaN seed layer varied from 10 nm to 25 nm. Fig.Figure 23 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the TaN foils in nm, as indicated in the figure. The enhanced magnetic permeability and the Snoek product were 937 at 0.5 GHz and 1.76 when the thickness of the TaN seed layer was approximately 20 nm. The magnetic permeability of the FeN(50 nm) / TaN(20 nm) / glass structure was approximately 32% lower than that of the FeNB(50 nm) / FeTaN(20 nm) / glass structure (i.e., 1386). The magnetic permeability of the FeNB(50 nm) / TaN(20 nm) / glass structure was approximately 24% higher than that of the FeN(50 nm) / TaN(20 nm) / glass structure (i.e., 716). The magnetic seed layer exhibited a higher permeability than the non-magnetic seed layer. A summary of magnetic spectrum measurements for Fe 72 N 18 B 10 / Ta 88 N 12 The double-layer films are shown in Table 12. The last two rows contain details about the reference samples. Table 12 Top layer FeNB(nm) Lower layer TaN (nm) µ' at 0.5GHz µ' at 1.0 GHz µ' at 1.5GHz f r (GHz) Snoek product (×1012) µ' tanδ µ' tanδ µ' tanδ 10 10 821 0.58 941 0.09 1598 0.20 2.01 1.65 15 15 866 0.11 1043 0.12 2004 0.33 1.87 1.23 20 20 937 0.17 1065 0.01 1827 0.32 1.88 1.76 25 25 708 0.43 862 0.13 1378 0.16 2.06 1.46 50* 20(FeTaN) 1386 0.15 1581 0.13 2740 0.17 1.87 2.59 50 (FeN)* 20 716 0.20 901 0.14 1939 0.17 2.13 1.53 *Reference example Magnetic permeability for FeTaN / TaN / glass structure

[0054] With reference to Fig. In 24, the thickness of the magnetic upper FeTaN layer was set at 50 nm. Fig. Figure 24 shows µ' (solid lines) and µ'' (dashed lines) for different thicknesses of the TaN sheets in nm, as indicated in the figure. The thickness of the nanomagnetic TaN layer varied from 10 nm to 25 nm. The increased magnetic permeability and the Snoek product were 832 at 0.5 GHz and 1.63 when the thickness of the TaN layer was approximately 20 nm. The magnetic permeability of the FeTaN(50 nm) / TaN(20 nm) / glass structure was approximately 38% lower than that of the FeTaN(50 nm) / FeNB(20 nm) / glass structure (i.e., 1386). The magnetic permeability of the FeTaN(50 nm) / TaN(20 nm) / glass structure was approximately 14% higher than that of the FeN(50 nm) / TaN(20 nm) / glass structure (i.e., 716). A summary of magnetic spectrum measurements for Fe 83 Ta6N 11 / Ta88 N 12 The double-layer film is shown in Table 13. The last row contains details of the reference sample. The last two rows contain details of the reference samples. Table 13 Top layer FeTaN(nm) Lower layer TaN(nm) µ' at 0.5GHz µ' at 1.0 GHz µ' at 1.5GHz fr(GHz) Snoek product (×1012) µ' tanδ µ' tanδ µ' tanδ 10 10 669 0.68 911 0.18 1538 0.29 2.03 1.36 15 15 714 0.49 1029 0.10 1814 0.25 1.99 1.42 20 20 832 0.38 975 0.15 1697 0.29 1.96 1.63 25 25 807 0.30 906 0.28 984 0.89 1.83 1.48 50 20 (FeNB) 1386 0.20 1581 0.14 2740 0.17 1.87 2.59 20 (FeN) 20 716 0.17 901 0.01 1939 0.32 2.13 1.53

[0055] Example 8: Magnetic permeability and Snoek product diagram of the FeN-based or FeTaN-based multilayer structure Magnetic permeability (at 0.5 GHz) and Snoek product diagram of the FeN-based structure

[0056] With reference to Fig. Figure 25 shows the magnetic permeability diagrams at 0.5 GHz of the FeN-based film for the single-layer film, the bilayer film, and the three-layer structure. The increased magnetic permeability around 1800 GHz was observed in the bilayer film with the 20–25 nm FeNB seed layer.

[0057] With reference to Fig.Figure 26 shows the Snoek product diagrams of the FeN-based film for the single-layer film, the bilayer film, and the three-layer film. The increased Snoek product of approximately 2.0–3.5 × 10¹² was observed in the bilayer film with the 20–25 nm FeNB seed layer. Magnetic permeability (at 0.5 GHz) and Snoek product diagram of the FeTaN-based structure

[0058] In Fig. Figure 27 shows the magnetic permeability diagram of the FeTaN-based film for the single-layer, double-layer, and triple-layer films. The increased magnetic permeability of 1300 was observed in the double-layer film with the 20–25 nm FeNB seed layer.

[0059] In Fig.Figure 28 shows the Snoek product diagrams of the FeTaN-based film for the single-layer, two-layer, and three-layer structures. The increased Snoek product of approximately 2.0 × 10¹² was observed in the two-layer film with the 20–25 nm FeTaN or FeNB seed layer.

[0060] The following describes some aspects of multilayer magnetic foil, articles containing it, and methods for its production.

[0061] Aspect 1: A multilayer magnetic foil comprising a substrate; a first magnetic layer arranged on the substrate, wherein the first magnetic layer is Fe (50-80) N (10-20) B (1-20) M (0-10) comprising, wherein M is Si, Ta, Zr, Ti, Co or a combination thereof; and a second magnetic layer arranged on top of the first magnetic layer, wherein the second magnetic layer is Fe (50-90) N (10-50) or Fe (60-90) N (1-10) Ta (5-30)comprising; wherein the multilayer magnetic foil according to the invention has, over a frequency range of 1 to 5 GHz, a magnetic permeability of greater than or equal to 1800, preferably greater than 2000, particularly preferably greater than 3000, or 1800 to 5000 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz; a magnetic loss tangent of less than or equal to 0.3, preferably less than or equal to 0.1, or 0.01 to 0.3 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz; and a cutoff frequency of greater than or equal to 1 GHz, greater than or equal to 1 GHz, or greater than or equal to 2 GHz, preferably greater than or equal to 5 GHz, or 1 to 8 GHz.

[0062] Aspect 2: The multilayer magnetic foil of Aspect 1, wherein the substrate comprises a glass, a polymer or a ceramic, preferably a ceramic.

[0063] Aspect 3: The multilayer magnetic foil according to one or more of the preceding aspects, wherein the first magnetic layer has a thickness of 10 to 100 nanometers and the second magnetic layer has a thickness of 10 to 400 nanometers.

[0064] Aspect 4: The multilayer magnetic foil according to one or more of the preceding aspects, further comprising: an additional first layer comprising Fe (50-80) N (10-20) B (1-20) , which is arranged on the second layer; and an additional second magnetic layer comprising Fe (50-30) N (10-50) or Fe (60-90) N (1-10) Ta (5-30) , which is located on the additional first magnetic layer.

[0065] Aspect 5: The multilayer magnetic foil according to aspect 4, with further additional first and second magnetic layers arranged alternately on the additional second magnetic layer.

[0066] Aspect 6: The multilayer magnetic foil according to one or more of aspects 4 to 5, wherein the first magnetic layer and the second magnetic layer have a total thickness of 20 to 500 nanometers.

[0067] Aspect 7: Object comprising the multilayer film according to one or more of aspects 1 to 6, wherein the object is preferably a filter, a transformer, an inductor, an antenna, an electronic integrated circuit chip or an electromagnetic shielding device.

[0068] Aspect 8: The subject matter of aspect 7, wherein the subject matter is a component of an electronic device, preferably a mobile phone, a desktop computer, a laptop, a notebook, a wireless or LAN network, a power supply, an amplifier, a voltage-controlled oscillator, a shrink current transformer, and particularly preferably an integrated electronic device.

[0069] Aspect 9: Method for forming the multilayer magnetic foil according to one or more of Aspects 1 to 6, wherein the method comprises: depositing the first magnetic layer on one side of the substrate; and depositing the second magnetic layer on a side of the first magnetic layer opposite the substrate.

[0070] Aspect 10: The method according to aspect 9, wherein the deposition includes rf / DC sputtering, electron beam deposition or a combination thereof.

[0071] Aspect 11: The procedure according to aspect 10, which further includes the application of an additional first layer on one side of the second layer opposite the first layer.

[0072] Aspect 12: The procedure according to aspect 11, further comprising the deposition of an additional second layer on a side of the additional first layer opposite the second layer.

[0073] Aspect 13: The method according to one or more of Aspects 9 to 12, comprising adjusting the thickness of each layer to adjust the magnetic loss tangent of the magnetic multilayer film, the magnetic anisotropy of the magnetic multilayer foil, or both.

[0074] Aspect 14: A multilayer magnetic foil, manufactured according to the process of one or more of aspects 9 to 13.

[0075] "Film," as used here, includes planar layers, plates, and the like, as well as other three-dimensional, non-planar shapes. A layer may also be macroscopically continuous or discontinuous. Unless otherwise specified, the test standards are the most recent at the time of submission.

[0076] The endpoints of all ranges directed at the same component or property are inclusive, can be combined independently, and include all intermediate points and ranges. For example, ranges from "to 25" or "5 to 20" include the endpoints and all intermediate values ​​of the ranges from "5 to 25" such as 10 to 23, etc.

[0077] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as they are commonly understood by a person skilled in the art in the field to which this invention belongs.

Claims

[1] A multilayer magnetic film comprising: a substrate; a first magnetic layer arranged on the substrate, wherein the first magnetic layer is Fe (50-80) N (10-20 )B (1-20) M (0-10) includes, where M is Si, Ta, Zr, Ti, Co or a combination thereof; and a second magnetic layer arranged on top of the first magnetic layer, where the second magnetic layer is Fe (50-90) N (10-50) or Fe (60-90) N (1-10 )Ta (5-30) includes; the multilayer magnetic foil exhibits a frequency range of 1 to 5 GHz, a magnetic permeability of greater than or equal to 1800, preferably greater than or equal to 2000, particularly preferably greater than or equal to 3000 over a selected frequency band in the frequency range, preferably over a frequency band of 1 to 10 GHz; a magnetic loss tangent of less than or equal to 0.3, preferably less than or equal to 0.1, over a selected frequency band in the frequency range, preferably over a frequency band from 1 to 10 GHz; and a cutoff frequency greater than or equal to 1 GHz, or greater than or equal to 2 GHz, preferably greater than or equal to 5 GHz. [2] The multilayer magnetic foil according to claim 1, wherein the substrate comprises a glass, a polymer or a ceramic, preferably a ceramic. [3] The multilayer magnetic foil according to one or more of the preceding claims, wherein the first magnetic layer has a thickness of 10 to 100 nanometers, and The second magnetic layer has a thickness of 10 to 400 nanometers. [4] The multilayer magnetic foil according to one or more of the preceding claims, further comprising: an additional first layer, comprising Fe (50-80) N (10-20)B (1-20) , which is arranged on the second layer; and an additional second magnetic layer, the Fe (50-90) N (10-50) or Fe (60-90) N (1-10) Ta (5-30) encompasses and is arranged on the additional first magnetic layer. [5] The multilayer magnetic foil according to claim 4, comprising further additional first and second magnetic layers arranged alternately on the additional second magnetic layer. [6] The multilayer magnetic foil according to one or more of claims 4 to 5, wherein the first magnetic layer and the second magnetic layer have a total thickness of 20 to 500 nanometers. [7] An object comprising the multilayer magnetic foil according to one or more of claims 1 to 6, wherein the object is preferably a filter, a transformer, an inductor, an antenna, an electronic integrated circuit chip or an electromagnetic shielding device. [8] Subject matter according to claim 7, wherein the subject matter is a component of an electronic device, preferably a mobile phone, a desktop computer, a laptop, a notebook, a wireless or LAN network, a power supply, an amplifier, a voltage-controlled oscillator, a shrink current transformer, particularly preferably an integrated electronic device. [9] Method for producing the multilayer magnetic foil according to one or more of claims 1 to 6, wherein the method comprises: Deposition of the first magnetic layer on one side of the substrate; and Deposition of the second magnetic layer on a side of the first magnetic layer opposite the substrate. [10] Method according to claim 9, wherein the deposition comprises rf / DC sputtering, electron beam deposition or a combination thereof. [11] Method according to claim 10, further comprising the deposition of an additional first layer on a side of the second layer opposite the first layer. [12] Method according to claim 11, further comprising the deposition of an additional second layer on a side of the additional first layer opposite the second layer. [13] Method according to one or more of claims 9 to 12, comprising adjusting the thickness of each layer to adjust the magnetic loss tangent of the multilayer magnetic film, the magnetic anisotropy of the multilayer magnetic foil or both. [14] Multilayer magnetic foil, manufactured according to the method of one or more of claims 9 to 13.

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