Nanogranular magnetic films, magnetic cores, and electronic components

Abstract

This invention provides nanogranular magnetic films, magnetic cores, and electronic components with a high saturation magnetic flux density Bs, a high real part of the complex permeability when driven at a high frequency of 100 MHz, and a small tanδ. [Solution] The nanogranular magnetic film 1 has a structure in which the first phase 11 is composed of a nano-sized metallic phase containing Fe and Co, and a second phase 12 containing oxygen and nitrogen, with the first phase 11 dispersed in the second phase 12. The metallic phase contains one or more crystallites, and the mode of the crystallite diameter of the crystallites in the nanogranular magnetic film 1 on a volume basis is 1.5 nm or more and 6.0 nm or less.

Description

[Technical Field]

[0001] This disclosure relates to nanogranular magnetic films, magnetic cores, and electronic components. [Background technology]

[0002] In recent years, mobile devices such as smartphones and smartwatches have been required to have larger display screens and increased battery capacity, while simultaneously being smaller and lighter. To meet these conflicting demands, miniaturization of circuit boards is crucial, and among them, miniaturization of power supply circuits, which occupy a large area on the circuit board, is particularly important. Miniaturization of inductors, which have a large mounting area, is especially required.

[0003] Increasing the drive frequency of the power supply circuit is particularly effective in miniaturizing inductors. Currently, the market demands inductors with large inductance at drive frequencies of 100 MHz or higher.

[0004] To realize the above-mentioned inductor, thin-film inductors using a thin-film magnetic material with a high magnetic resonance frequency as the core material are being considered. However, thin films fabricated by vacuum deposition methods (such as sputtering) generally tend to have very large internal stresses and strains. Therefore, thin films fabricated by vacuum deposition methods tend to have an increased loss coefficient tanδ.

[0005] When using thin-film magnetic materials containing Co-based amorphous magnetic materials (such as CoZrTa), the low resistivity of Co-based amorphous magnetic materials tends to increase the effect of eddy current losses. Therefore, the loss coefficient tanδ of the thin-film magnetic material tends to increase. For example, to keep the tanδ of the thin-film magnetic material below 0.1 at a driving frequency of 100 MHz, the film thickness of the thin-film magnetic material must be 500 nm or less.

[0006] Therefore, when using a thin-film magnetic material containing a Co-based amorphous magnetic material as the core material for a thin-film inductor with a thickness of several micrometers or more, it is necessary to insert an insulating film such as an SiO2 film between thin-film magnetic materials with a thickness of 500 nm or less to electrically isolate them. In other words, the core material of a thin-film inductor with a thickness of several micrometers or more must have a multilayer structure of at least several tens of layers. The manufacturing cost of a core material with a multilayer structure increases as the number of layers increases.

[0007] Nanogranular magnetic films, as described in Patent Documents 1 to 6, are known as thin films that possess both relatively high saturation magnetic flux density and high resistivity. By using these nanogranular magnetic films to fabricate the core material of a thin-film inductor, the number of layers can be reduced, thereby lowering manufacturing costs. For this reason, thin-film inductors that use nanogranular magnetic films as the core material are being investigated. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. H11-77739 [Patent Document 2] Patent No. 3152647 [Patent Document 3] Japanese Patent Publication No. 2005-276367 [Patent Document 4] Patent No. 3809418 [Patent Document 5] Patent No. 3956061 [Patent Document 6] Patent No. 6618298 [Overview of the project] [Problems that the invention aims to solve]

[0009] This disclosure aims to provide a nanogranular magnetic film with a large saturation magnetic flux density Bs, a high real part of the complex permeability when driven at a high frequency of 100 MHz, and a small tanδ.

Means for Solving the Problem

[0010] In order to achieve the above object, the nanogranular magnetic film according to the present disclosure is a nanogranular magnetic film having a structure in which a first phase is dispersed in a second phase, where the nanogranular magnetic film has a nanosized metal phase containing Fe and Co as the first phase and has oxygen and nitrogen in the second phase, the metal phase contains one or more crystallites, and the most frequent value of the crystallite diameter of the crystallites in the nanogranular magnetic film on a volume basis is 1.5 nm or more and 6.0 nm or less.

[0011] The most frequent value of the crystallite diameter of the crystallites may be 2.0 nm or more and 5.0 nm or less.

[0012] The value obtained by dividing the nitrogen concentration of the nanogranular magnetic film by the sum of the oxygen concentration and the nitrogen concentration of the nanogranular magnetic film may be 0.090 or more and 0.50 or less on an atomic number basis.

[0013] The volume ratio of the first phase may be 48% or more and 90% or less in total.

[0014] The volume ratio of the first phase may be 48% or more and 70% or less in total.

[0015] The magnetic core according to the present disclosure has the above nanogranular magnetic film.

[0016] The electronic component according to the present disclosure has the above nanogranular magnetic film.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic cross-sectional view of a nanogranular magnetic film. [Figure 1A] It is a bright-field TEM image of the cross section of a nanogranular magnetic film. [Figure 1B] It is an enlarged image of FIG. 1A. [Figure 1C] This is an enlarged image of Figure 1B. [Figure 2] This is a schematic diagram showing a cross-section of the manufacturing equipment. [Figure 3] This is a schematic diagram of the manufacturing equipment. [Figure 4] This is a schematic diagram of the manufacturing equipment. [Figure 5] This is a schematic diagram of a diffraction chart. [Figure 6] This is a schematic diagram of a diffraction chart. [Figure 7] This is a schematic diagram of a diffraction chart. [Modes for carrying out the invention]

[0018] The embodiments of this disclosure will be described below with reference to the drawings.

[0019] As shown in Figure 1, the nanogranular magnetic film 1 according to this embodiment has a structure in which the first phase 11 is dispersed in the second phase 12.

[0020] Figures 1A and 1C show bright-field STEM images. Figure 1B is a magnified image of the area indicated by the square in Figure 1A, and Figure 1C is a magnified image of the area indicated by the square in Figure 1B. The black areas in each image represent the first phase, which is the metallic phase, and the white areas in each image represent the second phase, which consists of SiO2 and Si3N4. By observing the STEM images at an appropriate magnification, it can be seen that the first phase has a shape close to a sphere. Furthermore, it can be seen that the first phases are separated from each other by the second phase.

[0021] The nanogranular magnetic films shown in Figures 1A to 1C can be confirmed to have the structure shown in Figure 1, that is, a structure in which the first phase 11 is dispersed in the second phase 12.

[0022] Furthermore, the presence of a lattice pattern in the bright-field STEM image indicates that the first phase, which is the metallic phase, possesses a crystalline structure.

[0023] A nanogranular magnetic film has the above structure, and the first phase 11 is a metallic phase with an average size of 30 nm or less and contains a magnetic material, while the second phase 12 is a thin film mainly composed of a material that has a higher electrical resistance than the first phase 11 and is not a resin (not an organic polymer compound). Specifically, the material mainly included in the second phase 12 is one or more inorganic materials selected from oxides, nitrides, fluorides, oxynitrides, oxyfluorides, and their mixed phases.

[0024] There are no particular restrictions on the method for confirming that the second phase 12 is mainly composed of substances other than resins. For example, a method using XPS can be used. By using XPS, the amount of carbon contained in the second phase 12 can be quantified, and at the same time, the bonding state of the carbon contained in the second phase 12 can be determined. If the amount of carbon contained in the second phase 12 is trace, that is, if the carbon content ratio to the total amount of elements other than magnetic metal elements (e.g., Fe, Co, and Ni) and H in the second phase 12 is 20 at% or less, or if the presence of carbon bonding characteristic of resins is not confirmed in the second phase 12, then it can be said that the second phase 12 is mainly composed of substances other than resins.

[0025] There are no particular restrictions on the method for confirming that the second phase 12 is mainly composed of a material having a higher electrical resistance than the first phase 11. For example, first, the composition of the first phase 11 is measured. A thin film with the same composition as the first phase 11 is deposited on a substrate to prepare a substrate for measuring the electrical resistance of the first phase 11. A substrate for measuring the electrical resistance of the second phase 12 is prepared in the same manner as the substrate for measuring the electrical resistance of the first phase 11. Then, the electrical resistance of each thin film deposited on each electrical resistance measuring substrate is compared.

[0026] Thin strips produced by liquid quenching, sintered bodies obtained by sintering powder, and molded bodies obtained by machining bulk material are not nanogranular magnetic films, even if they have a structure in which the first phase 11 is dispersed in the second phase 12.

[0027] The nanogranular magnetic film 1 has a nano-sized metallic phase (a metallic phase with a size of 30 nm or less) containing Fe and Co as the first phase 11. The nano-sized metallic phase may also contain X1 in addition to Fe and Co. X1 may be one or more selected from Ni, B, C, P, V, Cr, Mn, Cu, Zn, Nb, Mo, Ru, Rh, Pd, Ag, Sn, Ta, W, Ir, Pt, and Au.

[0028] In the nanogranular magnetic film 1, the size of the first phase 11 may be up to 30 nm or less. There are no particular restrictions on the method for measuring the size of the first phase 11, but in this embodiment, the size is determined by analysis using the FP method. The reason for using the FP method will be explained later. When performing cross-sectional analysis of the nanogranular magnetic film 1 by TEM, the equivalent circular diameter of the first phase 11 in the cross-section of the nanogranular magnetic film 1 may be used as the size of the first phase 11.

[0029] Each metallic phase contains one or more crystallites. Each metallic phase may consist of only one or more crystallites. Each metallic phase may also contain amorphous materials in addition to crystallites.

[0030] Phase 11 has the compositional formula Fe a Co b X1 c It may be expressed as an atomic ratio and have a composition that satisfies 0.30 ≤ a ≤ 0.90, 0.10 ≤ b ≤ 0.70, 0.00 ≤ c ≤ 0.10, and a + b + c = 1.

[0031] Phase 11 may contain elements other than Fe, Co, and X1. The ratio of the total content of elements other than Fe, Co, and X1 to the total content of Fe, Co, and X1 may be 10 at% or less, or 5 at% or less.

[0032] The nanogranular magnetic film 1 has O and N in the second phase 12. In addition to O and N, it may also have M and / or X2 in the second phase 12. M may be one or more selected from Si, Al, Ga, Mg, Zr, Hf, and rare earth elements, and X2 may be one or more selected from F and S. There is no particular limitation on the type of rare earth element, and it may be Y, La, etc. Any of the oxides, nitrides, and oxynitrides contained in the second phase 12 may be any of the oxides of M, nitrides of M, and oxynitrides of M. Also, a part of the second phase 12 may contain fluoride.

[0033] The second phase 12 has a composition formula M d O e N f X2 g (atomic ratio) and may have a composition that satisfies 0.10 ≦ f / (e + f) ≦ 0.50, 0.00 ≦ g ≦ 0.03, and d + e + f + g = 1.

[0034] The second phase 12 has a composition formula M d O e N f X2 g When represented by (atomic ratio), the nanogranular magnetic film 1 may have elements other than M, O, N, and X2 in the second phase 12. The ratio of the total content of elements other than M, O, N, and X2 to the total content of M, O, N, and X2 may be 10 at% or less, or may be 5 at% or less.

[0035] Also, the second phase 12 has a composition formula M d O e N f X2 g (atomic ratio) and may have a composition that satisfies M being one or more selected from Si, Al, Ga, Mg, Zr, Hf, rare earths, 0.20 ≦ d ≦ 0.50, 0.10 ≦ f / (e + f) ≦ 0.50, 0.00 ≦ g ≦ 0.03, and d + e + f + g = 1.

[0036] The second phase 12 has a composition formula M d O e N f X2 gWhen expressed in terms of atomic ratio, the nanogranular magnetic film 1 may have elements other than M, O, N, and X2 in the second phase 12. The ratio of the total content of elements other than M, O, N, and X2 to the total content of M, O, N, and X2 may be 10 at% or less, or 5 at% or less.

[0037] There are no particular restrictions on the volume ratio of Phase 11 to the total volume of Phase 11 and Phase 212. For example, it may be 48% to 90%, or 48% to 70%. That is, when the volume ratio of Phase 11 is V1 and the volume ratio of Phase 212 is V2, V1 / (V1+V2) may be 0.48 to 0.90, or 0.48 to 0.70. The larger the volume ratio of Phase 11 to the total volume of Phase 11 and Phase 212, the higher Bs will be, but the lower the resistivity will be.

[0038] There are no particular restrictions on the method for analyzing the composition of the first phase 11 and the second phase 12 in the nanogranular magnetic film 1, or on the method for measuring the volume ratio V1 / (V1+V2) of the first phase 11 to the total volume of the first phase 11 and the second phase 12. For example, it can be calculated from the XRF measurement results of the nanogranular magnetic film 1. Alternatively, the area ratio can be calculated from the area of ​​the first phase 11 to the total area of ​​the first phase 11 and the second phase 12 by observing the cross-section of the nanogranular magnetic film 1 with a TEM. In this case, the area ratio is converted to a volume ratio.

[0039] When analyzing the composition of the first phase 11 and the second phase 12 of a nanogranular magnetic film 1 using XRF, a problem arises due to the low quantitative accuracy of elements from the first period and some elements from the second period, particularly O and N. However, TEM-EDX can confirm that O and N are relatively present in one of the two phases, the other being one or the other. "A specific element is relatively present in only one phase" means that, based on the number of atoms, the content of a specific element in one phase is more than 10 times that of the same element in the other phase. In this case, the phase with the lower content is considered not to contain the specific element.

[0040] There are no particular restrictions on the method for quantifying the N and O content in the entire nanogranular magnetic film 1. For example, it can be quantified using the impulse heating melt extraction method. For instance, the value obtained by dividing the nitrogen concentration of the nanogranular magnetic film 1 by the sum of the oxygen and nitrogen concentrations of the nanogranular magnetic film 1 (hereinafter sometimes simply referred to as "nitrogen / (oxygen + nitrogen)") may be between 0.090 and 0.50 on an atomic basis, or between 0.10 and 0.50. If oxygen and nitrogen are relatively contained only in the second phase 12, nitrogen / (oxygen + nitrogen) can be considered equal to the above f / (e+f). Alternatively, the N and O content may be quantified from TEM-EDX mapping images.

[0041] The following describes a method for determining the volume ratio of the first phase 11 to the second phase 12 of a nanogranular magnetic film by combining the results of compositional analysis of the nanogranular magnetic film using XRF and the results of measuring the ratio of O to N in the nanogranular magnetic film by impulse heating melt extraction.

[0042] The ratio of the total number of oxygen atoms in the oxide of M contained in the second phase 12 to the total number of nitrogen atoms in the nitride of M can be considered to be the same as the ratio of O to N obtained by the impulse heating extraction method. Therefore, the volume V2 of the second phase can be obtained from the concentration of M obtained from the XRF measurement results, the ratio of the oxide of M to the nitride of M obtained by the impulse heating extraction method, the composition of the oxide of M, the molar mass of the oxide of M, the density of the oxide of M, the composition of the nitride of M, the molar mass of the nitride of M, and the density of the nitride of M. The volume V1 of the first phase 11 can be obtained from the compositional analysis results of the XRF, the composition of each atom contained in the first phase 11, the molar mass of each atom contained in the first phase 11, and the density of the first phase 11. From the above, the volume ratio of the first phase to the second phase can be determined.

[0043] The crystallites contained in the first phase 11 have a crystalline structure. Having a crystalline structure makes it easier for the saturation magnetic flux density Bs to increase.

[0044] There are no particular restrictions on the method for confirming the crystal structure of crystallites contained in Phase 11. For example, the crystal structure can be confirmed by analyzing the X-ray diffraction pattern using XRD, or by analyzing the electron diffraction pattern using TEM, etc.

[0045] The nanogranular magnetic film 1 may contain only the first phase 11 and the second phase 12, but it may also contain other phases besides the first phase 11 and the second phase 12. There are no particular restrictions on the proportion of the other phases, but when observing the cross-section of the nanogranular magnetic film 1 with a TEM, the area proportion of the other phases may be 10% or less. Furthermore, some or all of the other phases may be voids.

[0046] As shown in Figure 1, all the first phase 11 particles may be separated from each other, or some of the first phase 11 particles may be in contact with each other. In this case, the equivalent diameter of the circle calculated from the area of ​​the contacting particles, which are treated as a single particle, must be 30 nm or less on average.

[0047] The mode of the crystallite diameter of the volume-based crystallites in the nanogranular magnetic film 1 is 1.5 nm or more and 6.0 nm or less. The mode of the crystallite diameter of the volume-based crystallites in the nanogranular magnetic film 1 may also be 2.0 nm or more and 5.0 nm or less. When the mode of the crystallite diameter of the volume-based crystallites in the nanogranular magnetic film 1 is within the above range, the saturation magnetic flux density Bs of the nanogranular magnetic film 1 is improved, the real part of the complex permeability is increased, and tanδ (loss coefficient) is decreased. Hereafter, unless otherwise specified, when simply referred to as "permeability," it refers to the real part of the complex permeability.

[0048] The following describes the method for measuring the mode of the crystallite size in a nanogranular magnetic film 1 based on volume.

[0049] Conventionally, when confirming the crystallite size distribution of crystallites in nanogranular magnetic films, a TEM was used to observe the cross-section of the nanogranular magnetic film, and the crystallite size distribution was confirmed by using the equivalent circular diameter of the crystallites within the observation field as the crystallite size.

[0050] However, observations using TEM are very costly in terms of both money and time.

[0051] Furthermore, in order to measure the crystallite size of crystallites with a crystallite size of several nanometers using TEM, it is necessary to use a high observation magnification. However, when observing at high magnification, the number of crystallites whose crystallite size can be measured decreases. Therefore, it is difficult to measure the crystallite size of a sufficient number of crystallites to obtain an accurate distribution of crystallite sizes.

[0052] When performing TEM observation, it is necessary to perform microsampling using FIB to process the sample to a thickness of 10-50 nm. Then, it is necessary to obtain a transmission image of the sample obtained by microsampling. In the nanogranular magnetic film 1, the mode of the crystallite diameter on a volume basis is nanoscale, so the first phase 11 may overlap in the direction of electron beam transmission. When the first phase 11 overlaps in the direction of electron beam transmission, the crystallites contained in the first phase 11 may appear larger than they actually are. In addition, the first phase 11 on the surface of the sample obtained by microsampling may have its surface removed by processing. Therefore, the crystallites contained in the first phase 11 on the surface of the sample may appear smaller than they actually are.

[0053] For the reasons stated above, it is difficult to accurately measure the crystallite size of crystallites contained in the first phase 11 when performing TEM observation on the nanogranular magnetic film 1.

[0054] For powder particles contained in a powder, it is easy to determine the mode of the particle size distribution on a volume basis by using a particle size analyzer. However, conventionally, it has been difficult to determine the mode of the crystallite size distribution on a volume basis for nanogranular magnetic films 1.

[0055] Generally, in XRF (X-ray fluorescence analysis) and XRD (X-ray diffraction), the FP (Fundamental Parameter) method is sometimes used for the analysis of unknown samples or samples for which it is difficult to prepare standard samples.

[0056] In this embodiment, by performing XRD (X-ray diffraction) measurements on the nanogranular magnetic film 1 and analyzing the obtained measurement results using the FP method, the crystallite size distribution on a volume basis can be obtained, and the mode can be measured.

[0057] The following describes methods for obtaining the crystallite size distribution of crystallites and for measuring the mode.

[0058] First, X-ray diffraction is performed on the nanogranular magnetic film 1 using an X-ray diffractometer with 2θ = 30° to 70° and a step of 0.02° to obtain a diffraction chart.

[0059] By analyzing the diffraction chart using the FP method, a histogram representing the volume-based grain size distribution of crystallites is created.

[0060] The diffraction chart contains numerous peaks (crystal peaks and / or halo patterns). First, we determine the peaks observed in the diffraction chart at 2θ = 44° to 45°. This is because at least some peaks originating from nano-sized metal particles are observed around 2θ = 44° to 45°.

[0061] Next, determine the peaks included in the diffraction chart for 2θ = 30° to 70°. There are no particular restrictions on the method of determining the peaks. For example, you may use the peak search function of analysis software to determine the peaks. Furthermore, you may manually add any peaks that were not determined by the analysis software as needed.

[0062] Subsequently, the background is adjusted appropriately so that all peaks originating from nano-sized metal particles are included in the diffraction chart. In other words, the background and the peaks originating from nano-sized metal particles are separated. To put it another way, the peaks originating from nano-sized metal particles do not appear at values ​​lower than the background.

[0063] Schematic diagrams of diffraction charts for 2θ = 35° to 55° are shown in Figures 5 to 7. In Figures 5 to 7, a single broad peak appears. This is because Figures 5 to 7 are schematic diagrams used to explain the background.

[0064] In Figure 5, a straight line connects 2θ=36° and 2θ=54°. In Figure 5, the peak originating from nano-sized metal particles does not appear in the region below the straight line, so the straight line connecting 2θ=36° and 2θ=54° can be considered the formal background.

[0065] Unlike Figure 5, Figure 6 shows that when a straight line is drawn between 2θ=36° and 2θ=54°, the peak originating from linear nano-sized metal particles appears in a region lower than the straight line. In this case, the straight line connecting 2θ=36° and 2θ=54° cannot be considered the formal background.

[0066] In the case of Figure 6, a straight line connecting 2θ=36° and 2θ=54° is used as a provisional background, and then the provisional background is adjusted to determine the formal background line as shown in Figure 7.

[0067] Specifically, a provisional background is created by drawing a straight line between 2θ=36° and 2θ=54°. Then, the height of this provisional background is adjusted as needed to determine the straight line that will become the official background. There are no particular restrictions on how the height of the provisional background is adjusted. For example, it can be adjusted using the background refinement function included in the analysis software, or it can be adjusted manually. After that, refinement is performed in the range of 2θ=35° to 55°. Comparing Figure 6 and Figure 7, the shapes of the diffraction charts appear slightly different. This is because the appearance has changed due to the use of the background refinement function.

[0068] From the peaks originating from nano-sized crystal particles, we can hypothesize the type of crystal phase containing those peaks. The analysis may then be further refined within the range of 2θ = 35° to 55°. From the type of crystal phase and the corresponding peaks, we can determine the crystallite size contained within each crystal phase. This allows us to obtain a volume-based crystallite size distribution.

[0069] Next, a histogram is created from the volume-based crystallite size distribution. The mode of the crystallite size can be identified from the created histogram. There are no particular restrictions on the spacing of the crystallite sizes when creating the histogram, but it should be small enough to identify the mode of the crystallite size with sufficient accuracy.

[0070] The thickness of the nanogranular magnetic film 1 is arbitrary. For example, it may be between 50 nm and 100,000 nm (between 50 nm and 100 μm). A suitable thickness may be appropriately selected depending on the application. There are no particular restrictions on the method for measuring the thickness of the nanogranular magnetic film 1. For example, it can be measured using a TEM, SEM, step thickness gauge, etc. Furthermore, the reliability of the obtained measurement results may be confirmed by regulating the results between multiple measuring devices in advance.

[0071] The method for producing a nanogranular magnetic film according to this embodiment will be described below.

[0072] The nanogranular magnetic film according to this embodiment is manufactured by a sputtering method using the manufacturing apparatus shown in Figures 2 to 4. Figure 2 is a schematic diagram showing a cross-section of the manufacturing apparatus. Figure 3 is a schematic diagram of the manufacturing apparatus (particularly the rotating plate 111a and substrate 113) observed along the direction of the arrow III-III in Figure 2. Figure 4 is a schematic diagram of the manufacturing apparatus (particularly the shutter 131 and sputtering target 123) observed along the direction of the arrow IV-IV in Figure 2.

[0073] A substrate 113 on which a nanogranular magnetic film is sputtered is fixed to the rotating plate 111a of the rotating member 111. The rotating plate 111a is also fixed to the rotating shaft 111b.

[0074] The type of substrate used as the substrate 113 for sputtering the nanogranular magnetic film is arbitrary. Examples include silicon substrates, silicon substrates with oxide films, MgO substrates, (non-magnetic) ferrite substrates, sapphire substrates, glass substrates, white glass substrates, and glass epoxy substrates. However, the type of substrate is not limited to these, and various ceramic substrates and various semiconductor substrates can be used.

[0075] Components (e.g., coils, wiring) that make up a product or part (e.g., a thin-film inductor) may be fabricated on the various substrates described above. For example, coil patterns and wiring patterns for thin-film inductors may be fabricated on a substrate for thin-film inductors.

[0076] Furthermore, foils or sheets of metals or resins can be used as substrates 113 instead of the various substrates mentioned above. For example, metal foils such as Ni, Cu, and Al can be used as substrates 113.

[0077] As a pretreatment for the substrate 113, it is preferable to perform surface treatment under atmospheric pressure using the UV / O3 method and surface treatment in a vacuum, such as reverse sputtering, ion milling, or plasma cleaning. Magnetic films for thin-film inductors have a thick film thickness, so film delamination due to stress is a major problem. However, by performing both of the above surface treatments, the film delamination problem is greatly improved. There are no particular restrictions on the processing time for each surface treatment. For example, the processing time for the UV / O3 method may be 0.1 minutes or more and 60 minutes or less. Also, when reverse sputtering is performed as a surface treatment in a vacuum, the processing time for reverse sputtering may be 0.1 minutes or more and 60 minutes or less.

[0078] There are no particular restrictions on the shapes of the rotating plate 111a and shutter 131 shown in Figures 3 and 4. For example, the outer circumference may be a perfect circle. Let C' be the intersection of the dotted line C in Figure 2 and the surface of the rotating plate 111a, which has a substrate 113, and let C'' be the intersection of the dotted line C in Figure 2 and the shutter 131. Point C' is the center of the rotating plate 111a, which has a perfect circle on its outer circumference, and point C'' is the center of the shutter 131, which has a perfect circle on its outer circumference.

[0079] The sputtering target 123 is mounted on the cathode 121. The type of sputtering target 123 is arbitrary. A composition that will ultimately yield a magnetic film with the desired composition is appropriately selected.

[0080] There are no particular restrictions on the type of cathode 121 included in the sputtering apparatus; it is sufficient if a nanogranular magnetic film can be deposited on the substrate 113 by sputtering.

[0081] As shown in Figure 4, the shutter 131 has a hole above the sputter target 123.

[0082] Next, rotational deposition is performed. Specifically, the rotating plate 111a is rotated by rotating the rotating shaft 111b while sputtering is performed. As a result, a nanogranular magnetic film is intermittently deposited on the substrate 113. This forms a pseudo-multilayer film of nanogranular magnetic film. In other words, in rotational deposition, a pseudo-multilayer film of nanogranular magnetic film is formed by repeating a deposition process in which a nanogranular magnetic film is deposited and a relaxation process in which a nanogranular magnetic film is not deposited.

[0083] In rotary deposition, the time it takes for the nanogranular magnetic film to be deposited on the substrate 113 can be changed by appropriately adjusting the rotation speed of the rotating plate 111a and the lengths of L1 to L5. By appropriately adjusting the positional relationship between the sputtering target 123 and the substrate 113, the sputtering speed can be changed, which in turn changes the minimum incident angle of the sputtered particles deposited on the substrate 113. As a result of these changes, the deposition time per layer of the pseudo-multilayer nanogranular magnetic film (hereinafter sometimes referred to as continuous deposition time) and the deposition thickness per layer (hereinafter sometimes referred to as continuous deposition thickness) can be changed.

[0084] In reality, the boundaries between the films cannot be confirmed even using TEM, so it is described as a "pseudo-multilayer film." The formation of a pseudo-multilayer film of nanogranular magnetic film results in a nanogranular magnetic film in which the mode of the crystallite diameter on a volume basis is between 1.5 nm and 6.0 nm. Furthermore, various properties of the formed nanogranular magnetic film are improved. The reason for this is not clear, but it is thought to be because the stress within the nanogranular magnetic film is relieved by the intermittent deposition of the nanogranular magnetic film.

[0085] There are no particular restrictions on the continuous film deposition time or the continuous film deposition thickness. The continuous film deposition time may be between 0.7 seconds and 5.0 seconds. The continuous film deposition thickness may be between 0.4 nm and 3.0 nm.

[0086] In particular, to suitably control the nitrogen / (oxygen + nitrogen) ratio in the second phase, it is preferable to control the nitrogen and oxygen concentrations in the process gas used during sputtering. Specifically, it is preferable to use a gas obtained by mixing nitrogen and oxygen with an inert gas (e.g., noble gases such as Ar, Kr, Xe, and Ne) as the process gas. In this embodiment, it is particularly preferable to use a gas to which 2 vol% to 10 vol% of nitrogen and 0.001 vol% to 0.1 vol% of oxygen have been added.

[0087] The optimal nitrogen and oxygen concentrations in the process gas depend on the structure of the sputtering apparatus and / or the structure of the cathode 121 included in the sputtering apparatus. The key factor is the N / (N+O) ratio in the final nanogranular magnetic film composition. The nitrogen and oxygen concentrations in the process gas are controlled to achieve the target N / (N+O) ratio in the final nanogranular magnetic film composition.

[0088] By applying a magnetic field to a nanogranular magnetic film formed by sputtering and then performing heat treatment, crystalline particles can be suitably incorporated into the first phase. There are no particular restrictions on the heat treatment temperature; for example, it may be 350°C to 400°C. There are no particular restrictions on the heat treatment time; for example, it may be 0.1 hours to 10 hours. There are no particular restrictions on the magnitude of the magnetic field; for example, it may be between 0.1 kOe and 30 kOe. The higher the heat treatment temperature and the longer the heat treatment time, the larger the crystallite size tends to be.

[0089] In particular, when using a gas containing 6 vol% to 7 vol% nitrogen and 0.1 vol% or less oxygen, and when the heat treatment temperature is 380°C to 400°C, the increase in the mode of the crystallite size associated with an increase in the volume proportion of the first phase is suppressed. As a result, it becomes easier to obtain nanogranular magnetic films with good properties even when the volume proportion of the first phase is increased.

[0090] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment. For example, in the above manufacturing method, the cathode is fixed and the substrate is rotated, but any manufacturing method that can form a pseudo-multilayer film of nanogranular magnetic film is also acceptable, other than a method in which one of the substrate or the cathode is rotated.

[0091] There are no particular limitations on the applications of the nanogranular magnetic film according to this embodiment. The nanogranular magnetic film, and / or the magnetic core containing the nanogranular magnetic film, are particularly suitable for use in electronic components that operate at high frequencies of 100 MHz or higher. [Examples]

[0092] The present disclosure will be described in detail below based on examples. Hereinafter, when referring to the thickness of a nanogranular magnetic film obtained by rotational deposition, the term "thickness of the nanogranular magnetic film" refers to the total thickness of the pseudo-multilayer nanogranular magnetic film. In experimental examples where the thickness of the nanogranular magnetic film is not specifically mentioned, deposition was performed so that the thickness was within the range of 1.70 μm ± 10%. As described later, in experimental examples where the thickness of the nanogranular magnetic film is not specifically mentioned, the target thickness was set to 1.70 μm. The reason for setting the target thickness to 1.70 μm is to ensure stable measurement of permeability even in samples with low permeability of about 10. be.

[0093] Experimental Example 1 Nanogranular magnetic films were deposited on substrates using the apparatus shown in Figures 2 to 4. L1=90mm, L2=2inch, L3=3inch, L4=2inch, and L5=4inch. A 2mm thick sputtering target with a composition that yields nanogranular magnetic films with the compositions shown in each table was attached to the cathode of the sputtering apparatus. An SPF430H sputtering apparatus (manufactured by Anelva Corporation) was used. The thin film compositions shown in each table have been rounded to one decimal place. Therefore, the sum of the content percentages of each element may not equal 100.

[0094] For various characteristic evaluations, a Φ2-inch, 0.28mm thick silicon substrate with a thermal oxide film was used. For compositional analysis, a Φ2-inch, 0.28mm thick sapphire substrate was used. For nitrogen / oxygen measurement, a 50mm square, 50μm (0.05mm) thick Ni foil was used. For step thickness measurement, a 0.28mm thick silicon substrate with straight lines drawn on its surface using a resist pen was used.

[0095] When drawing lines on the surface with the resist pen, specifically, a straight line perpendicular to the orientation flat of the silicon substrate was drawn from the center of the orientation flat of the silicon substrate to the opposite side of the orientation flat of the silicon substrate. Resist was formed in the area where the straight line was drawn with the resist pen.

[0096] For substrates other than the silicon substrate used for measuring step thickness, a surface treatment using the UV / O3 method was performed for 30 minutes as a pretreatment.

[0097] Subsequently, all substrates were attached to the center of a φ3-inch, 0.5mm thick silicon substrate, then placed in a sputtering apparatus, vacuum was applied, and reverse sputtering was performed for 5 minutes. The atmosphere was set to Ar gas pressure of 1 Pa, and the RF power supply output was set to 100 W. In Comparative Example 6, neither pretreatment nor reverse sputtering was performed.

[0098] After re-evacuating the deposition chamber of the sputtering apparatus, nanogranular magnetic films were deposited on all substrates by sputtering. The RF power supply output was set to 400W. The process gas flowing during deposition was a mixture of Ar gas and nitrogen gas and / or oxygen gas at the nitrogen and oxygen concentrations shown in the respective tables. If not specified in the tables, the nitrogen concentration was 4 vol% and the oxygen concentration was 0.01 vol%.

[0099] In all examples and comparative examples except Comparative Example 5, the rotating plate was rotated during sputtering. The rotation speed was 12 rpm, the continuous film deposition time was 1.7 s, and the continuous film deposition thickness was 1.0 nm.

[0100] (film thickness) The substrate for measuring the step thickness after film deposition was immersed in acetone, and the resist was removed from the substrate by lift-off using an ultrasonic cleaner. After resist removal, the substrate was immersed in IPA (isopropanol) and cleaned using an ultrasonic cleaner. The substrate was then dried by removing any remaining organic solvent with a nitrogen blow. Subsequently, the step thickness was measured at a total of five points using a step gauge (KLA Tencor P-16+): the center point of the substrate, points at ±75 mm from the center of the substrate, and points at ±150 mm from the center of the substrate. The average value of the step thickness was used as the total thickness of all thin films deposited simultaneously. In all examples and comparative examples, it was confirmed that the thickness of the thin films was within ±10% of the target thickness (1.70 μm unless otherwise specified).

[0101] (Nitrogen / (Oxygen + Nitrogen)) The substrates for nitrogen / (oxygen + nitrogen) measurement were heat-treated in a vacuum using a magnetic field heat treatment furnace (manufactured by Toei Kagaku Sangyo Co., Ltd.). Unless otherwise specified, the heat treatment conditions were a temperature of 400°C, a treatment time of 1 hour, and an applied magnetic field of 3 kOe.

[0102] A substrate for nitrogen / oxygen measurement after heat treatment, with an area of ​​3 cm². 2 The substrate was cut in the manner described. The cut substrate was placed in a capsule, and the nitrogen / (oxygen + nitrogen) ratio was measured using the impulse heating melt extraction method. The impulse heating melt extraction method was performed using an oxygen-nitrogen analyzer (LECO TC600).

[0103] (composition) The composition of the first phase, the composition of the second phase, and V1 / (V1+V2) were confirmed by using XRF (Primus4, Rigaku Corporation) on thin films deposited on a substrate for compositional analysis and heat-treated.

[0104] The following describes the specific method for confirming V1 / (V1+V2) in this embodiment. First, it was assumed that all elements corresponding to the element M of the second phase quantified by XRF (for example, Si, Al, Ga, Mg, Zr, Hf, and rare earth elements) exist in the second phase as oxides or nitrides, and that other elements (excluding oxygen, nitrogen, and fluorine (= light elements)) exist in the first phase. In experimental examples other than Experimental Example 4 described later, element M is Si. The ratio of O to N in the nanogranular magnetic film deposited on Ni foil, which was deposited and heat-treated simultaneously with the substrate for compositional analysis, was measured by the impulse heating and melting method. It was assumed that all elements M of the second phase were oxidized or nitrided. Then, the volume V2 of the second phase was calculated from the ratio of the oxide and nitride of M, the composition of the oxide of M, the molar mass of the oxide of M, the density of the oxide of M, the composition of the nitride of M, the molar mass of the nitride of M, and the density of the nitride of M. The volume V1 of the first layer was calculated from the compositional analysis results of the XRF, the composition of each atom in the first phase 11, the molar mass of each atom in the first phase, and the density of the first phase. Then, V1 / (V1+V2) was calculated.

[0105] (characteristic) Substrates cut to a 6mm square size for various property evaluations after film deposition were heat-treated in a vacuum using a magnetic field heat treatment furnace (manufactured by Toei Kagaku Sangyo Co., Ltd.). Unless otherwise specified, the heat treatment conditions were a temperature of 400°C, a treatment time of 1 hour, and an applied magnetic field of 3kOe.

[0106] The saturation magnetic flux density Bs of magnetic films deposited on substrates for various characteristic evaluations after heat treatment was measured using a VSM (Tamagawa Seisakusho Co., Ltd. TM-VSM331483-HGC). Specifically, BH characteristics were acquired using the VSM at a maximum applied magnetic field of 10,000 Oe, and Bs was calculated from the acquired BH characteristics. A Bs of 0.75 T or higher was considered good.

[0107] The resistivity of magnetic films deposited on substrates for various characteristic evaluations after heat treatment was calculated from the sheet resistance and film thickness obtained using a Mitsubishi Chemical Loresta EP. A resistivity of 500 μΩcm or higher was considered good, and 1000 μΩcm or higher was considered even better.

[0108] Permeability and tanδ (loss factor) were measured using a high-frequency permeability measuring instrument (PMF-3000, manufactured by Ryowa Electronics Co., Ltd.). The values ​​for permeability and tanδ used were those obtained at a measurement frequency of 100 MHz. A permeability of 80 or higher was considered good, and a tanδ of 0.100 or lower was considered good.

[0109] In this embodiment, the mode of the crystallite size was measured by the following method. First, the nanogranular magnetic film deposited on a substrate for various property evaluations after heat treatment was subjected to X-ray diffraction using an X-ray diffractometer (SmartLab Studio2 manufactured by Rigaku Corporation) with 2θ = 30° to 70° and a step of 0.02° to obtain a diffraction chart.

[0110] By analyzing the diffraction chart obtained by X-ray diffraction using the fission function (FP) method, a histogram representing the volume-based grain size distribution of crystallites was created.

[0111] The FP method analysis was performed using the "Powder XRD" attached to the X-ray diffractometer. In this embodiment, first, the peak observed at 44° to 45° in the diffraction chart was determined. Next, the peaks in the diffraction chart from 2θ=30° to 70° were determined using the peak search function of the analysis software. Furthermore, peaks that were not determined by the analysis software were manually added by visual inspection as needed. Subsequently, the background was adjusted as appropriate so that all peaks originating from nano-sized metal particles observed in the diffraction chart were included in the diffraction chart. Specifically, a provisional background was created by drawing a straight line between 2θ=36° and 2θ=54°, and then the height of this provisional background was adjusted as needed. When adjusting the height of the provisional background, the background refinement function included in the analysis software was used.

[0112] Subsequently, the axial divergence model of the FP model in the "Powder XRD" instrument model was set to Ida, the peak shape of the profile fitting was set to the FP method, and the crystallite size distribution type was set to a log-normal distribution.

[0113] Next, the crystalline phase was identified. Specifically, the type of crystalline phase was first assumed. Depending on the composition of each sample, it was assumed that the crystalline phase consisted of either Fe, FeCo, or FeNi with a body-centered structure. Specifically, the crystalline phase was assigned DB card number 01-071-7173. Then, the analysis was refined again in the range of 35° to 55°, and the type of crystalline phase and the size of the crystallites contained in each crystalline phase were identified from the crystal peaks. Finally, a volume-based crystallite size distribution was obtained.

[0114] Then, a histogram was created from the volume-based crystallite size distribution, and the mode was identified from the resulting histogram. The spacing of the crystallite sizes was kept sufficiently small during histogram creation. In this example, it was set to 0.05 nm or less.

[0115] Table 1 shows examples and comparative examples in which the mode of the crystallite size was changed by varying the film deposition conditions.

[0116] [Table 1]

[0117] As shown in Table 1, Examples 1-6 and 6a, which have a composition within a specific range and whose mode of crystallite size is within a predetermined range, exhibited good properties.

[0118] In contrast, Comparative Examples 1 and 2, where the nitrogen concentration in the process gas was relatively too low, showed a larger mode in the crystallite size. Furthermore, Comparative Examples 1 and 2 had excessively high tanδ values.

[0119] Comparative Example 3, where the oxygen concentration in the process gas was relatively too low, showed a large mode in the crystallite size. Furthermore, Comparative Example 3 had an excessively high tanδ.

[0120] Comparative Example 4, where the oxygen concentration in the process gas was relatively too high, showed a smaller mode in the crystallite size. Furthermore, Comparative Example 4 had excessively low Bs, excessively low magnetic permeability, and excessively high tanδ.

[0121] Comparative Example 5, in which film deposition was performed without substrate rotation and did not result in a pseudo-multilayer film, had excessively low Bs and permeability, and excessively high tanδ.

[0122] Comparative Example 6, in which neither UV / O3 surface treatment nor reverse sputtering was performed, showed insufficient adhesion of the magnetic film to the substrate, resulting in film peeling.

[0123] Furthermore, Table 2 shows Examples 7-11, which were carried out under the same conditions as Examples 1-3 and 5-6, except that V1 / (V1+V2) was changed to 47%. Table 2 also shows Examples 12-16, which were carried out under the same conditions as Examples 1-3 and 5-6, except that V1 / (V1+V2) was changed to 72%.

[0124] [Table 2]

[0125] As shown in Table 2, Examples 7-16, which are nanogranular magnetic films having a composition within a specific range and whose mode of crystallite size is within a predetermined range, exhibited good properties similar to Examples 1-3 and 5-6.

[0126] Experimental Example 2 Table 3 shows examples and comparative examples that were carried out under the same conditions as Example 3 of Experimental Example 1, except that the nitrogen concentration in the process gas was changed and the heat treatment temperature was changed to the temperatures shown in Table 3. Figures 1A to 1C are TEM images of the cross-section of Example 19.

[0127] [Table 3]

[0128] As shown in Table 3, Examples 17-26, 21a, and 26a, which are nanogranular magnetic films having a composition within a specific range and whose mode of crystallite size is within a predetermined range, exhibited good properties similar to those of Example 3.

[0129] In contrast, Comparative Examples 7-9, where the mode of the crystallite size was too small, had too low a Bs value and too high a tanδ value. Furthermore, Comparative Examples 7 and 8 also had too low a magnetic permeability.

[0130] Experimental Example 3 Table 4 shows examples prepared under substantially the same conditions as Example 19 of Experimental Example 2, except that the composition of the first phase was changed. Examples 27-30 are samples in which the FeCo ratio was changed from that of Example 19. A sputtering target adjusted so that V1 / (V1+V2) was 58% was used. A film was deposited.

[0131] Example 31 has a first phase composition of Fe 55 Co 35 Ni 10 To achieve this, five 5mm x 5mm x 1mmt Ni chips were placed in suitably controlled positions on the sputtering target used in Example 19 to prepare a sample.

[0132] Examples 32-52 have a first phase composition that is generally Fe 59 Co 39 To achieve X12, metal or alloy chips of type X1 shown in Table 4 were placed in a suitable number at suitably controlled positions on the sputtering target used in Example 19. Furthermore, samples were prepared using the sputtering target with adjusted composition.

[0133] [Table 4]

[0134] As shown in Table 4, Examples 27-52, in which the mode of the crystallite size remained within a predetermined range even when various elements were added to the nanogranular magnetic film, exhibited good properties similar to Example 19.

[0135] Experimental Example 4 Tables 5, 6, and 7 show examples prepared under substantially the same conditions as Example 19, except that the composition of the second phase was changed from Example 19 by including specified amounts of Al2O3, Ga3O4, MgF2, MgO, ZrO2, HfO2, Y2O3, and La2O3 in the sputtering target.

[0136] Table 5 shows Examples 53-56, in which some or all of the SiO2 in the sputtering target of Example 19 is replaced with Al2O3. The method for confirming the ratio of O to N in the nanogranular magnetic film and V1 / (V1+V2) is the same as in Experimental Example 1, except that the element M is Si and / or Al.

[0137] Table 6 shows Examples 57-60 in which some or all of the SiO2 in the sputtering target of Example 19 is replaced with Ga2O3. The method for confirming the ratio of O to N in the nanogranular magnetic film and V1 / (V1+V2) is that element M is Si and / or Ga. Aside from the point, it is the same as in Experimental Example 1.

[0138] Table 7 shows Examples 61-66, in which 5 vol% of the SiO2 contained in the sputtering target of Example 19 was replaced with other compounds (oxides or fluorides). Specifically, fluorides were used as the other compound in Example 54, and oxides were used as the other compound in Examples 55-59. The method for confirming the ratio of O to N in the nanogranular magnetic film and V1 / (V1+V2) is the same as in Experimental Example 1, except that the type of element M is Si and Mg (Examples 61, 62), Si and Zr (Example 63), Si and Hf (Example 64), Si and Y (Example 65), and Si and La (Example 66).

[0139] [Table 5]

[0140] [Table 6]

[0141] [Table 7]

[0142] Tables 5, 6, and 7 show that even when the composition of the second phase is changed, the nanogranular magnetic films having a composition within a specific range and the mode of the crystallite diameter being within a predetermined range exhibited good properties similar to those of Example 19.

[0143] Experimental Example 5 Table 8 shows examples and comparative examples that were carried out under substantially the same conditions, except that V1 / (V1+V2) was changed from Example 19. Similarly, Table 9 shows examples and comparative examples that were carried out under substantially the same conditions, except that V1 / (V1+V2) was changed from Example 21.

[0144] [Table 8]

[0145] [Table 9]

[0146] Tables 8 and 9 show that the smaller V1 / (V1+V2) was, the smaller the mode of the crystallite size on a volume basis tended to be. Furthermore, Examples 67-73, in which the mode of the crystallite size on a volume basis was within a predetermined range, exhibited good properties similar to Example 19. In addition, Examples 74-77, in which the mode of the crystallite size on a volume basis was within a predetermined range, exhibited good properties similar to Example 21.

[0147] In contrast, Comparative Examples 10 and 12, where the mode of the crystallite size on a volume basis was too small, resulted in Bs being too low, permeability too low, and tanδ too high. Comparative Examples 11 and 13, where the mode of the crystallite size on a volume basis was too large, resulted in tanδ being too high.

[0148] Experimental Example 6 Examples 78 to 82 were conducted under the same conditions as Example 19, except that the target film thickness was changed. In Example 78, the target film thickness was set to 0.05 μm; in Example 79, to 0.50 μm; in Example 80, to 5.0 μm; in Example 81, to 10 μm; and in Example 82, to 30 μm. The results are shown in Table 10.

[0149] [Table 10]

[0150] Table 10 shows that Examples 78-82, which have a composition within a specific range even when the film thickness is changed and whose mode of crystallite diameter is within a predetermined range, had properties very similar to those of Example 19. In other words, it is considered that the properties of nanogranular magnetic films with a composition within a specific range are very small in terms of film thickness.

[0151] Experimental Example 7 Examples 83 to 87 were carried out under substantially the same conditions as in Example 19, except that the substrate to which the film was deposited was changed. The results are shown in Table 11.

[0152] [Table 11]

[0153] Table 11 shows that even when the substrate was changed, the nanogranular magnetic films having a composition within a specific range and the mode of the crystallite size within a predetermined range, as measured by Examples 83-87, exhibited properties very similar to those of Example 19. In other words, it is considered that the properties of nanogranular magnetic films having a composition within a specific range are very substrate-dependent.

[0154] In all the examples described in Tables 1 to 11, the first phase is composed of Fe a Co b X1 c The composition is expressed as (atomic ratio), and it was confirmed that X1 is one or more elements selected from Ni, B, C, P, V, Cr, Mn, Cu, Zn, Nb, Mo, Ru, Rh, Pd, Ag, Sn, Ta, W, Ir, Pt, and Au, and that the following conditions are met: 0.30 ≤ a ≤ 0.90, 0.10 ≤ b ≤ 0.70, 0.00 ≤ c ≤ 0.10, and a + b + c = 1.

[0155] Experimental Example 8 Table 12 shows examples and comparative examples that were carried out under substantially the same conditions, except that V1 / (V1+V2) was changed from Example 21a.

[0156] [Table 12]

[0157] Table 12 shows that the smaller V1 / (V1+V2) was, the smaller the mode of the crystallite size on a volume basis tended to be. Furthermore, Examples 88-98, in which the mode of the crystallite size on a volume basis was within a predetermined range, exhibited good properties similar to Example 21a.

[0158] In contrast, Comparative Example 14, in which the mode of the crystallite size on a volume basis was too small, resulted in a Bs value that was too low, a magnetic permeability that was too low, and a tanδ value that was too high. Comparative Example 15, in which the mode of the crystallite size on a volume basis was too large, resulted in a resistivity that was too low, a magnetic permeability that was too low, and a tanδ value that was too high.

[0159] In all the examples described in Tables 1 to 12, the second phase is composed of the same formula as M d O e N f X2 g It was confirmed that the composition has the following characteristics: (atomic ratio), M is one or more elements selected from Si, Al, Ga, Mg, Zr, Hf, and rare earth elements such as Y and La, X2 is one or more elements selected from F and S, and satisfies 0.20 ≤ d1 ≤ 0.45, 0.00 ≤ g ≤ 0.05, and d1 + e + f + g = 1.

[0160] In all the examples described in Tables 1 to 12, it was confirmed that the nitrogen / (oxygen + nitrogen) ratio in the entire nanogranular magnetic film was substantially equal to the f / (e+f) ratio in the second phase. [Explanation of Symbols]

[0161] 1…Nanogranular magnetic film 11…Phase 1 12...Phase 2 111... Rotating member 111a... Rotating plate 111b... Rotation axis 113... Circuit board 121... Cathode 123... Spatter target 131...Shutter

Claims

1. A nanogranular magnetic film having a structure in which the first phase is dispersed in the second phase, The nanogranular magnetic film has a nano-sized metallic phase containing Fe and Co as the first phase, and oxygen and nitrogen as the second phase. The aforementioned metallic phase contains one or more crystallites, A nanogranular magnetic film in which the mode of the crystallite diameter of the crystallites in the nanogranular magnetic film, based on volume, is 1.5 nm or more and 6.0 nm or less.

2. The nanogranular magnetic film according to claim 1, wherein the mode of the crystallite size of the crystallites is 2.0 nm or more and 5.0 nm or less.

3. The nanogranular magnetic film according to claim 1 or 2, wherein the value obtained by dividing the nitrogen concentration of the nanogranular magnetic film by the sum of the oxygen concentration and nitrogen concentration of the nanogranular magnetic film is 0.090 or more and 0.50 or less on an atomic basis.

4. The nanogranular magnetic film according to claim 1 or 2, wherein the total volume proportion of the first phase is 48% or more and 90% or less.

5. The nanogranular magnetic film according to claim 1 or 2, wherein the total volume proportion of the first phase is 48% or more and 70% or less.

6. A magnetic core having a nanogranular magnetic film according to claim 1 or 2.

7. An electronic component having a nanogranular magnetic film according to claim 1 or 2.

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