KR20130098452A - Particulate alloy thin film and their manufacturing method - Google Patents

Abstract

PURPOSE: An alloy granulated thin film and a manufacturing method thereof are provided to supply an alloy thin film which forms an insulation layer with high specific resistance as well as high magnetic flux density. CONSTITUTION: A manufacturing method of an alloy granulated thin film comprises the following steps. An alloy thin film which is formed on a solid substrate is treated with heat by supplying hydrogen including vapor to an alloy thin film (230). A part of first solute elements which have large oxygen effinity are selectively oxidized. The alloy thin film is granulated to form an insulation layer. The oxidized first solute elements form an insulation layer (240) on a granulated alloy thin film and a solid substrate after the alloy thin film is granulated. [Reference numerals] (210) Arrange an alloy thin panel and perform the purging of devices; (220) Generate a gas mixture of hydrogen and vapor; (230) Heat treatment; (240) Generate an alloy grained thin film

Description

Alloy particle thin film and their manufacturing method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the granulation of alloy thin films. In particular, by heat treatment of an alloy thin film made on a solid substrate in a hydrogen mixed gas containing water vapor, the first element of the alloy is selectively oxidized and the film gradually changes discontinuously, resulting in discontinuous thin film formation. Alternatively, the present invention relates to an alloy granulated thin film in which an insulating layer is formed on an alloy thin film by causing selective oxidation to be granulated, and a method of manufacturing the same.

The present invention is the result of a research conducted under the support of the Ministry of Education, Science and Technology in 2011 (Research Project Name: General Researcher Support, Project Title: Forming a High Quality Insulation Film for Soft Magnetic Metal Powders).

Iron-based alloys in which silicon (Si), aluminum (Al), magnesium (Mg), chromium (Cr), titanium (Ti), zirconium (Zr), hafnium (Hf), etc., are added to iron (Fe). Widely used as a material of magnetic elements. Such iron-based alloys are generally used by coating an insulating layer to reduce power loss, increase electrical resistance, reduce eddy current loss, and reduce coercive force to reduce hysteresis loss.

The iron alloy powder is mainly used to coat the insulating layer on the iron alloy. The iron alloy powder is mainly made of atomizing or grinding, and is made of fine powder through vacuum deposition or reduction in aqueous solution. do.

Among methods for coating an insulating layer on an iron alloy, a method for producing an iron alloy powder using magnesium (Mg) oxide (MgO) is disclosed in US Patent Publication No. 2008 / 0003126A1 (published Jan. 3, 2008). producing soft magnetic metal powder coated with MG-containing oxide film and method for producing composite soft magnetic material using said powder 'and' Iron powder coated with MG-, published in US 2009 / 0174512A1. containing oxide film '.

On the other hand, when the iron alloy powder is fixed to a solid substrate and intended to be used for applications such as a high frequency filter or a thin film inductor, it may be manufactured using a screen printing method or the like, mainly by mixing with a vacuum deposition method or a polymer binder.

The conventional method of manufacturing a thin film using the iron-based alloy powder is prepared by applying an iron-based alloy powder having an insulating layer formed on a substrate, there is a technically very difficult problem to precisely control the thickness of the applied powder to a few μm or less.

In particular, due to the miniaturization and high response of the electromagnetic circuit, the ferroalloy thin film must be manufactured to maintain high magnetic flux density and high magnetic flux density. Therefore, an insulating layer covering the ferroalloy powder must be sufficiently secured. To be applied thin enough to the conventional manufacturing method has a problem that can not provide an insulating layer and a coating layer having a minimum thickness and sufficient performance.

Accordingly, an object of the present invention for solving the above problems is to provide an alloy particle thin film and a method of manufacturing the same that can provide an alloy thin film having a high magnetic flux density while forming an insulating layer having a high resistivity.

In addition, another object of the present invention is to provide an alloy granular thin film and a method for manufacturing the alloy thin film which can provide an alloy thin film having a high resistivity with improved performance while having a simple manufacturing process.

In order to achieve the above object, the present invention is to fix the alloy powder widely used as a material of electric, electronic and magnetic elements such as motors, actuators, yokes, cores, reactors to a solid substrate to use in the form of an alloy thin film, In order to precisely adjust the thickness of the powder to be applied to several μm or less, the first solute element of the alloy is first heat-treated in a hydrogen mixed gas containing water vapor by an alloy thin film made on a solid substrate by sputtering, vacuum deposition, plating, or the like. The film gradually changes discontinuously during the oxidizing reaction and finally becomes granular, thereby improving the properties of the alloy thin film forming the insulating layer.

In addition, the alloy particle thin film according to the present invention is an XY thin film (X = Au, Pt, Ag, Ni, Fe, Cu, Co, Zn, Sn, V, Mn, Y = Al, Si, Ti, Mg, Hf, The first solute element (Y = Al) contained in the alloy thin film is made by Zr (hereinafter referred to as “alloy thin film”) made of sputtering, vacuum deposition, or electroplating on an oxide substrate, and then supplied with hydrogen containing steam to heat treatment. , Si, Ti, Mg, Hf, Zr) is selectively oxidized and the alloy thin film is granulated to form an insulating layer having a high specific resistance.

The alloy granular thin film according to the present invention for achieving the above object is heat-treated by supplying hydrogen containing water vapor to the alloy thin film formed on a solid substrate, the agent having a high affinity for oxygen among the solute elements included in the alloy thin film A portion of the one solute element is selectively oxidized, and the alloy thin film is granulated, and the oxidized first solute element forms an insulating layer on the granulated alloy thin film and the solid substrate.

In addition, the alloy granular thin film manufacturing method according to the present invention for achieving the above object is affinity with oxygen among the solute elements included in the alloy thin film by supplying hydrogen containing water vapor to the alloy thin film formed on a solid substrate. Selectively oxidizing a part of the large first solute element causes the alloy thin film to be granulated, and the oxidized first solute element forms an insulating layer on the granulated alloy thin film and the solid substrate. It is done.

In this case, the first solute element is at least one of silicon (Si), aluminum (Al), magnesium (Mg), chromium (Cr), titanium (Ti), zirconium (Zr) and hafnium (Hf). .

In this case, the alloy thin film is the first solute element and gold (Au), platinum (Pt), silver (Ag), nickel (Ni), iron (Fe), copper (Cu), cobalt (Co), zinc (Zn) ), Tin (Sn), vanadium (V), and manganese (Mn), and an alloy with at least one of the second solute elements.

The present invention does not manufacture an alloy thin film having an insulating layer by screen printing, sputtering, vacuum deposition, or electrocoating an alloy powder coated with an insulating layer on a substrate, but forms an insulating layer having a high resistivity on the alloy thin film by selective oxidation. By doing so, there is an effect that a process can be made simple and an alloy thin film in which an insulating layer with high specific resistance is high can be produced.

As a result, an alloy thin film having a simple and thin thickness and having a constant insulating layer can be manufactured, thereby increasing the quality of the product and lowering the manufacturing cost.

In addition, since the present invention can form an ultra-thin insulating layer having a high resistivity and maintain a high magnetic flux density, it is possible to produce ultra-small and high-performance electronic devices, components and products.

1 is a device configuration for the production of alloy granulated thin film according to the present invention,
2 is a view showing a manufacturing process of an alloy granular thin film according to the present invention;
Figure 3 is a photograph sequentially showing the shape change of the surface of the thin film according to the heat treatment time in the manufacturing process of the alloy granular thin film according to the present invention,
4 is a view showing the results of analyzing the chemical composition and component mapping of the white particles shown in (e) of FIG.
5 is a graph showing the change in the specific resistance of the thin film according to the heat treatment time in the alloy granulation thin film manufacturing process according to the present invention,
Figure 6 is a graph of the measurement of the magnetization curve of the thin film according to the heat treatment time in the alloy particle thin film manufacturing process according to the present invention,
7 is a component change graph according to the depth of the alloy particle thin film according to the present invention,
8 is a graph analyzing the binding energy of Al according to the depth of the alloy particle thin film according to the present invention,
9 is a graph showing the X-ray diffraction analysis results of the alloy particle thin film according to the present invention,
10 is a cross-sectional schematic of the alloy granulated thin film prepared according to the present invention,
11 and 12 are graphs showing the change in permeability according to the frequency of the alloy granular thin film according to the present invention,
13 and 14 are graphs showing changes in permeability according to frequencies of CoZrNb and FeCoNiB soft magnetic thin films, which are currently developed for comparison with the permeability characteristics of alloy granular thin films according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. It should be noted that the same configurations of the drawings denote the same reference numerals as possible whenever possible. Specific details are set forth in the following description, which is provided to provide a more thorough understanding of the present invention. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In particular, in the following description of the alloy particle thin film and the method for manufacturing the same according to the present invention with reference to the drawings, the alloy will be described as a representative embodiment using Fe-Al. For convenience of explanation, only iron (Fe) and aluminum (Al) are used as an example, and the first solute elements such as aluminum (Al) forming an alloy thin film are silicon (Si), aluminum (Al), and magnesium (Mg). ), Chromium (Cr), titanium (Ti), zirconium (Zr) and hafnium (Hf) may be at least one, and a second solute element such as iron (Fe) forming an alloy thin film with the first solute element. Silver (Au), Platinum (Pt), Silver (Ag), Nickel (Ni), Iron (Fe), Copper (Cu), Cobalt (Co), Zinc (Zn), Tin (Sn), Vanadium (V) And manganese (Mn).

Therefore, in the following Fe-Al thin film refers to the alloy thin film, the alloy thin film according to the present invention is finally produced an alloy thin film treated according to the alloy granulation method according to the present invention.

First, Figure 1 is a block diagram of a manufacturing apparatus for producing an alloy particle thin film according to the present invention, Figure 2 is a view showing a manufacturing process of the alloy particle thin film according to the present invention.

Prior to the preparation of the alloy granular thin film according to the present invention, an alloy thin film (Fe-Al thin film) is prepared. The Fe-Al thin film is a sputtered Fe-Al alloy on an oxide substrate to a predetermined thickness. In one embodiment of the present invention, the Fe-Al thin film is obtained by oxidizing a silicon wafer at 1000 ^° C. to grow a silicon oxide having a thickness of 200 nm. Then, a Fe-Al thin film having a thickness of 200 nm was prepared by sputtering at room temperature on a silicon oxide substrate using Fe-5wt.% Al as a target in an RF sputtering machine.

1 and 2, in the method of manufacturing the alloy granular thin film according to the present invention, first, the Fe-Al thin film 110 prepared in step 210 is positioned in the heat treatment part 120 (furnace) of FIG. 1. After purging is carried out with nitrogen (130, N ₂ ) to remove the oxygen remaining in the heat treatment unit 120 and the pipe. Accordingly, all of the oxygen remaining in the pipe from the nitrogen and hydrogen storage units 130 and 140 to the water vapor mixing unit 150, the condensing unit 160, and the heat treatment unit 120 is removed by nitrogen.

Subsequently, when purging in step 210 is completed, hydrogen of 100-2000 SCCM (Standard Cubic Centimeter per Minute) passed through ion-exchanged water maintained at 10 ^o C in the steam mixing unit 150 is maintained at -17 ^o C again. Passing through the condensation unit 160 is a copper tube is formed to produce a hydrogen-vapor mixture gas with a dew point of -17 ^° C (step 220). Subsequently, the Fe-Al thin film 110 is heat treated for 10-200 minutes while applying the mixed gas mixed in step 220 to the heat treatment part 120 maintained at 900 ^° C. (step 230).

Meanwhile, the hydrogen supply confirmation unit 170 of FIG. 1 confirms whether hydrogen is supplied to the heat treatment unit 120, and the hydrogen removal unit 180 removes the hydrogen introduced when confirming the hydrogen supply.

3 is a photograph sequentially showing the shape change of the surface of the thin film according to the heat treatment time in the manufacturing process of the alloy granular thin film according to the present invention, (a), (b), (c), (d), (e) Is a scanning electron microscope (Scanning Electron Microscop, SEM) photograph of the surface heat-treated Fe-Al thin film 110 for 0, 50, 60, 100, 200 minutes, respectively, and (f) has a dew point of -169 ^o C. Scanning microscope photograph of the surface of a thin film heat-treated at 900 ^° C. for 200 minutes with hydrogen gas.

Scanning electron micrographs shown in (a), (b), (c), (d) and (e) of FIG. 3 are all heat-treated at 900 ° C. in wet hydrogen having a dew point of −17 ° C. , (f) is heat treated at 900 ^° C. for 200 minutes in a hydrogen gas having a dew point of -169 ^° C. containing almost no water vapor, and (a), (b), It is shown together for the comparison with the shape of Fe-Al thin film 110 of (c), (d), (e).

Referring to FIG. 3A, a thin film not subjected to heat treatment shows a smooth surface like a general alloy thin film. In (a), the upper left particle is an adsorbate on the surface.

Next, when the Fe-Al thin film 110 is heat-treated for 50 minutes, as shown in (b), white particles having a diameter of 1 μm or less may be uniformly generated in the entire thin film, and the Fe-Al thin film 110 may be 60 After a minute heat treatment, as shown in (c), the white particles grow considerably and coarse, but show discontinuous particle shape.

After 100 minutes of heat treatment, the white particles no longer grow as shown in (d) but change more discontinuously with each other, and after 200 minutes of heat treatment, the particles become individual particles which are not connected as in (e). .

Looking at (f) in comparison with the above-mentioned (a), (b), (c), (d), and (e), the Fe-Al thin film 110 of (f) is 10 to 50, as shown in (b). White spots are seen, like a film heat-treated for a minute, but the size is larger than (b). That is, when the Fe-Al thin film 110 was heat-treated with two different types of steam-hydrogen mixtures with dew point -169 ^o C and -17 ^o C, the alloy thin film had a large difference in surface shape.

Looking at the causes of the change of each of the photos shown in Figure 3, first, the Fe-Al thin film 110 is sputtered on the oxide substrate and then heat treated in wet hydrogen, the alloy thin film and the oxide substrate surface is not good wettability (wetability) each other The alloy thin film is coarsened and spherical to reduce interfacial energy. At this time, since the activation energy must be large in order for Fe and Al atoms to be easily diffused, coarsening or spheroidization easily occurs at a high temperature, but when the heat treatment is performed at a low temperature, the coarsening phenomenon does not easily occur.

Nevertheless, according to the present invention, while Al is moved to the Fe-Al and Al ₂ O ₃ interface as the selective oxidation proceeds, the Fe atom is supplied with energy so that the Fe atom can be easily moved, thereby selecting even at a relatively low temperature. Oxidation leads to coarsening or spheroidization. However, care must be taken at low temperatures because of the moisture oxidation of the alloy thin films.

FIG. 4 shows the results of analyzing the chemical composition and the component mapping of the white particles shown in FIG. 3 (e), which are selectively oxidized at 900 ° C. for 200 minutes in wet hydrogen having a dew point of −17 ° C. FIG. Chemical composition of Fe-Al thin film and energy dispersive spectroscopy (EDS) analysis photos by composition are shown.

As shown in Figure 4, the chemical composition of the white particles (A) is 4.75at.% Oxygen, 4.46at.% Aluminum, 90.79at.% Iron, the chemical composition of the black background (B) is 47.42at.% Oxygen, 33.59 at% aluminum and 19 at% iron. Considering that there are small white particles on the black background, the black background is mostly composed of Al ₂ O ₃ film, and the white particles are Fe 4.68, which is much reduced aluminum than the initial composition Fe-9.8at.% Al due to the much oxidation of aluminum. It has a composition of at.% Al. The results of FIG. 4 are also consistent with the component mapping images of Fe, Al, and Si of the bottom of the component mapping.

5 is a graph showing a change in the specific resistance of the thin film according to the heat treatment time during the alloy granulation thin film manufacturing process according to the present invention, the heat treatment unit 120 to maintain a hydrogen-vapor mixed gas having a dew point of -17 ^o C at 900 ^o C ) Is the change of the resistivity of thin film according to the heat treatment time when heat-treating the Fe-Al thin film for 0-200 minutes.

Referring to FIG. 5, the resistivity decreases during the initial 5 minutes, but gradually increases and heat treatment for 100 minutes increases the resistivity by about 33 times compared to the unheat-treated thin film. However, after 200 minutes of heat treatment, the specific resistance becomes too large, which is beyond the measurable limit. From the results of FIG. 5, it can be seen that when the Fe-5at.% Al thin film is heat-treated, aluminum is selectively oxidized to gradually thicken the aluminum oxide layer on the surface.

6 is a graph measuring a thin film magnetic curve according to the heat treatment time in the granulation alloy thin film manufacturing process in accordance with the present invention, dew point -17 ^o C in a hydrogen-0-200 minutes, Fe-Al thin film of water vapor mixed gas at 900 ^o C It shows the result of measuring the magnetization curve according to the heat treatment time by vibrating sample magnetometer (VSM).

Referring to FIG. 6, the thin film not subjected to heat treatment not only has excellent soft magnetic properties but also shows a magnetization curve of a square shape. However, as the heat treatment time passes, the magnetization curve of the rectangle changes obliquely. This is because as the heat treatment time increases, as shown in FIG. 3, the Fe—Al thin film gradually changes discontinuously and the anti-magnetic field increases between the Fe—Al particles.

In particular, after 200 minutes of heat treatment, most of them are in the form of individual particles, and the anti-magnetic field becomes very large. However, in the Fe-Al thin film heat-treated in high purity hydrogen, selective oxidation does not occur, and thus coarsening or spheroidization does not occur largely to maintain the magnetization curve of the rectangle.

In the alloy granular thin film according to the present invention, the aluminum content is decreased in the Fe—Al thin film due to the selective oxidation of Al, so that the saturation magnetization of the heat-treated thin film is larger than that of the unheated thin film.

In particular, the alloy granular thin film according to the present invention is heat-treated Fe-5wt.% Al thin film for 100, 200 minutes as measured in the case that the particles are not connected to each other as shown in (d), (e) of FIG. As the magnetization curve slopes near the origin, the permeability of the Fe-Al thin film can be maintained at very high frequencies.

7 is a graph of the composition change according to the depth of the alloy particle thin film according to the present invention, after the Fe-5wt.% Al thin film heat treated at 900 ^o C for 20 minutes with a mixture of water vapor and hydrogen with a dew point of -17 ^o C It was measured by X-ray photoelectron spectroscopy (XPS). Component analysis according to the depth using the XPS of FIG. 6 is to remove the surface by sputter etching with Ar ions and the like, and then analyze the components of the surface. In this analysis, the etching rate is about 1 nm per minute.

7, during a 50-minute etch time seen that the iron is detected only aluminum and oxygen is hardly detected, and there, and only the Al ₂ O ₃ present the surface of the alloy particle formation thin film according to the present invention, a thickness of about 50 It can be seen that it is less than nm.

8 is a graph analyzing the binding energy of Al according to the depth of the alloy particle thin film according to the present invention, showing the result of analyzing the binding energy of aluminum according to the depth through XPS.

Referring to FIG. 8, as the distance from the surface decreases, the binding energy between molecules decreases from 74.3 eV to 73 eV, so that Al ₂ O ₃ exists on the surface and metal aluminum exists inside. The chemical shift of aluminum from ₂ O ₃ to metallic aluminum can be clearly seen.

9 is a graph showing the results of X-ray diffraction analysis of the alloy particle thin film according to the present invention. The Fe-5 wt.% Al alloy thin film heat-treated at 900 ^° C. for 200 minutes with a hydrogen-vapor mixture gas having a dew point of -17 ^° C. a shows an x- ray diffraction analysis, Fe-Al phase and the γ -Al ₂ O ₃ in addition to the Fe-Al-O, the oxide can be detected diffraction lines not generated oxides, such as Fe-O γ -Al ₂ O ₃ phase can be confirmed.

10 is a cross-sectional schematic diagram of the alloy granulated thin film prepared according to the present invention, showing a cross-sectional schematic diagram of the alloy granulated thin film prepared according to the present invention with reference to the experimental results of FIGS.

Referring to FIG. 10, the coarsened Fe-Al alloy particles 113 are in contact with the substrate 111, and the substrate 111 and the coarse Fe-Al alloy particles 113 are Al ₂ O ₃ oxide layers. Surrounded by (115), it is assumed that fine Fe-Al alloy particles 117 are evenly distributed in the Al ₂ O ₃ oxide layer 115.

Therefore, the alloy granular thin film prepared according to the present invention is made of aluminum oxide (Al ₂ O ₃ ) surface, and the aluminum content of the Fe-Al thin film 11 is reduced, the saturation magnetic flux density increases.

As described above, the method for producing an alloy particle thin film according to the present invention and the alloy particle thin film produced according to the present invention are coated with an insulating layer having a high resistivity by selective oxidation, and thus maintain a high magnetic flux density, thereby miniaturizing and responding It satisfies the minimum thickness and sufficient performance requirements for the electromagnetic circuits required for refining.

11 and 12 are graphs showing the change of magnetic permeability according to the frequency of the alloy granular thin film according to the present invention. The hydrogen-vapor mixture gas having a dew point of -17 ^o C was heat treated at 900 ^o C for 100 and 200 minutes, respectively. It shows the change of permeability according to the frequency of Al thin film.

11 and 12, the real permeability is maintained at 10 GHz, it can be seen that the alloy particle thin film according to the present invention can be applied to magnetic devices that must operate up to 10 GHz.

13 and 14 are graphs showing the change in permeability according to the frequency of CoZrNb and FeCoNiB soft magnetic thin films, which are currently developed for comparison with the permeability characteristics of alloy granular thin films according to the present invention, and the real permeability up to 4.5 and 6.5 GHz, respectively. maintain. Therefore, it was confirmed that the alloy granular thin film according to the present invention can maintain higher permeability up to ultra-high frequency than the conventional soft magnetic thin film.

As described above, the method for producing an alloy particle thin film according to the present invention solves the problems of the method of fixing the alloy powder coated with the existing insulating layer to a solid substrate and produces an alloy particle thin film having more simple and high performance. can do.

In particular, the method for producing an alloy particle thin film according to the present invention is not only an iron alloy particle thin film but also gold (Au), platinum (Pt), silver (Ag), nickel (Ni), copper (Cu), cobalt (Co), An alloy granular thin film containing zinc (Zn), tin (Sn), vanadium (V), manganese (Mn), or the like can be produced.

In addition, the alloy particle thin film according to the present invention has a high permeability compared to the conventional soft magnetic thin film can be applied to an ultra-small and high performance electronic device.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

Claims (6)

Hydrogen containing water vapor is supplied to the alloy thin film formed on the solid substrate and heat-treated to selectively oxidize a part of the first solute element having a high affinity for oxygen among the solute elements included in the alloy thin film, and the alloy thin film particles. And the oxidized first solute element forms an insulating layer on the granulated alloy thin film and the solid substrate.
The method of claim 1, wherein the first solute element,
Alloy alloy thin film, characterized in that at least any one of silicon (Si), aluminum (Al), magnesium (Mg), chromium (Cr), titanium (Ti), zirconium (Zr), hafnium (Hf).
The method of claim 1, wherein the alloy thin film,
The first solute element and gold (Au), platinum (Pt), silver (Ag), nickel (Ni), iron (Fe), copper (Cu), cobalt (Co), zinc (Zn), tin (Sn) And an alloy with at least one of the second solute elements of vanadium (V) and manganese (Mn).
Hydrogen containing water vapor is supplied to the alloy thin film formed on the solid substrate and heat-treated to selectively oxidize a part of the first solute element having a high affinity with oxygen among the solute elements included in the alloy thin film so that the alloy thin film is granulated. And the oxidized first solute element forms an insulating layer on the granulated alloy thin film and the solid substrate.
The method of claim 4, wherein the solute element,
Method for producing an alloy particle thin film, characterized in that any one of silicon (Si), aluminum (Al), magnesium (Mg), chromium (Cr), titanium (Ti), zirconium (Zr), hafnium (Hf).
The method of claim 4, wherein the alloy thin film,
The first solute element and gold (Au), platinum (Pt), silver (Ag), nickel (Ni), iron (Fe), copper (Cu), cobalt (Co), zinc (Zn), tin (Sn) , Vanadium (V) and manganese (Mn) of at least one of the second solute element alloy.

Images