KR20140067193A - Method of manufacturing porous composite thin film and the porous composite thin film for electrode - Google Patents

Abstract

A method for manufacturing a porous composite according to the present invention includes: a composite thin film forming process for forming a cross-deposited composite thin film where a first layer including a first thin film forming material and a second layer including a second thin film forming material are alternatingly deposited; and a composite heat treatment process for forming a porous composite by heat treating the cross-deposited thin film. By using the method for manufacturing a porous composite according to the present invention, a porous composite can be easily manufactured, thereby utilizing the porous composite as an electrode of an electrochemical conversion element and replacing a meticulous refined structure of electrodes of a secondary battery, a fuel cell, and a super capacitor for an enhancement in performance.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing a porous composite thin film,

The present invention relates to a method for producing a porous oxide composite and a porous oxide composite for electrodes, and more particularly, to a method for producing a porous thin film by cross-deposition of two different materials and heat treatment. Such a thin film can be applied as a porous oxide composite that can be utilized as an electrode of an electrochemical conversion device such as a secondary cell, a fuel cell, and a super capacitor.

In the fabrication of electrochemical conversion devices such as secondary cells, fuel cells, and supercapacitors, the thin film deposition process is an important process directly related to the performance of the electrochemical conversion device manufactured.

In order to fabricate an electrochemical conversion device by a thin film process by vacuum deposition, a step of depositing a porous electrode on both sides of a dense solid electrolyte produced by a vapor deposition method is necessary. However, the vapor deposition method has a limitation in depositing a porous thin film, and has been manufactured by depositing electrodes in the form of dense thin films.

There is a difference in the performance of the electrochemical conversion apparatus including such a thin film depending on the shape of the thin film constituting the electrode. Therefore, it is necessary to propose a method of replacing the existing dense electrode with porosity so that the electrochemical conversion apparatus can achieve high performance by controlling the shape of the thin film constituting the electrode. It is also necessary to change the electrode material itself.

There has been no report on a technique of depositing an oxide material as an electrode material, which is one of the important factors determining the performance of an electrochemical conversion device, as a porous material by using the same vacuum deposition method as an electrolyte production method and utilizing it as an electrode. Only a technique of making a platinum layer single layer porous is reported.

The present invention relates to a new method for easily manufacturing a porous electrode by a vacuum evaporation method to solve such a problem, and also to employ oxide as a material of an electrode under such a method.

In the electrochemical conversion apparatus, a known method of producing a porous electrode is a method of mixing a target powder with an organic material and applying the same, or a method of impregnating a porous substrate with the powder (Japanese Patent No. 0691558, Production of Solid Oxide Fuel Cell Method 2007.02.28). However, these methods are entirely different techniques that can not be combined with vacuum deposition processes such as sputtering due to the nature of the process itself.

In addition, a method of fabricating a porous electrode by vacuum evaporation using some noble metals such as platinum and gold is known (refer to [2], X. Wang et al., [5], thermal stability of nanoporous metallic electrodes at elevated temperatures: J. Power Sources, (2008), Document 3, Patent Registration No. 10-0448519, Porous Electrode and Thin Film Electrolyte Preparation Method for Micro Electrochemical Device, 2004.09.02) It is impossible to achieve high performance by forming a complex pore structure of multiple layers, and it is also impossible to apply to various materials such as oxides.

The present invention provides a method for manufacturing an oxide and a composite electrode capable of realizing multi-layered microstructure rather than a single layer by cross-depositing two different materials by using a vacuum deposition process.

An object of the present invention is to provide a method for producing an oxide, a metal-oxide composite thin film and the like capable of realizing multilayer microstructure. This makes it possible to manufacture a porous electrode in place of the conventional thin film electrode. In addition, unlike the conventional case, a porous electrode can be manufactured not only by a metal porous electrode made of platinum but also by various metals or metal oxides. A porous electrode is manufactured by an easy method, As well as to provide a method of employing it.

In order to accomplish the above object, a method of manufacturing a porous composite according to an embodiment of the present invention includes a first layer including a first thin film forming material and a second layer including a second thin film forming material, A composite thin film forming process for forming a deposited composite thin film; And a composite heat treatment process in which the cross-deposited composite thin film is heat-treated to form a porous composite.

The composite thin film forming process may include a first layer forming step of forming a first layer on one surface of a support using a first thin film forming material and a second layer forming step of forming a first thin film forming material on the first thin film forming material, And a second layer forming step of forming a second layer on an upper surface (upper surface) of the layer.

The composite thin film formation process may include repeating the first layer formation step and the second layer formation step so that the cross-deposited composite thin film is formed by alternately repeating the first layer and the second layer. have.

The heat treatment step may be performed after the first layer forming step or after the second layer forming step.

The method of manufacturing the porous composite may further include an etching process for performing chemical etching after the composite heat treatment process.

The chemical etching may include the step of immersing the porous composite in an etching solution, and the etching solution may include NH ₄ OH and H ₂ O ₂ .

The formation of the thin film selected from the first layer, the second layer and the combination thereof may be performed by an RF sputtering method, a DC sputtering method, or a Pulsed Laser Deposition method . ≪ / RTI >

In the composite heat treatment process, the heat treatment may be performed at 300 to 800 ° C under an oxygen atmosphere.

The first thin film forming material may include an oxide and a first metal, and the second thin film forming material may include a second metal.

The first metal included in the first thin film forming material and the second metal contained in the second thin film forming material may be the same metal, and the first thin film may include a first thin film including the oxide and the first metal Forming material may be co-deposited.

The first and second metals may be selected from the group consisting of Ag, Au, Al, Sn, Li, Co, Mn, Ni, (Fe), lanthanum (La), and samarium (Sm).

According to another embodiment of the present invention, a cross-coated composite thin film for forming a porous composite includes a first layer including a first thin film forming material and a second layer including a second thin film forming material on an upper surface of the first layer And a layer where the layer is located is repeatedly formed.

The first layer may be a co-deposition of an oxide and a metal, and the second layer may be a metal deposition.

The porous thin film according to another embodiment of the present invention is a porous thin film prepared by heat-treating the cross-deposited composite thin film, wherein irregular porous pores are uniformly distributed on the surface and inside of the porous thin film, The size is 0.01 to 0.2 microns, the specific surface area is 2.5 to 50 m ² / g, and the thickness of the thin film is 0.1 to 30 microns.

Hereinafter, the present invention will be described in more detail.

The process for preparing the porous composite of the present invention includes a composite thin film formation process and a composite heat treatment process.

The composite thin film forming process is a process of forming a cross-deposited composite thin film in which a first layer including a first thin film forming material and a second layer including a second thin film forming material are alternately deposited.

The composite thin film forming process may include a first layer forming step of forming a first layer on one surface of a support using a first thin film forming material and a second layer forming step using a second thin film forming material different from the first thin film forming material, And a second layer forming step of forming a second layer on the upper surface (top surface) of the substrate.

The formation of the thin film selected from the first layer, the second layer and the combination thereof may be performed by an RF sputtering method, a DC sputtering method, or a Pulsed Laser Deposition method . ≪ / RTI > When the porous composite formed by the porous composite material is used as an electrode, the thin film formation process can be performed in the same chamber as the chamber for vacuum-depositing the electrolyte, so that no additional equipment is required for deposition of the thin film , It is possible to exclude the influence of contamination of foreign matter.

The first thin film forming material may include an oxide and a metal, and the second thin film forming material may include a metal. In this case, it is possible to form a cross-deposited composite thin film by a simple and convenient method for use as an electrode, and a porous composite excellent in utilization as a porous electrode can be easily manufactured.

The first thin film forming material or the second thin film forming material may be at least one selected from the group consisting of silver (Ag), gold (Au), aluminum (Al), tin (Sn), lithium (Li), cobalt (Co), manganese (Ni), iron (Fe), lanthanum (La), and samarium (Sm).

The oxide may be a metal oxide containing at least two elements selected from the group consisting of lithium (Li), cobalt (Co), manganese (Mn), and nickel (Ni)

The oxide may be a metal oxide containing at least three elements selected from the group consisting of lithium (Li), iron (Fe), phosphor (P), and fluorine (F).

The oxide may be a metal oxide containing two or more elements selected from the group consisting of lanthanum (La), cobalt (Co), manganese (Mn), samarium (Sm), and strontium (Sr).

The composite thin film forming process includes a cross-deposition process in which the first layer forming step and the second layer forming step are repeated so that the first and second layers are alternately repeatedly formed in the cross- Lt; / RTI > The cross-deposition process may be performed at room temperature or in a heated state.

In the forming of the composite thin film, the first layer forming step and the second layer forming step are formed by simultaneously depositing an oxide and a metal in the first layer forming step, and in the second layer forming step The second layer may be formed by depositing a metal. The ratio of oxides and metals in the first layer can be adjusted by changing the magnitude of the DC power, and when the DC power is applied at a high power, the content of the metal component in the first layer can be increased.

The porosity of the final porous thin film can be adjusted by making the execution time of the first layer forming step long or short, and the number of repetition of forming the first layer and the second layer at the intersections is adjusted to increase the thickness of the entire poly- The thickness of the porous electrode can be adjusted.

The cross-deposited composite thin film formed by alternately repeating the first layer in which oxide and metal are co-deposited and the second layer in which metal is deposited is formed by heat treatment to easily form a porous thin film formed by dispersing pores, oxides, and metals The porous thin film thus formed can be utilized as an electrode of an electrochemical conversion device.

The heat treatment step may be performed after the first layer forming step or after the second layer forming step. When the heat treatment step is performed after the first layer formation step or after the second layer formation step, the thin film of the first layer or the first layer and the second layer may be crystallized by the heat treatment.

The composite thin film formation process may include repeating the first layer formation step and the second layer formation step so that the cross-deposited composite thin film is formed by alternately repeating the first layer and the second layer. have. The cross-deposited composite thin film thus formed can be formed into a porous composite through a heat treatment process of the composite, and the porous composite thus formed can be used as a porous electrode.

The composite heat treatment process includes heat-treating the cross-deposited composite thin film to form a porous composite. In the composite heat treatment process, the heat treatment may be performed at 300 to 800 ° C under an oxygen atmosphere. When the composite heat treatment process is performed in the temperature range described above, a porous thin film having high porosity and particle size does not change even at a high temperature.

In the method for producing a porous composite, the composite heat treatment may be performed at a temperature of ½ to ¾ of the melting point of the metal included in the first layer or the second layer. When the composite heat treatment process is performed at such a temperature range, a highly durable porous thin film having no change in porosity and particle size even at a high temperature can be obtained.

The method of manufacturing the porous composite may further include an etching process for performing chemical etching after the composite heat treatment process. If the method of preparing the porous composite further includes the etching process, the porosity of the porous composite may be increased.

The chemical etching may include a step of immersing the porous composite in an etching solution. The etching solution may be applied as long as it can increase the porosity by widening the pores of the porous composite. Preferably, the etching solution includes NH ₄ OH and H ₂ O ₂ .

The porosity of the porous composite body can be controlled by including the etching process, so that a porous composite body having porosity and physical properties suitable for use as an electrode can be manufactured.

The method of producing porous composite of the present invention makes it possible to easily produce a porous composite, the thickness and kind of the porous composite produced are easily deformed, and porosity can be controlled. The porous thin film produced by this method can be used as an electrode of an electrochemical conversion apparatus. Unlike the conventional method in which a porous thin film other than platinum is difficult to form, the porous thin film can be applied as an electrode material using various oxides and metal materials A porous thin film can be provided. In other words, by cross-depositing two different materials using a vacuum deposition process, a multi-layered microstructure other than a single layer can be realized, and a method for manufacturing the porous composite electrode by oxidizing it can be provided.

The porous composite material can replace conventional dense thin film electrodes, which facilitates control of thickness, porosity and material.

The cross-deposited composite thin film according to another embodiment of the present invention includes a first layer including a first thin film forming material and a second layer including a second thin film forming material on an upper surface (upper surface) of the first layer Units are repeatedly formed.

The first thin film forming material and the second thin film forming material may be different materials. Here, the term " different materials " means materials made of different materials, and they are not completely made of the same material. Even if some elements overlap, It corresponds to different materials. The cross-deposited composite thin film is then subjected to heat treatment or the like to form a porous composite, and such porous composite may be utilized as an electrode.

The first layer may be a co-deposition of an oxide and a metal, and the second layer may be a metal deposition. The description of the oxide and the metal overlaps with the description of the method of manufacturing the porous composite, so description thereof will be omitted.

The cross-deposited composite thin film can be easily converted into a porous structure, and a thin film of a porous structure can be formed using a metal or a metal oxide other than a conventional noble metal such as platinum. Thus, an oxide thin film, an oxide- The thin film can be used as an electrode of an electrochemical conversion device such as a secondary cell, a fuel cell, and a supercapacitor.

The porous composite material of the present invention can easily produce a porous composite material, and can easily change the thickness and material type of the produced porous composite material, and can adjust porosity. The porous thin film produced by this method can be used as an electrode of an electrochemical conversion apparatus. Unlike the conventional method in which a porous thin film other than platinum is difficult to form, the porous thin film can be applied as an electrode material using various oxides and metal materials A porous thin film can be provided. In other words, by cross-deposition of two different materials using a vacuum deposition process, a multi-layered microstructure can be realized instead of a single layer, and the porous composite can be produced by oxidizing it. Such a porous composite can be formed into a dense thin film Can be substituted for the electrode of FIG.

Such a porous thin film can be utilized as an electrode of an electrochemical conversion device including a secondary cell, a fuel cell, and a supercapacitor. By replacing the dense microstructure of a conventional electrode with a porous microstructure, electrochemical conversion The performance of the apparatus can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a thin film formed by co-deposition of oxide and metal on a substrate and metal deposition.
Fig. 2 is a schematic view of a thin film obtained by cross-deposition after heat treatment.
FIG. 3 is a scanning electron microscope (SEM) image of actual microstructure after heat treatment of a thin film formed by co-deposition of oxide and metal on the substrate and metal deposition (SSC, metal Ag).
FIG. 4 is a scanning electron microscope (SEM) photograph of actual microstructure after chemical etching of the microstructure of FIG. 3; FIG.
5 is a scanning electron microscope (SEM) image of a cross section of a thin film formed according to Comparative Example 1. FIG.
6 is a scanning electron microscope (SEM) image of a cross section of a thin film formed according to Comparative Example 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like parts are designated with like reference numerals throughout the specification.

Example  One

Porous thin films were prepared by selecting SSC (strontium samarium cobalt oxide, Sm _{0 .5} Sr _{0 .5} CoO ₃ ) as the oxide and Ag as the metal.

The porous film is, three gadolinium oxide Solarium _{(.9 GDC, Ce 0 Gd 0} .1 O 2 -δ, thickness 100nm), the tree ium zirconium oxide (YSZ, Yttria-stabilized zirconia, the thickness 100nm), silicon oxide (SiO ₂ and a thickness of 1 μm) were cross-deposited on the silicon substrate, and the SSC-Ag composite layer and the Ag layer were cross-deposited on the silicon substrate, followed by heat treatment. The thin film of Example 1 can be utilized as a positive electrode of a fuel cell.

FIG. 1 is a schematic view of a thin film formed by performing simultaneous vapor deposition of an oxide and a metal on a substrate and metal deposition, and FIG. 2 is a schematic view after the thin film of FIG. 1 is subjected to heat treatment. Hereinafter, each step of Example 1 will be described in detail with reference to Figs. 1 and 2. Fig.

1) Preparation of substrate

SiO ₂ layers (12, 22, insulating layer) were deposited on the Si substrates (11, 21). A YSZ thin film was deposited on the SiO ₂ layer (12, insulation layer) by RF magnetron sputtering. The deposition was carried out at 400 DEG C while the gas pressure was maintained at 5 mTorr and a small amount of oxygen was implanted. A GDC thin film layer was deposited on the YSZ thin film layer. The GDC thin film layer was formed using the same method as the YSZ thin film formation. The YSZ thin film layer and the GDC thin film layer function as the electrolytes 13 and 23 having ionic conductivity.

At this time, after the initial vacuum degree was maintained at 5 * 10 ^-6 Torr or less, the deposition process was performed under a gas pressure of 5 mTorr and RF power of 200 W in a pure argon atmosphere to remove oxide layers and impurities in the target surface Min for the first time.

In order to crystallize the electrolyte (13, 23) layer including the two thin film layers, a separate heat treatment process was performed. The heat treatment for crystallization of the electrolyte (13, 23) layer is performed at 700 DEG C using an oxygen atmosphere, and can be performed in a chamber or in a separate heating furnace.

2) Cross-deposited composite thin film  formation

In order to deposit the porous electrode, SSC and Ag were co-sputtered on the electrolyte layer to form a first layer (co-deposited layer) 14. At this time, SSC was fixed at RF power of 200 W and Ag was used at 20 to 40 W of DC power. At this time, the chamber pressure was kept at 5 mTorr while flowing a small amount of oxygen. The Ag content in the SSC-Ag composite thin film can be changed by the DC power, and the Ag content in the SSC-Ag composite thin film can be increased by using a high power. The second layer (15, metal layer) was formed by depositing Ag on the SSC-Ag composite thin film under conditions of 5 mTorr and DC power of 20 W alone.

During the deposition, the initial vacuum degree of the sputtering was maintained at 5 × 10 ^-6 Torr or lower for cleaning the surface of the workpiece target, and the gas pressure was 5 mTorr in a pure argon atmosphere, RF power 300 W (in the case of SSC), DC power 40 W Ag), the first cleaning step and the second cleaning step were performed.

The process of forming the first layer and the second layer was performed for one cycle to perform cross-deposition 10 times in total, thereby forming a thin film layer corresponding to the electrode.

A scanning electron microscope (SEM) photograph of the thus formed thin film layer is shown in FIG. 3, and a porous thin film can be obtained as shown in FIG.

3) Complex heat treatment process

The composite thin film thus formed was heated to 700 ° C. in an oxygen atmosphere, and heat treatment was performed to perform a composite heat treatment process. 2, a thin film layer corresponding to an electrode on which the first layer and the second layer are alternately deposited is transformed into a thin film layer having a structure including pores 24, an oxide 25 and a metal 26, Crystallization also occurred.

An etching process was performed in order to increase the porosity of the thin film having the structure in which the pores 24, the oxide 25 and the metal 26 were mixed. The etching process was a chemical etching method, and the porous composite formed by heat-treating the cross-deposited composite thin film was etched in an etching solution in which NH ₄ OH and H ₂ O ₂ were mixed in a volume ratio of 1: 1, And then eluted.

A scanning electron microscope (SEM) photograph of the porous composite thus prepared is shown in FIG. Referring to FIG. 4, it was confirmed that the porosity was improved by the heat treatment and the etching.

Example  2

Oxide LCO (Lithium Cobalt Oxide, LiCoO ₂₎ in order to produce a porous film, and the metal is to prepare a porous thin film by selecting the Ag.

The porous thin film was formed by laminating an LCO-Ag composite layer and Ag (Al) on a substrate of aluminum oxide (AO, Al ₂ O ₃ substrate) platinum (Pt, thickness 1,000 nm) and silicon oxide (SiO ₂ , Layer was cross - deposited and then heat - treated. The thin film of Example 2 can be utilized as a positive electrode of a secondary battery.

FIG. 1 is a schematic view of a thin film formed by performing simultaneous deposition of an oxide and a metal on a substrate and metal deposition, and FIG. 2 is a schematic view after the thin film of FIG. 1 is subjected to heat treatment. Hereinafter, each step of Example 1 will be described in detail with reference to Figs. 1 and 2. Fig.

1) Preparation of substrate

SiO ₂ layers (12, 22, insulating layer) were deposited on the AO substrates (11, 12). Pt thin films (13, 23, current collecting layer) were deposited on the SiO ₂ layer (12, insulating layer) by DC sputtering. DC sputtering was carried out by maintaining the gas pressure at 400 캜 and 5 mTorr. The deposited Pt thin films (13, 23, current collecting layer) function as a current collector layer of the secondary battery oxide anode.

At this time, the initial vacuum degree was kept at 5 * 10 ^-6 Torr or less, and then, in order to remove the oxide layer on the target surface of the material to be deposited and prevent impurities from entering, a gas pressure of 5 mTorr in a pure argon atmosphere, It was done after a while before cleaning.

The deposited Pt thin films (13, 23, current collecting layer) can be subjected to a separate heat treatment process for crystallization, and the heat treatment is performed at 700 ° C. using an oxygen atmosphere. The heat treatment may be performed in the chamber or in a separate heating furnace.

2) Cross-deposited composite thin film  formation

In order to deposit the porous electrode, a first layer (co-deposited layer) was formed by co-sputtering LCO and Ag on the current collecting layers 13 and 23. At this time, the LCO was fixed to RF power of 200 W and the DC power of 20 to 40 W was used. At this time, the chamber pressure was kept at 5 mTorr and a small amount of oxygen was supplied. The Ag content in the LCO-Ag composite thin film can be changed by the DC power, and the Ag content in the LCO-Ag composite thin film can be increased by using a high power. The second layer (15, metal layer) was formed on the LCO-Ag composite thin film under the conditions of 5 mTorr and DC power of 20 W alone.

The initial vacuum degree of the sputtering was maintained at 5 * 10 ^-6 Torr or less in order to clean the surface of the target material during the deposition, and the gas pressure was 5 mTorr, RF power 300 W (in the case of LCO), DC power 40 W , The first cleaning step and the second cleaning step were performed, respectively.

The process of forming the first layer and the second layer was performed for one cycle to perform cross-deposition 10 times in total, thereby forming a thin film layer corresponding to the electrode.

3) Complex heat treatment process

The composite thin film thus formed was heated to 700 ° C. in an oxygen atmosphere, and heat treatment was performed to perform a composite heat treatment process. 2, a thin film layer corresponding to an electrode on which the first layer and the second layer are alternately deposited is transformed into a thin film layer having a structure including pores 24, an oxide 25 and a metal 26, Crystallization also occurred.

The etching process was further performed to increase the porosity of the thin film having the structure in which the pores 24, the oxide 25 and the metal 26 were mixed. The etching process was a chemical etching method, and the porous composite formed by heat-treating the cross-deposited composite thin film was etched in an etching solution in which NH ₄ OH and H ₂ O ₂ were mixed in a volume ratio of 1: 1, And then eluted. The porous composite thus formed can be utilized as a positive electrode of a secondary battery.

Comparative Example  One

Unlike the above embodiment, a thin film was formed on the substrate by simultaneously depositing SSC and Ag. In the simultaneous deposition, SSC was performed under the condition of RF power of 200 W and Ag at DC power of 40 W, and the microstructure thereof was observed with a scanning electron microscope. The thin film section of Comparative Example 1 was observed with a scanning electron microscope, and the microstructure of the section was shown in Fig. Referring to FIG. 5, it was confirmed that the cross-section of the thin film of Comparative Example 1 formed by co-deposition rather than cross-deposition was a thin film having a porosity that was grown in a column shape.

Comparative Example  2

On the substrate, only Pt was deposited to produce a porous form, and a thin film of Comparative Example 2 was prepared. The deposition was carried out at a DC power of 100 W and the microstructure was observed with a scanning electron microscope. The cross section of the thin film of Comparative Example 2 was observed with a scanning electron microscope, and the result is shown in Fig. Referring to FIG. 6, it can be seen that the thin film of Comparative Example 2 having a porous structure after Pt alone was formed with a single-layer porous microstructure. In Examples 1 and 2, It is judged that the structure is in contrast to that of the thin film.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

11: substrate 12: insulating layer
13: electrolyte or current collector layer 14: co-deposition layer
15: metal deposition layer 21: substrate
22: Insulating layer 23: Electrolyte or current collecting layer
24: pore 25: oxide
26: Metal

Claims (14)

A composite thin film forming process in which a first layer including a first thin film forming material and a second layer including a second thin film forming material are alternately deposited to form a cross-deposited composite thin film, and
A composite heat treatment process in which the cross-deposited composite thin film is heat-treated to form a porous composite
≪ / RTI > The method according to claim 1,
The composite thin film forming process
A first layer forming step of forming a first layer on one surface of a support with a first thin film forming material, and
Forming a second layer on the upper surface (upper surface) of the first layer with a second thin film forming material different from the first thin film forming material
≪ / RTI > 3. The method of claim 2,
Wherein the composite thin film formation process includes repeating the first layer formation step and the second layer formation step so that the cross-deposited composite thin film is formed by alternately repeating the first layer and the second layer. A method for producing a porous composite thin film. 3. The method of claim 2,
Wherein the heat treatment step is performed after the first layer forming step or after the second layer forming step. The method according to claim 1,
Wherein the porous composite body further comprises an etching step of performing chemical etching after the heat treatment of the composite body. The method according to claim 1,
Wherein the chemical etching comprises immersing the porous composite in an etching solution, wherein the etching solution comprises NH ₄ OH and H ₂ O ₂ . 3. The method of claim 2,
The formation of the thin film selected from the first layer, the second layer and the combination thereof may be performed by an RF sputtering method, a DC sputtering method, or a Pulsed Laser Deposition method Wherein the porous composite thin film is formed by a method comprising the steps of: The method according to claim 1,
Wherein the heat treatment in the composite heat treatment process is performed at 300 to 800 DEG C under oxygen atmosphere. The method according to claim 1,
Wherein the first thin film forming material comprises an oxide and a first metal,
Wherein the second thin film forming material comprises a second metal. 10. The method of claim 9,
The first metal included in the first thin film forming material and the second metal included in the second thin film forming material are the same metal,
Wherein the first thin film is formed by simultaneously depositing a first thin film forming material including the oxide and the first metal. 11. The method of claim 10,
The first and second metals may be selected from the group consisting of Ag, Au, Al, Sn, Li, Co, Mn, Ni, Is one selected from the group consisting of iron (Fe), lanthanum (La), and samarium (Sm). And a second layer including a first thin film forming material and a second layer including a second thin film forming material on an upper surface (upper surface) of the first layer are repeatedly formed, Composite Thin Film for Cross - Deposition Forming. 13. The method of claim 12,
Wherein the first layer is a co-deposition of an oxide and a metal, and the second layer is a deposition of a metal. A porous thin film produced by heat-treating a cross-deposited composite thin film according to claim 12, wherein irregular porous pores are uniformly distributed on the surface and inside of the porous thin film,
Wherein the porous thin film has an average pore size of 0.01 to 0.2 microns, a specific surface area of 2.5 to 50 m ² / g, and a thickness of 0.1 to 30 microns.

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