JP2016047961A - Aluminum nitride thin film, formation method of aluminum nitride thin film, and electrode material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an aluminum nitride thin film excellent in conductivity, by plasma on the surface of an aluminum substrate.SOLUTION: There is provided a method for forming an aluminum nitride thin film by irradiating an aluminum substrate 8 with plasma 7 containing nitrogen A and oxygen B. The thin film is preferably 5,000 nm, and is conductive (10 ohm or less in the thickness direction) and amorphous. An electroconductive polymer layer of polyaniline or the like may be laminated furthermore for an electricity storage device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive aluminum nitride thin film, a method for forming an aluminum nitride thin film, and an electrode material.

  Currently, metal materials are used for battery electrodes, electroluminescence elements, and the like. Further, in order to utilize the metal material as a more chemically stable material, for example, the surface of the metal material is treated with a plasma containing nitrogen (nitrogen ions) while maintaining a high temperature of 420 to 590 ° C. A method of forming a nitride layer and providing a material excellent in corrosion resistance and insulation is disclosed (Patent Document 1).

  In particular, as a metal material used for an electrode or the like, an aluminum material is used because it is excellent in weight reduction, workability, and economy. However, in general, an aluminum material has a problem that chemical resistance is insufficient. Therefore, by forming a chemically very stable aluminum nitride (AlN) film on the surface of this aluminum material, Not only chemical properties but also insulation and thermal conductivity can be imparted.

JP 2006-257466 A

  However, a metal material having a low melting point such as an aluminum material has a problem because it cannot properly perform plasma treatment in a high temperature state as in Patent Document 1.

  Moreover, since an aluminum nitride film usually has an insulating property, it is not suitable for use in an electrode or the like that requires electrical conductivity.

  Thus, as a result of intensive studies, the present inventors have found the following aluminum nitride thin film and have completed the present invention.

  That is, the aluminum nitride thin film of the present invention is an aluminum nitride thin film containing at least nitrogen and oxygen, is in an amorphous state, and has conductivity.

  The aluminum nitride thin film of the present invention preferably has a resistance in the film thickness direction of 10Ω or less.

  The method for forming an aluminum nitride thin film of the present invention is a method for forming the aluminum nitride thin film on an aluminum substrate, and a step of preparing a mixed gas of nitrogen and a dopant gas containing at least oxygen into plasma, It is preferable to include a step of irradiating the plasma on the aluminum base material in an atmosphere of 660 ° C. or lower to form an aluminum nitride thin film on the aluminum base material.

  In the method for forming an aluminum nitride thin film of the present invention, the mixed volume ratio of nitrogen and oxygen (oxygen / nitrogen) in the mixed gas is preferably a value exceeding 0.

In the method for forming an aluminum nitride thin film of the present invention, it is preferable that a plasma output when the plasma is irradiated is 3 kW / cm ² or less.

  In the method for forming an aluminum nitride thin film of the present invention, the pressure when irradiating the plasma is preferably 1 MPa or less.

  The method for forming an aluminum nitride thin film of the present invention is selected from the group consisting of an atmospheric pressure plasma apparatus (for example, a glow discharge plasma apparatus, a corona discharge plasma apparatus, a barrier discharge plasma apparatus, a microwave plasma apparatus, and an electron cyclotron resonance plasma apparatus). The plasma is preferably prepared by at least one atmospheric pressure plasma apparatus).

  In the method for forming an aluminum nitride thin film of the present invention, the thickness of the aluminum nitride thin film on the aluminum base (plate, foil, and particles) is preferably 5000 nm or less.

  The electrode material of the present invention preferably has a conductive polymer layer on the aluminum nitride thin film.

  Since the aluminum nitride thin film of the present invention is excellent in chemical stability such as conductivity and corrosion resistance, and heat conduction characteristics, it is an electrode material for power storage devices and battery devices, electrodes for semiconductor light emitting devices and power power supply devices. It becomes useful in fields such as materials and constituent layers, electrode materials and constituent layers of MOSFET devices, medical base materials, and corrosion protection films.

Schematic diagram of plasma processing equipment Graph showing the relationship between plasma output and film thickness of aluminum nitride thin film Graph showing the relationship between the working distance and the film thickness of the aluminum nitride thin film Graph showing the relationship between the resistance in the film thickness direction of the aluminum nitride thin film / aluminum substrate after the corrosion resistance evaluation and the aluminum substrate without surface treatment Graph showing the relationship between plasma power and resistance in the direction of film thickness of aluminum nitride thin film / aluminum substrate Schematic diagram of resistance measuring device for aluminum nitride thin film / aluminum substrate sample Graph showing the relationship between plasma irradiation time and aluminum nitride film thickness Graph showing the relationship between plasma irradiation time and resistance in the film thickness direction of aluminum nitride thin film / aluminum substrate Thin film X-ray diffraction pattern of plasma-treated aluminum nitride thin film / aluminum substrate (when X-ray incident angles are 0.5 ° and 2.0 °) Thin film X-ray diffraction pattern of aluminum nitride thin film / aluminum substrate treated with atmospheric pressure plasma X-ray fluorescence spectrum of plasma-treated aluminum nitride thin film / aluminum substrate X-ray fluorescence spectrum of aluminum nitride thin film / aluminum substrate treated with atmospheric pressure plasma Relationship between the resistance in the film thickness direction (between both ends) of an aluminum nitride thin film / aluminum substrate treated with atmospheric pressure plasma and the temperature of the aluminum substrate Relationship between film thickness of aluminum nitride thin film treated with atmospheric pressure plasma and aluminum substrate temperature

  Hereinafter, embodiments of the present invention will be described in detail.

<Method of forming aluminum nitride thin film>
The method for forming an aluminum nitride thin film of the present invention is a method for forming the aluminum nitride thin film on an aluminum substrate, and a step of preparing a mixed gas of nitrogen and a dopant gas containing at least oxygen into plasma, It is preferable to include a step of irradiating the plasma on the aluminum base material in an atmosphere of 660 ° C. or lower to form an aluminum nitride thin film on the aluminum base material. In the present invention, since plasma irradiation can be performed in an atmosphere of 660 ° C. or lower, from the viewpoints of reduction of equipment costs, reduction of work processes, improvement of workability, environmental friendliness, etc. Is useful. In addition, by performing plasma treatment in an atmosphere at 660 ° C. or lower, an amorphous aluminum nitride thin film can be obtained instead of a crystalline aluminum nitride thin film as in the case of performing plasma treatment in a high temperature atmosphere. Is guessed. Further, although the detailed reason is not clear, it is presumed that when at least oxygen is contained in the aluminum nitride thin film, it becomes an impurity, and conductivity is imparted to the aluminum nitride thin film itself.

As a more specific method for forming an aluminum nitride thin film, the following steps (i) to (iv) are preferably included. The aluminum nitride thin film (passive layer) obtained by these steps is in an amorphous state and has conductivity.
(I) A step of immersing the aluminum substrate in an aqueous sodium hydroxide solution to remove an oxide film (passive) formed on the surface of the aluminum substrate.
(Ii) A step of preparing a mixed gas of nitrogen and a dopant gas containing at least oxygen.
(Iii) A step of preparing the mixed gas into plasma.
(Iv) A step of irradiating the plasma on the aluminum base material in an atmosphere of 660 ° C. or lower to form an aluminum nitride thin film on the aluminum base material.
Below, each process (i)-(iv) is demonstrated in detail.

(I) A step of immersing an aluminum base in an alkaline aqueous solution to remove an oxide film (passive) formed on the surface of the aluminum base. An aluminum base usually forms an oxide film (passive) on the surface. However, it is known that when this oxide film is present, it becomes difficult to form an aluminum nitride thin film on the surface of the aluminum substrate. Then, the said oxide film can be removed by immersing an aluminum base material in alkaline aqueous solution like sodium hydroxide aqueous solution. For example, when using an aqueous sodium hydroxide solution as the alkaline aqueous solution, the concentration is preferably adjusted to 0.2 to 10% by mass, more preferably 0.5 to 5% by mass, and the immersion time as It is preferably 1 minute or longer, more preferably 2 to 20 minutes.

(Ii) Step of preparing a mixed gas of nitrogen and a dopant gas containing at least oxygen As long as the mixed gas used in the present invention can prepare a dopant gas containing nitrogen and at least oxygen into plasma, Although it can be used without particular limitation, the mixed volume ratio of nitrogen and oxygen in the mixed gas (oxygen / nitrogen) is preferably a value exceeding 0, more preferably 0.01 to 0.5, More preferably, it is 0.02-0.3. When the mixing ratio is used, a non-crystalline aluminum nitride thin film can be obtained by plasma irradiation under an atmosphere of 660 ° C. or lower, and conductivity can be imparted, which is a preferable embodiment.

  Further, by setting the ratio of nitrogen (element) to aluminum (element) in the aluminum nitride (AlN) thin film to 1 or less (preferably less than 1), the stoichiometric composition of aluminum nitride is nitrogen (element): When aluminum (element) deviates from 1: 1, the resistance in the film thickness direction of the aluminum nitride thin film itself is lowered, and thereby the resistance in the film thickness direction of the aluminum nitride thin film is 10 Ω or less. An aluminum nitride thin film can be formed. In this way, by forming an aluminum nitride thin film on the surface of the aluminum substrate, the formation of an oxide film due to oxidation on the surface of the aluminum substrate is suppressed, and the passive layer is formed by electrolytic polymerization on the surface of the aluminum nitride thin film. The contact resistance with the conductive polymer layer is significantly reduced, and an electrode material excellent in conductivity can be obtained, which is a preferred embodiment. In addition, in order to make the said ratio 1 or less, it can implement by methods, such as changing the mixing volume ratio (oxygen / nitrogen) of nitrogen and oxygen in the said mixed gas.

  Other than nitrogen and oxygen contained in the plasma, other elements may be included as long as the characteristics of the aluminum nitride thin film of the present invention are not deteriorated. However, it is preferable not to use a highly toxic element such as boron from the viewpoint of the environment. For example, an inorganic system such as carbon dioxide containing carbon, an organic small molecule, or the like may be included. These are effective because they act as impurities in the aluminum nitride thin film and serve to impart conductivity.

(Iii) Step of Preparing the Mixed Gas into Plasma FIG. 1 shows a plasma processing apparatus (a general plasma processing apparatus can be used) used in the step of preparing the mixed gas into plasma. The configuration of the plasma processing apparatus includes a process chamber, a vacuum line, a gas introduction line, a plasma discharge electrode, and a DC power source for plasma discharge.
The pressure in the process chamber is not particularly limited, but is preferably 1 MPa or less, more preferably 1 Pa to 0.2 MPa, still more preferably 1 to 30 Pa, and particularly preferably 2 MPa. ~ 20Pa.
In the plasma irradiation step, after the inside of the process chamber in FIG. 1 is evacuated using a vacuum pump, a nitrogen gas and a dopant gas containing at least oxygen gas are introduced into the process chamber, and the entire vacuum range is set to the above-mentioned range. After setting to a range (for example, 2 to 20 Pa), using a direct current power source, an applied voltage (preferably 0.3 to 5.0 kV, more preferably 0.5 to 3.0 kV) is applied to the plasma discharge electrode, and The plasma of the introduced gas is generated by applying an applied current (3 to 100 mA is preferable, more preferably 5 to 30 mA).

(Iv) A step of irradiating the plasma on the aluminum base material in an atmosphere of 660 ° C. or less to form an aluminum nitride thin film on the aluminum base material. In the sputtering method or the CVD method, an aluminum nitride thin film having corrosion resistance can be formed. However, in these methods, it is difficult to form an aluminum nitride thin film having conductivity as well as corrosion resistance. Conventionally, the temperature of the aluminum substrate surface during plasma treatment must be kept high.
However, in the present invention, any of the above preparation methods is used, and the temperature of the aluminum substrate surface during the plasma treatment is preferably 660 ° C. or less, more preferably 300 ° C. or less, and still more preferably. , 100 ° C. or less, particularly preferably 10 to 80 ° C., most preferably 15 to 50 ° C., so that an aluminum nitride thin film having an amorphous state and conductivity can be obtained. This is a preferred mode.

  The aluminum nitride thin film irradiates (injects) plasma on the surface of the aluminum substrate by applying a positive voltage to the aluminum substrate in a discharge plasma containing at least nitrogen and oxygen (simply referred to as “plasma”). ). The positive voltage to the aluminum substrate is preferably 0.3 to 5.0 kV, more preferably 0.4 to 3.0 kV, and still more preferably 0.5 to 2.5 kV. is there.

The plasma output upon irradiation with the plasma is preferably 3 kW / cm ² or less, more preferably 0.5 W / cm ^{2 to 2} kW / cm ² , and still more preferably 1 W / cm ² to 1.5 kW / cm ² . By adjusting to the plasma output, an aluminum nitride thin film having an amorphous state and conductivity can be obtained, which is a preferred mode.

  The plasma irradiation time when irradiating the plasma is preferably more than 0 seconds and not more than 10 hours, more preferably 1 second to 8 hours, still more preferably 30 seconds to 6 hours. Yes, particularly preferably 1 minute to 5 hours, and most preferably 10 minutes to 1 hour.

In the plasma irradiation step, an atmospheric pressure plasma apparatus (for example, a glow discharge plasma apparatus, a corona discharge plasma apparatus, a barrier discharge plasma apparatus, and a microwave plasma apparatus, not near low pressure (such as vacuum) but near atmospheric pressure, It is also possible to generate and irradiate plasma using at least one atmospheric pressure plasma device selected from the group consisting of electron cyclotron resonance plasma devices. Use of an atmospheric pressure plasma device in the vicinity of atmospheric pressure (preferably atmospheric pressure) makes it particularly useful in terms of economics such as production lines and operating costs as compared with the case of performing a plasma irradiation process at low pressure. It is.
For example, in the microwave plasma irradiation process using a microwave plasma apparatus, the pressure in the process chamber is not particularly limited, but from the viewpoint of economy, it is performed near atmospheric pressure using microwave plasma. However, this is a more preferable embodiment.
As specific conditions for the microwave plasma irradiation process, for example, a nitrogen gas and a dopant gas containing at least oxygen gas are introduced into the process chamber near atmospheric pressure, and a microwave generator (frequency is 1 GHz to 10 GHz). And more preferably 2 GHz to 3 GHz, and still more preferably 2.3 GHz to 2.6 GHz), the introduced gas can be vibrated, plasma can be generated, and irradiation can be performed. By using this process, plasma irradiation can be performed even in the vicinity of atmospheric pressure as compared with the case of low pressure, which is useful in terms of economics such as production lines and operation costs.
As the plasma power in the microwave plasma irradiation step ^can be carried out at ^{0.5W / cm 2 ~2kW / cm 2} , as the temperature of the aluminum substrate surface during the plasma treatment, 660 ° C. or less ( Preferably, plasma irradiation is possible even in a low temperature atmosphere of 100 ° C. or lower, more preferably 20 ° C. to 50 ° C., and near atmospheric pressure, and a general plasma irradiation process (in a high temperature atmosphere, Compared with low pressure conditions), it is also useful in terms of economics such as production lines and operating costs.

  The plasma irradiation time is preferably 1 second to 10 hours, more preferably 1 minute to 5 hours, still more preferably 30 seconds to 3 hours, and particularly preferably 1 minute to 2 hours. It is.

<Aluminum substrate>
Although the said aluminum base material is not specifically limited, The aluminum foil etc. which are generally used for an electrical power collector use can be used. In addition, the lower the purity of the aluminum base material, the more the amount of corrosion of the aluminum base material during charging / discharging when used as a current collector for a lithium ion secondary battery or electric double layer capacitor, and the surface resistance increases. In addition, the electrode life may be reduced and the battery characteristics may be deteriorated. Therefore, the purity of the aluminum base material is preferably 99.0% by mass or more, more preferably 99.5% by mass or more, and still more preferably 99.9% by mass or more. In addition, the aluminum base material is not particularly limited in shape, but for example, includes a shape including a plate shape, a foil shape, and a particle shape.

  Although the thickness of the said aluminum base material is not specifically limited, It is preferable that it is 5-100 micrometers, More preferably, it is 10-50 micrometers. If it is the thickness of the said aluminum base material, there is no possibility that a fracture | rupture etc. of an aluminum base material may arise in a manufacturing process, and the point of mass, manufacturing cost, etc. are preferable.

<Aluminum nitride thin film>
The aluminum nitride thin film of the present invention is an aluminum nitride thin film containing at least nitrogen and oxygen, and is characterized by being in an amorphous state and having conductivity. The aluminum nitride thin film of the present invention is a passive layer having excellent corrosion resistance (chemical stability) that is not affected by strong acids, strong alkalis, saline solutions and the like. Moreover, since the said aluminum nitride thin film is an amorphous state, although a detailed reason is not clear, it has electroconductivity and also forms the aluminum nitride thin film as a passive layer on the surface of an aluminum base material Thus, on the surface of the aluminum nitride thin film, the contact resistance with the conductive polymer layer formed by electrolytic polymerization can be remarkably reduced, and an electrode material excellent in conductivity can be obtained, which is a preferred embodiment.

  The thickness of the aluminum nitride (AlN) thin film is preferably 5000 nm or less, more preferably 30 to 1500 nm, still more preferably 30 to 1000 nm, and particularly preferably 50 to 600 nm.

  The thickness of the aluminum nitride (AlN) thin film includes the gas volume ratio of a dopant gas including nitrogen and oxygen, the plasma output, the plasma irradiation time, and the distance between the aluminum substrate and the plasma irradiation port (this distance is referred to as Working Distance). It is also possible to control it.

  The resistance in the film thickness direction of the aluminum nitride (AlN) thin film is preferably 10Ω or less, more preferably 0.1 to 10Ω, and still more preferably 0.2 to 3Ω. If it is in the said range, since it will show what is called electroconductivity and will not show insulation like a normal aluminum nitride film, it can be used for an electrode etc., and becomes a desirable mode.

<Electrode material>
The electrode material of the present invention preferably has a conductive polymer layer on the aluminum nitride thin film. By having a conductive polymer layer on the conductive aluminum nitride thin film, an electrode material in which the aluminum nitride thin film and the conductive polymer layer are integrated can be obtained, and battery devices such as power storage devices can be collected. It can be used for electrical objects and is useful.

<Conductive polymer>
The monomer (conductive polymer monomer) constituting the conductive polymer layer on the aluminum nitride thin film is included in the electrolytic solution used in the electrolytic polymerization method, and is oxidized by the electrolytic polymerization method. The compound is not particularly limited as long as the compound is polymerized and exhibits conductivity. For example, examples of the monomer include cyclic compounds such as pyrrole, thiophene, aniline, and phenylene, and derivatives such as alkyl groups and oxyalkyl groups. Among them, hetero five-membered cyclic compounds such as pyrrole, thiophene and aniline and derivatives thereof are preferable, and in particular, in the case of conductive polymers containing pyrrole, aniline and derivatives thereof, the production is easy, and the conductive polymer is It is preferable because it is chemically stable. Two or more of these monomers can be used in combination.

<Electrolyte anion (dopant)>
In the electrolytic polymerization method, the electrolyte anion (dopant) blended in the electrolytic solution together with the monomer is not particularly limited as long as it is a compound that dissolves in a solvent used for electrolytic polymerization. Examples of the electrolyte anion include derivatives such as halogen, halogen acid, nitric acid, sulfuric acid, arsenic acid, antimonic acid, boric acid, phosphoric acid, carboxylic acid, sulfonic acid, sulfoimide, sulfomethide, and dye compounds. It is done. Further, as the constituent of the electrolyte anion, specifically, perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, hexafluoroarsenic acid, hexafluoroantimonic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, bis (trifluoromethanesulfonyl) imide, tris (trifluoromethanesulfonyl) methide, benzylethyl- [4 ′-(4 ″-(benzylethylamino) -diphenylmethylene) -2 ′, 5-cyclohex Sadenylidene] ammonium-2 ′ ″, 3,3 ′ ″-trisulfonic acid, 3-hydroxy-4- [2-sulfo-4- (4-sulfophenylazo) phenylazo] -2,7-naphthalene A disulfonic acid can be illustrated. Along with these, examples of the salt with a counter ion include derivatives such as alkali metal salts, ammonium salts, phosphonium salts, imidazolium salts, and iodonium salts. More specifically, examples of the salt include lithium salt, sodium salt, tetrabutylammonium salt, tetrabutylphosphonium salt, 1,3-dimethylimidazolium salt, and 4-isopropyl 4′-methyldiphenyliodonium salt. . Among the constituents of the electrolyte anion, those containing a fluorine atom (supporting electrolyte) are preferably used, compounds having an alkylated sulfonyl group and derivatives thereof are more preferable, and trifluoromethanesulfonate ions (or bis) (Trifluoromethanesulfonyl) imide ion) or a supporting electrolyte containing an anion containing a plurality of fluorine atoms with respect to the central atom is more preferred. Two or more of the supporting electrolytes can be used in combination. In addition, when the said supporting electrolyte ionizes, the said electrolyte anion can be produced | generated and the said electrolyte anion will act as a dopant in the conductive polymer layer used by this invention. In addition to the electrolyte, an ionic liquid or the like can also be blended.

The trifluoromethanesulfonic acid ion is a compound represented by the chemical formula CF ₃ SO ₃ ^— . An anion containing a plurality of fluorine atoms with respect to the central atom has a structure in which a plurality of fluorine atoms are bonded to a central atom such as boron, phosphorus, antimony and arsenic. The anion containing a plurality of fluorine atoms with respect to the central atom is not particularly limited, but includes tetrafluoroborate ion (BF ₄ ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ), hexafluoroantimonate ion. (SbF ₆ ⁻ ) and hexafluoroarsenate ion (AsF ₆ ⁻ ) can be exemplified. As the anion containing a plurality of fluorine atoms with respect to the central atom, one kind of anion may be used, or a plurality of kinds of anions may be used at the same time. Furthermore, a trifluoromethanesulfonate ion and a plurality of kinds of central atoms may be used. On the other hand, an anion containing a plurality of fluorine atoms may be used simultaneously.

  Although content in the electrolyte solution is not particularly limited, the electrolyte anion is preferably contained in the electrolyte solution in an amount of 0.1 to 35% by mass, and more preferably 1 to 20% by mass. Within the above range, by conducting electropolymerization using the supporting electrolyte, a conductive polymer layer having an excellent capacity density can be obtained in the electricity storage device.

<Other additives>
In addition to the monomer and electrolyte anion (dopant) (or supporting electrolyte), the electrolytic solution used in the electropolymerization method may further include polyethylene glycol, polyacrylamide, phenolic hydroxyl group-containing compounds, ionic liquids, and the like. Additives can be blended.

<Solvent of electrolyte>
The solvent contained in the electrolytic solution at the time of the electrolytic polymerization is not particularly limited. For example, when the conductive polymer obtained by the electrolytic polymerization is used for an electricity storage device, the capacity density is 30 Ah / kg. In order to easily adjust as described above, in addition to the electrolyte anion (dopant) (or supporting electrolyte), at least one bond selected from ether bond, ester bond, carbonate bond, hydroxyl group, nitro group, sulfone group and nitrile group Alternatively, it is preferable to include an organic compound containing a functional group and / or a halogenated hydrocarbon as a solvent for the electrolytic solution, and it is more preferable to include one or more solvents having an ester bond. Two or more of these solvents can be used in combination. Moreover, it can also be set as the solvent by water alone, and it can be used even if it mixes water and another solvent.

  Examples of the organic compound include 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane (an organic compound containing an ether bond), γ-butyrolactone, and ethyl acetate. Nbutyl acetate, t-butyl acetate, 1,2-diacetoxyethane, 3-methyl-2-oxazolidinone, methyl benzoate, ethyl benzoate, butyl benzoate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate , Dioctyl phthalate, benzyl-2-ethylhexyl phthalate (an organic compound including an ester bond), propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate (an organic compound including a carbonate bond) , Et Lenglycol, 1-butanol, 1-hexanol, cyclohexanol, 1-octanol, 1-decanol, 1-dodecanol, 1-octadecanol (above, organic compound containing hydroxyl group), nitromethane, nitrobenzene (above, nitro group ), Sulfolane, dimethylsulfone (above, organic compound containing sulfone group), acetonitrile, butyronitrile, benzonitrile (above, organic compound containing nitrile group), 1,3-dimethyl-2-imidazolidinone Can be illustrated. In addition to the above-mentioned examples, the organic compound may have any two or more bonds or functional groups among the ether bond, ester bond, carbonate bond, hydroxyl group, nitro group, sulfone group and nitrile group in the molecule. It may be an organic compound contained in combination. They are, for example, methyl 3-methoxypropionate, 2-phenoxyethanol and the like.

  The halogenated hydrocarbon is not particularly limited as long as at least one hydrogen in the hydrocarbon is substituted with a halogen atom and can stably exist as a liquid under electrolytic polymerization conditions. It is not something. Examples of the halogenated hydrocarbon include dichloromethane and dichloroethane. Although only one kind of the halogenated hydrocarbon can be used as a solvent in the electrolyte solution, two or more kinds can be used in combination. The halogenated hydrocarbon may be used by mixing with the organic compound, or a mixed solvent with an organic solvent may be used as a solvent in the electrolytic solution.

<Working electrode (current collector)>
In order to obtain the conductive polymer layer, a polymerizing electrode having an aluminum nitride thin film on the surface of the aluminum substrate can be used. Since the normally used aluminum nitride film is insulative, an electrode material in which a conductive polymer layer is formed by electrolytic polymerization on an electrode having an aluminum nitride film is used as an electrode for a primary battery, an electrode for a secondary battery, If the aluminum nitride film is insulative when it is desired to be used for a capacitor electrode, a solar cell electrode, an electroluminescence element, or the like, there is a possibility that the electropolymerization itself cannot be carried out sufficiently. However, since the aluminum base material having the aluminum nitride thin film in the present invention has conductivity, it can be used as a working electrode for polymerization and is useful. The shape of the polymerization working electrode is not particularly limited, and a conductive polymer layer can be easily formed. In particular, when used as an electrical storage device, and other electronic devices such as inorganic and organic solar cell devices and transistors, those having a low specific gravity, such as the aluminum substrate (Al, Al alloy, etc.) The present invention can be applied not only as a working electrode for polymerization but also directly to an electrode material (current collector, collector electrode) having a conductive polymer layer.

<Electropolymerization conditions>
The conductive polymer layer can be obtained by using a known electropolymerization method of a conductive polymer monomer, and any of a constant potential method, a constant current method, and an electric sweep method can be used. For example, the conditions for the electrolytic polymerization method include a current density of 0.01 to 20 mA / cm ² , a polymerization time of 0.4 to 100 hours, a reaction temperature of −70 to 80 ° C., and good film quality conductivity. In order to obtain a polymer, it is preferably carried out under conditions of a current density of 0.1 to 5 mA / cm ² , a polymerization time of 1 to 20 hours, a reaction temperature of −40 to 40 ° C., and a reaction temperature of −30 to 30 ° C. It is more preferable that the conditions are satisfied.

<Power storage device>
The electrode material having a conductive polymer layer on the aluminum nitride thin film of the present invention can be used for an electricity storage device. In the electricity storage device, a current collector constituting an electrode, the electrode can be used as either a positive electrode or a negative electrode itself, the electrode is preferably used as a positive electrode, and the electrode is used as a negative electrode and More preferably, it is used for the positive electrode. When the electrode is used as a positive electrode, the power storage device is a lithium ion battery, a lithium battery, a redox capacitor, an electric double layer capacitor, or the like, so that a high capacity density can be obtained.

  The electricity storage device will contain an electrolyte, and the electrolyte can be a known electrolyte, and if it contains an anion that can function as an electrolyte anion (dopant) used during the electrolytic polymerization, There is no particular limitation, and an electrolytic solution used during the electrolytic polymerization can be used. The solvent contained in the electrolytic solution is not particularly limited, and water or a polar organic solvent can be used. The polar organic solvent is not particularly limited as long as it is chemically stable and can be used as a reaction field for an electrochemical reaction. Examples thereof include a solvent for an electrolytic solution used during the electrolytic polymerization. can do. As the polar organic solvent, propylene carbonate and γ-butyrolactone are preferable because the ionic conductivity of the electrolytic solution is large. The solvent to be used is selected according to the metal species used for the current collector.

  Examples of the present invention are shown below, but the present invention is not limited to these.

(Example 1)
(1) An aluminum substrate (JIS alloy identification name: A1N30H, aluminum content: 99.3% by mass, thickness: 30 μm) is immersed in a 5% by mass sodium hydroxide aqueous solution for 2 minutes, The formed oxide film (passive) was removed.
(2) Mixed gas of nitrogen and dopant gas (oxygen gas: 21 vol%, carbon dioxide gas: 0.04 vol%) (nitrogen: dopant gas (mixing ratio) = 3.7: 1) (nitrogen: oxygen = 1) : 0.27) was introduced into the process chamber and the plasma output was controlled to generate plasma.
(3) Irradiating the plasma (distance between the aluminum substrate and the plasma irradiation port: 26 mm) at a plasma output of 3 W / cm ² for 30 minutes on the aluminum substrate at a temperature of 25 ° C. and a pressure of 2 Pa. An aluminum nitride thin film having a thickness of 140 nm was formed on the aluminum base material to obtain a polymerization working electrode.
(4) Subsequently, water is used as a polymerization solvent, aniline (manufactured by Wako Pure Chemical Industries, Ltd.) as a monomer is 0.5 mol / L, and sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.) is 1.0 mol / L as a supporting electrolyte. Was dissolved to obtain a polymerization electrolyte.
(5) As a polymerization electrode (current collector) and a counter electrode, a metal plate (for example, a nickel plate; the same applies hereinafter) is combined to prepare a polymerization cell, and the polymerization electrolyte is filled therein, On the polymerization working electrode, a polyaniline film (film thickness: 190 μm) was formed by electrolytic polymerization at a current density of 4 mA / cm ² and 25 ° C.
(6) The obtained polymerization working electrode (aluminum substrate having an aluminum nitride thin film) having a polyaniline film was washed with water to produce an electrode material formed from the polyaniline film and an aluminum substrate having an aluminum nitride thin film.

(Example 2)
(1) An aluminum base material (manufactured by Niraco Co., Ltd., product name: pure aluminum sheet, aluminum content: 99.99% by mass, thickness: 500 μm) is immersed in an aqueous 5% by weight sodium hydroxide solution for 2 minutes, The oxide film (passive) formed on the aluminum substrate surface was removed.
(2) Mixed gas of nitrogen and dopant gas (oxygen gas: 21 vol%, carbon dioxide gas: 0.04 vol%) (nitrogen: dopant gas (mixing ratio) = 3.7: 1) (nitrogen: oxygen = 1) : 0.27) is introduced into the process chamber, and the plasma output is controlled to generate plasma.
(3) Irradiating the plasma (distance between the aluminum substrate and the plasma irradiation port: 26 mm) at a plasma output of 3 W / cm ² for 30 minutes on the aluminum substrate at a temperature of 25 ° C. and a pressure of 2 Pa. An aluminum nitride thin film having a thickness of 140 nm was formed on the aluminum base material to obtain a polymerization working electrode.
(4) Subsequently, water is used as a polymerization solvent, aniline (manufactured by Wako Pure Chemical Industries, Ltd.) as a monomer is 0.5 mol / L, and sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.) is 1.0 mol / L as a supporting electrolyte. Was dissolved to obtain a polymerization electrolyte.
(5) A polymerization cell is prepared by combining a metal plate as the polymerization working electrode (current collector) and a counter electrode, and the polymerization electrolyte is filled therein, and a current density of 4 mA is formed on the polymerization working electrode. / in ^cm 2, 25 ° C., electrolytic polymerization to, polyaniline film (thickness: 190 .mu.m) was formed.
(6) The obtained polymerization working electrode (aluminum substrate having an aluminum nitride thin film) having a polyaniline film was washed with water to produce an electrode material formed from the polyaniline film and an aluminum substrate having an aluminum nitride thin film.

(Example 3)
(1) An aluminum substrate (manufactured by Daiwa Bussan Co., Ltd., product name: aluminum foil, thickness: 12 μm) is immersed in a 5% by weight aqueous sodium hydroxide solution for 2 minutes, and an oxidation formed on the surface of the aluminum substrate. The coating (passive) was removed.
(2) Mixed gas of nitrogen and dopant gas (oxygen gas: 21 vol%, carbon dioxide gas: 0.04 vol%) (nitrogen: dopant gas (mixing ratio) = 3.7: 1) (nitrogen: oxygen = 1) : 0.27) was introduced into the process chamber and the plasma output was controlled to generate plasma.
(3) Irradiating the plasma (distance between the aluminum substrate and the plasma irradiation port: 26 mm) at a plasma output of 3 W / cm ² for 30 minutes on the aluminum substrate at a temperature of 25 ° C. and a pressure of 2 Pa. An aluminum nitride thin film having a thickness of 140 nm was formed on the aluminum base material to obtain a polymerization working electrode.
(4) Subsequently, water is used as a polymerization solvent, aniline (manufactured by Wako Pure Chemical Industries, Ltd.) as a monomer is 0.5 mol / L, and sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.) is 1.0 mol / L as a supporting electrolyte. Was dissolved to obtain a polymerization electrolyte.
(5) A polymerization cell is prepared by combining a metal plate as the polymerization working electrode (current collector) and a counter electrode, and the polymerization electrolyte is filled therein, and a current density of 4 mA is formed on the polymerization working electrode. / in ^cm 2, 25 ° C., electrolytic polymerization to, polyaniline film (thickness: 190 .mu.m) was formed.
(6) The obtained polymerization working electrode (aluminum substrate having an aluminum nitride thin film) having a polyaniline film was washed with water to produce an electrode material formed from the polyaniline film and an aluminum substrate having an aluminum nitride thin film.

Example 4
(1) An aluminum substrate (JIS alloy identification name: A1N30H, aluminum content: 99.3% by mass, thickness: 30 μm) is immersed in a 5% by mass sodium hydroxide aqueous solution for 2 minutes, The formed oxide film (passive) was removed.
(2) Mixed gas of nitrogen and dopant gas (oxygen gas: 21 vol%, carbon dioxide gas: 0.04 vol%) (nitrogen: dopant gas (mixing ratio) = 3.7: 1) (nitrogen: oxygen = 1) : 0.27) was introduced into the process chamber and the plasma output was controlled to generate plasma.
(3) Irradiation of the plasma (distance between the aluminum base and the plasma irradiation port: 26 mm) at a plasma output of 2 W / cm ² for 30 minutes on the aluminum base at a temperature of 25 ° C. and a pressure of 2 Pa. An aluminum nitride thin film having a thickness of 110 nm was formed on the aluminum base material to obtain a polymerization working electrode.
(4) Subsequently, water is used as a polymerization solvent, aniline (manufactured by Wako Pure Chemical Industries) as a monomer is 0.5 mol / L, and sulfuric acid (manufactured by Wako Pure Chemical Industries) is 1.0 mol / L as a supporting electrolyte. L was dissolved to obtain a polymerization electrolyte.
(5) A polymerization cell is prepared by combining a metal plate as the polymerization working electrode (current collector) and a counter electrode, and the polymerization electrolyte is filled therein, and a current density of 4 mA is formed on the polymerization working electrode. Electrolytic polymerization was performed at 25 ° C./cm ² to form a polyaniline film (film thickness: 190 μm).
(6) The obtained polymerization working electrode (aluminum substrate having an aluminum nitride thin film) having a polyaniline film was washed with water to produce an electrode material formed from the polyaniline film and an aluminum substrate having an aluminum nitride thin film.

(Example 5)
(1) An aluminum substrate (JIS alloy identification name: A1N30H, aluminum content: 99.3% by mass, thickness: 30 μm) is immersed in a 5% by mass sodium hydroxide aqueous solution for 2 minutes, The formed oxide film (passive) was removed.
(2) Mixed gas of nitrogen and dopant gas (oxygen gas: 21 vol%, carbon dioxide gas: 0.04 vol%) (nitrogen: dopant gas (mixing ratio) = 3.7: 1) (nitrogen: oxygen = 1) : 0.27) was introduced into the process chamber and the plasma output was controlled to generate plasma.
(3) Irradiation of the plasma (distance between the aluminum substrate and the plasma irradiation port: 26 mm) at a plasma output of 4 W / cm ² for 30 minutes on the aluminum substrate at a temperature of 25 ° C. and a pressure of 2 Pa. An aluminum nitride thin film having a thickness of 260 nm was formed on the aluminum base material to obtain a polymerization working electrode.
(4) Subsequently, water is used as a polymerization solvent, aniline (manufactured by Wako Pure Chemical Industries) as a monomer is 0.5 mol / L, and sulfuric acid (manufactured by Wako Pure Chemical Industries) is 1.0 mol / L as a supporting electrolyte. L was dissolved to obtain a polymerization electrolyte.
(5) A polymerization cell is prepared by combining a metal plate as the polymerization working electrode (current collector) and a counter electrode, and the polymerization electrolyte is filled therein, and a current density of 4 mA is formed on the polymerization working electrode. / in ^cm 2, 25 ° C., electrolytic polymerization to, polyaniline film (thickness: 190 .mu.m) was formed.
(6) The obtained polymerization working electrode (aluminum substrate having an aluminum nitride thin film) having a polyaniline film was washed with water to produce an electrode material formed from the polyaniline film and an aluminum substrate having an aluminum nitride thin film.

(Example 6)
(1) An aluminum substrate (JIS alloy identification name: A1N30H, aluminum content: 99.3% by mass, thickness: 30 μm) is immersed in a 5% by mass sodium hydroxide aqueous solution for 2 minutes, The formed oxide film (passive) was removed.
(2) Mixed gas of nitrogen and dopant gas (oxygen gas: 21 vol%, carbon dioxide gas: 0.04 vol%) (nitrogen: dopant gas (mixing ratio) = 3.7: 1) (nitrogen: oxygen = 1) : 0.27) was introduced onto the aluminum substrate, and the plasma output was controlled to generate plasma.
(3) On the aluminum substrate, the plasma (distance between the aluminum substrate and the plasma irradiation port: 3 mm) at a temperature of 25 ° C. and atmospheric pressure, with a plasma output of 213 W / cm ² , i) 2 minutes, ii) Irradiated with a plasma irradiation time of 5 minutes, iii) 10 minutes, and iv) 30 minutes to form an aluminum nitride thin film on the aluminum substrate (for the film thickness of the aluminum nitride thin film in Table 1) i) to iv)).
FIG. 7 shows the relationship between the plasma irradiation time in the atmospheric pressure atmosphere and the film thickness of the aluminum nitride thin film. In addition, the plasma irradiation time in FIG. 7 plotted the case of 2 minutes, 5 minutes, 10 minutes, and 30 minutes.
From the result of FIG. 7, it was confirmed that the film thickness of the formed aluminum nitride thin film can be controlled by the plasma irradiation time.
FIG. 8 shows the relationship between the plasma irradiation time under atmospheric pressure and the resistance in the film thickness direction. In addition, the plasma irradiation time in FIG. 8 plotted the case of 0 minute, 2 minutes, 5 minutes, 10 minutes, and 30 minutes.
From the result of FIG. 8, it was confirmed that the resistance in the film thickness direction can be controlled by the plasma irradiation time.

(Example 7)
In (1) to (3) of Example 4, (3) the plasma (distance between the aluminum substrate and the plasma irradiation port: 26 mm on the aluminum substrate in an atmosphere at a temperature of 25 ° C. and a pressure of 0.2 Pa. ) With a plasma output of 2 W / cm ² and a plasma irradiation time of 30 minutes to form an aluminum nitride thin film (film thickness: 110 nm) on the aluminum base material. An aluminum nitride thin film was formed on the aluminum substrate. In addition, (4)-(6) of Example 4 was not implemented. That is, the polyaniline film was not formed.
The thin film X-ray diffraction measurement confirmed the diffraction peak of the aluminum substrate in the result of FIG. 9, but did not recognize the diffraction peak based on the aluminum nitride thin film, that is, it did not form a crystal structure. It was confirmed that an amorphous structure was formed.

(Example 8)
In (1) to (3) of Example 6, (3) the plasma (distance between the aluminum substrate and the plasma irradiation port: 3 mm) on the aluminum substrate at a temperature of 25 ° C. and an atmospheric pressure atmosphere. A method similar to that in Example 6 was used except that an aluminum nitride thin film (film thickness: 1910 nm) was formed on the aluminum substrate by irradiating with a plasma output of 1.2 kW / cm ² and a plasma irradiation time of 10 minutes. An aluminum nitride thin film was formed on the aluminum substrate.
The thin film X-ray diffraction measurement confirmed the diffraction peak of the aluminum base material in the results of FIG. 10, but no diffraction peak based on the aluminum nitride thin film was observed, that is, no crystal structure was formed. It was confirmed that an amorphous structure was formed.

Example 9
In the same manner as in Example 7, an aluminum nitride thin film was formed on the aluminum substrate.
According to the evaluation of nitrogen analysis on the aluminum substrate by X-ray photoelectron spectroscopy, in the result of FIG. 11, the N1s peak derived from the aluminum nitride thin film (layer) existing on the aluminum substrate surface ((c): Al—N) N1s peak ((d): Al—N—O) was confirmed.

(Example 10)
In the same manner as in Example 8, an aluminum nitride thin film was formed on an aluminum substrate.
According to the evaluation of nitrogen analysis on the aluminum substrate by X-ray photoelectron spectroscopy, in the result of FIG. 12, a large N1s peak ((c): Al—N) derived from the aluminum nitride thin film (layer) existing on the aluminum substrate surface. ) And N1s peak ((d): Al—N—O) were confirmed. In particular, by performing plasma treatment (atmospheric pressure microwave plasma treatment) in an atmospheric pressure atmosphere, the details are not clear, but the amount of nitrogen radicals generated is increased, compared with Example 9 having a degree of vacuum of 0.2 Pa. It was confirmed that the nitrided area on the surface of the aluminum substrate was large.

(Example 11)
In Example 8, except that the aluminum base material temperature was changed not only to 25 ° C but also 100 ° C, 200 ° C, 300 ° C, and 470 ° C, in the same manner as in Example 8, on the aluminum base material, A sample on which an aluminum nitride thin film was formed was prepared.
About these samples, when the temperature of the aluminum base material was changed from a low temperature (25 ° C.) to a high temperature (470 ° C.) in FIG. It was confirmed that the resistance value between both ends was lowered. This is presumed to be due to an increase in the missing concentration of the anionic element in the aluminum substrate due to the high temperature.

(Example 12)
In Example 8, except that the aluminum base material temperature was changed not only to 25 ° C but also 100 ° C, 200 ° C, 300 ° C, and 470 ° C, in the same manner as in Example 8, on the aluminum base material, A sample on which an aluminum nitride thin film was formed was prepared.
When the thickness of the aluminum nitride thin film was measured for these samples, no significant increase in the thickness of the aluminum nitride thin film was observed in the low temperature region (around 25-100 ° C.) in FIG. 14, but the high temperature region (approximately 100 ° C.). In the above, an increase in the thickness of the aluminum nitride thin film was observed. This is presumed to be based on an increase in the reaction rate between the nitrogen radical and aluminum.

(Evaluation method)
<Evaluation related to the thickness of the aluminum nitride thin film>
(1) Thickness measurement of aluminum nitride thin film The film thickness of the aluminum nitride thin film obtained in the examples was measured using a UV-visible spectrophotometer (V-660 UV-visible spectrophotometer, reflection measurement unit, manufactured by JASCO). The reflection spectrum was measured, and the film thickness was measured by the refractive index of aluminum nitride (see Table 1).

(2) Influence of Plasma Output on Aluminum Nitride Thin Film Thickness Similar to (1) above, the film thickness of the aluminum nitride thin film / aluminum substrate obtained by plasma irradiation (working distance is all 26 mm constant) is UV Measurement and evaluation were performed using a visible spectrophotometer (V-660 UV-visible spectrophotometer, reflection measurement unit, manufactured by JASCO). The results are shown in FIG.
In FIG. 2 (graph), the plasma output is plotted for 3 W / cm ² (Examples 1 to 3), 2 W / cm ² (Example 4), and 4 W / cm ² (Example 5). In order to confirm the influence on the film thickness of the aluminum nitride thin film on the output, the film thickness of the aluminum nitride thin film on other plasma outputs was also plotted.
From the results of FIG. 2, as the influence of the plasma output on the film thickness of the aluminum nitride thin film, the film thickness of the aluminum nitride thin film increased as the plasma output increased. From this result, it was confirmed that the film thickness of the aluminum nitride thin film can be controlled by easily controlling the plasma output.

(3) Influence on film thickness of aluminum nitride thin film in working distance In the example, aluminum nitride thin film / aluminum base material obtained by plasma irradiation was used in the same manner as in (1) above, using the reflection spectrum, and aluminum nitride. The thickness of the thin film was measured and evaluated. The results are shown in FIG.
In FIG. 3 (graph), when the plasma output is 3 W / cm ² (Examples 1 to 3), the working distance is plotted with respect to 0 mm, 15 mm, and 26 mm, and the aluminum nitride film thickness is plotted. cm ² and, instead of the 7W / cm ^2, 0 mm to Working Distance, 15 mm, in order to confirm the effect on the thickness of the aluminum nitride thin film for 26 mm, also plotted thickness of aluminum nitride thin film to other plasma power.
From the results of FIG. 3, it was confirmed that, as the influence of the working distance on the film thickness of the aluminum nitride thin film, when the plasma output is 3 W / cm ² , the film thickness of the aluminum nitride thin film decreases with the increase of the working distance. . This is presumably because the concentration of nitriding radicals important for the formation of aluminum nitride decreased with the increase in working distance.
Moreover, when the plasma output was 5 W / cm ² or more (5 W / cm ² and 7 W / cm ² ), it was confirmed that the film thickness of the aluminum nitride thin film increased as the working distance increased. This is presumably because the kinetic energy of nitrogen radicals in plasma increased with the reduction of the working distance at the plasma output of 5 W / cm ² or more, and the concentration of nitrogen radicals used to form the aluminum nitride thin film decreased. Is done.
From the above, it was confirmed that the film thickness of the aluminum nitride thin film can be easily controlled by the working distance at each plasma output.

<Evaluation of crystal structure>
(Thin film X-ray diffraction measurement)
In the X-ray diffraction measurement, evaluation was performed using an X-ray diffractometer (RINT 2500 type, manufactured by Rigaku Corporation). Using Cukα as the X-ray source, the X-ray output was performed at a tube voltage of 40 kV and a tube current of 100 mA, and the measurement range of the diffraction line (scanning axis; 2θ) was 20 ° to 70 °. The measurement was performed in a thin film X-ray measurement mode in which the X-ray incident angles were 0.5 ° and 2.0 ° (see FIGS. 9 and 10). In addition, regarding the diffraction lines of Al (111), Al (200), and Al (220) in FIG. 9 and FIG. 10, Phys. Status Solidi A, 1992, 130,. 273-292, Popovic S., Grzeta B., Ilakovac V., Kroggel R., Wendrock G., Loffler H ..

<Corrosion resistance>
(Alkali resistance, salt water resistance, and acid resistance)
In order to evaluate the corrosion resistance of the aluminum nitride thin film / aluminum substrate obtained by plasma irradiation, the aluminum nitride thin film / aluminum substrate and the aluminum substrate not subjected to surface treatment in the following three types of solutions: Was immersed for 3 hours, and the influence on the resistance in the film thickness direction of the aluminum nitride thin film with respect to the strongly alkaline solution, the alkaline aqueous solution, the strongly acidic solution, and the saline is shown in FIG. In addition, the case where corrosion resistance was a level which does not have a problem practically was evaluated as (circle) (refer Table 1).
In addition, in FIG. 4 (graph), the aluminum nitride thin film / aluminum substrate of Examples 1 to 3 (front bar graph in FIG. 4) and the aluminum substrate not subjected to surface treatment (comparative example, in FIG. 4) With respect to the rear bar graph), the resistance in the film thickness direction (Ω) was measured (see Table 1).
Moreover, the same evaluation was performed also about Examples 4-6 (not shown and refer to Table 1 for the evaluation result).
Immersion solution A: strong alkaline solution (30 mmol / L) [LiOH (manufactured by Kanto Chemical Co., Ltd.) and methanol (manufactured by Kanto Chemical Co., Ltd.) (pH 12.4)]
Immersion solution B: alkaline aqueous solution (20 vol%) [aqueous solution (pH 11) containing hydrazine monohydrate (manufactured by Kanto Chemical Co., Ltd.) and methanol (manufactured by Kanto Chemical Co., Ltd.)]
Immersion solution C: saline (1 mol / L) [NaCl (manufactured by Kanto Chemical Co., Inc.)]
Immersion solution D: Strongly acidic solution, sulfuric acid (1 mol / L) [H ₂ SO ₄ (Wako Pure Chemical Industries, Ltd.)]
From the results of FIG. 4, the resistance in the film thickness direction of the aluminum nitride / aluminum base materials obtained in Examples 1 to 3 was compared with the aluminum base material (comparative example) not subjected to surface treatment (no surface treatment). Although immersed in the immersion solutions A, B, C, and D, no significant change was confirmed. From these results, it was confirmed that the aluminum nitride thin film obtained in the examples was excellent in alkali resistance, acid resistance, and salt water resistance. In addition, the corrosion resistance test was performed using an aluminum nitride thin film / aluminum base material before polyaniline polymerization.

<Conductivity>
(Resistance in film thickness direction (resistance between both ends))
The resistance in the film thickness direction of the aluminum nitride thin film / aluminum substrate obtained in the example was brought into contact with an electrode probe (area: 1 cm ² ) as shown in FIG. The resistance was measured by an LCR HiTester 3522), and the conductivity was evaluated. The results are shown in FIG.
In FIG. 5 (graph), the plasma output is plotted for 3 W / cm ² (Examples 1 to 3), 2 W / cm ² (Example 4), and 4 W / cm ² (Example 5). In order to confirm the influence of the resistance in the film thickness direction of the aluminum nitride thin film / aluminum substrate, the resistance in the film thickness direction of the aluminum nitride thin film / aluminum substrate with respect to other plasma outputs was also plotted. In addition, all the working distances at the time of plasma irradiation here were 26 mm.
From the results of FIG. 5, as the influence on the resistance in the film thickness direction of the aluminum nitride thin film / aluminum base material, when the plasma output is less than around 4.5 W / cm ² , the film thickness direction of the aluminum nitride thin film / aluminum base material On the other hand, in the case where the plasma output exceeds about 4.5 W / cm ² , the resistance in the film thickness direction of the aluminum nitride thin film / aluminum base material was sharply increased. About this cause, it is estimated that the resistance in the film thickness direction increased because the nitrogen radical generation concentration increased with the plasma output.
Moreover, also about i) -iv) of Example 6, resistance was measured and electroconductivity was evaluated (refer FIG. 8 and Table 1).

<Nitrogen analysis on aluminum substrate by X-ray photoelectron spectroscopy>
Nitrogen analysis by X-ray photoelectron spectroscopy was evaluated using AXIS-ULTRA DLD manufactured by Shimadzu Corporation-KRATOS. The X-ray source was a monochromatic Alkα ray (1484.6 eV), and the X-ray output was 75 W. The degree of vacuum during measurement analysis was 10 ⁻⁸ Torr or less, and the binding energy range was 392 eV to 405 eV, and N1s analysis was performed.

Note) (-) other than the units in Tables 1 and 2 indicates that evaluation is not performed.

  From the results of Table 1 and Table 2, in all examples, the crystallinity is in an amorphous state, excellent in corrosion resistance, and a conductive polymer layer can be prepared on an aluminum nitride thin film. It was confirmed that the resistance value in the film thickness direction was small, indicating conductivity.

  Since the aluminum nitride thin film of the present invention is excellent in conductivity and corrosion resistance, a battery such as a current collector of a lithium ion secondary battery, a current collector of a lithium ion capacitor, a current collector of a conductive polymer aluminum electrolytic capacitor, etc. Power storage device parts for capacitors and capacitors, electronic parts such as flexible circuit boards, partition walls for fuel cells, electrode materials for solar cells, water electrolysis electrodes, electrodes for electroplating and other electrodes (for example, for organic solar cells), high conductivity Working electrode and counter electrode during polymerization of molecules, auxiliary electrode of conductive polymer actuator, base and counter electrode of working electrode of conductive polymer actuator, mechanism parts (electromagnetic wave shield, antenna, etc.), filler material, heat exchanger Useful for cooling fins, semiconductor light emitting devices, power supply devices, MOSFET devices, medical substrates, corrosion protection films, etc. A.

A: Nitrogen gas B: Oxygen gas (dopant gas)
C: Air (dopant gas)
1: Gas introduction line 2: DC power supply 3: Positive voltage (+)
4: Negative voltage (-)
5: Plasma discharge electrode 6: Plasma irradiation port 7: Plasma 8: Aluminum base material 9: Working distance
10: Sample fixing table 11: Process chamber 12: Vacuum drawing line 13: Rotary pump 14: LCR meter 15: Electrode 16: Aluminum nitride thin film 17: Resistance in film thickness direction (measurement)
(A): X-ray incident angle (0.5 °)
(B): X-ray incident angle (2.0 °)
(C): N1s peak due to Al—N (d): N1s peak due to Al—N—O

Claims (9)

An aluminum nitride thin film containing at least nitrogen and oxygen, which is in an amorphous state and has conductivity. The aluminum nitride thin film according to claim 1, wherein a resistance in a film thickness direction is 10Ω or less. A method of forming the aluminum nitride thin film according to claim 1 or 2 on an aluminum substrate,
A step of preparing a mixed gas of nitrogen and a dopant gas containing at least oxygen into plasma, and irradiating the plasma on the aluminum base material in an atmosphere of 660 ° C. or lower to nitride the aluminum base material A method for forming an aluminum nitride thin film, comprising the step of forming an aluminum thin film. 4. The method for forming an aluminum nitride thin film according to claim 3, wherein a mixed volume ratio (oxygen / nitrogen) of nitrogen and oxygen in the mixed gas exceeds 0. The method for forming an aluminum nitride thin film according to claim 3 or 4, wherein the plasma output upon irradiation with the plasma is 3 kW / cm ² or less. The method for forming an aluminum nitride thin film according to any one of claims 3 to 5, wherein a pressure when the plasma is irradiated is 1 MPa or less. The method for forming an aluminum nitride thin film according to any one of claims 3 to 6, wherein the plasma is prepared by an atmospheric pressure plasma apparatus. The method for forming an aluminum nitride thin film according to any one of claims 3 to 7, wherein a thickness of the aluminum nitride thin film on the aluminum substrate is 5000 nm or less. An electrode material comprising a conductive polymer layer on the aluminum nitride thin film according to claim 1.