JPS59209854A - Thin-film changed into multilayer and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a functional multilayer thin film and a method for producing the same.

Functional inorganic thin films are being actively considered for application as devices mainly related to electronic equipment, such as various sensors, transparent conductive films, semiconductors, dielectrics, piezoelectric M1 magnetic films, and the like.

As methods for producing these thin films, methods using vacuum technology, such as vacuum evaporation and sputtering, are employed, and a wide variety of thin films can be produced.

However, the manufacturing method of NfG4 using this vacuum technology has disadvantages such as high equipment cost, high utility cost, difficulty in increasing the area, low productivity and high price, and is not suitable for applied fields. The current situation is that there are limitations. Furthermore, in order to make a sliding metal compound containing two or more metal components into a thin film, the vapor pressure of each metal component must be different, and some metals may have different valences, producing compounds other than the intended ones. Therefore, there are many cases where the stoichiometry and crystallinity of the target compound cannot be stably obtained.

1. There is also a movement to effectively utilize the functions of these functional thin films by stacking thin films, each with its own function, to add new complex functions and to develop devices with new functions.

The present invention relates to a multilayered thin film that can have such novel functions and a method for manufacturing the same.The present invention relates to a multilayered thin film that can have such novel functions, and a method for manufacturing the same.The present invention relates to a multilayered thin film that can have such novel functions and a method for producing the same.New functional materials can be created by multilayering thin films with compositions that are difficult to manufacture using conventional vacuum technology, or thin films with large areas. The purpose is to create.

The method for producing a thin film of the present invention is characterized by dissolving one or more organometallic compounds in a solvent, applying the solution onto a substrate, and thermally decomposing the solution.

As the organometallic compound used in the present invention, one or more of metal alkoxides, metal-organic complex compounds, or reaction products thereof are used, and when two or more metal alkoxides are used, an organic chelating agent is added. It is preferable to do so.

Examples of the metal alkoxide include metal alkoxides of a single composition, partial metal alkoxides, composite metal alkoxides, and multimers of these metal alkoxides. Examples of metal atoms include lithium, sodium,
Potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, nickel, cobalt, copper, zinc, cadmium, mercury, boron, aluminum, gallium, indium,
Examples include thallium, silicon, germanium, m 2 , G 2 , arsenic, antimony, bismuth, selenium, tellurium, and lanthanoid metals.

As a compound that forms an alkoxide with a metal, the general formula H
OR (R is a hydroxylated or non-hydroxylated alkyl group or aryl group having 1 to 20 carbon atoms)
Any monohydric or polyhydric alcohol having an alcoholic hydroxyl group represented by the above formula may be used. Preferred specific examples include methyl alcohol, ethyl alcohol, n-propyl alcohol, isobutyl alcohol, n-butyl alcohol, isobutyl alcohol, pentyl alcohol, hexyl alcohol, 2-ethylhexyl alcohol, octyl alcohol, 7-butyl alcohol, and lauryl alcohol. Alcohol, 1,4-butanediol, glycerin,
Examples include ethylene glycol, octyl alcohol, and monoalkyl ether of ethylene glycol.

Examples of the functional group other than the alkoxy group of the partial metal alkoxide include a halogen atom, a hydroxyl group, a β-diketone, or a residue of an organic acid.

Specific examples of metal alkoxides that can be used in the present invention include the above-mentioned H.
O, Bradley) et al., metal alkoxides (
Metal alkoxides), 1978, Academic Press
) can also be used.

The metal-organic complex compound may be any compound as long as it has a common solvent with the metal alkoxide and forms the desired composite metal oxide by thermal decomposition, and metal β-diketone complexes are particularly preferred.

Examples of the metal forming the metal-organic complex compound include the metals used for the metal alkoxides.

Examples of the β-diketone include acetylacetone, benzoylacetone, dibenzoylacetone, diisobutyrylmethane, dipivaloylmethane, 3-methylpentane-2,4-dione, 2,2-dimethylpencune-3,5
-dione or their fluorinated products, and acetylacetone is particularly preferred.

The vine metal β-diketone complex used in the present invention includes:
In addition to the above, R C Mehrotra (R,0,,M
metal beta diketones and allied derivatives (metal beta diketones and allied derivatives)
Dilcetones and A11ied der
Examples include metal ketone complexes described in ``Academic Press'', 1978, Academic Press.

Preparation of a composite metal solution does not require a particular solvent when two or more types of organometallic compounds are compatible, but a common solvent is required when they are not compatible.

Common solvents include, for example, monohydric or polyhydric alcohols; carboxylic acid esters; ketones; Hensen, toluene,
Examples include aromatic solvents such as xylene, dioxane, ethers such as tetrahydrofuran, and one or more mixed solvents. Among them, monohydric or polyhydric lower alcohols; lower carboxylic acid esters: ethers such as dioxane and tetrahydrofuran can be widely used in various combinations of metal alkoxides and metal ketone complexes, but specific solvents are It may be selected as appropriate depending on the combination of organometallic compounds.

In the case of metal alkoxide and metal ketone complexes, even in combinations in which one or both of them are not soluble in the solvent, aldehyde is added in step 1. A homogeneous solution can be obtained by heat treatment if necessary. The heat treatment is usually preferably carried out at a temperature below the reflux temperature of the solvent.

Preferred aldehydes include aldehydes having 1 to 8 carbon atoms, particularly formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, and the like.

In addition, as a method for producing a composite metal solution, there is a method in which an organic chelating agent is added to two or more metal alkoxides to stabilize and homogenize the solution. In a mixed system of two or more metal alkoxides, preferably dissolved in a common solvent, an organic chelating agent such as E+DTA (ethylenediaminetetraacetic acid), NTA (trilotriacetic acid), UDA (
uramyl diacetic acid), dimethylglyoxime, dithizone,
Oxine, β-diketones, glycine, methyl acetoacetate, ethyl acetoacetate and monohydric carboxylic acids such as lylunic acid, oleic acid, octylic acid, oxalic acid,
One or more polyhydric carboxylic acids such as citraconic acid, maleic acid, phta-AI acid, and naphthenic acid, especially β-
A solution having a desired composition can be easily prepared by adding one or more of diketone, methyl acetoacetate, ethyl acetoacetate, and monocarboxylic or polycarboxylic acids and forming a homogeneous solution. If an insoluble precipitate occurs, it can be dissolved by adding aldehyde and heating in the same manner as described above. As the metal alkoxide 1 common solvent and aldehyde used, those exemplified above can be used.

The thus obtained bonding metal solution is applied to a substrate and thermally decomposed to produce a metal compound thin film.

Methods for obtaining a composite metal compound layer include, for example, a method in which a composite metal solution is applied onto a substrate by spraying, coating, spin coating, etc., and then heated and pyrolyzed, or a method in which the solution is sprayed onto a substrate heated to a decomposition temperature. Usually used when a metal alkoxide is used alone, such as by gasifying a solution and then heating it for thermal decomposition, or by depositing the decomposed product on a substrate while being decomposed by plasma or laser light, or by printing. methods may be employed.

The thermal decomposition temperature is preferably 300°O or higher.

In order to form multiple layers, it is important to stack the next thin film after the organic components of the applied thin film are completely removed by thermal decomposition or volatilization, but especially when the film is thin, it is important to stack the next thin film after forming multiple layers. A firing treatment may also be performed. It should be noted that if the thickness of the produced film in one step exceeds 1 μm, cracks may occur during thermal decomposition or the adhesion to the substrate may deteriorate, which is not preferable.

Furthermore, by changing the heat treatment atmosphere, various metal compound thin films can be formed. For example, it is possible to produce oxide thin films in the air or oxygen atmosphere, metal nitrite N films in a nitrogen atmosphere, metal sulfide thin films in a hydrogen sulfide atmosphere, and metal (or alloy) thin films in a reducing atmosphere such as hydrogen. becomes. Further, the substrate needs to be made of a material that can withstand heat treatment processes, and is preferably made of polyimide, metal, glass, ceramics, or the like.

When using such a thin film manufacturing method, it is possible to manufacture thin films with various compositions that are difficult to manufacture using methods using vacuum technology. ferromagnetic thin films with a spinel structure such as nickel ferrite and cobalt ferrite, ferromagnetic thin films with a magneto-dopplerite structure such as barium ferrite and strontitium ferrite, and other composite metals containing two or more metal elements. It is possible to easily manufacture large-area N films using simple equipment.

The multilayer thin film of the present invention can be obtained by performing the above thin film manufacturing process at least once.

That is, the above thin film manufacturing process may be repeated two or more times, or a thin film forming method using vacuum technology may be used in combination to form multiple layers, but at least one layer must include a composite metal compound layer with a thickness of 10 μm or less. It is. It is not preferable for the thickness of the composite metal compound layer to exceed 10 μm due to its function and manufacturing method.

The multilayer thin film of the present invention is a transparent conductive film mainly composed of tin oxide or indium oxide, PbTiO3 or (PbX-La1-x) (T
iy-Zr1-y ) 03 thin film, optical memory made by stacking transparent conductive films, electrical polarizing element, multilayer capacitor made by alternately stacking conductive films and ferroelectric materials such as barium titanate, (
A wide range of applications can be expected in magnetic recording materials in which soft magnetic films such as NiX-Zr1-z ) and Fe2O4 and 00Fe204 or Bs0.6Fθ203 are laminated, as well as other optical-related devices, sensors, filters, and storage materials.

Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 15 g of tin tetraisopropoxide and 0.7 g of antimony triisopropoxide were added to 100 g of absolute ethyl alcohol.
A solution for forming a transparent conductive film was prepared. On the other hand, barium acetylacetonate) 8.49 titanium tetraisopropoxide? Add the solution to absolute ethyl alcohol 1009,
Further, 1 g of paraformaldehyde was added while stirring with heating to form a homogeneous solution, and the solvent was further changed from ethyl alcohol to tetrahydrofuran to obtain a barium titanate solution.

The solution for forming a transparent conductive film was then dip-coated onto quartz glass at a pulling rate of 5 cm for 7 minutes, heated at a temperature increase rate of 10°C/min to <SODoo, and fired at that temperature for 1 hour. After cooling, a barium titanate solution was applied in the same manner and fired. The above treatment was repeated to obtain a transparent thin film consisting of four layers.

When the obtained multilayer thin film was measured by WSAH (surface photoelectron spectroscopy), it was found that antimony-doped tin oxide films and barium titanate films were alternately laminated to a thickness of about 50 OA.

This product can be expected to be used as a transparent multilayer capacitor.

Example 2 Iron triethoxide 10 so that Fe:N1=2:1
A nickel ferrite solution was obtained by dissolving 6.72 g of nickel acetylacetonate and 6.72 g of nickel acetylacetonate in 100 g of heated absolute ethyl alcohol.

On the other hand, 1 g of barium acetylacetonate and 6 iron triethoxide were added so that Fe:Ba=12:1.
829 was added to anhydrous ethyl alcohol 1009, and while stirring with heating, 0.59% of paraformaldehyde was added to obtain a barium ferrite solution.

Spread 10 cm of nickel ferrite solution on a quartz glass plate.
After dipping at a rate of 1/min, it was fired at a heating rate of 1000/min for 800° for 1 hour, cooled, and then a barium ferrite solution was applied thereon under the same conditions, followed by heat treatment. The obtained thin film is a red semi-transparent thin film, and as a result of surface analysis by ESOA, thin films with the target beryllum ferrite composition (Fao 6Fθ203) and niranal ferrite composition NiFe2O4 have a diameter of about 1.000A and about 5ooX, respectively. It was found that the layers were laminated to a thickness of .

Claims (1)

[Scope of Claims] 1. A multilayer thin film containing at least one composite metal compound layer with a thickness of 10 μm or less. 2. The multilayer thin film according to claim 1, wherein the composite metal compound is a composite metal oxide. A composite metal compound layer with a thickness of 10 μm or less, characterized by performing a thin film manufacturing process at least once in which a composite metal solution prepared by dissolving 31 types or 2 or more types of organometallic compounds in a solvent is applied onto a substrate and then heat-treated. A method for producing a multilayer thin film containing at least one layer of