JP2001114600A - Metal oxide structure and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal oxide structure comprising plural metal oxide fine crystals each having a specific size, especially the structure which can preferably be used as a light-releasing element, and to provide a method for producing the same. SOLUTION: This metal oxide structure comprises plural metal oxide fine crystals each having a cross section diameter (converted into a circle) of 0. 01 to 100 μm and epitaxially grown on a substrate. The method for producing the metal oxide structure comprises evaporating at least one metal compound which has an evaporating or subliming property and can react with at least one oxide-forming substance to form the metal oxide, and then reacting the obtained gas of the metal compound with the oxide-forming substance on a substrate placed in a reaction zone containing the oxide-forming substance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal oxide structure composed of a plurality of metal oxide microcrystals, and more particularly to a metal oxide structure preferably used as a light emitting device and a method of manufacturing the same.

[0002]

2. Description of the Related Art The use of metal oxides as wide-gap semiconductors as light emitting devices has been widely studied. As light emission from the metal oxide, for example, there is a method of using a metal oxide in which microcrystals epitaxially grown are densely arranged. As a method for obtaining the metal oxide, for example, Solid State Physics, 33 (1998), pp. 59-64.
There is a method described on the page. However, according to the method described in this paper, the metal oxide is produced only by a laser MBE apparatus composed of a vacuum apparatus and an excimer laser, but the metal organic pyrolysis method (hereinafter referred to as M) described in the present invention is used.
A method for obtaining the metal oxide by an OCVD method is not disclosed.

Further, as a method of forming a metal oxide using MOCVD under normal pressure, for example, Journal of the Ceramic Society of Japan, 105 (1997), pp. 551 to 554 (1997) Journal of the Ceramic So
city of Japan, 105 (1997) p
p. L551 to R554). However, the method described in the article only forms a titanium oxide thin film, and does not teach or suggest epitaxial growth.

[0004]

The present invention relates to a metal oxide structure composed of a plurality of metal oxide microcrystals having a specific size, particularly a structure preferably used as a light emitting device, and a method of manufacturing the same. Things.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a structure preferably used as a photon emitting device, and as a result, have found that a metal oxide composed of a plurality of metal oxide microcrystals having a specific size is obtained. The present inventors have found a structure and a method for manufacturing the same, and have completed the present invention. That is, the present invention provides: (1) a metal oxide structure comprising a plurality of metal oxide microcrystals having a cross-sectional circle-equivalent diameter of 0.01 to 100 μm and epitaxially grown from a substrate. (2) The metal oxide microcrystals have a size of 1 on the surface of the metal oxide structure.
0.1 to 1,000,000 per area of 0 μm × 10 μm
The metal oxide structure according to (1), wherein the metal oxide structure is present at a density of individual pieces. (3) The metal oxide microcrystals form protrusions of the metal oxide structure, and the ratio of the length of the protrusions to the circle-converted diameter of the metal oxide microcrystals is 0.01 or more (1). Or (2)
The metal oxide structure according to claim.

(4) The metal oxide structure according to any one of (1) to (3), wherein the central axes of the metal oxide microcrystals are parallel to each other. (5) In the periodic table, the metal in the metal oxide is a group 1 group other than hydrogen, a group 2 group other than hydrogen, a group 13 except boron, and a group other than carbon 14
Group 15, 15 group except nitrogen, phosphorus and arsenic and 3, 4, 5,
(1) to (1) to containing at least one member selected from the group consisting of 6, 7, 8, 9, 10, 11, and 12 groups.
The metal oxide structure according to any one of (4). (6) The metal in the metal oxide is Zn, Si, Al, S
The metal oxide structure according to any one of (1) to (5), which contains at least one selected from n, Ti, Zr, and Pb. (7) The metal oxide structure according to any one of (1) to (6), wherein the metal oxide is a metal oxide single crystal.

(8) A light emitting device comprising the metal oxide structure according to any one of (1) to (7). (9) vaporizing a metal compound which is volatile or sublimable and which is capable of forming a metal oxide by reacting with at least one oxide-forming substance; The metal according to any one of (1) to (8), wherein a gas is obtained, and the obtained metal compound gas is reacted on a substrate placed in a reaction zone containing the oxide-forming substance. A method for manufacturing an oxide structure. (10) A metal compound obtained by vaporizing a metal compound which is volatile or sublimable and is capable of forming a metal oxide by reacting with at least one oxide-forming substance. (9) The method for producing a metal oxide structure according to (9), wherein a gas is obtained, and a reaction zone containing the obtained metal compound gas and the oxide-forming substance is an atmospheric pressure atmosphere. About.

Hereinafter, the present invention will be described in detail. The metal oxide microcrystal in the present invention is a metal oxide crystal,
For example, a crystal habit can be confirmed one by one by a conventionally known method such as a scanning electron microscope (hereinafter, referred to as SEM) or an atomic force microscope (hereinafter, referred to as AFM). The equivalent circle diameter of the cross section is preferably 0.01 to 100 μm. If the circle-converted diameter is less than 0.01 μm,
It is difficult to obtain a grown microcrystal, and if it exceeds 100 μm, the light emission effect of the microcrystal is poor, which is not preferable.

Here, the circle-converted diameter is a value twice the square root of the area obtained by calculating the cross-sectional area by a conventionally known method such as image analysis and dividing the obtained area by the pi. expressed. In addition, the cross section referred to here is one of the length of the protrusion.
2 indicates a plane at a distance of / 2.

The metal oxide structure of the present invention is preferably grown epitaxially on a substrate. Whether or not the metal oxide structure is epitaxially grown on the substrate can be confirmed by ordinary X-ray diffraction.
In particular, a method of confirming by observing the in-plane orientation relationship between the substrate and the metal oxide by the φ scan method is preferably used. The metal oxide structure may have a projection. The protrusion in the present invention refers to an object having a mountain-shaped raised portion, a block-like or a rod-like structure. As the shape of the projection, the ratio of the length to the circle-converted diameter of the cross section, that is, the aspect ratio is 0.01%.
That is all.

The term "length of the projection" as used herein refers to the length from the position where the projection substantially projects from the surface to the top of the projection. The length depends on the intended use and is not limited, but is usually 0.00
It is preferably from 1 to 10,000 μm. When the metal oxide of the present invention has a plurality of protrusions, each of the protrusions may not have the same shape. That is, the projections may be aggregates having different aspect ratios and different lengths. In this case, the aspect ratio and length of the present invention are indicated by average values. The average value of the aspect ratio is represented by a weighted average value of the aspect ratio of the protrusion in the cross section of the structure having a width of 200 μm. The average value of the length is represented by a weighted average value of the lengths of the protrusions in a range of 10 μm × 10 μm on the metal oxide surface.

When the projection on the metal oxide is a metal oxide crystal, it is preferable that the crystal axes are in the same direction (the crystal axis directions are aligned). For example, the fluctuation of the crystal axis direction measured by the X-ray rocking curve method is preferably within 10 degrees. More preferably, it is within 5 degrees. The ratio of the protrusions on the surface is 10 μm ×
It is preferably 0.1 to 1,000,000 per 10 μm area, more preferably 0.1 to 100,000.
And more preferably 1 to 10000. If this value is less than 0.1, the effect of light emission by the microcrystals is poor, and if it exceeds 1,000,000, it is difficult to obtain a grown structure, which is not preferable.

The structure according to the present invention comprises a metal oxide. The metal oxide in the present invention means that the metal species in the periodic table is Group 1 other than hydrogen, Group 2 or 13 excluding boron.
Group, 14 excluding carbon, 15 excluding nitrogen, phosphorus and arsenic
Tribe, Po and 3, 4, 5, 6, 7, 8, 9, 10, 1
It is an oxide that is an element belonging to Groups 1 and 12. As the metal species, for example, Li, Na, K, Rb, Cs, B
e, Mg, Ca, Sr, Ba, Al, Ga, In, T
1, Si, Ge, Sn, Pb, Sb, Bi, Po, S
c, Y, La, Th, Ce, Pr, Nd, Pm, Sm,
Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, L
u, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo,
W, Mn, Tc, Re, Fe, Ru, Os, Co, R
h, Ir, Ni, Pd, Pt, Cu, Ag, Au, Z
n, Cd, Hg and the like, and among these, Li, Na, K, Rb, Cs, Be, Mg, Ca, S
r, Ba, Al, Ga, In, Tl, Si, Ge, S
n, Pb, Sb, Bi, Sc, Y, La, Ce, Th,
Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn,
Re, Fe, Ru, Os, Co, Rh, Ir, Ni, P
d, Pt, Cu, Ag, Au, Zn, Cd, and Hg, and more preferably Li, K, Mg, Ca, Sr,
Ba, Al, In, Si, Sn, Pb, Th, Y, C
e, Ti, Zr, V, Nb, Ta, Cr, Mo, W, M
n, Fe, Co, Ni, Pd, Pt, Cu, Ag, Z
n and Cd.

These metals can be used alone or in combination of two or more. For example,
MgO, Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , SnO
₂ , TiO ₂ , ZnO, barium titanate, SrTiO
₃ , LiNiO ₃ , PZT, YBCO, YSZ, YA
G, ITO (In ₂ O ₃ / SnO ₂ ) and the like.
Further, an alkali metal and another metal can be used in combination. For example, Ta, Nb and or KTaO ₃ in combination alkali metal or the like, to form a composite oxide such as NbLiO _3, can be a metal oxide.

The metal oxide may be basically crystalline or amorphous, but is more preferably crystalline. Even if the crystalline material is one or more single crystals, even if it is polycrystalline,
One or more semi-crystalline materials having both an amorphous part and a crystalline part may be used, or a mixture thereof. Particularly preferably, it is a single crystal. The shape of the metal oxide structure may be any as long as it has a substantially flat and / or curved surface, but a plate shape is more preferable. The size of the structure is not particularly limited, but when the structure is plate-shaped, the thickness is 0.0
It is preferably from 01 μm to 100 mm, more preferably from 0.002 μm to 50 mm, most preferably from 0.005 μm to 10 mm. The structure of the present invention comprises:
It includes a metal oxide substrate having a metal oxide structure on it or a substrate other than a metal oxide substrate. For example, according to the manufacturing method illustrated below,
Usually, a metal oxide structure is first formed on a substrate.

Next, a preferred method for forming the metal oxide structure according to the present invention will be described. The metal oxide in the present invention can be produced, for example, by converting a metal compound, which is a raw material of the metal oxide, into a gas and / or fine particles and reacting it with oxygen, water, ammonia, or the like. At this time, the metal compound is not particularly limited as long as it has a metal in the metal oxide of the target structure and reacts with oxygen, water, ammonia or the like to form an oxide.

Examples of such a metal compound include alkoxides in which the hydrogen of the hydroxyl group of an alcohol is replaced with a metal at the atom of the metal or metal-like element, and acetylacetone, ethylenediamine, bipiperidine, and bipyrazine at the atom of the metal or metal-like element. , Cyclohexanediamine, tetraazacyclotetradecane, ethylenediaminetetraacetic acid, ethylenebis (guanide), ethylenebis (salicylamine), tetraethylene glycol, aminoethanol, glycine, triglycine, naphthyridine, phenanthroline, pentanediamine, pyridine,
One or two ligands selected from salicylaldehyde, salicylideneamine, porphyrin, thiourea, etc.
Fe, Cr, Mn, Co, Ni, Mo, V, W, having various kinds of complexes having a carbonyl group as a ligand
Various metal carbonyls such as Ru, carbonyl group, alkyl group, alkenyl group, phenyl or alkylphenyl group, olefin group, aryl group, conjugated diene group including cyclobutadiene group, and cyclopentadienyl group. Various metal compounds and metal halide compounds having one or more ligands selected from trienyl groups such as a dienyl group, a triene group, an arene group, a cycloheptatrienyl group and the like can be used. . Also, metal complexes can be used. Among them, complexes such as acetylacetone and alkoxides are more preferably used.

As the complex in the present invention, β-
Distribution of diketones, ketoesters, hydroxycarboxylic acids or salts thereof, various Schiff bases, ketoalcohols, polyamines, alkanolamines, enol active hydrogen compounds, dicarboxylic acids, glycols, ferrocenes, etc. A compound in which one or more ligands are bonded.

Specific examples of the compound serving as a ligand of the complex used in the present invention include acetylacetone, ethylenediamine, triethylenediamine, ethylenetetramine, bipiperidine, cyclohexanediamine, tetraazacyclotetradecane, ethylenediaminetetraacetic acid, ethylenebis (Guanide), ethylenebis (salicylamine), tetraethyleneglycol, diethanolamine, triethanolamine, tartaric acid, glycine, triglycine, naphthyridine, phenanthroline, pentanediamine, salicylaldehyde, catechol, porphyrin, thiourea, 8-hydroxyquinoline, 8-hydroxyquinaldine, β-aminoethyl mercaptan, bisacetylacetone ethylenediimine, eriochrome black T, oxy , Quinaldic acid salicylaldoxime, picolinic acid, glycine, dimethylglyoxime oxy Mato,
Dimethylglyoxime, α-benzoinoxime, N,
N'-bis (1-methyl-3-oxobutylidene) ethylenediamine, 3-{(2-aminoethyl) amino}-
1-propanol, 3- (aminoethylimino) -2-
Butane oxime, alanine, N, N'-bis (2-aminobenzylidene) ethylenediamine, α-amino-α-
Methylmalonic acid, 2-{(3-aminopropyl) amino} ethanol, aspartic acid, 1-phenyl-1,
3,5-hexanetrione, 5,5 ′-(1,2-ethanediyldinitrilo) bis (1-phenyl-1,3-hexanedione), 1,3-bis {bis [2- (1-ethyl [Benzimidazolyl) methyl] amino {-2-propanol, 1,2-bis (pyridine-α-aldimino) ethane, 1,3-bis {bis (2-pyridylethyl) aminomethyl} benzene, 1,3-bis} Bis (2-pyridylethyl) aminomethyl} phenol, 2,2′-bipiperidine, 2,6-bis {bis (2-pyridylmethyl)
Aminomethyl 4-methylphenol, 2,2'-bipyridine, 2,2'-bipyrazine, hydrotris (1-
Pyrazolyl) borate ion, catechol, 1,2-cyclohexanediamine, 1,4,8,11-tetraazacyclododecane, 3,4: 9,10-dibenzo-1,5,
8,12-tetraazacyclotetradecane-1,11-
Diene, 2,6-diacetylpyridine dioxime, dibenzyl sulfide, N- {2- (diethylamino) ethyl} -3-amino-1-propanol, o-phenylenebis (dimethylphosphine), 2- {2- (dimethyl Amino) ethylthiodiethanol, 4,4'-dimethyl-
2,2′-bipyridine, N, N′-dimethyl-1,2-
Cyclohexanediamine, dimethylglyoxime, 1,
2-bis (dimethylphosphino) ethane, 1,3-bis (diacetylmonooximino) propane, 3,3 ′
-Trimethylene dinitrobis (2-butane oxime)
1,5-diamino-3-pentanol dipivaloylmethane, 1,2-bis (diphenylphosphino) ethane, diethyldithiocarbamate ion, N, N'-bis {2
-(N, N'-diethylaminoethyl) aminoethyl
Oxamide, ethylenediaminetetraacetic acid, 7-hydroxy-4-methyl-5-azahept-4-en-2-one, 2-aminoethanol, N, N'-ethylenebis (3-carboxysalicylideneamine), 1, 3-bis (3-formyl-5-methylsalicylideneamino) propane, 3-glycylamino-1-propanol, glycylglycine, N ′-(2-hydroxyethyl) ethylenediaminetriacetic acid, hexafluoroacetylacetone,
Histidine, 5,26: 13,18-diimino-7,1
1: 20,24-dinitrodibenzo [c, n] -1,
6,12,17-tetraazacyclodocosin, 2,6-
Bis {N- (2-hydroxyphenyl) iminomethyl}
-4-methylphenol, 5,5,7,12,12,1
4-hexamethyl-1,4,8,11-tetraazacyclotetradecane-N, N "-diacetate, 1,2-dimethylimidazole, 3,3'-ethylenebis (iminomethylidene) -di-2,4-pentane Dione, N, N'-bis (5-amino-3-hydroxypentyl) malonamide, methionine, 2-hydroxy-6-methylpyridine, methyliminodiacetic acid, 1,1-dicyanoethylene-
2,2-dithiol, 1,8-naphthyridine, 3- (2
-Hydroxyethylimino) -2-butanone oxime,
2,3,7,8,12,13,17,18-octaethylporphyrin, 2,3,7,8,12,13,17,
18-octamethylporphyrin, oxalic acid, oxamide, 2-pyridylaldoxime, 3- {2- (2-pyridyl) ethylamino} -1-propanol, 3- (2-
Pyridylethylimino) -2-butanone oxime, 2-
Picolylamine, 3- (2-pyridylmethylimino)-
2-butanone oxime, dihydrogen diphosphite, 3-
n-propylimino-2-butanone oxime, proline, 2,4-pentanediamine, pyridine, N, N'-
Dipyridoxylideneethylenediamine, N-pyridoxylideneglycine, pyridine-2-thiol, 1,5-bis (salicylideneamino) -3-pentanol, salicylaldehyde, N-salicylidenemethylamine, salicylic acid , N- (salicylidene) -N '-(1-methyl-3
-Oxobutylidene) ethylenediamine, salicylideneamine, N, N'-disalicylidene-2,2'-biphenylylenediamine, N, N'-disalicylidene-2-methyl-2- (2-benzylthioethyl) ethylenediamine, N , N'-Disalicylidene-4-aza-1,7-heptanediamine, N, N'-disalicylideneethylenediamine, N-salicylideneglycine, salicylaldoxime, N, N'-disalicylidene-o-phenylenediamine , N, N'-disalicylidenetrimethylenediamine, 3-salicylideneamino-1-propanol, tetrabenzo [b, f, j, n] -1,5,9,13-tetraazacyclohexadecine, 1,4,7-triazacyclononane, 5,14-dihydrodibenzo [b, i]-
1,4,8,11-tetraazacyclotetradecine, tris (2-benzimidazolylmethyl) amine, 6,
7,8,9,16,17,18,19-octahydrodicyclohepta [b, j] -1,4,8,11-tetraazacyclotetradecene, 4,6,6-trimethyl-3,
7-diazanone-3-ene-1,9-diol, tris (3,5-dimethyl-1-pyrazolylmethyl) amine,
2,2 ′: 6 ′, 2 ″ -terpyridine, 5,7,7,1
2,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, tetrahydrofuran, tris (2-pyridylmethyl) amine, N, N, N ′,
N'-tetramethylurea, N, N'-bis (3-aminopropyl) oxamide, N, N, N ', N'-tetrakis (2-pyridylmethyl) ethylenediamine, all-
cis-5,10,15,20-tetrakis @ 2-
(2,2′-dimethylpropionamido) phenyl diporphyrin, 5,10,15,20-tetraphenylporphyrin, 1,4,7-tris (2-pyridylmethyl) -1,4,7-triazacyclononane , Hydrotris (1-pyrazolyl) borate, 3,3′4-trimethyldipyrromethene, trimethylenediaminetetraacetic acid,
3,3'5,5'-tetramethyldipyrromethene, 5,1
0,15,20-tetrakis (p-triporphyrin)
And the like.

In forming the metal oxide structure, it is more preferable to form the metal oxide using a specific substrate. As a method for forming the metal oxide, any method such as a method of reacting gas and / or fine particles of a metal compound with the metal oxide on the substrate surface, and a method of depositing and / or laminating the metal oxide that has become fine particles may be used. . In addition, both of these methods can be used in combination.

The specific substrate referred to herein is, for example, a metal oxide single crystal plate such as aluminum oxide, a semiconductor single crystal, ordinary ceramic, a metal containing silicon, glass, or the like.
It refers to plastic and the like. When using glass or plastic, it is preferable that the surface is subjected to an orientation treatment. Of these, metals containing silicon, metal oxides, and ZnTe, GaP, and GaAs are preferably used.
s, semiconductor single crystal such as InP. One factor in selecting a single crystal seed preferably used as the substrate is that the lattice constant of the formed metal oxide crystal seed is close to the lattice constant of the single crystal seed used as the substrate. The lattice constant can be measured by a conventionally known method such as a wide-angle X-ray diffraction method. This value is a ratio represented by the lattice constant of the surface of the metal oxide crystal seed in contact with the substrate / the lattice constant of the surface of the single crystal seed used as the substrate in contact with the metal oxide crystal of 0.8. ~ 1.2, preferably 0.9 ~ 1.1
Is more preferable, and particularly preferably 0.95 to 1.05.

Particularly preferably used are, specifically, silicon, aluminum oxide, magnesium oxide, Sr
It is a single crystal of a metal oxide such as TiO ₃ . The crystals in this case may be one or more single crystals, polycrystals, one or more semi-crystalline materials having both an amorphous part and a crystalline part, or a mixture thereof. You may. Most preferably, it is a single crystal. In this case, it is preferable that the substrate surface is a specific surface of the single crystal. In particular,
For example, when selected as a metal oxide forming titanium oxide, the (100) plane is selected for a magnesium oxide substrate, and when selected as a metal oxide forming zinc oxide, a (111) plane is selected for a silicon substrate. More preferably, the substrate has a (0001) plane and the SrTiO ₃ substrate has a (001) plane. The substrate may or may not be included in the metal oxide structure.

The amount of the gaseous and / or particulate metal compound is also controlled by the degree of supersaturation. The degree of supersaturation in the present invention is defined as [(actual vapor pressure−equilibrium vapor pressure) / equilibrium vapor pressure] × 100. In order to obtain the metal oxide in the present invention, the degree of supersaturation is preferably 1% or more. It is more preferably at least 10%, particularly preferably at least 20%.

A gas used as a medium for spraying a gas and / or a fine metal compound is as follows.
There is no particular limitation as long as it does not react with the metal compound used. Specific examples include an inert gas such as nitrogen gas, helium, neon, and argon; carbon dioxide gas; organic fluorine gas; and organic substances such as heptane and hexane. Among these, an inert gas is preferable from the viewpoint of safety and economy. In particular, nitrogen gas is the most preferable in terms of economy.

When forming a metal oxide on a substrate by spraying a gas and / or a metal compound which has been turned into fine particles with a gas, the distance between the outlet of the metal compound and the surface of the metal oxide is as large as possible. The distance is preferably determined by the ratio of the distance between the outlet and the surface of the metal oxide / the length of the long axis of the opening. This value is preferably 0.01 to 1, more preferably 0.05 to 0.7, particularly preferably 0.1 to 0.
5 Although this ratio varies depending on the shape of the outlet, a ratio of 1 or more is not preferable because the metal compound is not effectively converted to a metal oxide and the efficiency is poor.

The temperature of the substrate itself when the metal oxide is formed is not particularly limited as long as the solid metal oxide is formed near and on the surface of the substrate. Affects shape. Preferably 0-1
000 ° C, more preferably 20 to 900 ° C, particularly preferably 100 to 900 ° C. The conditions for forming the metal oxide structure in the present invention are not necessarily determined only by the concentration, temperature and substrate temperature of the metal compound sprayed on the substrate. For example, the needle-like metal oxide structure of the present invention can be obtained in a balance between the temperature at which the metal compound is released and the temperature of the substrate. That is, controlling the concentration, release rate, temperature, substrate temperature, and the like of the metal compound sprayed on the substrate is an important factor for obtaining the metal oxide structure of the present invention.

When the substrate is a metal oxide, the metal oxide is more preferably grown epitaxially on the substrate. Whether or not the metal oxide is epitaxially grown on the substrate can be confirmed by a usual X-ray diffraction method. In particular, a method of confirming by observing the in-plane orientation relationship between the substrate and the metal oxide by the φ scan method is preferably used. If oxygen, water, ammonia, etc. are present in the system, a metal oxide is formed in the apparatus before release, clogging and the like occur, and a metal oxide having a desired form cannot be obtained. Absent. However, when the reaction rate of the metal compound with oxygen, water, ammonia or the like is extremely low, oxygen, water, ammonia or the like may be coexisted in the system in advance.

The atmosphere in which the gas and / or the fine particles of the metal compound and the substrate are present may be under reduced pressure, normal pressure or increased pressure. However, when the process is performed under a high degree of reduced pressure, for example, under an ultra-vacuum, the growth rate of the metal oxide is low, and the productivity is poor.
When the process is performed under pressure, there is no problem with the growth rate of the metal oxide, but equipment for pressurization is required. Usually 0.0
It is preferably carried out at from 01 to 20 atm, more preferably from 0.1 to 10 atm. Most preferably, it is normal pressure.

[0029] The reaction time required to form the metal oxide is not particularly limited. It differs depending on the reaction conditions and the type of the raw material. For example, when zinc acetylacetonate is used as the raw material, it is preferably 10 minutes or more at normal room temperature and normal pressure. It is more preferably at least 30 minutes, particularly preferably at least 1 hour. When tetraisopropoxytitanate is used as a raw material, it is preferable that the temperature be 3 minutes or less at normal room temperature and normal pressure. More preferably, it is 90 seconds or less.

In forming the metal oxide, the metal compound may be mixed into gas and / or fine particles, or the gas and / or fine metal compound may be mixed. In addition, both of these methods can be used in combination.

FIG. 1 shows a schematic diagram of an example of a reaction apparatus preferably used in the present invention. N ₂ is dehydrated by a liquid nitrogen trap. In the metal compound heating tank, the metal compound is heated by a heater to become gas and / or fine particles, and N ₂
Is sprayed onto the substrate via the nozzle and the slit. The line after the heating tank is heated by the ribbon heater. A with the (0001) plane facing the slit on the substrate
An l ₂ O ₃ single crystal plate is used. The metal compound forms the metal oxide structure described in the present invention on the substrate heated by the heater.

When the metal oxide in the present invention is used for a light emitting device or the like, for example, the metal oxide can be used by coating with a conductive substance. The conductive substance in the present invention refers to a substance having a specific resistivity of 10 Ω / m or less. Preferably, it is 1 Ω / m or less. Specifically, metal and / or metal paste, ITO (In ₂ O ₃ / S
nO ₂ ), conductive resin, carbon thin film, diamond thin film and the like. The type of metal is not particularly limited, but specific examples include copper, nickel, chromium, iron, gold, silver, palladium, aluminum, zinc, tin, silicon, titanium, and alloys thereof.

Next, a method for forming or bonding a conductive substance and a metal oxide will be described. As this method, a method of directly forming a conductive material on a metal oxide and a method of directly bonding a metal oxide and a conductive material are known. As a method of forming a conductive substance directly on a metal oxide,
A method of physically or chemically forming a conductive material on a metal oxide through a gas phase or a liquid phase, and includes plating, coating, and printing such as vapor deposition, sputtering, dipping, and solution plating.

The method of directly bonding the metal oxide and the conductive material is not only a known method such as baking, but also Japanese Patent Publication No.
No. 13515, JP-A-61-17475, that is, a powder of the conductive substance or a powder as a main component of the conductive substance is interposed between the conductive substance and the metal oxide. And a method of performing heat treatment by heating at a temperature lower than the melting point of the conductive substance in a reactive or inert atmosphere.

The structure of the present invention can be used by attaching a metal oxide and two or more external electrodes that are not electrically connected to each other with the metal oxide interposed therebetween. Any shape may be used as long as the metal oxide and the external electrode are electrically connected. The external electrode may be connected to the metal oxide at any portion as long as the external electrodes are not electrically connected to each other. The number of external electrodes is preferably three or less. The number may be four or more, but in that case, it is preferable that they are connected to three or less portions that do not substantially show conductivity with each other via another conductive substance. As a method of forming or bonding the conductive material and the external electrode, a method such as a method of bonding with a solder or a method of wire bonding is used in addition to the method described in the case of the conductive material and the metal oxide. Further, the metal oxide structure according to the present invention can be used by attaching an excitation source. The excitation source in the present invention refers to an object that irradiates a metal oxide structure with electromagnetic waves such as electrons and light to excite electrons in the metal oxide.

The metal oxide in the present invention includes an insulator, a conductor, a solid electrolyte, a fluorescent display tube, an EL device, a ceramic capacitor, an actuator, a laser oscillator, a cold cathode device, a ferroelectric memory, a piezoelectric, Mr,
Electronic materials such as varistors and superconductors, electromagnetic wave shielding materials,
Photodielectrics, optical switches, optical sensors, solar cells, optical wavelength conversion elements, optical elements such as light absorption filters, sensor materials such as temperature sensors and gas sensors, surface modifiers, surface protective agents, antireflective agents, antibacterial, It can be used as a surface modifier for the purpose of antifouling effect or the like, a catalyst in a gas phase, a liquid phase or both phases, a carrier thereof and the like. It is preferably a light emitting element or a light oscillation element, and more preferably a laser light oscillation element. The light in the present invention may be any of ultraviolet light, visible light, and infrared light.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

(Embodiment 1) Using the apparatus schematically shown in FIG.
Was. Zn (C_Five H₇ O_Two ) _Two Charge
I do. Heat the metal compound heating tank to bring the internal temperature to 115 ° C.
Was. Al just below the blowing slit_Two O_Three Two single crystals
Heat to 550 ° C so that the (0001) plane faces the slit
I set it. 2.4 dm for metal compound heating tank^Three / Min
Dry nitrogen gas is introduced at a flow rate of Zn (C_Five H₇ O_Two )
_Two To Al_Two O_Three Sprayed onto single crystal. Start spraying
20 minutes later, Zn (C_Five H₇ O_Two )_Two Spraying
Ceased. Take out one of the obtained metal oxides,
Gold as metal oxide by sputtering
After vapor deposition on the whole, observation by SEM was performed. this
In order to clarify the three-dimensional shape of the structure,
The structure thus obtained was subjected to SEM observation from a cross section. Obtained S
The EM image is shown in FIG.

Example 2 The internal temperature of the metal compound heating tank was set to 1
A metal oxide structure was obtained under the same conditions as in Example 1 except that the temperature was 45 ° C. and the flow rate of the dry nitrogen gas was 0.6 dm ³ / min. One of the obtained metal oxides was taken out, gold was deposited as a conductive substance on the entire metal oxide by sputtering, and then observed by SEM. At this time, in order to clarify the three-dimensional shape of the structure, the obtained structure was subjected to SEM observation from a plane and a cross section. The obtained SEM images are shown in FIGS.

(Example 3) The internal temperature of the metal compound heating tank was set to 1
A metal oxide structure was obtained under the same conditions as in Example 1, except that the temperature was set to 45 ° C. and the flow rate of the dry nitrogen gas was set to 4.8 dm ³ / min. One of the obtained metal oxides was taken out, gold was deposited as a conductive substance on the entire metal oxide by sputtering, and then observed by SEM. At this time, in order to clarify the three-dimensional shape of the structure, the obtained structure was subjected to SEM observation from a plane and a cross section. The obtained SEM images are shown in FIGS.

[0040]

According to the present invention, a metal oxide structure composed of a plurality of metal oxide microcrystals, particularly a metal oxide structure preferably used as a light emitting device, can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of a metal oxide reactor preferably used in the present invention.

FIG. 2 is an SEM photograph of the structure obtained in Example 1 observed from a cross section and a plane direction. However, this structure is S
The whole is covered with a conductive material for EM observation.

FIG. 3 is an SEM photograph of the structure obtained in Example 2 observed from a cross section and a plane direction. However, this structure is S
The whole is covered with a conductive material for EM observation.

FIG. 4 is an SEM photograph of the structure obtained in Example 3 observed from a cross section and a plane direction. However, this structure is S
The whole is covered with a conductive material for EM observation.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasushi Kishimoto 1-3-1 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Asahi Kasei Kogyo Co., Ltd. 4G077 AA03 AB09 BB01 BB03 BB04 BB07 BB09 BB10 DA11 4K030 AA11 BA42 BA43 BA44 BA45 BA46 BA47 BB02

Claims (10)

[Claims] 1. A circle-converted diameter of a cross section of 0.01 to 100 μm.
And a metal oxide structure comprising a plurality of metal oxide microcrystals epitaxially grown from a substrate. 2. The method according to claim 1, wherein the metal oxide microcrystals are 0.1 to 100 μm per 10 μm × 10 μm area on the surface of the metal oxide structure.
2. The metal oxide structure according to claim 1, which is present at a density of 0000. 3. The metal oxide microcrystals form protrusions of the metal oxide structure, and the ratio of the length of the protrusions to the circle-converted diameter of the metal oxide microcrystals is 0.01 or more. Item 1
Or the metal oxide structure according to claim 2. 4. The metal oxide structure according to claim 1, wherein the central axes of the metal oxide microcrystals are parallel to each other. 5. The metal in the metal oxide includes, in the periodic table, Group 1 except for hydrogen, Group 2 except for boron, Group 14 except for carbon, Group 15 except for nitrogen, phosphorus and arsenic, and 3,
The metal oxide structure according to any one of claims 1 to 4, wherein the metal oxide structure includes at least one member selected from the group consisting of 4, 5, 6, 7, 8, 9, 10, 11, and 12 groups. 6. The metal in the metal oxide is Zn, Si, A
The metal oxide structure according to any one of claims 1 to 5, comprising at least one selected from l, Sn, Ti, Zr, and Pb. 7. The metal oxide structure according to claim 1, wherein the metal oxide is a metal oxide single crystal. 8. A light-emitting device comprising the metal oxide structure according to claim 1. 9. At least one volatile or sublimable metal compound which is capable of reacting with at least one oxide-forming substance to form a metal oxide is vaporized. A metal compound gas is obtained, and the obtained metal compound gas is reacted on a substrate placed in a reaction zone containing the oxide-forming substance.
9. The method for producing a metal oxide structure according to any one of 8. 10. A method comprising vaporizing at least one volatile or sublimable metal compound capable of reacting with at least one oxide-forming substance to form a metal oxide. The method for producing a metal oxide structure according to claim 9, wherein a metal compound gas is obtained, and a reaction zone containing the obtained metal compound gas and the oxide-forming substance is an atmospheric pressure atmosphere.