WO1999057345A1 - Functional element for electric, electronic or optical device and method for manufacturing the same - Google Patents

Abstract

A functional element for an electric, electronic or optical device comprising a substrate and a plurality of metal oxide needles standing on the upper surface thereof, wherein the metal oxide needles extend upward from the upper surface of the substrate with their central axes being arranged substantially parallel one another, have a specific weighed average diameter in terms of a circle and a specific weighed average aspect ratio, and are present in a specific density on the upper surface of the substrate. The element is manufactured by a method comprising vaporizing a metal compound capable of forming a metal oxide through reacting with a substance having an ability to form an oxide and blowing the resultant gas of the metal compound onto the surface of the substrate which is placed in a reaction region wherein a substance forming an oxide is present and is heated to a temperature higher than that of the gas of the metal compound.

Description

Functional element for electric, electronic or optical device, and method of manufacturing the same

TECHNICAL FIELD The present invention relates to a functional element for an electric, electronic or optical device.

More specifically, the present invention relates to a functional element for an electric, electronic or optical device, which comprises a substrate and a plurality of needle-shaped metal elements extending on an upper surface thereof.

The needle-shaped metal oxide, wherein the needle-shaped metal oxide extends upward from the upper surface of the substrate, and the respective central axes thereof are arranged substantially parallel to each other. The object has a specific weighted average circle-converted diameter and a specific weighted average aspect ratio, and the acicular metal oxide is present at a specific density on the upper surface of the substrate. It relates to a functional element to be described. The present invention also relates to a method for manufacturing this functional element. The functional element for an electric, electronic or optical device of the present invention has an excellent feature that the thickness can be reduced despite the very large surface area of the metal oxide on the substrate. It has excellent performance as a component for various electric, electronic or optical devices. Prior Art Metal oxides are used for various purposes by taking advantage of the various functions of metal oxides. For example, a ceramic capacitor using a ferroelectric function and a gas sensor using a resistance function First, it is used as a variety of electric and electronic components, such as magnetic tapes or magnetic heads, utilizing its magnetic material function. Recently, application to optical components such as an optical switch utilizing an optical waveguide function and an ultraviolet laser single oscillation element utilizing an optical oscillation function is being studied.

When used for these applications, the metal oxide generally has a flat surface. For example, in a ceramic capacitor, a metal oxide having a ferroelectric function (for example, titanium titanate) is used in the form of a laminated product sandwiched between planar electrodes. ing. Also, magnetic tapes are used in the form of a metal oxide (eg, chromium oxide) film formed on a polymer film. However, when used in these applications, the performance can be significantly improved by increasing the surface area of the metal oxide depending on the application. For example, in the case of the above capacitor, its most important performance is capacitance. The higher the capacitance, the better the performance, but the capacitance is proportional to the surface area of the metal oxide and inversely proportional to the thickness. That is, the larger the surface area of the metal oxide, the higher the capacitance, and the smaller the thickness of the metal oxide, the higher the capacitance. For this reason, the current mainstream capacitor is one in which electrodes and metal oxides are laminated close to about 100 layers. That is, by increasing the number of layers, the surface area of the metal oxide is increased, and the thickness of the electrode and the metal oxide is reduced as much as possible. This makes it a high-capacitance capacitor. However, multi-layering by laminating electrodes and metal oxides in many layers is very disadvantageous in terms of productivity and economy.

 Therefore, for example, if a metal oxide consisting of only one layer can be made to have a surface area equal to or greater than that of a multilayer capacitor that is currently used with the same thickness, that is, if a high capacitance can be obtained, Multi-layer soldering not only improves productivity and economy, but also makes it possible to use a capacitor with a higher capacitance. The metal oxide has a structure that can be reduced in thickness even if the surface area is increased, so that it can be used in various applications currently used, such as the above-mentioned capacitor example. Thus, it can be an improved electrical / electronic component or optical component, and can also be a component that allows for new product development.

As a method for increasing the surface area of the metal oxide, it is known to form a needle-shaped metal oxide whisker. For example, Japanese Patent Application Laid-Open No. 50-65797 discloses that zinc and a zinc alloy composed of a metal having a higher boiling point than zinc or a mixture thereof are heated in an oxygen-containing atmosphere, and are heated on a substrate. A method for producing a zinc oxide whisker, characterized in that a needle-shaped zinc oxide whisker is produced. However, the purpose of producing this zinc oxide whisker is to separate the generated whiskers from the substrate and to separate the whiskers themselves from resin or ceramic. It is used as a reinforcing agent or a semiconductor to increase the strength of a box or the like. It is a structure consisting of a substrate and a sheet of power formed on its surface. It is not disclosed for use as a part.

 There is also a report that nanocrystals of Z η θ formed on a substrate are used as an ultraviolet laser—oscillator [Solid State Physics, vol.

33, No. 1, ρ · 59-64 (1998)]. However, the nanocrystal of {η} formed on the substrate has a height of 5 nm and a circle-equivalent diameter of 100 nm, that is, the ratio of the length of the cross-section to the circle-equivalent diameter (the length of the cross-section). The diameter is extremely small (0.05 in circle), and there is a limit to increasing the surface area with a small thickness. Summary of the Invention

Under such circumstances, the present inventors have aimed for use as an electric, electronic or optical component, and have been made up of a substrate and a metal oxide formed on the surface thereof, and a surface area of the metal oxide. We worked diligently to develop a functional device with the advantageous structure of large and small thickness. As a result, surprisingly, it comprises a substrate and a plurality of needle-shaped metal oxides extending to an upper surface thereof, wherein the needle-shaped metal oxides extend upward from an upper surface of the substrate, and each of the needle-shaped metal oxides extends upward. The central axes are arranged substantially parallel to each other, and the needle-shaped metal oxide has a weight-average circle-converted diameter of 0.01 to 100, 000; and a weight of 0.1 or more. Having an average aspect ratio, and A function wherein the group oxide is present at a density of 0.01 to 100,000 per unit area of 1 Om X 1 O i rn on the upper surface of the substrate. It has been found that the conductive element has an excellent feature that the surface area is extremely large despite the extremely small thickness of the metal oxide. The present inventors have also reported that functional elements having such characteristics include, for example, energy-saving electron-emitting elements capable of emitting electrons at a low voltage, high-capacitance capacitor elements, and high-density memories. Advantageously used for devices for electric or electronic devices such as devices, high-sensitivity sensor devices, etc., and for laser devices, especially devices for optical devices such as lasers with low wavelengths such as ultraviolet light, and highly integrated optical switch devices. We found that it could be applied. Based on this finding, the present invention has been completed.

 Therefore, one object of the present invention is to provide an excellent feature that the metal oxide formed on the substrate and the surface thereof has a small thickness despite its very large surface area. It is an object of the present invention to provide a functional element for an electric, electronic or optical device which has excellent performance as a component for various electric, electronic or optical devices.

 Another object of the present invention is to provide a manufacturing method for effectively and efficiently manufacturing the above-described functional element for electric, electronic, or optical devices.

The above and other objects, features and advantages of the present invention are set forth in the following detailed description and claims, taken in conjunction with the accompanying drawings. Enclosure, power becomes clear. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a schematic diagram showing an example of a production facility preferably used for producing the functional element of the present invention;

 FIGS. 2 (a) and 2 (b) are scanning electron microscope (SEM) photographs of the functional device obtained in Example 1 obliquely observed from above, and FIG. 2 (a) and FIG. Fig. 2 (b) shows different magnifications;

 FIG. 3 is an SEM photograph of the functional device obtained in Example 2 observed from directly above;

 FIG. 4 is an SEM photograph of the functional element obtained in Example 3 observed from directly above;

 FIG. 5 is a SEM photograph of the functional device obtained in Example 4 observed obliquely from above;

 FIG. 6 is a SEM photograph of the functional device obtained in Example 5 observed obliquely from above;

 FIG. 7 is a SEM photograph of the functional device obtained in Example 6 observed obliquely from above;

 FIG. 8 is a vertical sectional view of a circuit device including the functional element (shown in FIG. 7) obtained in Example 6.

 (Explanation of code)

1 substrate (A 1 ₂ 0 ₃₎ 2 Acicular metal oxide (ZnO)

 3 Nickel (Ni) electrode formed by sputtering

4, 8 copper plate

 5 Insulated wire

 6 Silicon (S i) plate

 7 Conductive paste Detailed description of the invention

 According to one aspect of the present invention, there is provided a functional element for an electric, electronic or optical device,

 A substrate and a plurality of needle-shaped metal oxides extending to an upper surface thereof, wherein the needle-shaped metal oxides extend upward from an upper surface of the substrate, and have respective central axes substantially parallel to each other. And the needle-shaped metal oxide is 0.0 :!換算 100,000 μm, which is the weighted average diameter of a circle having an area equal to the area of the cross section of the needle-shaped metal oxide. The cross section is a cross section taken along a plane perpendicular to the central axis of the acicular metal oxide at a central portion located at 12 of the length of the acicular metal oxide. ,

The acicular metal oxide has a weighted average aspect ratio of 0.1 or more, and the weighted average aspect ratio is determined by the weight of the acicular metal oxide with respect to the above-mentioned weighted average circle-converted diameter. Defined as the ratio of the average length, the needle-like metal oxide is 1 μm πα Χ 10 μm on the upper surface of the substrate. a functional element characterized by being present at a density of 0.01 to 100,000 per unit area having m

Is provided.

 According to another aspect of the present invention, there is provided a method for producing a functional element for electric, electronic or optical devices, comprising:

 (a) At least one kind of metal compound having volatility or sublimability, which reacts with at least one kind of oxide-forming substance to form a metal oxide corresponding to the metal compound. Vaporizing a metal compound capable of forming a metal compound gas,

 (b) spraying the obtained metal compound gas on the surface of a substrate placed in a reaction zone containing the oxide-forming substance and heated to a temperature higher than the temperature of the metal compound gas, The surface of the substrate is brought into contact with the metal compound gas in the presence of a substance forming substance, and at this time, the contact is made to grow a plurality of needle-like metal oxides on the surface of the substrate, and the functional element of the present invention For a time sufficient to form

Is provided.

 Next, in order to facilitate understanding of the present invention, first, basic features and preferred embodiments of the present invention will be listed.

1. A functional element for an electric, electronic or optical device,

A substrate, and a plurality of acicular metal oxides extending to an upper surface thereof, wherein the acicular metal oxides are directed upward from an upper surface of the substrate. The needle-shaped metal oxide has a weight-average circle-equivalent diameter of 0.01 to 100,000 m, and the central axes thereof are arranged substantially parallel to each other. The weighted average circle-converted diameter is defined as the weighted average diameter of a circle having an area equal to the area of the cross section of the acicular metal oxide, and the cross section is 2 of the length of the acicular metal oxide. A cross section obtained along a plane perpendicular to the central axis of the needle-shaped metal oxide at the central portion,

 The acicular metal oxide has a weighted average aspect ratio of 0.1 or more, and the weighted average aspect ratio is determined by the weight of the acicular metal oxide with respect to the above-mentioned weighted average circle-converted diameter. Defined as the ratio of the average lengths, the needle-shaped metal oxides are in a unit area of 10 mx 10 μm on the upper surface of the substrate. A functional element that exists at a density of individual pieces.

2. The functional element according to item 1, wherein the acicular metal oxides are mutually held using at least one substance selected from the group consisting of an organic substance, an inorganic substance, and a metal.

3. The functional element as described in 1 above, which is an electron emission element for an electric or electronic device.

4. The functional element as described in 1 above, which is a capacitor element for an electric or electronic device. 0

5. The functional element as described in 1 above, which is a memory element for an electric or electronic device.

6. The functional element as described in 1 above, which is a sensor element for an electric or electronic device.

7. The functional element as described in 1 above, which is a laser oscillation element for an optical device.

8. The functional element according to item 1, which is an optical switch element for an optical device.

9. A method for producing a functional element for an electric, electronic or optical device, the method comprising:

 (a) at least one kind of metal compound having volatility or sublimability and reacting with at least one kind of oxide-forming substance to form a metal oxide corresponding to the metal compound; The vaporizable metal compound is vaporized to obtain a metal compound gas,

(b) spraying the obtained metal compound gas on the surface of a substrate placed in a reaction zone containing the oxide-forming substance and heated to a temperature higher than the temperature of the metal compound gas, Contacting the surface of the substrate with the metal compound gas in the presence of a substance forming substance In this case, the contact is performed for a time sufficient to grow a plurality of needle-like metal oxides on the surface of the substrate and to form the functional element described in item 1 above. .

10. The method according to the above item 9, wherein in the step (b), the metal compound gas is blown together with the carrier gas.

11. The method as described in 9 above, wherein the reaction zone contains air at atmospheric pressure.

1 2. The metal component of the metal compound is at least one selected from the group consisting of elements from Groups 1 to 15 of the periodic table, excluding hydrogen, boron, carbon, nitrogen, phosphorus, and arsenic. 10. The method according to the above item 9, which comprises the following elements:

1 3. The method according to the above item 9, wherein the metal component of the metal compound comprises at least one element selected from the group consisting of zinc, silicon, aluminum, tin, titanium, zirconium and lead. . Hereinafter, the present invention will be described in detail.

 First, the functional element for an electric, electronic or optical device of the present invention will be described.

The functional element for an electric, electronic or optical device of the present invention comprises: a substrate; A plurality of needle-like metal oxides (i.e., metal oxide whiskers) extending to the upper surface thereof, wherein the needle-like metal oxides extend upward from the upper surface of the substrate, and each of the centers thereof. It has a structure in which the axes are arranged substantially parallel to each other. However, the needle-shaped metal oxide may be a metal oxide having a shape such as a mountain-shaped raised shape, a rod shape or a prism shape. The thickness of the needle-shaped metal oxide is preferably such that the weighted average circle-converted diameter of the cross section is from 0.01 to ί ,, Ο Ο Ο m. Further, it is preferably in the range of 0.01 to 10 Oim, most preferably in the range of 0.1 to 10 μπι. Here, the weighted average circle-equivalent diameter is the square root of the square 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. It is expressed as a double value and is defined as the weighted average diameter of a circle having an area equal to the area of the cross section of the acicular metal oxide. Note that the above-mentioned cross section is a cross section obtained along a plane facing the central axis of the needle-shaped metal oxide at a central portion located at 1 Z 2 of the length of the needle-shaped metal oxide. When the weighted average circle-equivalent diameter is less than 0.0 Olym, it is difficult to stably obtain the grown needle-shaped metal oxide, and when it exceeds 100000 μm, the needle-shaped metal oxide becomes needle-shaped. The effect of increasing the surface area by the metal oxide is poor and not preferred.

The ratio of the weighted average length to the weighted average circle-converted diameter (length / cross-section circle-converted diameter), that is, the weighted average aspect ratio (hereinafter often simply referred to as “aspect ratio”) is 0. 1 or more, preferably Is greater than 0.5, more preferably greater than 1.0. If the aspect ratio is smaller than 0.1, the effect of increasing the surface area by the acicular metal oxide does not appear. The aspect ratio is preferably 100,000 or less, more preferably 100,000 or less, and particularly preferably 1,000 or less.

 The weighted average length of the needle-shaped metal oxide varies depending on the intended use, but is not particularly limited. In general, it is preferably from 0.1 to 100,000 m, and from 1 to 1,0 m. 0 0 m is preferred. If the length of the needle-shaped metal oxide is less than 0.1 m, the effect of increasing the surface area of the needle-shaped metal oxide is poor, and if it exceeds 1 1, Ο Ο πι, it is difficult to maintain the strength of the functional element. Becomes However, even when the length exceeds 100,000 μμπι, as described later, sufficient strength can be maintained by holding the acicular metal oxides with each other with an organic substance, an inorganic substance, or the like. It is possible.

In the present invention, the weighted average circle-converted diameter, the weighted average length, and the weighted average aspect ratio of the needle-shaped metal oxide are determined by SEM observation according to the following method. First, the sample of the functional element is cut along a plane extending through the center of the upper surface and extending parallel to the longitudinal direction of the acicular metal oxide. With respect to the obtained cross section (one), starting from the above-mentioned center, a range of 100 in each of right and left in a direction perpendicular to the longitudinal direction of the acicular metal oxide (total of 20 θ ί πχ Observed by SEM, a plurality of acicular metal oxides observable from the cross-sectional side within that range Of these, only needle-shaped metal oxides that allow complete observation of the entire side surface of the needle-shaped metal oxide from the cross-sectional side (observation of visibility not blocked by other needle-shaped metal oxides) are weighted. Average circle conversion Find the diameter and weighted average length. The weighted average aspect ratio is defined as the ratio of the weighted average length to the weighted average circle diameter. The shape of the acicular metal oxide is not particularly limited as long as the aspect ratio is 0.1 or more. For example, in the case of a rod, the shape does not change from the root to the tip, the diameter does not change from the root to a distance from the root to the tip, and the diameter of the root is small. The diameter increases once at the tip, then gradually decreases again, and gradually decreases from the root to the tip, but near the tip. Some have shapes such as pyramids, truncated pyramids, cones, truncated cones, and hemispheres, depending on the distance. Furthermore, in the case of a prism, the specific shape differs depending on the crystal structure. In many cases, it is a square prism. There are also prisms with other polygons in cross-sectional shape.

The shape of the tip of the needle-shaped metal oxide is not particularly limited, but when the shape of the tip is a plane, the shape of the tip is, for example, a truncated cone or a truncated pyramid. If the shape of the tip is a line, the shape of the tip is a line consisting of two or more planes, for example, a mountain ridgeline. Adjacent planes are connected by one side. When the shape of the tip is a point, the shape of the tip is, for example, a cone or a pyramid. The preferred shape of the tip shape depends on the application used. For example, when the functional device of the present invention is used as an electron-emitting device, it is easier for the needle-shaped metal oxide to emit electrons when the tip is sharp. It is a well-known phenomenon that lightning falls on a lightning rod (sharp tip), but on the other hand, the tip is sharp when a voltage is applied to an object to emit electrons. The present inventors have confirmed that the conical shape makes it much easier to emit electrons.

In the functional element of the present invention, it is essential that the respective central axes of the needle-shaped metal oxides (in the case of crystals, the longitudinal crystal axes) are arranged substantially in parallel with each other. It is preferable that all of them are available. For example, in the case of a component for an electric or electronic device using the functional element of the present invention as an electron-emitting device, the electron-emitting ability is higher when the respective central axes are parallel to each other. This is because the height is not constant unless they are parallel. If the height is not constant, low heights do not emit electrons, only high ones emit electrons from the tip. Therefore, the needle-shaped metal oxides whose central axes are arranged parallel to each other have a larger number of tips that function for electron emission, and the electron emission ability is inevitably higher. Further, when the shape of the needle-shaped metal oxide is prismatic, it is preferable that the opposing surfaces in the prism have parallel portions. New For example, in the case of a component for an electric or electronic device using the functional element of the present invention as a laser oscillation element, the laser oscillation function is higher when the opposing surfaces in the prism are parallel to each other.

 Examples of the material of the substrate used for the functional element include a metal oxide single crystal such as aluminum oxide, a semiconductor single crystal, a ceramic, a silicon, Fe, and Ni. Metal, glass, plastic, and the like. The thickness of the substrate is not particularly limited, but is preferably Ι Ο μπ! 〜10 O mm. Commercially available materials of these materials can be purchased, cut, and subjected to secondary processing as desired, and used as the substrate of the functional element of the present invention. The shape and size of the substrate are not particularly limited as long as the surface has a substantially planar portion suitable for growing a needle-shaped metal oxide, and may be a plate, a rectangular parallelepiped, a prism, or a triangular prism. Various shapes of substrates can be used. The size of the substrate may vary greatly depending on the use of the functional element, and any desired size can be used. (For example, the value related to the size may be on the order of tens of meters, or may be on the order of millimeters.)

In the functional element of the present invention, the density at which the needle-shaped metal oxide is present on the substrate is as follows: 0.01 to L per unit area having lOiumXlOm on the upper surface of the substrate. It is preferable that the number is 0.10 to 100, and the number is 0.1 to 100, more preferably 1 to 100,0. 0 is preferred. If the density is less than 0.01, the effect of increasing the surface area of the acicular metal oxide is poor and not preferable. In order to increase the surface area of the needle-shaped metal oxide present on the substrate, it is preferable to increase the density, but it is preferable to increase the surface area by 10 μm X 10 0 μπι per unit area. If the number exceeds 0,000, the thickness of each needle-like metal oxide must be reduced as a result, and the strength of the needle-like metal oxide is out of the practical range and is preferred. Not good.

The needle-shaped metal oxide in the functional element of the present invention includes hydrogen (Group 1), boron (Group 13), carbon (Group 14), nitrogen (Group 15), phosphorus (Group 15), and arsenic. Except for (Group 15), oxides of at least one element selected from the group consisting of elements of Groups 1 to 15 of the periodic table are preferred. Specific metal types include, for example, L i, N a, K, R b, C s, Be, M g, C a, S r, B a, A l, G a, In, T l, S i, G e, S n, P b, S b, B i, S c, Y, L a, Th, C e, P r, N d, P m, S m, E u, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, M n, T c, R e, F e, R u, O s, C o, R h, I r, N i, P d, P t, C u, A g, A u, Z n, C d, And at least one component such as H g, preferably L i, N a, K, R b, C s, Be, M g, C a, S r, B a, A l, G a, In, T l, S i, G e, 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, Pd, Pt, Cu, Ag, Au, Zn, Cd, and Hg And more preferably L i, K, M g, C a, S r, B a, A l, In, S i, S n, P b, T h, Y, Ce, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Pd, Pt, Cu, Ag , Zn, and Cd at least as one component. In particular, when S i, A l, S n, T i, Z r, P b, and Z n are at least one component, particularly, the functional element of the present invention has a function for an electric, electronic or optical component device. It is preferable because it is suitable for a sexual element. These metals can be used alone or in combination of two or more. For example, M g 〇, A 1 2 O 3, I η 2 Ο 3, S i 0 ₂ , S n 〇 ₂ , T i 0 ₂ , Ζ η Ο, barium titanate, S r T i 0 ₃ , PZT, YBCO, YSZ, YAG, ITO (InzOa / SnOz)

(That is, indium t in oxide). It is also possible to use a combination of aluminum and other metals. For example, that you use T a, to form a N b and alkali metal such as L i N i combines _{0 3, KT a O 3,} N b L i 0 Yo I Do composite oxide of ₃ Can also. The needle-like metal oxide in the functional element of the present invention may be basically crystalline or amorphous, but is more preferably crystalline. The crystalline material may be one or more single crystals, polycrystalline, one or more semi-crystalline materials having both an amorphous part and a crystalline part, or a mixture thereof. Good. Particularly preferred is a single crystal.

 When two or more metal oxides are used, the metal oxides may be mixed to form a single layer, or metal oxide layers having different compositions may be stacked.

 The functional element of the present invention basically comprises a substrate and a plurality of needle-like metal oxides extending upward from the upper surface thereof. A planar metal oxide film is formed between them. That is, the structure may be such that a metal oxide film is first formed on the surface of the substrate, and a needle-shaped metal oxide grown thereon is formed. The functional element of the present invention may have such a structure.

 Next, a preferred production method for producing the functional element for an electric, electronic or optical device of the present invention will be described.

The functional element of the present invention is manufactured by vaporizing a metal compound as a raw material of a needle-shaped metal oxide and bringing the obtained metal compound gas into contact with a substrate in the presence of an oxide-forming substance. It can be. That is, the functional element of the present invention has volatility or sublimability and reacts with an oxide-forming substance to form a metal oxide. The resulting metal compound gas is vaporized, and the obtained metal compound gas is sprayed onto the surface of the substrate with a nozzle or the like to bring the surface of the substrate into contact with the metal compound gas in the presence of the oxide-forming substance. According to the above, it can be manufactured by growing a plurality of metal oxides on the surface of the substrate. In the present invention, the oxide-forming substance is a substance capable of reacting with a metal compound serving as a raw material of a needle-shaped metal oxide to finally form an oxide. Means a substance that reacts with For example, when a zinc Asechiruase Tone DOO as a metal compound [Z n (C 5 H 7 O 2) 2], Z n (C 5 H 7 0 2) 2 reacts with water (H ₂ 〇) Finally, an oxide (ZnO) can be formed via a route presumed to be a two-step reaction as shown in the following formula. Thus, in the present invention, water is one example of an oxide-forming substance.

Z n (C5H7O2) 2 + H ₂ 0 → Z n (OH) ₂ + 2 C ₅ H ₈ OZ n (OH) 2 → Z n O + H ₂ 0

In order to grow a plurality of metal oxides from the surface of the substrate, when the metal compound gas is blown onto the substrate surface, the substrate is placed in a reaction zone containing the oxide-forming substance and the temperature of the metal compound gas is increased. It must be heated to a higher temperature. this At this time, the reaction zone preferably contains air at atmospheric pressure, and a metal compound gas is blown onto the surface of the substrate together with a carrier gas made of an inert gas such as nitrogen gas. This is preferred. Also, the contact between the surface of the substrate and the metal compound gas causes a plurality of acicular metal oxides to grow on the surface of the substrate, and extends to the functional element of the present invention, that is, the substrate and the upper surface thereof A plurality of needle-shaped metal oxides, the needle-shaped metal oxides extending upward from the upper surface of the substrate, and their central axes are arranged substantially parallel to each other. The acicular metal oxide has a weighted average circle-converted diameter of 0.01 to 100.0 μπι, and a weighted average aspect ratio of 0.1 or more; Objects are present at a density of 0.01 to 100,000 per unit area of 1ΟμιηΧ1 O jum on the upper surface of the substrate, sufficient to form a functional element. Time is needed.

When the method for producing a functional element of the present invention is carried out industrially, the reaction zone where the substrate is placed contains air, and the vaporized metal compound is contained in the air of the reaction zone. It is highly economical and technically easy to grow needle-like metal oxide from the substrate by reacting with water, ammonia and the like, which is preferable. Further, it is preferable that the reaction zone is at normal pressure, that is, at atmospheric pressure, because a large capital investment is not required. The present inventors refer to this manufacturing method performed in an air atmosphere at atmospheric pressure as “atmospheric pressure open type CVD”. Generally, the CVD method (chemical vapor A method of forming a metal oxide crystal on a substrate surface by deposition is known. However, conventional CVD is generally performed under vacuum. In the method carried out under this vacuum, even if the metal compound gas is sprayed on the substrate, the concentration of the metal compound gas existing on the surface of the substrate is extremely low because the vacuum is applied. When growing metal oxides, it takes a very long time for crystals and non-crystals to grow into a needle-like structure, and no such attempt has been made in the past. According to the present inventors, according to the “atmospheric pressure open type CVD”, a metal compound can be sprayed at a high concentration on a substrate because of atmospheric pressure, so that the growth rate of the metal oxide is high and the needle-shaped metal It was found that an oxide was obtained. Furthermore, the present inventors have developed a technique for forming, on a substrate, needle-shaped metal oxides extending upward from the upper surface of the substrate and having their respective central axes arranged substantially parallel to each other at a high density. As a result of examining the preferred conditions, the present invention was adjusted by appropriately adjusting the conditions such as the temperature of the metal compound gas, the concentration of the metal compound gas sprayed on the substrate, the speed of the spray, and the temperature of the substrate. It has been found that a functional element can be easily obtained. As described above, Japanese Patent Application Laid-Open No. 50-65797 discloses that a zinc alloy or a mixture thereof composed of a metal having a higher boiling point than zinc and zinc is heated in an atmosphere containing oxygen. Also disclosed is a method for producing zinc oxide whiskers, characterized in that acicular zinc oxide whiskers are formed on a substrate. This product Although the fabrication method is not clearly described, a metal oxide is formed on the substrate (wall surface of the device) under atmospheric pressure. However, the technology disclosed in this publication merely provides a whisker obtained by cutting the obtained whisker from a substrate (wall surface of the device) and using the whisker as a reinforcing agent for resin or ceramics. There is no technical idea to use a structure made of a needle-shaped metal oxide formed on the surface thereof as a functional element for an electric, electronic or optical device.

 As described above, the metal compound used as a raw material for forming the acicular oxide when producing the functional element of the present invention has a volatile or sublimable property, and the above-described oxide-forming substance For example, it is a metal compound capable of forming a metal oxide corresponding to the above metal compound by reacting with oxygen, water and the like contained in the atmosphere. In the present invention, the metal compound also includes a simple metal. In addition, a substance that does not exist in the normal atmosphere, such as ozone, is supplied and present in the reaction zone containing the oxide-forming substance on which the substrate is placed, and a metal that reacts with these and forms an oxide is formed. Compounds may be used.

Examples of such a metal compound include alkoxides in which the hydrogen of the hydroxyl group of an alcohol is substituted with a metal, atoms of a metal or a metal-like element, and acetyl acetate to an atom of a metal or a metal-like element. , Ethylenediamine, bipiperidine, bipyrazine, cyclohexanediamine, tetraazacyclotetradecane, ethylenediaminetetraacetic acid, ethylenebis (guanide) , Ethylenebis (salicylamine), tetraethylene glycol, aminoethanol, glycine, triglycine, naphthyridine, phenanthine mouthline, pentanzamine, pyridine , Salicylaldehyde, salicyldenamin, ponolefilin, thiourea, etc., various complexes having one or more ligands, F having a carbonyl group as a ligand Various metal carbonyls such as e, Cr, Mn, Co, Ni, Mo, V, W, and Ru; and carbonyl, alkyl, alkenyl, and phenol Conjugated gen groups such as heninole group, olefin group, aryl group, cyclobutadiene group, genenyl group such as cyclopentajenyl group, triene group, and phenyl group Various metal compounds and metal halide compounds having one or more ligands selected from lane groups, cycloheptatrienyl groups, and other trienyl groups can be used. You. Also, metal complexes can be used. Among these, metal acetyl acetate compounds, metal alkoxide compounds, and the like can be more preferably used. Examples of complexes that can be used as the metal compound in the production method of the present invention include J3-diketons, ketoesters, hydroxycarboxylic acids or salts thereof, and various kinds of salts as metals. One kind of ligands such as bases, ketoalcohols, polyamines, alkanolamines, phenolic active hydrogen compounds, dicarboxylic acids, dalicols, and fluoresceins Or 2 Compounds having more than one kind of bond can be mentioned.

Specific examples of the compound serving as a ligand of the complex that can be used as a metal compound in the production method of the present invention include, for example, acetylacetyl, ethylenediamine, triethylenediamine , Ethylenetetramine, bipiperidine, cyclohexanediamine, tetraazacyclotetradecane, ethylenediaminetetraacetic acid, ethylenebis (guanide), ethylenebis (guanide) Tilamine), tetraethylene glycol, diethanolamine, triethanolamine, tartaric acid, glycine, triglycine, naphthyridine, phenolic mouthline Pentapentamine, salicylaldehyde, catechol, porphyrin, thiourea, 8—hydroxyquinoline, 8—hydroxy Quinaldine, monoaminoethyl mercaptan, bisacetyl acetate ethylenedimine, eriochrome black T, oxine, salicylaldoxime quinalzinate, picolinic acid, glycine, dimethyl oximatate , Dimethyl glycol oxime, α-benzonium oxime, Ν, Ν'-bis (1-methyl-3-3-oxobutylidene) ethylenediamine, 3 — {(2—aminoethyl) amide 1) — 1-Pronol, 3— (Aminoethylimino) 1- 2—Butanoxime, alanine, Ν, Ν '— bis (2—aminobenzilidene) ethylenediamine, α - A Mi node on alpha - main switch luma Russia phosphate, 2 - {(3 - § Mi Bruno propyl) A Mi Bruno} e data Roh - le, Asunoヽ⁰ Ragin acid, 1 - off et sulfonyl one 1, 3, 5 Kisa down door Li-on, 5, 5 'single to (1, 2 - d data Njiirujini door re-opening) Bis (1-phenyl 1, 3-hexanedione), 1, 3-Bis {bis [2-(1-ethylbenzimidazoline) methyl] amino}-2-Pronono-1, 1 , 2—Bis (pyridin-α-aldimino) ethane, 1,3—Bis {bis (2—pyridylethylinole) aminomethylinole} benzene, 1,3—Bis {bis (2 Phenol, 2,2'-bipiperidine, 2,6—bis (bis (2—pyridylmethyl) aminomethyl) — 4— Methyl phenol, 2,2'-bibiridin, 2,2'-bipyrazine, hydrotris (1-bilazoline) Ionic borate, catechol, 1, 2- Cyclohexanediamine, 1,4,8,11—Tetraazacyclododecane, 3,4: 9,10—Dibenzo-1,5,8,12—Tetraazacyclotetradecane-1,1,1—Gen, 2,6—Diacetyl pyridindioxime, Dibenzyl sulfide ,、 — {2 — (Jetylamino) ethyl} — 3—Amino-1-pronool, ο—Fenylenebis (dimethylphosphine), 2 — {2- (Dimethylamino) ethylinoetha} Knol, 4, 4'-Dimethyl-1,2'-Bibiridin, Ν, —'- Dimethyl-1,2, -cyclohexanediamine, Dimethyldalioxime, 1,2-bis (Dimethylphosphino) ethane, 1,3—bis (diacetylmonooxyimimino) prononone, 3,3′—Trimethylenedinitrobis (2—butanoxime) 1,5—dia MINNO 3 — pentano — rudipine Lee Rume data down, 1, 2 - bis (Diphenylphosphino) ethane, ionic getyldithiocarbamate, N, N'-bis {2- (N, N'- cetylaminoethyl) aminoethyl} oxamide , Ethylenediaminetetraacetic acid, 7-hydroxy-14-methyl-5-azabut-2-one, 2-amine, 2-aminoethanol, N, N, ― Ethylenebis (3-carboxysalicylideneamine), 1,

3—Bis (3—Holminole 1—5-Methylsalicylideneamino) Propane, 3—Glycinoleamine 1—Prono, ⁰ Knol, Glycylglycine, N ' ― (2-Hydroxityl) Ethylenediaminetriacetic acid, Hexafluoroacetylaceton, Histidine, 5, 26: 13,18-Dimino 7,11: 1: 20,2

4-Dinitrodibenzo [c, n]-1,6,12,17-Tetraazacyclodocosin, 2,6-bis {N— (2-hydroxyphenyl) iminomethyl} — 4 チ ル チ ル エ, 5,

5, 7, 12, 12, 14-hexamethyl 1, 1, 4, 8, 11-tetraazacyclotetradecane 1, N "-diacetate, 1,2-dimethylimidazole , 3,3'-Ethylenebis (iminomethylidene) di-2,4-pentanedione, N, N'-bis (5-amino13-hydroxypentyl) malonamide , Methionine, 2-hydroxy-1-6-methylpyridine, methylimino-diacetic acid, 1,1-dicyanethylene-1,2-dithiol, 1,8-naphthyridine, 3 — (2 — Hydroxishechinoimimino) 1 2 — Butanoxoxime, 2, 3, 7, 8, 1, 2, 13, 17, 18 — Octaethylporphyrin, 2, 3, 7, 8, 12, 13, 17, 18 — Octamethylporphyrin, oxalic acid, oxa Mid, 2 — pyridyl al-doxime, 3 — {2-(2 — pyridinole) ethyl chloro} — 1 — prono. Nore, 3 — (2—Pyridylethylimino) 1—2—Butanonoxime, 2—Picolinolemin, 3— (2—Pyridinolemethyrimino) 1—2—Butanonoxime, 2 Dihydrogen phosphite ion, 3 — n — propylimino 1 2 — butanoxoxime, proline, 2, 4 — pentandiamine, pyridine, N, N′-dipyridoxy Redene diene diamine, N—pyridoxy dengue lysine, pyridin 1-2 — thiol, 1, 5 — bis (salicylidenamino) — 3 — pentanole, salicylaldehyde , N—Salicylidenemethylamine, salicylic acid, N— (Salicylidene) -1-N ′-(1—Methyl-13-oxobutylidene) Ethylenediamine, Salicydenite, N, N '-2,2'-Bif anyylene diamine, N, N'-Disaliethylidene-1 2-Methyl-2 ((2-benzino retioethyl) ethylene diamine, N, N'-Jisa N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N-N N'-di-sali-tri-diene-o-N-N-N'-di-sali-chi-ri-di-tri-m-diamine Noren, Tetrabenzo [b, f, j, η]- 1,5,9,13—Tetraazacyclohexadecin, 1,4,7—Triazacyclononane, 5,14—Dihydro dibenzo

[b, i]-1,4,8,11 One-Temperature Cyclo-Tradesin, Tris (2_benzimidazolinolemethyl) amine, 6, 7, 8, 9, 1 6, 17, 18, 19-octahydrosid mouth lip [b, j]-1, 4, 8, 1 1-tetrazide tetradecene, 4, 6, 6-trit Remethyl 3,7—Diazonone 3 —En 1, 9—Diol, Tris (3,5—Dimethyl 1 1 —Vilazolinoremethyl) amine, 2, 2 ': 6 ', 2 "—Terpyridin, 5, 7, 7, 12, 12, 14, 14—Hexamethyl-1,4,8,11—Tetraazacyclite tetradecane, Tetra Hydrofuran, Tris (2-pyridylmethyl) amide, Ν, Ν, Ν ', Ν' — Tetramethyl urea, Ν, Ν, monobis

(3 — aminopropyl) Oxamide, Ν, Ν, Ν ', Ν'-Tetrakis (2-pyridylmethyl) ethylenediamine, a 1 1-cis-5,10 , 15, 20 — Tetrakis {2 — (2, 2 '— dimethylpropionamide) phenyl} Porphyrin, 5, 10, 0, 15, 20 — Tetraf Enilporphyrin, 1,4,7—tris (2—pyridinolemethyl) 1-1,4,7—triazacyclononane, hydrotris (1—villazoline) ) Borate, 3,3,4-trimethylinoresipiromethene, trimethylenediamine tetraacetic acid, 3,3'5,5 '-tetramethyldipyrromethene, 5,1 0, 15, 20 — Tetrakis (p — Trinorepo Norrefulin).

As described above, the needle-shaped metal oxide of the functional element of the present invention extends upward from the upper surface of the substrate, and its central axes are arranged substantially parallel to each other. is necessary. The parallelism of each central axis of the needle-shaped metal oxide can be measured by the X-ray opening curve method, and the fluctuation in the direction in which the needle-shaped metal oxide extends is measured by this measurement method. It is preferable that the angle of (squashing based on a direction perpendicular to the surface of the substrate) be within 10 degrees, more preferably within 5 degrees. This fluctuation is often determined by the substrate used for the functional element of the present invention. When a metal containing silicon, a metal oxide, or a semiconductor single crystal such as ZnTe, GaP, GaAs, and InP is used as a substrate, the central axis parallelism fluctuates. But it is small. One factor in selecting a single crystal seed is that the lattice constant of the metal oxide crystal seed when the acicular metal oxide to be formed is a crystal and the lattice constant of the single crystal seed used as the substrate are close. Is preferred. The lattice constant can be measured by a conventionally known method such as a wide-angle X-ray diffraction method. This value is the lattice constant of the surface in contact with the metal oxide crystal species, in which the single crystal seed used as the substrate is in contact with the metal oxide crystal seed. Is preferably from 0.8 to 1.2, more preferably from 0.9 to 1.1, and particularly preferably from 0.95 to 1.05. Particularly preferred are, specifically, silicon and oxides. It is a single crystal of a metal oxide such as noremium, magnesium oxide, and SrTiO ₃ . In this case, the crystals 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. There may be. 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. Specifically, for example, when selected as a metal oxide forming titanium oxide, the (100) plane is selected as a metal oxide forming zinc oxide on a magnesium oxide substrate. In this case, the silicon substrate has a (111) plane, the aluminum oxide substrate has a (001) plane, and the SrTiO ₃ substrate has a (001) plane. I like it. When such a single crystal is used as a substrate, the fluctuation of the crystal axis can be generally suppressed to 5 degrees or less. When a non-single-crystal material such as ceramic, silicon, Fe, Ni, or other non-crystalline material is selected as the substrate, the fluctuation of the crystal axis generally tends to be large. In the case where these materials are used as a substrate in the present invention, the fluctuation of the crystal axis is preferably at most 20 degrees. Also, it is preferable that the angle be 15 degrees or less. Further, it is particularly preferable that the angle is 10 degrees or less. In the case of a substrate made of any of these materials, the fluctuation of the crystal axis can be reduced by subjecting the surface to an orientation treatment. When the functional element of the present invention is, for example, an electron-emitting element for an electric or electronic device, a laser-oscillating element for an optical device, or the like, needle-like metal oxides are arranged on a substrate at regular intervals. May be preferred to be present. As a method of producing needle-like metal oxides arranged at regular intervals, a substrate is prepared by a known fine processing method, for example, a carbon dioxide laser, a YAG laser, an electron beam or an X-ray lithography. This can be achieved by, for example, forming convex portions at regular intervals on the substrate by etching. The reasons are as follows. As described above, when the functional element of the present invention is manufactured by “atmospheric pressure open type CVD”, a metal compound is sprayed on the surface of the substrate to grow acicular metal oxide on the surface of the substrate. The growth from the convex part has priority over the part. Therefore, if convex portions arranged at regular intervals are formed on the substrate in advance, needle-like metal oxides arranged at regular intervals can be manufactured. When the functional element of the present invention is, for example, an electron-emitting element, a laser-oscillation element, or the like, the functional element may have needle-like metal oxides arranged at regular intervals obtained in this manner. I like it. At this time, it is preferable that the dispersion of the distance between one needle-like metal oxide and the needle-like metal oxide around the needle-like metal oxide is within 1 μπι of soil. Also, it is preferable that the distance is within ± 0.5 m. More preferably, it is within ± 0.25 m.

A preferred method for producing the functional element of the present invention will be described below. FIG. 1 is a schematic view of an example of a preferred manufacturing apparatus for manufacturing the functional element of the present invention.

N ₂ is such as door La-up by the re-cooling and dehydration to using liquid nitrogen, flow rate 1. Flow in the direction of the arrow in the 2 dm ³ / min. The chamber temperature 1 1 5 ° with a metal compound heated chamber set at _{C, Z n (C 5 H} 7 0 2) 2 was vaporized by re heated by the heater, resulting metal compound gas is a metal compound Is flushed with N ₂ and sprayed onto the substrate via the nozzle and the slit. The lines after the heating tank are heated by a ribbon heater (not shown). As a substrate, previously heated to (0 0 0 1) Mengasu Li Tsu me with A 1 ₂ O ₃ single crystal plate which faces, by Li 5 5 0 ° C to the heater. When blown gaseous Z n a _{(C 5 H 7 O 2)} 2 on the substrate on the substrate, the acicular metal oxide is grown on the substrate.

 When the volatile or sublimable metal compound is converted into a gas using the equipment shown in FIG. 1, a gaseous metal is required to obtain a needle-shaped metal oxide having a specific shape as in the present invention. It is important to control the temperature conditions of the compound and the substrate. The temperature of the gaseous metal compound varies depending on the metal compound used, but it is preferable to heat the metal compound to a temperature at which the metal compound volatilizes or sublimes or higher. It is more preferably from 30 to 600 ° C, particularly preferably from 50 to 300 ° C.

The metal compound thus gasified may be directly sprayed on the substrate, or another gas may be used as a medium (carrier gas). It may be used as a spray to form the acicular metal oxide. In particular, a method of spraying another gas as a medium to form acicular metal oxides is preferable. In this case, the preferred value of the flow rate of the medium gas (carrier gas) is related to the temperature at which the metal compound is vaporized and the atmosphere of the reaction zone where acicular metal oxides are formed. Under a normal pressure atmosphere at room temperature, a space volume value expressed by a value obtained by dividing the flow rate by the volume of the metal compound heating tank for 1 minute is preferably 20 Z minutes or less, more preferably 5 Z minutes. It is as follows.

 In the manufacturing method of the present invention, the growth rate of the acicular metal oxide is determined by the concentration of the metal compound gas on the substrate. It is an important factor to make the oxide of the group easier to obtain. The concentration of the metal compound gas on the substrate is basically determined by the degree of supersaturation of the vaporized metal compound on the substrate. The degree of supersaturation is specified by [{(actual vapor pressure) 1 (equilibrium vapor pressure)} equilibrium vapor pressure] X100. It is preferable that the degree of supersaturation when producing the acicular metal oxide in the present invention is 1% or more. Further, it is more preferably at least 10%, and particularly preferably at least 20%.

The gas (carrier gas) as a medium preferably used when spraying the vaporized metal compound is not particularly limited as long as it does not react with the metal compound used. Specific examples PTJ

 3 6

Examples thereof include an inert gas such as nitrogen gas, helium, neon, and argon; a carbon dioxide gas; an organic fluorine gas; and an organic substance such as heptane and hexane. Of these, inert gas is preferred from the viewpoint of safety and economy. In particular, nitrogen gas is the most preferred in terms of economy.

 When the vaporized metal compound is sprayed on the substrate to form needle-shaped metal oxide on the substrate, the distance between the outlet of the metal compound and the surface of the substrate is the size of the metal oxide to be formed. Depends on The preferred value of this distance varies depending on the shape of the outlet, and the distance between the outlet and the surface of the metal oxide is defined as the ratio of the length of the major axis of the opening. I like it. Further, 0.05 to 0.7 is more preferable, and 0.1 to 0.5 is particularly preferable. In general, when the ratio exceeds 1, the efficiency of conversion of the metal compound gas into the acicular metal oxide tends to decrease.

 The temperature of the substrate itself at the time of spraying the metal compound gas to form the needle-shaped metal oxide is higher than the temperature of the metal compound gas, and the temperature at which the metal oxide can be formed near and on the surface of the substrate. There is no particular limitation as long as this temperature is present, but this temperature may affect the shape of the formed acicular metal oxide. Therefore, this temperature is preferably from 0 to 800 ° C, more preferably from 20 to 800 ° C, and even more preferably from 100 to 700 ° C.

When producing the functional element of the present invention, the metal compound is volatilized or volatilized. Oxygen, water, etc., which reacts with the metal compound, are present in the system from the place where the metal compound gas is obtained by sublimation to the nozzle for blowing the obtained metal compound gas into the reaction zone. In this case, metal oxides are formed in the apparatus before being discharged into the reaction zone, and clogging occurs, so that it is not possible to obtain a needle-shaped metal oxide having a desired form. Not good. However, if the reaction rate of the metal compound with oxygen, water, etc. is extremely low, oxygen, water, etc. may be allowed to coexist in the system in advance.

 The atmosphere in the reaction zone where the vaporized metal compound contacts the substrate may be under reduced pressure, under normal pressure or under pressure. However, when performed under highly reduced pressure, for example in an ultra-vacuum, the acicular metal oxide must be grown over a long period of, for example, several days. This is not preferable for industrial implementation because the growth rate of the acicular metal oxide is low and the productivity is poor. When performed under pressure, there is no problem with the growth rate of the metal oxide, but it is not preferable because equipment for pressurization is required. In general, it is preferable to carry out at 0.01 to 20 atm, and 0.1 to: L 0 atm is more preferable, and it is more preferable to carry out at normal pressure. Especially preferred.

The reaction time required to form the acicular metal oxide is not particularly limited, but it is necessary to take a sufficient time to obtain the acicular metal oxide having an aspect ratio specified in the present application. Is preferred. In addition, the reaction time varies depending on the reaction conditions and the type of raw materials. For example, when zinc acetyl acetate is used as a metal compound raw material, needle-like metal oxides grow in about 5 minutes under an atmospheric pressure atmosphere, and grow to a length of 100 minutes in 300 minutes. You. However, when zinc acetyl acetate is used as the metal compound raw material, the reaction time is preferably longer than 10 minutes, and more preferably 15 minutes or longer. The reason for this is that the longer the reaction time, the larger the aspect ratio (the ratio of the length of the cross section to the circular equivalent diameter) and the larger the surface area. Also, when tetrasopropoxy titanate is used as the metal oxide raw material, a needle-like metal oxide (substantially rod-shaped) of 4 μm can be obtained in about 3 minutes.

 When forming an acicular composite metal oxide containing two or more metals, a metal compound can be mixed and vaporized, or a vaporized gaseous metal compound can be mixed. Les ,. Also, both methods can be used in combination.

In the functional element of the present invention, acicular metal oxides are present at a high density, and there is a gap between each of the acicular metal oxides. When the functional element of the present invention including a needle-shaped metal oxide having a special structure is used in an electric, electronic or optical device, deformation may occur during use depending on the form of use. That is, when physical stress is applied to the needle-shaped metal oxide, there is a possibility that many rod-shaped bodies (needle-shaped bodies) are knocked down. In order to prevent this, for example, thermoplastic resin, thermosetting resin, An organic material such as an instant adhesive such as an elastomer or cyanoacrylate, an inorganic material such as glass or ceramic, or a metal may be used to hold the acicular metal oxides together. You can also.

 Examples of thermoplastics used to hold needle-like metal oxides together include low, medium or high density polyethylene, polypropylene, polymethylpentene, polyvinyl chloride. , Polystyrene, acrylonitrile linoleic styrene copolymer (hereinafter abbreviated as "SAN resin"), acrylonitrile-butadiene-styrene copolymer ( Abbreviated as "ABS resin"), polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyphenylene ether, Polymethyl acrylate, polyetherimide, polysulfone, polyetherimide, polylate, polyphenylenesulfide, styrene One pig Copolymers and their hydrogenated compositions, etc., and polyblends and copolymers combining two or more of these, for example, polycarbonate and acrylonitrile Diene-styrene copolymers, poly (phenylene ether) and polystyrene, and the like can be mentioned.

Examples of thermosetting resins used to hold the needle-shaped metal oxides together include epoxy resins, xylene resins, guanamine resins, diaryl phthalate resins, vinyl ester resins, and phenolic resins. Nol resin, unsaturated polyester resin, furan resin, poly PT 1 7

4 0

Examples include mid, poly (P-hydroxybenzoic acid), polyurethane, maleic acid resin, melamine resin, and urine resin.

 Examples of elastomers used to hold needle-like metal oxides together include natural rubber, butadiene rubber, silicone rubber, polyisoprene rubber, chloroprene rubber, and ethylene propylene. Rubber, butynole rubber, isobutylene rubber, styrene butadiene rubber, styrene / isoprene / styrene block copolymer rubber, acryl rubber, acrylonitrile butadiene rubber, Synthetic rubbers such as hydrochloride rubber, chlorosolephonated polyethylene rubber, polysulfide rubber, and the like. In addition, polytetrafluoroethylene, petroleum resin, alkyd resin, etc. can be used. Further, cyanoacrylate, which is generally used as an instant adhesive, can also be used.

 The functional element of the present invention having a needle-shaped metal oxide having a special structure, which is obtained by the above-described manufacturing method, has an extremely high surface area of the needle-shaped metal oxide, and has a sharp tip depending on the type of metal used. It can be shaped like a prism, depending on the type of metal used, and has various other characteristics. It can be used for electronic, optical or optical devices.

Next, an electric, electronic, or optical device that can use the functional element of the present invention will be described with reference to examples. As an electric or electronic device, various metal oxide functions, namely, electron emission function, magnetic material function, electromagnetic wave shield function, piezoelectric material function, ferroelectric function, conductor function, resistance or insulation function, It can be used for equipment that utilizes the heat conversion function. In addition, as an optical device, it can be used for a device utilizing a transparent function, a light transmission / absorption / reflection function, a heat transmission / absorption / reflection function, a light oscillation function, an optical waveguide function, a photocatalytic function, and the like. .

 Specific examples of the functional element of the present invention and specific examples of the device using the functional element will be described below.

 (1) Electron emission device utilizing electron emission function

When zinc oxide is selected as the needle-like metal oxide in the functional element of the present invention, the needle-like metal oxide has a shape with a sharp tip. In general, it is known that a lightning rod with a sharp tip causes lightning to fall intensively, but the reverse theory is to use a needle-shaped metal oxide covered with a conductive material. According to the present invention, when a voltage is applied to a functional element containing a conductive element or a functional element made of a conductive needle-shaped metal oxide, electrons are easily emitted from the sharp tip of the needle-shaped metal oxide. They found out. That is, the present inventors have confirmed that the needle-shaped metal oxide has an electron emission capability of 10 times or more at the same voltage as that of a non-needle-shaped metal oxide, that is, a flat metal oxide. ing. When the functional element of the present invention is an electron-emitting element, for example, a part or the whole of the functional element having a sharp-pointed ZnO is covered with a conductive material or a needle-shaped metal oxide. By making the object itself conductive (for example, a needle-like metal oxide made of ZnO doped with A 1), it can be used as an electron-emitting device. The conductive material used at this time preferably has a specific resistivity of 10 ΩZm or less, and more preferably ΙΩΖπι or less. It is a child of a conductive material, for example, metals and or metal _{paste, Ι Τ Ο (I η 2} 0 3 / S η 0 2) conductive metal oxides such as, conductive resins. Although there is no particular limitation on the type of metal, specific examples include copper, nickel, chromium, iron, gold, silver, and nickel. Radium, aluminum, zinc, tin, silicon, titanium and their alloys.

Furthermore, after covering a part or the whole of the needle-shaped metal oxide of the functional element with a conductive material, or making the needle-shaped metal oxide itself conductive, By covering the tip with one or more conductive materials, it is possible to produce an electron-emitting device having a higher electron-emitting capability. The conductive materials include one in the periodic table except for hydrogen (Group 1), boron (Group 13), nitrogen (Group 15), phosphorus (Group 15), and arsenic (Group 15). If the element is a metal, it can be selected from oxides and carbonaceous materials. In particular, carbonaceous materials are preferred. Specific examples of the carbonaceous material include graphite, graphite, diamond, diamond-like carbon (DLC), and carbon nitride. Among these, especially die Diamond and diamond-like carbon are more preferable because of their high electron emission capability. Various methods such as vapor deposition, sputtering, diving, CVD, and PVD (physical calcium or deposition) can be used to form these conductive or easily conductive materials. Available.

 Examples of the electric / electronic device using the functional element of the present invention as an electron-emitting device include, for example, an electron-emitting device such as a cold-cathode tube of a liquid crystal display, a field-emission display, or a plasma display. And a television electron gun. It can also be used for flat fluorescent lamps, taking advantage of its ability to emit electrons over a large area. The flat fluorescent lamp is a type of fluorescent lamp that emits light on its surface differently from a normal fluorescent lamp having a tubular shape. The liquid crystal display currently used as a backlight can be used as a backlight not only in combination with a cold cathode tube and light guide plate on the side of a display device, but A flat fluorescent lamp can be used as a back light by itself.

As described above, the electron-emitting device including the functional element of the present invention easily emits electrons even at the same voltage as compared with a flat plate. Therefore, when the functional element of the present invention is used as an electric / electronic device, it is possible to obtain the same luminance as a conventional electric / electronic device at a low voltage. Therefore, by using the functional element of the present invention, it is possible to manufacture an energy-saving electric / electronic device that achieves high luminance at the same voltage as in the past. (2) Capacitor element utilizing ferroelectric function

The functional element of the present invention has a large surface area. Currently used capacitors are generally referred to as multilayer ceramic capacitors. As mentioned above, the performance of a capacitor is determined by its capacitance. The capacitance is proportional to the surface area and inversely proportional to the thickness of a ferroelectric material such as titanium titanate. A conventional multilayer ceramic capacitor has a high capacitance by forming a thin ferroelectric material into a multilayer of about 100 layers through electrodes. However, it is costly to produce a thin ferroelectric multilayered material industrially. The functional element of the present invention, for example, a functional element using a ferroelectric oxide such as titanium titanate as an acicular metal oxide can be used as a high-capacitance capacitor element. An insulating oxide such as zinc oxide is used as a needle-shaped metal oxide, and a thin film of a conductive material is first formed thereon, and then a ferroelectric oxide such as barium titanate is used. A high-capacitance capacitor can also be obtained by forming a thin film layer. Technically, the layer thickness of ferroelectrics, such as titanium titanate, in current multilayer ceramic capacitors cannot be reduced to less than 6 μπι. Considering that it is possible to obtain a thin needle-like metal oxide and that the functional element of the present invention has a large surface area, the static electricity of the capacitor using the functional element of the present invention is considered. The theoretical capacity is 30 times that of the current multilayer ceramic capacitor. In this case, a thin film of conductive material is further formed. By forming a thin film layer of a ferroelectric oxide such as barium titanate, that is, by forming two layers, the capacitance can be further increased. With three or more layers, it is possible to further increase the number of layers. As described above, examples of ferroelectric metal oxides that can be used when the functional element of the present invention is used as a capacitor include barium titanate and titanium titanate. And the like. These can be effectively used for "atmospheric pressure open CVD" for producing the acicular metal oxide of the present invention, but the method for forming acicular metal oxide is not particularly limited. Absent. Further, as the conductive material, for example, metal, ITO (I n ₂ 〇 ₃ / S n 〇 ₂₎ a conductive metal oxide such as can and Ruco use. The type of metal is not particularly limited, but specific examples include copper, nickele, chromium, iron, gold, silver, iron, radium, aluminum, zinc, tin, silicon, titanium, and the like. Alloy. As a method for forming the conductive film, various methods such as vapor deposition, sputtering, diving, CVD, and PVD can be used.

 Electric and electronic devices that use a functional element as a capacitor element have a high capacitance and can be used for small electric and electronic devices such as mobile phones.

(3) Memory device utilizing strong derivative function

Since the functional element of the present invention has a ferroelectric function, The development of a memory device utilizing the function, that is, a ferroelectric memory device is being promoted. Ferroelectric memory has the characteristics of being non-volatile, having a short access time, a long life, and low power consumption. For this reason, in recent years, development has been promoted as a non-contact IC card using ferroelectric memory. As a ferroelectric, PZT, that is, a metal oxide containing three elements, Pb, Zr, and Ti, is generally used, but the ferroelectric currently used is formed on a substrate. It is composed of a metal oxide exhibiting strong conductivity formed in a planar shape. For this reason, the memory property is low, and the use is limited.

 However, when the functional element of the present invention is used, a memory function can be imparted to each of the needle-shaped metal oxides, so that the memory element has a high storage capacity. be able to. Specifically, for example, the gap between each of the needle-shaped metal oxides is filled with an insulating material, and the insulating material embedded in every one or more of the needle-shaped metal oxides By connecting this to the transistor-side electrode, it is possible to create a memory having the same configuration as an aggregate of many insulating layers of a ferroelectric capacitor. And Examples of metal oxides exhibiting ferroelectricity include, for example, metal oxides containing three elements of Ba, Na and Nb, Sr and Nb in addition to PZT described above. Examples thereof include metal oxides containing elements as components.

Electricity and electricity using the memory comprising the functional element of the present invention Since the slave device has a high storage capacity, the functional device of the present invention can be used, for example, as a disk material such as a DVD (Digital Versatile Disc) or a storage device of a computer, which has become popular in recent years. Is very useful.

(4) Sensor element utilizing resistance function

The surface area of the functional element of the present invention is large. This large surface area can be used for sensor elements. In general, a sensor is a device that converts a physical quantity into a resistance value and detects it. There are temperature sensors, gas sensors, humidity sensors, and the like. For example, metal oxides such as nickel oxide, cobalt oxide, and barium titanate are used as temperature sensors. In addition, tin oxide, iron oxide, zinc oxide, and the like are used as gas sensors. Aluminum oxide, zinc oxide, zinc oxide, etc. are used as humidity sensors. Normally, when metal oxides are used as sensors, metal oxide thin films can be formed by vapor deposition or sputtering, or binders can be used to paste the metal oxides. For example, a method such as coating on a substrate is used. However, it is required to increase the sensitivity of the sensor or to improve the response. Since the functional element of the present invention has a large surface area, it can be used as a sensor with high sensitivity and high response. For example, a sensor is provided by providing electrodes on the tip of the needle-shaped metal oxide and the substrate surface. Electric The pole is not particularly limited as long as it is a conductive material.

 An electric / electronic device using a sensor composed of such a functional element has high sensitivity and high responsiveness, so it can be reduced in size and can detect subtle environmental changes. Therefore, the functional element of the present invention is very useful.

(5) Laser oscillation element utilizing optical oscillation function

In recent years, CDs (compact discs) have become widespread as information storage media, and red laser oscillation elements have been used for reading information from CDs. By using a low-wavelength laser, such as an ultraviolet laser, for reading information, it is possible to put more information on a CD, that is, to record at a higher density than a CD. . For this reason, the use of G a N (red laser wavelength of 410 nm vs. 6500 nm) laser oscillators is currently being studied. In order to use G a N as a laser oscillation element, an optical device that integrates three structures, a laser emission part, a mirror part that reflects a laser, and a current injection electrode, has been considered. At the same time, the composition of each part is different, and the heat generated by long-term use causes thermal mutual diffusion of atoms, resulting in a problem of reduced performance. However, when the functional element of the present invention, for example, a needle-shaped metal oxide composed of Zn, is used as an oscillation element, a laser having a wavelength (380 nm) lower than that of a GaN laser can be obtained. Can oscillate Therefore, higher-density recording is possible than when GaN is used for reading, and at the same time, high-speed transmission is also possible. Further, the optical device using the functional element of the present invention as a laser oscillation element has a simpler structure than using GaN as a laser oscillation element, and the performance is reduced due to thermal mutual diffusion of atoms. Nor. And a needle-like metals oxides, C o 〇 besides Z n O, ANATA one peptidase type T i O _2, Norechiru type T i 〇 _2, M n _{〇, B a T i 0 3,} C d O etc. the wavelength, each of which oscillates when using the metallic oxide, C 0 O in 3 1 0 nm, the anatase type T i 〇 ₂ 3 8 8 nm, rutile T i O ₂ in 3 5 4 nm, M It is 459 nm for nO, 459 nm for BaTi i3, and 539 nm for CdO, and is used as a low-wavelength laser oscillator. Can be. When using the laser oscillation element comprising the functional element of the present invention in an optical device, the functional element and the excitation source are used in combination. The excitation source excites the atoms that constitute the functional element by applying energy such as electromagnetic waves, heat, and current to the substrate.When the atoms de-excit and return to the ground state, they emit an electromagnetic wave with a certain wavelength. Lamps and electric currents are examples of the excitation source.

As described above, in Solid-State Physics, vol. 33, No. 1, p. 59-64 (1998), Zn nanocrystals formed on a substrate were described as an ultraviolet laser oscillator. Use has been reported. However, the ZnO nanocrystals formed on the substrate are The calculated diameter is 100 nm, that is, the aspect ratio (circular conversion diameter of the length Z section) is 0.05, and the needle-shaped metal oxide of the present invention is 0.1 or more. Very small. When a functional element containing a needle-shaped metal oxide having an aspect ratio of 0.1 or more is used as a laser oscillation element as in the present invention, laser oscillation becomes high. . The reason is considered as follows. Laser oscillation occurs perpendicular to the thickness direction of the metal oxide layer (the length direction of the needle-shaped metal oxide). Therefore, the output power increases as the thickness of the metal oxide layer increases. Therefore, the longer the needle-shaped metal oxide with a uniform central axis, that is, the larger the ratio of the length to the circle-equivalent diameter of the cross section (the length of the length Z cross-section circle), the larger the result. Thicker layers and higher output.

 In addition, the functional element of the present invention is a high-output laser-oscillator element because a large number of needle-like metal oxides having a certain size exist on the substrate.

 The optical device using the laser oscillation element comprising the functional element of the present invention can oscillate a laser having a wavelength lower than that of the conventional one. Accordingly, high-density information or high-speed transmission of high-sensitivity information becomes possible, and the functional element of the present invention is very useful.

(6) Optical switch element utilizing optical waveguide function

With the advancement of the advanced information society, information and communication systems have become more sophisticated The demand for capacity is extremely high. At present, most lines connecting ordinary households and telephone offices are electronic communication (metal wire-to-analog transmission method), and large-capacity information communication is difficult. Therefore, it is expected that the line connecting ordinary households to the telephone office will be replaced by optical fiber communication in the future. However, in order to achieve this, the same function as that for turning on and off the movement of electrons in electronic communication is required for optical fiber communication. That is, it is necessary to develop an optical switch. However, simply achieving the optical switch function does not reach the practical domain. At the same time as the optical switch function, high-integration technology for turning on and off information from many homes is required, but an optical switch that can handle this has not yet been developed. The functional element of the present invention has an optical switch function and is an optical switch element that can be highly integrated. An optical device using the functional element of the present invention as an optical switch element is, for example, an optical device in which each of the high-density needle-like metal oxides has an optical switch function. It measures integration. The optical switch function can be achieved by setting two electrodes on each needle-shaped metal oxide in the functional element of the present invention, applying a voltage between the electrodes, and shifting the phase. Can be. Such a highly integrated optical switch can be easily achieved by taking advantage of the feature of the functional element of the present invention that a large number of needle-like metal oxides are present on a substrate. At this time, the kind of the metal oxide used for the functional element of the present invention is not particularly limited. The optical device using the optical switch composed of the functional element of the present invention can be used as a highly integrated optical switch in the optical communication field, so that the information with the advance of the advanced information society in the future It is possible to respond to the sophistication and large capacity of the communication system.

 The representative examples of the electric / electronic device and the optical device in which the functional element of the present invention can be used have been described above. Other applications include insulators, conductors, solid electrolytes, fluorescent display tubes, and EL devices. Electric and electronic devices such as elements, actuators, piezoelectric bodies, thermistors, varistors, superconductors, thermoelectric emission elements, electromagnetic shielding materials, etc. or photodielectrics, optical sensors, solar cells And optical devices such as a light wavelength conversion element and a light absorption filter. The functional element of the present invention is characterized in that, for example, a needle-shaped metal oxide having a sharp tip extends upward from the upper surface of the substrate, and its central axes are arranged substantially parallel to each other. In addition, by utilizing the feature that the surface area is large, it can be used for various devices other than the above devices. For example, the thickness (circular diameter) of the needle-shaped metal oxide is 0.1 μππ, preferably 0.0 μπι.

If a functional element with a temperature of 5 μππ or less is used as a thermoelectric emission element, it can be used in a freezer. In recent years, the use of titanium oxide (in combination with a photosensitizer) as a wet-type solar cell has been studied. However, the functionality of the present invention including acicular metal oxide of titanium oxide has been studied. Since the element has a large surface area, the light irradiation area is large, and the efficiency of converting light into electricity can be increased. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

 Note that the fluctuation of the crystal axis (center axis) of the needle-shaped metal oxide obtained in the following examples is indicated by the angle of bending in a direction perpendicular to the surface of the substrate. Example 1

The functional device was manufactured using the apparatus schematically shown in FIG. Were charged zinc Asechiruase Tone one preparative the metal compound heated tank _{[Z n (C 5 H 7} 0 2) 2]. The metal compound heating tank was heated, and zinc acetyl acetate was vaporized at an internal temperature of 115 ° C. On the other hand, an Al ₂ 〇 ₃ single crystal plate (10 nini X 5 mm) serving as a substrate is placed on the heater located directly below the blow-out slit, and the (001) plane is slit. And heated to 550 ° C. 1 the metal compound heating tank. 2 dm ³ introduces Z min of the flow rate in dry nitrogen gas, the vaporized zinc Asechiruase Tone bets in the heating tank by entrained in nitrogen gas, A 1 ₂ O ₃ single in atmospheric pressure It was sprayed on the surface of the crystal plate. Three hundred minutes after the start of spraying, the functional element consisting of the substrate and the needle-shaped metal oxide (ZnO) grown thereon was removed from the apparatus.

Gold (conductive) is applied to the obtained functional element by sputtering. Was deposited to a thickness of 0.1 lm, and then observed with a scanning electron microscope (hereinafter abbreviated as SEM).

 In order to clarify the three-dimensional shape of the functional element, SEM observation was performed from an obliquely upper angle of the structure. The obtained SEM images are shown in FIGS. 2 (a) and 2 (b). The weighted average value of the circle-converted diameter of the cross section of this needle-shaped ZnO is 1.2 μιη, the weighted average value of the length is 100 μm, and the density is 1 μμπιΧ1 O ft m. The unit area was 500 pieces per unit area, and the fluctuation of the crystal axis was 0.9 degrees. Example 2

A 1 ₂ O ₃ and temperature 6 0 0 ° C of the single crystal plate, was prepared a functional element in the same manner as in Example 1 except that the flow rate of dry nitrogen gas to 2 dm ³ / min.

 Gold (conductive material) was vapor-deposited to a thickness of 0.1 μππι on the obtained functional element by sputtering, and then observed by SEM.

Figure 3 shows the obtained SEM image. As a result of SEM observation, the weighted average value of the circular equivalent diameter of the cross section of the needle-shaped ZnO was 3.6 μm, the weighted average value of the length was 80 μππι, and the density was Ο Ο μ πι Χ Ι Ο There were 300 per unit area having μπι, and the fluctuation of the crystal axis was 0.8 degrees. Example 3 Using the same apparatus as in Example 1, a functional element was manufactured. Te Tri source proxy Chita Natick preparative the metal compound heated tank _{[T i (0 C 3 H} 7 - i) 4] were charged. The metal compound heating tank was heated to evaporate tetrasilso proxy titanate at an internal temperature of 130 ° C. On the other hand, a MgO single crystal plate (10 mm X 5 mm) serving as a substrate is placed on the heater located directly below the blowout slit so that the (100) plane faces the slit. And heated to 450 ° C. Dry nitrogen gas is introduced into the metal compound heating tank at a flow rate of 1.5 dm ³ Z, and the vaporized tetrasoproxy titanate in the heating tank is entrained with the nitrogen gas. It was sprayed on the surface of the crystal plate. 3 0 seconds after the spraying starts and remove the functionality elements from the device consisting of a substrate and needle-like metal oxide grown thereon (T i 〇 _2).

 Gold (conductive material) was deposited to a thickness of 0.1 μππι on the obtained functional element by sputtering, and then observed by SEM.

Figure 4 shows the obtained SEM image. As a result of SEM observation, the weighted average value of the average circular equivalent diameter of the cross section of the needle-shaped Ti 0 ₂ was 0.8 μm, the weighted average value of the length was 5 μππι, and the density was Ι Ο μ πι Χ ΐ ιιη. It had 2500 pieces per unit area, and the crystal axis fluctuation was 2.1 degrees. Example 4 A functional element was manufactured in the same manner as in Example 3, except that the temperature of the MgO single crystal plate was set at 550 ° C.

 Gold (conductive substance) was evaporated to a thickness of 0.1 μππι on the obtained functional element by sputtering, and observed by SEM.

In order to clarify the three-dimensional shape of the functional element, SΕ 観 察 observation was performed from an obliquely upper angle of the structure. Figure 5 shows the obtained S image. As a result of SEM observation, the weighted average value of the circle-converted diameter of the cross section of the needle-shaped Ti 0 ₂ was 0.8 μππ, the weighted average value of the length was 3 μ, and the density was 10 πι Χ 10 μπα. And the fluctuation of the crystal axis was 1.0 degree. Example 5

Using the same apparatus as in Example 1, a functional element was manufactured. Were charged zinc Asechiruase Tone preparative the metal compound heated tank _{[Z n (C 5 Η 7} Ο 2) 2]. The metal compound heating tank was heated, and zinc acetyl acetate was vaporized at an internal temperature of 115 ° C. On the other hand, place a silicon plate (10 mm X 5 mm) on the heater above the heater located directly below the blow-out slit so that the (1 1 1) plane faces the slit. And heated to 550 ° C. Dry nitrogen gas is introduced into the metal compound heating tank at a flow rate of 1.2 dm ³ / min, and the vaporized zinc acetyl acetate in the heating tank is entrained with the nitrogen gas, and silicon dioxide is applied under atmospheric pressure atmosphere. Sprayed on the surface of the board. Three hundred minutes after the start of spraying, the functional element composed of the substrate and the needle-shaped metal oxide (ΖηΟ) grown thereon was removed from the apparatus.

 Gold (conductive material) was vapor-deposited to a thickness of 0.1 μππι on the obtained functional element by sputtering, and then observed by SEM.

 In order to clarify the three-dimensional shape of the functional element, SΕ 観 察 observation was performed from an obliquely upper angle of the structure. Figure 6 shows the obtained S image. As a result of SEM observation, the weighted average value of the circle-equivalent diameter of the cross section of this needle-like ΖηΟ was 2.8 μm, the weighted average value of the length was 70 μm, and the density was 10 m X l O jum. It had 470 pieces per unit area, and the fluctuation of the crystal axis was 3.9 degrees. Example 6

Using the same apparatus as in Example 1, a functional element was manufactured. Were charged zinc Asechiruase Tone preparative the metal compound heated tank _{[Z n (C 5 Η 7} Ο 2) 2]. The metal compound heating tank was heated to evaporate zinc acetyl acetate at an internal temperature of 115 ° C. On the other hand, the substrate on top of the heater located beneath the scan Li Tsu preparative out can blow A 1 ₂ 0 ₃ single crystal plate (1 0 mm X 5 mm) (0 0 0 1) plane force S scan Li Tsu It was set so as to face the heat and heated to 550 ° C. Dry nitrogen gas was introduced into the metal compound heating tank at a flow rate of 1.2 dm ³ / min to remove the vaporized zinc acetyl acetate in the heating tank with nitrogen. Along with the gas, it was sprayed onto the surface of the A12〇3 single crystal plate at atmospheric pressure. After 15 minutes from the start of spraying, the functional element consisting of the substrate and the needle-shaped metal oxide (ZnO) grown on it was removed from the device.

 Sputtered gold (conductive material) was deposited on the obtained functional element to a thickness of 0.1 nm and then observed by SEM.

In order to clarify the three-dimensional shape of the functional element, SEM observation was performed from an obliquely upper angle of the structure. Figure 7 shows the obtained SEM image. Results of S EM observation, weighted average 0 the yen diameter of the cross section of the needle Z n O 2 5 μ πι, weighted average length 0 5 / m, density of 1 0;.. U _m The number was 20000 per unit area having x1Om. Example 7 and Comparative Example

 A functional device was manufactured in the same manner as in Example 6, and a circuit (FIG. 8) using the obtained functional device as an electron-emitting device was created.

A 1 ₂ 0 ₃ substrate (1) and the acicular Z n O (2) made of functional element (1 0 mm X 5 mm) of 1 5 mm square sheet re co down of (S i) a plate (6) And put it in an SPF-332 sputtering machine manufactured by Nidec ANELVA, Japan, for 1 hour under the conditions of Ar atmosphere and pressure of 0.1 t0 rr. Was performed. Nickel-snow, nickel-plated, 8 m nickel A metal layer (3) was formed on the surface of the functional element and the silicon plate (6). The obtained functional device having the nickel layer formed thereon was used as an electron-emitting device.

 The electron-emitting device, the silicon plate (6), and the conductive paste (7) are connected so that the nickel layer (3) formed on the functional device and the copper plate (8) are connected via the conductive paste (7). ) And a copper plate (8). An external electrode was attached to the copper plate (8), and this external electrode was connected to a ground. On the other hand, a copper plate (4) covered with an insulating film (5) was prepared except for leaving a square portion of 2 mm square, and an external electrode was attached to this copper plate, and the external electrode was connected to the anode. The copper plate (4) covered with the insulating film (5) and the functional element formed with the nickel layer (3) are combined with the portion of the copper plate (4) not covered with the insulating film (5) and the nickel layer (3). Then, it was fixed via another silicon (S i) plate (6) so that the distance between them was 0.5 mm, and a circuit device whose cross section was as shown in Fig. 8 was created.

 As a comparative example, a circuit device was prepared in the same manner as described above, using a nickel flat plate of 1 O mm X 5 mm X 0.5 mm in place of the functional element having the nickel layer formed thereon.

Put created a circuit to vacuum tea Nba one, hurts ⁶ XI 0- 6 t 0 rr 〖the atmosphere of tea damper Ichi內. A current voltmeter was attached to the anode, and a high voltage power supply was attached to the ground, and the emission current was measured. When the functional device of the present invention is used as an electron-emitting device, the emission current when the potential difference between the anode and the ground of the circuit device is 5 kV is It was 5 μΑ. On the other hand, as a comparative example, the potential difference between the anode and the ground of a circuit device using a nickel plate without using a functional element was used.

The emission current at 5 kV was 0.4 μA.

Industrial applicability

 The functional element for an electric, electronic or optical device according to the present invention has an excellent feature that the thickness can be reduced despite the extremely large surface area of the metal oxide on the substrate. Having. Functional elements having such characteristics include, for example, energy-saving electron-emitting elements capable of emitting electrons at a low voltage, high-capacitance capacitor elements, high-density memory elements, and high-performance memory elements. It can be advantageously applied to elements for electric or electronic devices such as sensitivity sensor elements, laser oscillation elements, especially laser oscillation elements with low wavelengths such as ultraviolet light, and elements for optical devices such as highly integrated optical switch elements. It can be. Further, according to the method of the present invention, the electric, electronic or optical device of the present invention can be manufactured effectively and efficiently without requiring a large capital investment. In the method of the present invention, for example, the reaction can be carried out in an air atmosphere at atmospheric pressure.

Claims

The scope of the claims 1. A functional element for an electric, electronic or optical device,  A substrate and a plurality of needle-shaped metal oxides extending to an upper surface thereof, wherein the needle-shaped metal oxides extend upward from an upper surface of the substrate, and have respective central axes substantially parallel to each other. The needle-shaped metal oxide has a weight-average circle-converted diameter of 0.01 to 100,000 μππι, and the weight-average circle-converted diameter corresponds to the needle-shaped metal oxide. Defined as the weighted average diameter of a circle having an area equal to the area of the cross-section of the oxide, the cross-section of the needle-shaped metal oxide at the center located at 12 of the length of the needle-shaped metal oxide. The cross section obtained along a plane perpendicular to the central axis is  The acicular metal oxide has a weighted average aspect ratio of 0.1 or more, and the weighted average aspect ratio is determined by the weight of the acicular metal oxide with respect to the above-mentioned weighted average circle-converted diameter. Defined as the ratio of the average length, the needle-shaped metal oxide is 0.1 μm per unit area of 10 μm × 10 μm on the upper surface of the substrate. A functional element characterized by being present at zero density. 2. The functional element according to claim 1, wherein the acicular metal oxides are mutually held using at least one kind of substance selected from the group consisting of an organic substance, an inorganic substance, and a metal. 3. The functional element according to claim 1, which is an electron emission element for an electric or electronic device. 4. The functional element according to claim 1, which is a capacitor element for an electric or electronic device. 5. The functional element according to claim 1, which is a memory element for an electric or electronic device. 6. The functional element according to claim 1, which is a sensor element for an electric or electronic device. 7. The functional element according to claim 1, which is a laser oscillation element for an optical device. 8. The functional element according to claim 1, which is an optical switch element for an optical device. 9. In the method of manufacturing functional elements for electrical, electronic or optical devices, (a) at least one metal compound having volatility or sublimability, which reacts with at least one oxide-forming substance to form a metal oxide corresponding to the metal compound; And possible gold Vaporizing the genus compound to obtain a metal compound gas,  (b) spraying the obtained metal compound gas on the surface of a substrate placed in a reaction zone containing the oxide-forming substance and heated to a temperature higher than the temperature of the metal compound gas, The surface of the substrate is brought into contact with the metal compound gas in the presence of a substance forming substance, wherein the contact is made by growing a plurality of acicular metal oxides on the surface of the substrate, and then contacting the substrate with the metal compound gas. A time sufficient to form said functional element. 10. The method according to claim 9, wherein in the step (b), the metal compound gas is blown together with a carrier gas. 11. The method according to claim 9, wherein the reaction zone contains air at atmospheric pressure. 12. The metal component of the metal compound is at least one selected from the group consisting of elements from groups 1 to 15 of the periodic table, excluding hydrogen, boron, carbon, nitrogen, phosphorus, and arsenic. The method of claim 9, comprising a species element. 13. The method of claim 9, wherein the metal component of the metal compound comprises at least one element selected from the group consisting of zinc, silicon, aluminum, tin, titanium, zirconium and lead. the method of.