JP3452222B2 - Cold cathode electron source device and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold cathode electron source device and a method for manufacturing the same.

[0002]

2. Description of the Related Art A field emission type electron source cannot be manufactured with a thermionic emission type electron source because it can be manufactured to a micron size by utilizing a semiconductor fine processing technique and is easily integrated and batch processed. It is expected to be applied to GHz band amplifiers, high-power / high-speed switching elements, and electron sources for high-definition flat panel displays, and research and development have been actively conducted in Japan and overseas.

A conventional example of such a field emission electron source will be described below. As shown in FIG. 35, the thin film field emission type electron source proposed in Japanese Patent Laid-Open No. 63-274047 has a cold cathode 52 and a gate electrode 53 facing each other.
Electrons are emitted by forming a film on the insulating substrate 51 with a space of ˜2 μm and applying a voltage between the cold cathode 52 and the gate electrode 53 in vacuum. This cold cathode 52
Is formed by using FIB (Focused Ion Beam) technology, and in particular, the tip of the convex portion is formed to be sharp. However, when the FIB technique is used, it is difficult to increase the area of the element and the manufacturing cost becomes high.

On the other hand, patterning using a photolithography technique is appropriate in view of increasing the area and manufacturing cost. However, in the current photolithography technology, the diameter of the electron beam spot is the minimum patterning diameter, so the diameter is about 0.5 μm. Therefore, in order to form the tip of the cold cathode 52 sharp, various processes must be added. In this case, as the number of processes increases, the possibility of damage to the device during that period, particularly the damage to the tip of the cold cathode increases, resulting in a decrease in device yield. Also, most of these cold cathode sharpening processes are complicated and shape control is difficult.

The thin-film field emission type electron source proposed in Japanese Patent Laid-Open No. 3-49129 is as shown in FIG.
The cold cathode 63 and the gate electrode 64 are formed in parallel on the surface of the insulating layer 62 on the insulating substrate 61 by the method of cleavage and breaking by ultrasonic waves. However, in the case of the thin film field emission type electron source shown in FIG. 29, it is technically difficult to make the shape of the cold cathode 63 uniform because it is accompanied by breakage due to ultrasonic waves, and the cold cathode There is a problem that the thin film that forms 63 is greatly damaged.

The thin film field emission type electron source proposed in Japanese Unexamined Patent Publication No. 3-252025, as shown in FIGS. 37 and 38, uses an insulating substrate 7 using a photoetching technique.
Cold cathode 73 having a large number of convex portions on the insulating layer 72 on
After forming the, the tip of the convex portion is sharpened by using an isotropic etching technique. Note that in FIG. 30, 7
Reference numeral 4 is a gate electrode facing the cold cathode 73. But,
In the case of this electron source, it is difficult to control the shape of the cold cathode 73 depending on the etching conditions. Furthermore, it cannot be applied to the case where the undercut does not proceed due to the formation of the side wall protective film.

Further, in Japanese Unexamined Patent Publication No. 2-220337, a cold cathode 73 is made of a transition metal carbide, a metal oxide or a rare earth oxide, which is a low work function material that is chemically stable and easily emits electrons in a vacuum. It is disclosed to coat the surface of. However, it is difficult to cover only the cold cathode 73 and the like.

As described above, in the case of the conventional field emission type electron source, the shape of the cold cathode such as sharpening of the tip of the cold cathode cannot be set appropriately, or it has a low work function and is chemically stable. Such materials could not be used as cold cathodes because of the difficulty of fine processing. Therefore, there is a problem that it is not possible to obtain a stable field emission type electron source having good characteristics.

Further, US Pat. No. 5,011,003 discloses a field emission device in which a plurality of preformed emitter (cold cathode) body particles are arranged on a support. In this element, as shown in FIG. 39, a plurality of conductive objects 201 are arranged on a support 100, and the conductive objects 201 are bound to the support 100 by a binder 101. The conductive body 201 may be molybdenum, titanium carbide, etc., and preferably has a geometrically sharp edge so that the conductive body 201 acts as an emitter. Note that an insulating object 203 may be used as shown in place of or in addition to the conductive object 201, but in this case, when the insulating object 203 is covered with a conductive thin layer 202 and used. Has been done. The thickness of the layer of the binder 101 is about 0.5 μm, and the length (maximum dimension) of the coating of the conductive thin layer 202 of the conductive body 201 or the insulating body 203 is about 1.0 μm. The conductive object 201 is exposed. And
An actual field emission device is assembled by further adding an anode and a gate to such an emitter portion.

As shown in FIG. 40, such a field emission device has a support 1 carrying a plurality of emitters 201.
00, an insulating layer 409 is formed while leaving a part of the emitter body 201 uncovered. Further, over the insulating layer 409, a conductive layer 401 which functions as a gate for controlling the flow of electrons is provided.
Then, an insulating layer 402 is further provided over the conductive layer 401, and a screen 404 also functioning as an anode is provided over the insulating layer 402. A luminescence layer 403 is formed on the surface of the screen 404 facing the emitter body 201. Screen 404
Are bound by soldering or the like in a vacuum, and the closed space 40
6 is exhausted. Then, electrons are emitted from the emitter body 201 by applying a voltage, and light emission 408 is generated via the screen 404 by the action of the emitted electrons.

In the element shown in this specification, as is apparent from FIG. 40, a portion where the emitter body 201 and the insulating layer 409 come into contact with each other occurs. Therefore, when a voltage is applied, the voltage is concentrated at the insulating layer 409 and the voltage is concentrated. The risk of destruction increases as a result. In addition, in order to prevent this, the insulating layer 40
If 9 is thickened, it becomes necessary to increase the applied voltage for electron emission, which is not preferable.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cold electrode capable of being driven at a low voltage, stably obtaining a high emission current, excellent in processability of a cold cathode, and capable of increasing the area of an element. An electron source element and a manufacturing method thereof are provided.

[0013]

The above objects are achieved by the present invention described in (1) to (10) below. (1) A cold cathode electron source device having a cold cathode, the cold cathode being dispersedly contained in a cold cathode base material and the cold cathode base material, wherein the work function is more than the work function of the cold cathode base material. And a particle of a conductive material having a particle size smaller than the thickness of the cold cathode, the particles being dispersed in a state of being substantially separated from each other, and the particle protruding to the cold cathode surface. The cold cathode electron source element has an average particle size of 0.05 to 50 nm as determined by X-ray diffraction, and the particles are contained in an amount of 1 to 50% by volume based on the cold cathode substrate. (2) The cold cathode electron source element according to (1) above, wherein the cold cathode is obtained by depositing a component of the cold cathode base material and a component of the conductive material by a vapor phase method. (3) A cold cathode electron source device having a cold cathode, wherein the cold cathode is dispersedly contained in a cold cathode base material and the cold cathode base material, and the work function is more than the work function of the cold cathode base material. And a particle of conductive material having a particle size smaller than the thickness of the cold cathode, the particles being dispersed substantially separated from each other, and the particle being exposed on the cold cathode surface. The average particle diameter of the particles obtained by X-ray diffraction is 0.05 to 50 nm, and the components constituting the cold cathode substrate and the components of the conductive material are subjected to the reactive ion plating method or A method for manufacturing a cold cathode electron source element by depositing by a simultaneous sputtering method to obtain a cold cathode electron source element. (4) The method for manufacturing a cold cathode electron source element according to (3), wherein the particles are contained in an amount of 1 to 50% by volume with respect to the cold cathode substrate. (5) The method for manufacturing a cold cathode electron source element according to the above (3) or (4), wherein the particles are projected on the surface of the cold cathode. (6) A cold cathode electron source device having a cold cathode, the cold cathode being dispersedly contained in a cold cathode base material and the cold cathode base material, wherein the work function is more than the work function of the cold cathode base material. And a particle of conductive material having a particle size smaller than the thickness of the cold cathode, the particles being dispersed substantially separated from each other, and the particle being exposed on the cold cathode surface. When obtaining the cold cathode electron source element, a step of forming the cold cathode conductive layer for an amorphous or microcrystalline cold cathode by a vapor phase method, and subjecting the cold cathode to a heat treatment A method of manufacturing a cold cathode electron source element manufactured by a process. (7) The method for manufacturing a cold cathode electron source element according to the above (6), wherein the temperature of the heat treatment is a temperature from a film forming temperature to 700 ° C. (8) A cold cathode electron source device having a cold cathode, wherein the cold cathode is dispersed and contained in a cold cathode base material and the cold cathode base material, and the work function is higher than the work function of the cold cathode base material. And a particle of conductive material having a particle size smaller than the thickness of the cold cathode, the particles being dispersed substantially separated from each other, and the particle being exposed on the cold cathode surface. The average particle diameter of the particles obtained by X-ray diffraction is 0.05 to 50 nm, and a thin layer of the component that constitutes the cold cathode substrate and a thin layer of the component that constitutes the particles of the conductive material. A method of manufacturing a cold cathode electron source element, which is manufactured by alternately laminating layers and forming a cold cathode conductor layer by a vapor phase method. (9) The method for manufacturing a cold cathode electron source element according to the above (8), wherein the thin layer of the component constituting the particles of the conductive material has a thickness of 0.5 nm to 50 nm. (10) The cold cathode electron according to (9), wherein after the cold cathode conductor layer is formed, the cold cathode conductor layer is heat-treated at a temperature from the film forming temperature of the cold cathode conductor layer to 700 ° C. Method of manufacturing source element.

[0014]

According to the cold cathode electron source element of the present invention, in the cold cathode provided on the substrate, a conductive material having a work function lower than that of the cold cathode substrate is used for the cold cathode substrate. It is dispersed and contained as particles having a particle size sufficiently smaller than its own thickness. For this reason, it is possible to extract electrons at a low voltage and obtain a high emission current. Further, since the cold cathode base material can be processed by a normal photo process and etching, an arbitrary shape can be easily set, and the area of the cold cathode electron source element can be increased. Further, since the particles of the conductive material are dispersed in a state of being exposed or protruding on the surface of the cold cathode, electrons can be drawn out at a low voltage due to the concentration of the electric field, and a high emission current can be obtained. The effect of reducing the average particle size of the particles of the conductive material is that a high emission current can be obtained, and a large number of electron emission points can be formed, and stable emission current characteristics can be obtained.

From these, it is not necessary to form the cathode shape to have the tip portion having a small radius of curvature by a complicated process as in the prior art.

A cold cathode conductor layer containing an amorphous or microcrystalline element that constitutes the cold cathode substrate and the above-mentioned element that constitutes the conductive material is formed, and this conductor layer is heat-treated. By forming the cold cathode by forming the cold cathode, it becomes easy to manufacture the cold cathode. Further, the crystallinity of each of the cold cathode base material and the above conductive material is enhanced. When the crystallinity of the cold cathode base material is increased, the purity of the cold cathode base material is also improved, etching is facilitated in a short time, and the workability of the cold cathode base material is significantly improved, and
Production cost is reduced. Further, when the crystallinity of the above-mentioned conductive material is enhanced, electrons can be extracted at a low voltage and a stable and high emission current can be obtained. Further, by separating the film forming step and the heat treatment step, high production efficiency can be obtained.

Further, a thin layer of an element that constitutes the cold cathode base material and a thin layer of an element that constitutes particles of the conductive material are alternately laminated to form a conductor layer for a cold cathode, and then this cold layer is formed. If the conductor layer for the cathode is processed into a cold cathode, the particle size of the particles of the conductive material can be controlled by the film thickness of the thin layer of the element that constitutes the particles of the conductive material, so the cold cathode can be easily manufactured. Becomes More specifically, by setting the thickness of the thin layer of the element constituting the particles of the conductive material within a predetermined range, the thin layer becomes an island-like structure without taking a continuous film structure, It is possible to form a cold cathode conductor layer having a structure in which particles of a conductive material are dispersed in a cold cathode substrate.

This cold cathode conductor layer can be easily etched by an etchant of the cold cathode substrate,
This makes it possible to form a cold cathode. At the same time, it is possible to uniformly and reproducibly form a structure in which conductive material particles are projected or exposed on the cross section of the etched cold cathode. Therefore, a cold cathode electron source element that can be driven at a low voltage and that can stably obtain a high emission current can be manufactured with high yield.

By further heat-treating this cold cathode conductor layer, the crystal grain size of the particles of the cold cathode base material and the conductive material is increased, and at the same time, the conductive material taken in as impurities in the cold cathode base material. Of the particles of the conductive material for the cold cathode substrate, and the elements of the cold cathode substrate, which are incorporated as impurities in the particles of the conductive material and the elements of the Dispersibility of Therefore, when forming a cold cathode, it is possible to increase the etching rate by chemical etching, and the average particle size of the particles of the conductive material is about the thickness of the thin layer of the element constituting the particles of the conductive material. As a result, it is possible to form a cold cathode electron source element having uniform electron emission characteristics over a wide area.

[0020]

Specific Structure The specific structure of the present invention will be described in detail below. The cold cathode electron source element of the present invention has a cold cathode base material on an insulating substrate, and in the cold cathode base material, a conductive material is dispersed as an emitter substance to form a cold cathode. ing. In this case, the conductive material is fine particles having a particle size sufficiently smaller than the thickness of the cold cathode itself,
The individual particles are dispersed in a state of being substantially separated from each other and are exposed on the surface of the cold cathode. As the conductive material, a material having a work function smaller than that of the cold cathode base material is used.

By having such an element structure,
Electrons can be extracted at a low voltage without requiring complicated processing steps, and a high emission current can be obtained. On the other hand, when the particle diameter of the conductive material is larger than the thickness of the cold cathode, it becomes difficult to perform fine processing of the cold cathode, and a short circuit with the gate electrode easily occurs. Further, if the work function relationship of both materials is outside the above range, the effect of the present invention cannot be obtained.

As such a cold cathode electron source device, there is, for example, the structure shown in FIG. In the cold cathode electron source element shown in FIG. 1, an insulating layer 2 is provided on the surface of an insulating substrate 1,
Further, a cold cathode (emitter) 10 is provided on the insulating layer 2, and a gate electrode 7 is formed at a position close to the cold cathode 10. The cold cathode 10 is composed of the cold cathode base material 4 in which the conductive fine particles 8 formed of a conductive material are dispersed and contained as described above.

In order to manufacture a cold cathode electron source device having good characteristics, the conductive fine particles 8 having a particle size as small as possible are formed by using a material having a low work function and a chemically stable property as described above. At the same time, the cold cathode 10 and the gate electrode 7 may be designed to be arranged close to each other.

The particle size of the conductive fine particles 8 in this case is 0.5 to 50 nm, preferably 0.5 to 20 nm, determined from the strongest orientation peak of the X-ray diffraction analysis (XRD) spectrum according to Scherrer's formula. More preferably, it is 1 to 10 nm. In addition, a transmission electron microscope (TE
According to M) observation, when preferable film formation is carried out, primary particles of the conductive fine particles are present at the grain boundaries of the cold cathode base material component. The number average particle diameter of the primary particles obtained from this TEM photograph is 0.5 to 50 nm, preferably 0.5 to 20 nm, and more preferably 1 to 10 nm. In addition, TE
In M observation, it may be observed as secondary particles (aggregate structure such as spherical or island-like) which is an aggregate of primary particles depending on the film forming conditions, but single particles (primary particles) which are separated from each other. ).

The conductive fine particles 8 are preferably dispersed uniformly in the cold cathode base material 4, and thereby a high emission current can be obtained. Further, the conductive fine particles 8 are preferably dispersed in a state of being exposed or protruding on the surface of the cold cathode 10 as shown in the drawing. By doing so, electrons can be extracted at a low voltage due to the concentration of the electric field, and a high emission current can be obtained. The conductive fine particles 8 are the cold cathode 1
Although it is exposed on the surface of No. 0, as a result of etching described later, it usually projects from the surface.

The distance d between the cold cathode 10 and the gate electrode 7 (see FIG. 1 and FIGS. 6, 10 and 19 described later) is 0.1 to 0.1.
It is preferably about 20 μm.

As the conductive fine particles 8, a material having a low work function which is chemically stable and easily releases electrons in vacuum is used. That is, TiC, ZrC, HfC, Ta
Metal carbides such as C, NbC, MoC, WC, TaN,
Metal nitrides such as TiN, ZrN and HfN, LaB ₆ ,
A rare earth metal boride such as TaB, TiB ₂ , ZrB ₂ , HfB ₂ or a transition metal boride; diamond; conductive carbon such as graphite or a material containing at least one of these is used.

As the material of the cold cathode base material 4, when the conductive fine particles 8 are a carbide, a good conductor material which is not easily carbonized, for example, Ag, Cu, Ni, Al, Cr.
Etc., when the conductive fine particles 8 are nitrides, a good conductor material that is difficult to be nitrided, for example, Ag, Cu, Ni, Cr
In the case where the conductive fine particles 8 are borides, a good conductor material that is difficult to be borated, such as Ag, Cu, Cr,
Alternatively, a material containing at least one kind of them can be used. A preferable combination of such a conductive material and a cold cathode base material is ion plating or reactive sputtering to be described later, or to form a mixed film of both materials and heat-treat them. When the films are alternately formed, there are almost no restrictions on the cold cathode base material, various materials can be used, and the metal elements of both materials may be the same. In the present invention, metal carbide is preferably used as the conductive material.

As described above, the work function of the conductive material forming the conductive fine particles 8 is smaller than the work function of the cold cathode base material forming the cold cathode base material 4. Specifically, in terms of physical properties as a material, the work function of the conductive material is preferably 4.0 eV or less, more preferably 1.0 to 4.0 eV, while the work function of the cold cathode base material is 3.8 eV or more,
More preferably, it is 3.9 to 5 eV. From these, it is preferable to select a material having a work function difference of 0.2 eV or more, preferably about 0.4 to 4.0 eV, between the two materials.

Here, the work function is the minimum work size required to extract electrons from a solid into a vacuum, and X
Line photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UP
S)) and the value of each material is, for example, HA
NDBOOK of TEHRMONIC PROPERTIES, VS Fomenko, PLEN
UN PRESS DATA DIVIISION NY 1966 etc.).

The specific resistances of the conductive material and the cold cathode base material are 1 × 10 ^-5 Ωcm at room temperature in the bulk state.
~ 1 Ωcm and 1 × 10 ^-4 Ωcm or less (usually 1 × 10 ^-6 Ω
cm to 1 × 10 ⁻⁴ Ωcm) is preferable.

The ratio of the conductive fine particles 8 to the cold cathode substrate 4 is preferably 1 to 50% by volume, more preferably 3 to 45% by volume, especially 5 to 30% by volume, and further preferably 25% by volume or less. .

By using such a ratio, the effect of the present invention is improved. On the other hand, when the ratio of the conductive fine particles 8 decreases, the density of the conductive fine particles 8 such as TiC protruding on the end face of the cold cathode 10 processed by etching described later is low, and the conductive fine particles do not substantially contain the conductive fine particles. Only electron emission characteristics equivalent to On the other hand, if the proportion of the conductive fine particles 8 is too large, the dispersibility between the conductive fine particles 8 becomes poor, making it difficult to etch the cold cathode base material 4 and making it difficult to concentrate the electric field on each conductive fine particle 8. Become.

The thickness of the cold cathode 10 is 100 to 200.
It is preferably 0 nm, particularly preferably about 300 to 1000 nm. With such a thickness, the effect of the present invention is improved. On the other hand, if it is too thin, the probability of disconnection increases, and if it is too thick, etching processing takes time, resulting in high cost and insufficient processing accuracy.

Examples of the material of the insulating substrate 1 used in the present invention include various glasses, silicon wafers, various ceramics such as alumina, and the like. The size may be appropriately selected according to the purpose and application, but the thickness is 0.3 to
It may be about 5.0 mm.

In the structure of FIG. 1, the cold cathode 10 is installed on the insulating substrate 1 via the insulating layer 2, but the insulating layer 2 is
SiO ₂ , Ta ₂ O ₅ , Y ₂ O ₃ , MgO, Si ₃ N ₄
It may be formed of an insulating material such as
It is about 2.0 μm. The gate electrode 7 is made of Cr,
Mo, Ti, Nb, Zr, Hf, Ta, Al, Ni, C
It may be made of a metal such as u or W or an alloy thereof, and its thickness is about 0.1 to 1.0 μm.

Next, a method for manufacturing the cold cathode electron source element shown in FIG. 1 will be described. First, as shown in FIG. 2, the insulating layer 2 is formed on the surface of the insulating substrate 1 to have a predetermined thickness. The insulating layer 2 may be formed by a sputtering method or the like.

Next, as shown in FIG. 3, a thin film in which the conductive fine particles 8 are finely dispersed in the cold cathode base material 4 is formed to a predetermined thickness to form a cold cathode 10. The cold cathode 10 at this time may be formed by a vacuum thin film forming method such as an ion plating method, a sputtering method, or a vapor deposition method, but a reactive ion plating method or a co-sputtering method is preferable.

According to the reactive ion plating method, the substrate temperature is set to about 100 to 500 ° C., and the cold cathode substrate 4 and the conductive fine particles 8 are heated by electron beam using an evaporation source such as an alloy. If necessary, a gas is introduced as a C source, an N source or a B source. The C source gas is C ₂ H ₂ , C ₂ H ₄ , C ₂ H ₆ , CH _4, etc., the N source gas is NH ₃ , N ₂ , N ₂ H _2, etc., and the B source gas is A reactive gas such as B ₂ H ₆ may be used. The gas pressure at this time may be about 1.0 × 10 ^-2 Pa to 0.2 Pa, the probe current for ionization is about 1 to 5 and the bias voltage between the substrate and the hearth is about 1 to 5 kV. .

When the simultaneous sputtering method is used, a sputtering apparatus as shown in FIG.
A chip 12 made of a conductive fine particle material or its constituent elements is placed on a target 11 made of a cold cathode base material such as
(The surface has the insulating layer 2) may be placed opposite. In this case, the pressure is about 0.1 to 2.0 Pa, and the atmosphere is CH ₄ , C ₂ H ₆ , which becomes a C source, depending on the material of the conductive fine particles 8 and the like.
Hydrocarbon gas such as C ₂ H ₄ and C ₂ H ₂ and N as N source
A reactive gas G such as a nitride gas such as ₂ , NH ₃ or N ₂ H ₂ or a boride gas such as B ₂ H _{6 serving as a} B source may be appropriately introduced. RF power of power supply 13 is 0.3-5 kW
The substrate temperature may be about 100 to 500 ° C.
Further, if necessary, a negative bias voltage of about 500 V or less may be applied to the anode side.

As shown in FIG. 9, the cold cathode 10 may be formed by forming an amorphous or microcrystalline cold cathode conductor layer 9 and heat treating the cold cathode conductor layer 9. . The cold cathode conductor layer 9 at this time is composed of the constituent elements of the cold cathode base material and the constituent elements of the conductive fine particles.
It is preferable that the film is formed by the reactive co-sputtering method or the like using the above sputtering apparatus. Specifically, the target 11 and the chip 12 and the insulating substrate 1 may be arranged in the same manner as in the case of the simultaneous sputtering method. However, the substrate temperature is 0 to 100 ° C., particularly a temperature around room temperature (about 15 ° C. to 30 ° C.), the pressure is about 0.1 to 2.0 Pa, the atmosphere is an inert gas such as Ar, and the cold cathode 10 is composed. The C source, the N source, or the reactive gas serving as the B source, which is introduced in accordance with the above, may be introduced. The total flow rate is about 20 to 100 sccm, and when the reactive gas is introduced, Ar, etc. 80 to 99 of inert gas
It should be about%. The RF power of the power supply 13 is 0.
It may be about 3 to 3.0 kW.

The conductor layer 9 for cold cathode thus obtained
Is heat-treated. By such heat treatment, the amorphous or microcrystalline cold cathode conductor layer 9 is crystallized,
As shown in FIG. 3, the cold cathode in which the conductive fine particles 8 are finely dispersed in the cold cathode substrate 4 is formed.

It can be confirmed from the results of X-ray diffraction analysis (XRD) that the conductor layer 9 for cold cathode after film formation is amorphous or microcrystalline, and that it is crystallized by heat treatment. it can.

The heat treatment method is not particularly limited, and the method is performed in vacuum using a resistance heater, and Ar is used in a diffusion furnace.
And the like, or a method using an excimer laser. Since the heat treatment temperature at this time is effective at a film formation temperature or higher, the film formation temperature may be set to 700 ° C., and usually 250 ° C. to 700 ° C.
C., and more preferably 300 to 600.degree. If the heat treatment temperature is too low, wet etching with a nitric acid-phosphoric acid-based etching solution described below tends to be difficult. It is considered that this is because the growth of the conductive fine particles 8 is insufficient and the cold cathode base material 4 contains a large amount of impurities. These impurities are unreacted substances, and are considered to be Ti, C (including amorphous substances) when the conductive fine particles 8 are TiC, for example. Further, when the heat treatment temperature becomes high, the glass substrate is softened, and as a result, warpage, film peeling, or the like occurs on the substrate, which makes it difficult to manufacture an element. Therefore, inexpensive glass cannot be used as the substrate material, and it becomes necessary to use an expensive heat-resistant material such as quartz.

The heat treatment time depends on the heat treatment temperature, and if the temperature is high, the treatment time can be shortened.
Hold for 5-5 hours.

Next, as shown in FIG. 4, the cold cathode 10
After the resist 5 is provided thereon, the cold cathode 10 is molded using a photo process and wet etching with an etching solution such as nitric acid-phosphoric acid, and the insulating layer 2 is further coated with buffered fluoric acid (BHF) or the like. Wet etching is performed using the etching solution of. At this time, the cold cathode 10
The upper resist is not removed as it is. The patterning of the cold cathode 10 by the photo process at this time is performed by, for example, FIG.
As shown in. Further, as shown in FIG. 5, a film 6 and a gate electrode 7 made of the same material as the gate electrode, such as a Cr film, are formed on the entire surface by a vapor deposition method or the like to a predetermined thickness.
After that, as shown in FIG. 6, the resist 5 and the film 6 such as a Cr film are removed by a stripping solution.

The cold cathode electron source element of the present invention is not limited to the configuration shown in FIG. 1 and may be the one shown in FIG. The cold cathode electron source device shown in FIG. 10 is different from that shown in FIG. 1 in the manufacturing method of the cold cathode 10, and except that the gate electrode 7b is arranged via the gate insulating layer 14b. It has the same configuration.

In the cold cathode 10 in this case, a thin layer of an element forming the cold cathode base material 4 and a thin layer of an element forming the conductive fine particles 8 are alternately laminated to form a cold cathode conductor layer. It is preferably produced by heat treatment and further processing this conductor layer. In order to adopt such a manufacturing method, as described above, for example, when the conductive fine particles 8 are a carbide, a nitride, or the like, the material of the cold cathode base material 4 is a good conductor material that is hard to be carbonized or nitrided. There is no limit. Examples of the combination of the material of the conductive fine particles 8 and the material of the cold cathode base material 4 include TiC and Ti, TiC and Mo, Ta.
Like the combination of C and Mo, Ti, Zr, Nb, Mo,
Carbides of transition metals such as Hf, Ta, W and Cr, Ni, C
u, Al, Ti, Zr, Nb, Hf, Ta, W and the like; like TaN and Nb, ZrN and W,
Nitride of transition metals such as Ti, Zr, Nb, Mo, Hf, Ta, W and Cr, Ni, Cu, Al, Ti, Zr, N
b, Hf, Ta, W, etc. combination; LaB ₆ and Mo,
La, Ce, Pr, G like the combination of TaB and Zr
Borides of rare earth metals or transition metals such as d, Ti, Ta and Cr, Ni, Cu, Al, Ti, Zr, Nb, Hf, T
a, W, etc .; and the like. The gate insulating layer 14b in FIG. 10 is made of SiO ₂ similarly to the other insulating layers.
The thickness is about 0.1 to 2.0 nm. Other configurations are the same as those in FIG.

Next, a method of manufacturing the cold cathode electron source element of FIG. 10 will be described. First, as shown in FIG.
The insulating layer 2 is formed on the surface of the insulating substrate 1 to have a predetermined thickness by a sputtering method or the like.

Next, as shown in FIG. 12, the insulating layer 2
17, the thin layer 3a of the element that constitutes the cold cathode substrate 4 and the thin layer 3b of the component that constitutes the conductive fine particles 8 are alternately laminated on the surface of The conductor layer 3 for cold cathode is formed by the alternating deposition layers of.

To form these alternating deposited layers, for example, as shown in FIG. 17, a target 15 made of a cold cathode base material such as Ni and a conductive fine particle material such as TiC or its constituent elements are used. It suffices to perform multi-source sputtering by using the configured target 16, and a turntable on which the insulating substrate 1 (having the insulating layer 2 on the surface) is mounted is opposed to these targets 15 and 16 while rotating the target. A film is formed.

When forming the thin layer 3a of the constituents of the cold cathode substrate 4, sputtering is carried out by introducing only an inert gas G1 such as Ar. Further, when forming the thin layer 3b of the component that constitutes the conductive fine particles 8, in the case of a material such as carbide,
Reactive gas G2 such as hydrocarbon together with the inert gas G1
Is introduced to perform reactive sputtering. These film formations are performed alternately and at different positions. As a result, it is possible to suppress the generation of impurities such as amorphous carbon as compared with the case where two targets arranged at different positions are used and the reactive gas G2 is constantly introduced to perform sputtering.

As described above, in order to alternately perform sputtering and reactive sputtering in the same vacuum chamber,
For example, it may be performed by controlling the opening / closing of the shutter 18. Further, in order to further suppress the generation of impurities, a shutter is also provided on the substrate 1 side, and the opening / closing of the shutter on the substrate 1 side is controlled in synchronization with the opening / closing of the shutter 18 on the opposing targets 15 and 16. Good.

The substrate temperature is about 100 to 400 ° C., the pressure is about 0.1 to 2.0 Pa, and the flow rate of the atmospheric gas is 20 in total.
˜100 sccm, and when introducing the reactive gas, it may be about 1-20% of the whole.

The RF power of the power source 17 is 0.3 to
It may be about 3.0 kW, and when performing sputtering for forming the thin layer 3a of Ni or the like, the anode side may be grounded, and the thin layer 3b of the constituent element of the conductive fine particles 8 is formed. When performing reactive sputtering for this purpose, a negative bias voltage of about 500 V or less may be applied to the substrate side, if necessary.

Further, it is possible to perform sputtering and reactive sputtering alternately by using only the material of the cold cathode base material 4 as a target. For example, in the case of a combination such as TiC-Ti, as shown in FIG. 18, a rotary table on which the insulating substrate 1 is placed is placed opposite to a target 21 made of a cold cathode base material such as Ti, and sputtering and alternating sputtering are performed. Perform reactive sputtering.

At the time of performing the sputtering for forming the thin layer 3a of Ti or the like, only the inert gas G1 such as Ar is introduced and the reactive sputtering for forming the thin layer 3b of the constituent component of the conductive fine particles 8 is performed. When performing
An inert gas G1 such as the above and a reactive gas G2 such as a hydrocarbon may be introduced. The specific conditions are the same as above. In order to further prevent the generation of impurities such as amorphous carbon, as shown in FIG. 18, the shutters 25 and 26 provided on both the target 21 side and the substrate 1 side at the time of switching the atmosphere gas. It is preferable to open and close.

The thickness of the thin layer 3a, which is a constituent of the cold cathode substrate 4, is preferably about 1 to 100 nm, more preferably about 10 to 40 nm. With such a thickness, the cold cathode 10 having excellent dispersibility of the conductive fine particles 8 can be obtained. On the other hand, if the thickness is too thick, the amount of the conductive fine particles 8 dispersed will be small, and substantially the same characteristics as in the case of forming only the cold cathode base material 4 will be obtained, and if it is too thin, the dispersion of the conductive fine particles 8 will be obtained. Property deteriorates, and fine processing becomes difficult.

The thickness of the thin layer 3b which is a constituent of the conductive fine particles 8 is 0.5 nm to 50 nm (5 A to 500 A), preferably 1 nm to 10 nm (10 A to 100 A). With such a thickness, the cold cathode 10 having excellent dispersibility of the conductive fine particles 8 can be obtained. On the other hand, when the thickness is reduced, the nucleation of crystals that become conductive fine particles such as TiC is insufficient, so that impurities such as amorphous Ti and C mixed films are easily deposited, and even after heat treatment, TiC and the like are not deposited. The crystal volume ratio of the conductive fine particles does not improve so much. Also,
It is difficult to form thin layers with good reproducibility. On the other hand, if the thickness becomes too thick, a continuous film structure is formed, and the structure in which microcrystalline particles such as TiC are dispersedly contained in the cold cathode base material such as Ni cannot be obtained. Although heat treatment gives a structure in which fine crystal structure particles such as TiC are partially contained,
Since a substantially continuous film structure is maintained, it is difficult to etch the cold cathode conductor layer.

Further, the thickness ratio of the thin layer 3b and the thin layer 3a is about 1/99 to 1/2, preferably 1/50 to 1/3 for the thin layer 3b / thin layer 3a. preferable. Also,
The number of laminated layers may be about 5 to 30 layers, respectively, and the bottom layer may be a thin layer 3a composed of the constituent elements of the cold cathode substrate 4.

Since the thin layer 3b of TiC or the like at the time of film formation is thin, it has an island-like structure rather than a continuous structure in which the entire surface is covered with TiC or the like, and TiC and the like are amorphous. This is a so-called microcrystal state in which microcrystals are mixed. This can be confirmed by a cross-sectional TEM.

It is possible to obtain a thin layer 3b of the constituent components of the conductive fine particles 8 having good crystallinity depending on the sputtering conditions and the like, but normally, the above-mentioned heat treatment is performed on the cold cathode conductor layer 3 after film formation. Is preferred. By such heat treatment, the crystallinity of the conductive fine particle material such as TiC is improved, and the dispersibility of the conductive fine particles 8 is improved. The heat treatment method and conditions are the same as above. According to the cross-section TEM observation, the conductor layer 3 for cold cathode after the heat treatment has a structure in which the conductive fine particles 8 such as TiC are almost uniformly dispersed in the cold cathode substrate 4 such as Ni as shown in FIG. It has been confirmed that the particles have changed, and that each fine particle such as TiC is a crystal in the above particle size range. Further, the improvement of the crystallinity of the conductive fine particle material such as TiC can be confirmed by the X-ray diffraction analysis method.

The steps after forming the cold cathode conductor layer 3 in this manner are almost the same as those for manufacturing the one shown in FIG.

First, a resist 5 is provided on a portion corresponding to a cold cathode on a cold cathode conductor layer 3 composed of a cold cathode base material 4 such as Ni and conductive fine particles 8 such as TiC. The cold cathode conductor layer 3 is processed into the cold cathode 10 by wet etching using an etching solution such as nitric acid-phosphoric acid, and the insulating layer 2 is wet-etched with an etching solution such as BHF. At this time, the resist is left as it is and not removed. The structure formed by this process is shown in FIG. To process the cold cathode conductor layer 3 into the cold cathode 10, dry etching such as reactive ion etching (RIE) may be used instead of the above wet etching.

Further, as shown in FIG. 15, an insulating film 14a such as SiO ₂ having a predetermined thickness and a film 7a of a predetermined material having a predetermined thickness for the gate electrode are formed on the entire surface in this order by vapor deposition or the like. A film is formed and at the same time, a gate insulating layer 14b such as SiO ₂ is formed.
Then, the gate electrode 7b is formed.

In this case, unnecessary SiO is deposited on the resist 5.
_{Since there is} the insulating film 14a such as ₂ and the film 7a made of the same material as the unnecessary gate electrode such as Cr, the unnecessary Si
The insulating film 14a such as O ₂ and the unnecessary film 7a are applied to the resist 5
Is lifted off to manufacture the cold cathode electron source element shown in FIG. At this time, the structure of the cold cathode electron source element array is, for example, that shown in FIG.

The cold cathode electron source element of the present invention can have the structure shown in FIG. The cold cathode electron source element shown in FIG. 19 has the same structure as that shown in FIG. 10 except that the cold cathode 10 is directly arranged on the insulating substrate 1 without an insulating layer. is there.

The cold cathode electron source element described above has a so-called lateral emitter structure. Besides, in the present invention, a vertical emitter structure may be used. The vertical emitter can be a high-density element that has more elements per unit area than the horizontal emitter, and is relatively easy to apply to devices that require XY matrix wiring, such as flat panel displays. It can be realized by various processes.

The cold cathode electron source element shown in FIG. 20 has a cold cathode 40 and a gate electrode 7b surrounding the cold cathode 40. In the illustrated example, both the outer shape of the cold cathode 40 and the inner peripheral shape of the gate electrode 7b are shown. It is circular. Even with this structure, the present invention has an advantage that it is not necessary to finely process the emitter into a cone shape. This element is manufactured according to the steps of FIGS. First, as shown in FIG. 21, after the emitter wiring layer 32 is deposited on the glass substrate 1, it is processed into a predetermined wiring pattern by a conventional photolithography technique. Next, as shown in FIG. 22, a conductive spacer layer 36 is formed on the surface of the emitter wiring layer 32, and a cold cathode conductor layer 33 is further deposited by alternate sputtering. After that, the cold cathode conductor layer 33 is heat-treated. As a result, the material of the conductive fine particles in the conductor layer 33 for the cold cathode is the island-shaped structure 33 as shown in FIG.
The structure changes from b to the fine particle dispersion structure as shown in FIG. 23, and the conductive fine particles 38 are formed. At the same time, the cold cathode substrate 33a in the conductor layer 33 for cold cathode is changed to the cold cathode substrate 34 with increased crystallinity, and the conductor layer 40 for cold cathode in which the conductive fine particles 38 are dispersed in the cold cathode substrate 34 is formed. Will be formed.

After that, as shown in FIG. 24, a circular resist pattern 35 is formed on the surface of the cold cathode conductor layer 40 in a predetermined element region by a photolithography technique.
The cold cathode conductor layer 40 is etched. Then, the spacer layer 36 is processed by, for example, a dry etching method to form the structure shown in FIG. Furthermore, FIG.
As shown in FIG. 3, in order to form the gate insulating layer 14b and the gate electrode 7b, a film made of the same material as the gate insulating layer 14b and a film made of the same material as the gate electrode 7b are formed on the entire surface in this order by a vapor deposition method or the like. To do. Resist 35 here
Since the unnecessary film 14a and the film 7a are present on the upper side, they are immersed in a resist stripping solution to remove the resist and the unnecessary films 14a and 7a. As a result, the cold cathode electron source device shown in FIG. 20 is manufactured. After that,
The gate electrode layer 7b and the gate insulating layer 14b are photoetched to form a gate wiring pattern as shown in FIG. 26, for example.

The cold cathode element source element of the present invention is not limited to the above examples, but may be various kinds.

FIG. 2 shows an application example of the cold cathode electron source device of the present invention.
7 shows. FIG. 27 shows an example in which a cold cathode electron source element having a cold cathode 10 and a gate electrode 7b via a gate insulating layer 14b on an insulating substrate 1 is used as an electron source for a flat panel display. There is. As shown in the figure, by applying a voltage to the cold cathode 10 and the gate electrode 7b, an electric field is concentrated on the surface of the cold cathode 10 and electrons e are emitted. The electrons e reach the anode 30 carrying the fluorescent material layer 31 on the surface thereof in a state where the emission amount thereof is appropriately controlled by the action of the gate electrode 7b. Then, the fluorescent substance layer 31 emits light by the action of the electrons at this time. In addition, the cold cathode electron source element of the present invention can be applied to a high frequency amplifier, a switching element, and the like.

[0073]

EXAMPLES The present invention will be described in more detail below by showing specific examples of the present invention. Example 1 The cold cathode electron source element shown in FIG. 1 was manufactured according to the steps of FIGS. First, as shown in FIG. 2, the surface of the glass insulating substrate 1 (1.1 mm thick) was deposited insulating layer 2 of SiO ₂ to a thickness of 1μm by sputtering. Next, by the reactive ion plating method,
As shown in FIG. 3, TiC as the conductive fine particles 8
A thin film in which particles were finely dispersed in Ni as a cold cathode base material 4 was formed to a thickness of 0.3 μm to obtain a cold cathode 10.

In the reactive ion plating, the substrate temperature is 400 ° C., the Ni-50% Ti alloy is electron beam heated as a vapor deposition source, and C ₂ H ₂ gas is introduced as a C source at 0.11 Pa for ionization. Probe current is 2A, substrate-
The bias voltage between the hearths was 2 kV.

Next, as shown in FIG. 4, the cold cathode 10
After the resist 5 is provided thereon, the cold cathode 10 is patterned by a photo process as shown in FIG. 7, and wet etching is further performed using a nitric acid-phosphoric acid-based etching solution to form the insulating layer 2. Was wet-etched with BHF. At this time, the resist 5 on the cold cathode 10 was not removed as it was. Further, as shown in FIG. 5, the Cr film 6 and the C as the gate electrode 7 are formed on the entire surface.
The r film was formed to a thickness of 0.3 μm by the vapor deposition method. After that, as shown in FIG. 6, the resist 5 and the Cr film 6 were removed by a stripping solution.

Thus, the cold cathode electron source element of FIG. 1 was obtained. The distance d between the cold cathode 10 and the gate electrode is about 0.7.
μm. The average particle size of the TiC particles in the cold cathode is about 5 nm from the TiC (200) plane peak of XRD,
The average particle size of the primary particles from the TEM photograph was about 5 nm. The ratio of TiC particles to the Ni matrix was about 25% by volume. The work function of TiC is 3.53 eV, and the work function of Ni is 4.50 eV.

When the driving voltage for electron emission of this cold cathode electron source element was examined, electron emission was confirmed from around a gate voltage of 20 V, and the emission current fluctuation was 5% or less. In the case of the conventional cold cathode electron source device, the gate voltage is 8
Electron emission was confirmed from around 0 V, and emission current fluctuation was 20
Although it was about 40%, it means that the characteristics were greatly improved.

This is because TiC, which has a low work function and is not easily affected by an adsorbed gas or the like, was formed as the fine conductive fine particles 8, and that the cold cathode substrate which is a conductive matrix was used. Since the conductive fine particles 8 dispersedly contained in the material 4 and exposed or projected on the surface of the cold cathode substrate 4 can be formed at a high density, electron emission occurs from a low voltage and the electron emission amount increases. However, it is considered that the electron emission characteristics were averaged and stable electron emission characteristics could be obtained.

Further, since the conductive fine particles 8 themselves are chemically stable, it is difficult to perform a fine processing process such as etching. However, by etching the cold cathode substrate 4, the cold cathode electron source can be easily formed. An element can be formed.

At this time, the particle size of the conductive fine particles 8 is small,
Since it is in the exposed or projected state, it is not necessary to form the end portion of the cold cathode 10 particularly sharply, the manufacturing process is technically simplified, and the yield is also improved.

Example 2 After forming a SiO ₂ layer on a substrate in the same manner as in Example 1, T was added to Ni in the sputtering apparatus shown in FIG.
A thin film (0.3 μm thick) in which iC particles were finely dispersed was formed by the co-sputtering method. Simultaneous sputtering is a Ni target (thickness 3 mm, diameter 8 inches) 1
The Ti chip 12 was mounted on the No. 1 plate. 1 for Ti chip
Four pieces having a size of 0 mm × 10 mm × 1 mm were used. The degree of vacuum is 0.5 Pa, the atmosphere is ethylene gas (3 sccm) + argon gas (47 sccm), and the RF power of the power supply 13 is 1
The kW and substrate temperature were 200 ° C. At this time, a bias voltage of -200 V was applied to the anode side.

After forming the cold cathode conductor layer as described above,
As in the case of Example 1, a cold cathode was formed by photoprocess and wet etching with a phosphoric acid-nitric acid-based etching solution, and further SiO ₂ was wet-etched with a BHF etching solution. Further, a Cr film for a gate electrode was vapor-deposited to a thickness of 0.3 μm from the above under the condition of vertical incidence. Then, as in the case of Example 1, the resist and the unnecessary Cr film on the resist were removed by a stripping solution to obtain a cold cathode electron source element (FIG. 1). The distance between the cold cathode 10 and the gate electrode was the same as in Example 1. The average particle size of TiC particles in the cold cathode was about 1 nm from the result of XRD, and the average particle size of primary particles from the TEM photograph was about 1 nm. The ratio of TiC particles to the Ni matrix was 5% by volume.

Example 1 of this cold cathode electron source device
When the characteristics were examined in the same manner as in the above, in the case of the conventional cold cathode electron source element, electron emission was confirmed from around the gate voltage of 80 V, and the emission current fluctuation was about 20 to 40%.
In the case of the cold cathode electron source device, electron emission was confirmed from around a gate voltage of 40 V, and the emission current fluctuation was 5% or less.

This is because the work cathode has a low work function and can be formed of very chemically stable TiC which is not easily affected by the adsorbed gas or the like as fine conductive fine particles 8 and is a cold matrix substrate 4 which is a conductive matrix. Since the conductive fine particles 8 dispersedly contained and exposed or projected on the surface of the cold cathode substrate 4 can be formed at a high density, electron emission occurs from a low voltage, and the electron emission amount increases, It is considered that the electron emission characteristics were averaged and stable electron emission characteristics could be obtained. Further, since the conductive fine particles 8 themselves are chemically stable, it is difficult to perform a fine processing process such as etching. However, by etching the cold cathode base material 4, a cold cathode electron source element can be easily formed. it can. At this time, since the conductive fine particles 8 have a small particle size and are exposed or protruded, it is not necessary to form the end portion of the cold cathode 10 particularly sharply, and the manufacturing process is technically simplified. Therefore, the yield will be improved.

An element was manufactured in the same manner as the above element except that a TiC chip was used instead of the Ti chip. Further, a device was similarly prepared by using methane gas, propane gas, and acetylene gas instead of ethylene gas. All of these elements showed good characteristics as described above.

Example 3 As in Example 1, a SiO ₂ layer was formed on the substrate 1 (FIG. 2). Next, as shown in FIG. 9, using the sputtering apparatus of FIG. 8, a Ni—Ti—C-based amorphous alloy thin film (amorphous Ni-based alloy thin film containing TiC) for a cold cathode conductor layer 9 is formed. 0.3μ by reactive co-sputtering method
It was formed to a thickness of m. Simultaneous sputtering is performed by Ti tip 12 on Ni target (thickness 3 mm, diameter 8 inch) 11.
Was placed. Ti chip 12 has a size of 10 mm ×
Fifty pieces of 10 mm x 1 mm were used. Substrate temperature is room temperature (about 20 ° C.), pressure is 1 Pa, atmosphere is Ar gas and C
₂ H ₂ gas was introduced at a flow rate of 45 sccm and 5 sccm, respectively, and the RF power of the power source 13 was set to 1 kW.

Subsequently, the cold cathode conductor layer thin film was heat-treated. In this case, use a resistance heater
It was held at ℃ for 2 hours in vacuum. Then, in the same manner as in Example 1, a cold cathode electron source element as shown in FIG. 1 was obtained.

FIG. 28 shows the result of XRD (CuK α λ = 1.5418, filter: monochromator) before and after the heat treatment of the cold cathode conductor layer 9 in the above. As is clear from the results shown in FIG. 28, a halo showing an amorphous state is observed near 40 ° before the heat treatment, that is, after the formation of the cold cathode conductor layer. The halo near 25 ° indicates the glass of the substrate. On the other hand, after the heat treatment, X-ray diffraction peaks of TiC and Ni were observed. Therefore, it is considered that by performing the heat treatment, a cold cathode having a structure in which TiC particles as the conductive fine particles 8 are finely dispersed in Ni which is the cold cathode substrate 4 as shown in FIG. 3 is formed.

The distance d between the cold cathode 10 and the gate electrode in the above device was the same as in Example 1. The average particle size of TiC particles in the cold cathode was about 3 nm from the result of XRD, and the average particle size of primary particles was about 3 nm from the TEM photograph. The ratio of TiC particles to the Ni matrix was 25% by volume.

About this cold cathode electron source element, Example 1
When the characteristics of the conventional cold cathode electron source device were examined in the same manner as in 1., electron emission was confirmed from around the gate voltage of 80 V, and the emission current fluctuation was 20 to 40%. In the case of the source device, electron emission was confirmed from around a gate voltage of 30 V, and the emission current fluctuation was 5% or less. This is because TiC, which has a low work function and is not easily affected by an adsorption gas or the like, is formed as the fine conductive fine particles 8, and is dispersed and contained in the cold cathode base material 4. Further, since the conductive fine particles 8 exposed or projected on the surface of the cold cathode base material 4 which is a conductive matrix can be formed at a high density, electron emission occurs from a low voltage, and the electron emission amount increases, It is considered that the electron emission characteristics were averaged and stable electron emission characteristics could be obtained. Further, since the conductive fine particles 8 themselves are chemically stable, it is difficult to perform a fine processing process such as etching. However, by etching the cold cathode base material 4, a cold cathode electron source element can be easily formed. it can. At this time, since the conductive fine particles 8 have a small particle size and are exposed or protruded, it is not necessary to form the end portion of the cold cathode 10 particularly sharply, and the manufacturing process is technically simplified. Therefore, the yield will be improved.

Example 4 The cold cathode electron source element shown in FIG. 10 was manufactured according to the steps of FIGS. 11 to 15. First, as shown in FIG. 11, on the surface of the same glass insulating substrate 1 as in Example 1,
The SiO ₂ insulating layer 2 is formed to 200 by the sputtering method.
It was formed to a thickness of nm. Next, as shown in FIG.
Using the sputtering device shown in FIG.
The iC films were alternately laminated in this order to form a cold cathode conductor layer 3 composed of a Ni / TiC alternating deposition layer (FIG. 12). In this Ni / TiC alternate deposition sputtering, as shown in FIG. 17, using a Ni target 15 and a Ti target 16, the sputtering of a Ni film by argon and the reactive sputtering of Ti by argon and C ₂ H ₂ are alternately performed. Performed in a vacuum vessel.

In the case of Ni film, the target 15 has a thickness of 3 m.
m, 8 inches in diameter, Ni with a purity of 99.9% or more, substrate temperature 250 ° C., pressure 0.5 Pa, Ar gas flow rate 5
0 sccm, the RF power of the power source 14 was 1 kW, and the anode side was grounded to the ground, and each layer was deposited to a thickness of 30 nm.

In the case of the TiC film, the target 16 is made of Ti having a thickness of 3 mm and a diameter of 8 inches and a purity of 99.9% or more. The substrate temperature is 300 ° C., the pressure is 0.5 Pa, the Ar gas flow rate is 47 sccm, and the acetylene gas flow rate is. RF of 3sccm, power supply 17
A power of 1 kW and a bias voltage of -200 V were applied to the substrate side, and each layer was deposited to a thickness of 5 nm.

The control of the film thickness of the Ni film and the TiC film is as follows.
A single layer film of about 1 μm each was formed in advance under the same conditions as when forming the Ni film and the TiC film of the Ni / TiC alternating deposition layer, and the film formation rate was calculated in advance from the film thickness and the film formation time. , 30nm (Ni) and 5nm (TiC)
It was performed by calculating the film forming times corresponding to the above and setting the respective film forming times. Under the above conditions, 10 layers each of Ni and TiC are alternately laminated to form the Ni / Ti layer shown in FIG.
C alternating-deposit layer cold cathode conductor layer 3 (total thickness about 350 nm)
Was deposited.

After forming the cold cathode conductor layer 3 of the Ni / TiC alternating deposition layer, the cold cathode conductor layer 3 was heat-treated together with the substrate. The heat treatment was performed by holding in a vacuum at a treatment temperature of 500 ° C. for 2 hours using a resistance heater.

Next, a resist 5 is provided on a portion corresponding to the cold cathode on the conductor layer 3 for cold cathode in which the conductive fine particles 8 of TiC are dispersed in the cold cathode layer base material 4 of Ni, and then nitric acid-phosphoric acid system is used. The cold cathode conductor layer 3 was processed into the cold cathode 10 by wet etching using an etching solution, and the insulating layer 2 was further wet etched with a BHF etching solution. At this time, the resist was left as it was and not removed. The structure formed by this process is shown in FIG. Then, as shown in FIG. 15, a SiO ₂ film having a thickness of 500 nm and a Cr film having a thickness of 300 nm for the gate electrode are formed on the entire surface in this order by a vapor deposition method to form a gate insulating layer made of the SiO ₂ film. 14b,
A gate electrode 7b made of a Cr film was formed. In this case on top of the resist 5 there is unnecessary SiO ₂ film 14a and the unnecessary Cr film 7a, in this next, unwanted SiO ₂
The cold cathode electron source element shown in FIG. 10 was produced by lifting off the film 14a and the unnecessary Cr film 7a from the resist 5. FIG. 16 shows the structure of the cold cathode electron source element array.

In the above, the TEM observation of the cold cathode conductor layer 3 was performed after the film formation (before the heat treatment) and after the heat treatment.
Since the TiC thin layer during film formation is as thin as 5 nm,
It was found that the surface is not a structure in which TiC is entirely covered, but an island structure, and a state of so-called microcrystalline TiC in which amorphous and microcrystalline are mixed. On the other hand, after the heat treatment, T is contained in the Ni cold cathode substrate 4.
The iC conductive fine particles 8 were changed to a structure in which they were substantially uniformly dispersed, and each of the TiC fine particles was a single crystal having an average particle size of about 5 nm.

Such an improvement in crystallinity could be confirmed from the results of XRD. In addition, Ti calculated from the XRD results
The particle size of the C fine particles was about 5 nm. The distance d between the cold cathode 10 and the gate electrode in the above device was 0.4 μm. The ratio of TiC particles to the Ni matrix was about 15% by volume.

When the characteristics of this cold cathode electron source element were examined, in the case of the above cold cathode electron source element, electron emission was confirmed from around a gate voltage of 5 V, and the emission current fluctuation was 5
% Or less. Also, 40mA per 10,000 chips
It was possible to obtain a stable emission current for a long time. On the other hand, in the case of the conventional Mo cold cathode electron source element, electron emission was confirmed from around the gate voltage of 80 V, and the emission current fluctuation was 2
It was 0 to 40%. The maximum emission current obtained is 1
It was about 10 mA per 0000 chips.

This is because the conductive fine particles 8 have a low work function, are extremely chemically stable and are hardly affected by the adsorption gas, etc., and are dispersed and contained in the cold cathode substrate 4. In addition, since the conductive fine particles 8 exposed or projected on the surface of the cold cathode base material 4 can be formed at a high density, electron emission occurs from a low voltage, the electron emission amount increases, and the electron emission characteristic is improved. It is considered that stable electron emission characteristics were obtained by averaging. Further, since the conductive fine particles 8 themselves are chemically stable, it is difficult to perform a fine processing process such as etching. However, by etching the cold cathode base material 4, a cold cathode electron source element can be easily formed. it can. At this time, since the conductive fine particles 8 have a small particle size and are exposed or protruded, it is not necessary to form the end portion of the cold cathode 10 particularly sharply, and the manufacturing process is technically simplified. Therefore, the yield will be improved.

Example 5 Samples No. 1 and No. 2 were prepared in which the cold cathode conductor layer 3 of the cold cathode electron source element of Example 4 was processed as follows. First, in sample No. 1, Ni film (20 nm thick) and TiC
The film (10 nm thick) and 10 layers each were alternately laminated in this order. In this case, it was formed by using the same sputtering apparatus shown in FIG. 17 as in Example 4. The sputtering conditions and the like were the same as in Example 4.

Next, in the sample No. 2, the Ni film (20
(thickness: nm) and a TiC film (thickness: 5 nm) were alternately laminated in this order, 10 layers each. In this case, the sputtering apparatus shown in FIG. 17 was formed by using a double shutter system apparatus in which a shutter is also arranged on the substrate 1 side. Other sputtering conditions were the same as in Example 4.

X for the samples No. 1 and No. 2
The result of RD is shown in FIG.

From the results shown in FIG. 29, it is better to form a film by using a double-shutter type sputtering device.
It can be seen that the crystallinity of is improved. This is because the amorphous C with respect to the substrate 1 is better when the shutter is arranged also on the substrate 1 side.
It is considered that the accumulation of the like is suppressed.

Example 6 The cold cathode electron source element of Example 4 is the same as that shown in FIG. 19 except that the insulating layer of SiO ₂ is not interposed between the cold cathode 10 and the substrate 1. A cold cathode electron source device was obtained. The manufacturing method of this element was the same as in Example 4. For the conductor layer 3 for cold cathode, a glass substrate (trade name Corning # 7
059: manufactured by Corning Incorporated: 0.7 mm thick), a Ni film was formed directly on the NiC film, and a TiC film and a Ni film were alternately laminated. 11 layers of Ni film and TiC
The film has 10 layers, the Ni film has a thickness of 20 nm, and T
The thickness of the iC film was 5 nm. However, for the sputtering, a double shutter type device in which a shutter is also arranged on the substrate 1 side in FIG. 17 is used, and the TiC film has a substrate temperature of 300 ° C., a pressure of 0.5 Pa, an Ar gas flow rate of 46 sccm, an acetylene gas flow rate of 4 sccm, The RF power of the power source 17 was set to 1 kW, and the film was formed under the condition of grounding on the anode side. The Ni film is
A film was formed under the same conditions except that acetylene gas was not introduced.

After forming the cold cathode conductor layer 3 (total thickness: 270 nm) in this manner, the cold cathode conductor layer was heat-treated together with the substrate. The heat treatment was performed at 500 ° C. in a vacuum using a resistance heater, and this temperature was maintained for 1 hour.

Then, in the same manner as in Example 4, an element for cold cathode power supply was obtained. However, Mo was used as the material of the gate electrode.

In addition, TEM photographs after film formation (before heat treatment) and after heat treatment are shown in FIG. 30 (after film formation) and FIG. 31 (after heat treatment), respectively. These TEM photographs show Ni (40 nm) / TiC (5 nm) under the same conditions as the cold cathode conductor layer 3.
/ Ni (40 nm) laminated film (total thickness of about 85 nm) was obtained from the sample for TEM observation.

As is clear from these figures, TiC deposited in an island shape on polycrystalline Ni is shown in white before the heat treatment. TiC is a state of so-called microcrystalline TiC in which amorphous and microcrystalline are mixed. After the heat treatment, Ni was crystallized to some extent and the grain boundaries thereof were wide, and it is considered that TiC fine particles were present in the grain boundaries. As a result, the crystallinity and dispersibility of TiC are dramatically improved, and the conductor layer 3 for cold cathode after the heat treatment is performed.
Is considered to have changed to the structure shown in FIG.

FIG. 32 shows the results of XRD before and after heat treatment of the cold cathode conductor layer 3. From this, it can be seen that the peak strengths of Ni and TiC are increased by the heat treatment, which indicates that the crystallinity is improved.

The distance d between the cold cathode 10 and the gate electrode in the above device was 1.0 μm. Further, the average particle size of TiC particles in the cold cathode was about 5 nm from the result of XRD, and the average particle size of primary particles was about 5 nm from the TEM photograph. The ratio of TiC particles to the Ni matrix was about 20% by volume.

The characteristics of the above cold cathode power source element were examined. The results are shown in FIGS. 33 and 34. FIG. 33 is a graph showing the relationship between the gate voltage (Vg) and the emission current (Ie), and the emission current is per 100,000 chips. In addition, FIG. 34 shows Fowler-Nordhe
im) plot (F-N plot).

From these results, it was confirmed that the cold cathode power source device of the present invention emitted electrons at a gate voltage near 4V,
It can be seen that driving at low voltage is possible.

Example 7 A cold cathode electron source device of Example 6 was cooled in the same manner except that the cold cathode conductor layer 3 for forming the cold cathode 10 was an alternating laminated film of a Ti film and a TiC film. A cathode electron source element (see FIG. 19) was obtained. The cold cathode conductor layer 3 was formed using a sputtering apparatus in which a Ti target 21 (same as that in Example 4) shown in FIG. 18 was installed.
In this case, a Ti film (20 nm thick) is directly formed on the substrate 1,
Further, a TiC film (5 nm thick) was formed on this, and the number of layers was the same as in Example 6. The film forming conditions for the Ti film are those in Example 6.
According to the Ni film of Example 1, the TiC film was formed under the same conditions as in Example 6.

After forming the cold cathode conductor layer 3 (total thickness 270 nm) in this manner, the cold cathode conductor layer 3 was heat treated together with the substrate. The heat treatment was performed under the same conditions as in Example 6. Then, in the same manner as in Example 6, an element for cold cathode power supply was obtained. However, when the cold cathode conductor layer 3 was processed into the cold cathode 10, wet etching was not used, but reactive ion etching (RIE) was used. R at this time
The IE conditions were a pressure of 15 Pa, a CF ₄ flow rate of 40 sccm, an O ₂ flow rate of 10 sccm, an RF power of 500 W, and a substrate temperature of 30 ° C.

In the above, the cold cathode conductor layer 3 after the film formation (before the heat treatment) and after the heat treatment were respectively treated with T
EM observation and XRD measurement were performed. This result shows the same tendency as in Example 6, and it was found that the heat treatment improves the dispersibility and crystallinity of TiC. Therefore, it is considered that the cold cathode conductor layer 3 after the heat treatment has a structure as shown in FIG.

The distance d between the cold cathode 10 and the gate electrode in the above device was 0.7 μm. Further, the average particle size of TiC particles in the cold cathode was about 5 nm from the result of XRD, and the average particle size of primary particles was about 5 nm from the TEM photograph. The ratio of TiC particles to the Ti matrix was about 20% by volume. The work function of Ti is 3.
It is 95 eV.

Example 6 Regarding the Cold Cathode Power Supply Element
When the characteristics were examined in the same manner as in, good results similar to those in Example 6 were obtained.

Example 8 The cold cathode electron source element of Example 6 was cooled in the same manner as in Example 6, except that the cold cathode conductor layer 3 for forming the cold cathode 10 was an alternate laminated film of a Mo film and a TiC film. A cathode electron source element (see FIG. 19) was obtained. As the conductor layer 3 for cold cathode, an apparatus having the same configuration is used except that a Mo target (purity of Mo: 99.9% or more, size is the same) is installed in place of the Ni target in the sputtering apparatus used in Example 6. Formed. In this case, a Mo film (20 nm thick) was directly formed on the substrate 1, and a TiC film (5 nm thick) was further formed thereon, and the number of laminated layers was the same as in Example 6. The Mo film forming conditions are the same as those of the Ni film of Example 6, and the TiC film forming conditions are those of Example 6.
I went the same way.

In this way, after forming the cold cathode conductor layer 3 (total thickness 270 nm), the cold cathode conductor layer 3 was heat treated together with the substrate. The heat treatment was performed under the same conditions as in Example 6. Then, in the same manner as in Example 7, an element for cold cathode power supply was obtained.

In the above description, the cold cathode conductor layer 3 after the film formation (before the heat treatment) and after the heat treatment were respectively treated with T
EM observation and XRD measurement were performed. This result shows the same tendency as in Example 6, and it was found that the heat treatment improves the dispersibility and crystallinity of TiC. Therefore, it is considered that the cold cathode conductor layer 3 after the heat treatment has a structure as shown in FIG.

The distance d between the cold cathode 10 and the gate electrode in the above device was set to 0.7 μm. Further, the average particle size of TiC particles in the cold cathode was about 5 nm from the result of XRD, and the average particle size of primary particles was about 5 nm from the TEM photograph. The ratio of TiC particles to the Mo matrix was about 20% by volume. The work function of Mo is 4.
It is 3 eV.

Example 6 Regarding the Device for Cold Cathode Power Supply
When the characteristics were examined in the same manner as in, good results similar to those in Example 6 were obtained.

Example 9 The cold cathode electron source element shown in FIG. 20 was manufactured according to the steps of FIGS. First, as shown in 21,
Emitter wiring layer 32 on a 1.1 mm thick glass substrate
Was deposited to a thickness of 0.3 μm by a sputtering method, and then processed into a predetermined wiring pattern by a conventional photolithography technique.

Next, as shown in FIG. 22, as a spacer layer 36 and a cold cathode conductor layer 33, Mo (thickness: 200 nm) and Ni / T were formed on the surface of the emitter wiring layer 32.
aC was deposited by sputtering. In order to deposit the spacer layer 36 and the cold cathode conductor layer 33, a double shutter type sputtering apparatus as shown in FIG. 18 is used, and targets of Mo, Ni and Ta are arranged in the same vacuum container. It was formed continuously. Each of Mo, Ni, and Ta targets having a purity of 99.9% or more, a thickness of 3 mm, and a diameter of 8 inches was used.

The film formation conditions for Mo are as follows: substrate temperature 300 ° C., Ar
The gas flow rate was 50 sccm, the pressure was 0.5 Pa, the RF power of the power supply 17 was 1 kW, and the anode side was grounded. In the case of the Ni / TaC film, the Ni film (20 nm thick) and the TaC film (5 nm thick) were formed by the alternate lamination method similar to that in Example 6.
(Thickness) and 11 layers and 10 layers were alternately laminated in this order. The film forming conditions are the same as in Example 6 except that the Ti target is changed to the Ta target.

After forming the cold cathode conductor layer 33 (total thickness: 270 nm) in this manner, the cold cathode conductor layer was heat-treated together with the substrate. The heat treatment was performed at 500 ° C. in a vacuum using a resistance heater and held at this temperature for 1 hour. As a result of the heat treatment, TaC in the conductor layer for the cold cathode is shown in FIG.
The island-shaped structure 33b as shown in FIG. 2 changes to the fine particle dispersed structure as shown in FIG.

In the above, TEM observation and XRD measurement were performed on the cold cathode conductor layers 33 and 40 after the film formation (before the heat treatment) and after the heat treatment, respectively. This result showed a tendency similar to that of the Ni / TiC alternating deposition layer. By the heat treatment, the particle size of the TaC crystal particles became 5 nm, which was almost the same as the layer thickness, and it was found that the dispersibility and crystallinity were improved.

After that, as shown in FIG. 24, a circular resist pattern 35 having a diameter of 1 μm was formed on the surface of the cold cathode conductor layer 40 in a predetermined element region by a photolithography technique. Further, the heat-treated conductor layer 40 for cold cathode was etched using a nitric acid-phosphoric acid-based etchant. Next, the spacer layer 36 was processed by a dry etching method using a CF ₄ + O ₂ mixed gas to form the structure shown in FIG.

Then, as shown in FIG. 25, the gate insulating layer 14b (600 nm thick) and the gate electrode 7b (2
SiO ₂ and Cr were deposited on the entire surface in this order by a vapor deposition method in order to form a film having a thickness of 00 nm). Here, since the unnecessary SiO ₂ film 14a and the Cr film 7a are present on the resist 35, the resist and the unnecessary SiO ₂ film 14a and the Cr film 7a are removed by immersing the resist 35 in the resist stripping solution, as shown in FIG. The cold cathode electron source device shown was obtained. After that, the gate electrode layer 7b and the gate insulating layer 14b were photoetched to form a gate wiring pattern as shown in FIG. In addition, T in the cold cathode 40
The ratio of the aC particles to the Ni matrix was about 20% by volume. The work function of TaC is 3.93 eV.

When the characteristics of this cold cathode electron source device were examined in the same manner as in Example 6, the same good results as in Example 6 were obtained.

In addition, in Examples 6 to 9, Mo-T
When cold cathodes were similarly formed by combining various materials such as iN and Cr-LaB ₆ , and the characteristics were examined in the same manner, the same result was obtained.

[0133]

According to the present invention, since electrons can be drawn out at a low voltage, a high emission current can be obtained, and driving by an integrated circuit (IC), thin film transistor (TFT) or the like is possible, and high performance of the device can be obtained. In addition to achieving low power consumption and low power consumption, the cold cathode substrate can be processed by ordinary photoprocess and etching, and any shape can be set easily.
It is possible to provide a cold cathode electron source element capable of increasing the area of the element.

Preferably, since the particles of the conductive material are dispersed on the surface of the cold cathode in a state of projecting or being exposed, electrons can be drawn out at a low voltage due to the concentration of an electric field, and a high emission current can be obtained. An electron source element can be provided.

More preferably, by reducing the average particle size of the particles of the conductive material, it is possible to provide a cold cathode electron source element which can obtain a high emission current and exhibit stable emission current characteristics.

Further, in the method of forming the cold cathode by heat treatment, the workability of the cold cathode conductor layer by etching is improved, so that the productivity can be improved.

In the case of heat treatment, since the crystallinity of the conductive material is further enhanced, it is possible to provide a cold cathode electron source element which can extract electrons at a low voltage and has stable emission current characteristics.

Further, when the cold cathode is formed by the alternate layering method, the particle size of the particles of the conductive material can be controlled by the film thickness of the thin layer of the component constituting the particles of the conductive material, so that the electron extraction is performed. As a result of being able to control the voltage to be low, it is possible to obtain a cold cathode electron source device that has an electron extraction voltage that is one digit or more lower than conventional ones, and that has a stable and high emission current.

Further, the thickness of the thin layer of the component constituting the particles of the conductive material is set within a predetermined range so that the thin layer of the component constituting the particles of the conductive material is not in the continuous film structure but in the island structure. Then, it becomes possible to form a structure in which the particles of the conductive material are substantially dispersed in the cold cathode substrate. Therefore, it becomes possible to easily etch the cold cathode base material by an etchant of the material of the cold cathode base material, and to make the protruding or exposed structure of the conductive material particles uniform in the etched cross section. Since it can be formed with good reproducibility, it is possible to manufacture a cold cathode electron source element that can be driven at a low voltage and can stably obtain a high emission current with a high yield.

When the cold cathode conductor layer is further heat-treated, the crystal grain size of the particles of the cold cathode base material and the conductive material is increased, and the particles of the conductive material incorporated as impurities in the cold cathode base material are removed. The components that make up the cold cathode base material that are incorporated as impurities in the constituent components and the particles of the conductive material are precipitated at the crystal grain boundaries, and the dispersibility of the particles of the conductive material in the cold cathode base material is substantially improved. Increase. Therefore, when forming the cold cathode base material by etching, the etching rate by chemical etching can be increased. Further, since the average particle diameter of the particles of the conductive material is approximately the same as the thickness of the thin layer of the components constituting the particles of the conductive material, a cold cathode electron source device having uniform electron emission characteristics over a wide area is formed. be able to.

[Brief description of drawings]

FIG. 1 is a partially enlarged perspective view showing an example of a cold cathode electron source element of the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

FIG. 3 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

FIG. 4 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

FIG. 5 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

FIG. 6 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

7 is a plan view showing an example of patterning of the cold cathode electron source element of FIG. 1. FIG.

FIG. 8 is a schematic configuration diagram showing an example of a simultaneous sputtering apparatus used in the present invention.

FIG. 9 is a cross-sectional view showing a manufacturing process when the cold cathode of the cold cathode electron source element of FIG. 1 is formed by heat treatment.

FIG. 10 is a cross-sectional view showing another example of the cold cathode electron source element according to the present invention.

11 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

12 is a cross-sectional view showing the manufacturing process of the cold cathode electron source element of FIG.

13 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

14 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

15 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG.

16 is a plan view showing an example of the cold cathode electron source element array of FIG.

FIG. 17 is a schematic configuration diagram showing an example of a multi-source sputtering apparatus used in the present invention.

FIG. 18 is a schematic configuration diagram showing an example of a double shutter type sputtering apparatus used in the present invention.

FIG. 19 is a partially enlarged perspective view showing still another example of the cold cathode electron source element according to the present invention.

FIG. 20 is a cut end view showing still another example of the cold cathode electron source element according to the present invention.

FIG. 21 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG. 20.

22 is a cross-sectional view showing the manufacturing process of the cold cathode electron source element of FIG. 20. FIG.

23 is a cross-sectional view showing the manufacturing process of the cold cathode electron source element of FIG. 20. FIG.

FIG. 24 is a cross-sectional view showing the manufacturing process of the cold cathode electron source element of FIG. 20.

FIG. 25 is a cross-sectional view showing a manufacturing process of the cold cathode electron source element of FIG. 20.

FIG. 26 is a plan view showing an example of a gate wiring pattern of the cold cathode electron source element of FIG.

FIG. 27 is a cross-sectional view showing an example of application of a cold cathode electron source element of the present invention.

FIG. 28 is a diagram showing an X-ray diffraction result of the conductor layer for cold cathode after the film formation and the heat treatment in the present invention.

FIG. 29 is a view showing a comparison of X-ray diffraction results of the conductor layers for cold cathode in the present invention.

FIG. 30 shows T of the cold cathode conductor layer after film formation in the present invention.
It is an EM photograph.

FIG. 31 is a TEM photograph of a conductor layer for cold cathode after heat treatment in the present invention.

FIG. 32 is a view showing an X-ray diffraction result of the cold cathode conductor layer after the film formation and the heat treatment in the present invention.

FIG. 33 is a graph showing the relationship between the gate voltage and the emission current of the cold cathode electron source element according to the present invention.

FIG. 34 is a graph showing an FN plot of the cold cathode electron source device according to the present invention.

FIG. 35 is a partial perspective view showing an example of a conventional electron source.

FIG. 36 is a partial perspective view showing another example of a conventional electron source.

FIG. 37 is a partial perspective view showing still another example of the conventional electron source.

FIG. 38 is a partial perspective view showing still another example of the conventional electron source.

FIG. 39 is a partial cross-sectional view showing still another example of the conventional electron source.

FIG. 40 is a sectional view showing still another example of a conventional electron source.

[Explanation of symbols]

1 Insulating substrate 2 insulating layers 4,34 Cold cathode base material 7,7b Gate electrode 8, 38 Conductive material particles (conductive fine particles) 3, 9, 33 Cold cathode conductor layer 10, 40 cold cathode 14b Gate insulating layer

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-274043 (JP, A) JP-A-2-220337 (JP, A) Actual Kaihei 4-131846 (JP, U) Special Tables 5- 500585 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 1/304 H01J 9/02 JISST file (JOIS)

Claims (10)

(57) [Claims] 1. A cold cathode electron source device having a cold cathode, wherein the cold cathode is dispersed and contained in a cold cathode base material and has a work function of the work of the cold cathode base material. And a particle of a conductive material having a particle size lower than the function and smaller than the thickness of the cold cathode, the particles being substantially separated from each other and dispersed on the cold cathode surface. The average particle size of the particles is 0.05 to 5 as determined by X-ray diffraction.
A cold cathode electron source device having a particle size of 0 nm and containing 1 to 50% by volume of the particles with respect to the cold cathode substrate. 2. The cold cathode electron source element according to claim 1, wherein the cold cathode is obtained by depositing a component of the cold cathode base material and a component of the conductive material by a vapor phase method. 3. A cold cathode electron source device having a cold cathode, wherein the cold cathode is dispersed and contained in a cold cathode base material and has a work function of the work of the cold cathode base material. And a particle of a conductive material having a particle size lower than the function and smaller than the thickness of the cold cathode, the particles being substantially separated from each other and dispersed on the cold cathode surface. It is exposed and has an average particle size of 0.05 to 5 determined from X-ray diffraction of the particles.
A cold cathode electron source device having a thickness of 0 nm, which is obtained by depositing a component forming the cold cathode substrate and a component of the conductive material by a reactive ion plating method or a co-sputtering method to obtain a cold cathode electron source element. Production method. 4. The particles are 1 to the cold cathode substrate.
The method for manufacturing a cold cathode electron source element according to claim 3, wherein the content is 50% by volume. 5. The method for manufacturing a cold cathode electron source element according to claim 3, wherein the particles are projected on the surface of the cold cathode. 6. A cold cathode electron source device having a cold cathode, wherein the cold cathode is dispersed and contained in a cold cathode base material and has a work function of the work of the cold cathode base material. And a particle of a conductive material having a particle size lower than the function and smaller than the thickness of the cold cathode, the particles being substantially separated from each other and dispersed on the cold cathode surface. In obtaining the exposed cold cathode electron source element, the cold cathode, a step of forming an amorphous or microcrystalline cold cathode conductor layer by a vapor phase method, and heat treatment to the cold cathode conductor layer A method of manufacturing a cold cathode electron source element, which is manufactured by the step of applying. 7. The temperature of the heat treatment is 700 to film formation temperature.
The method for manufacturing a cold cathode electron source element according to claim 6, wherein the temperature is up to ° C. 8. A cold cathode electron source device having a cold cathode, the cold cathode being dispersedly contained in a cold cathode base material, and having a work function of the work of the cold cathode base material. And a particle of a conductive material having a particle size lower than the function and smaller than the thickness of the cold cathode, the particles being substantially separated from each other and dispersed on the cold cathode surface. It is exposed and has an average particle size of 0.05 to 5 determined from X-ray diffraction of the particles.
It is 0 nm, and a thin layer of a component forming the cold cathode base material and a thin layer of a component forming the particles of the conductive material are alternately laminated to form a conductor layer for a cold cathode by a vapor phase method. A method of manufacturing a cold cathode electron source element manufactured by performing the method. 9. The method for manufacturing a cold cathode electron source element according to claim 8, wherein the thin layer of the component constituting the particles of the conductive material has a thickness of 0.5 nm to 50 nm. 10. After forming the cold cathode conductor layer,
The method for producing a cold cathode electron source element according to claim 9, wherein the cold cathode conductor layer is heat-treated at a temperature from the film forming temperature of the cold cathode conductor layer to 700 ° C.