JPH11144605A - Electron emitting element, electron source, image forming device, and manufacture of electron emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron emitting element with small changes in the electron emission characteristics. SOLUTION: A conductive film 4 is connected to a couple of electrodes on a substrate 1 and has a gap 10 in a part thereof. A member 21 which is mainly made of carbon and is installed in the gap to be connected to the conductive film is provided, and a metal oxide 6 containing at least one element of nickel, iron, and cobalt is provided between the member 21 and the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron-emitting device, an electron source and an image forming apparatus using the same, and a method of manufacturing the electron-emitting device.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction type electron emission element.

As an example of the FE type, WPDyke & W.W.Dola
n, “Field emission”, Advance in Electron Physics, 8,
89 (1956) or CASpindt, “Physical Properties
of thin-film field emission cathodes with molybde
nium cones ", J. Appl. Phys., 47, 5248 (1976).

As examples of the MIM type, CAMead, “Oper
ation of Tunnel-Emission Devices ", J. Apply.Phys.32,
646 (1961) and the like are known.

As an example of the surface conduction electron-emitting device, M.
I. Elinson, Radio Eng. Electron Phys., 10, 1290, (196
5) and so on.

[0006] The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al., A device using an Au thin film [G. Ditmmer, Thin Solid Films, 9, 317 (1972)], In ₂
O ₃ / SnO ₂ by thin film [M.Hartwell and CGF
onsted, IEEE Trans. ED Conf., 519 (1975)], using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, 2]
2 (1983)].

As a typical device configuration of these surface conduction electron-emitting devices, the above-mentioned M.D. FIG. 19 shows an element configuration of the Hartwell. In FIG. 1, reference numeral 1 denotes an insulating substrate.
Reference numeral 4 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and the electron emission portion 5 is formed by an energization process called forming, which will be described later. Incidentally, the device electrode interval L in the figure is 0.5 to 1 mm, W '
Is set at 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, before the electron emission, the electron-emitting portion 5 is generally formed by applying a current to the conductive thin film 4 by a process called forming. That is, forming means applying a DC voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 4 and energizing the conductive thin film 4 to locally destroy, deform or alter the conductive thin film, thereby increasing the electrical conductivity. This is to form the electron-emitting portion 5 in a resistance state. In the electron emitting portion 5, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface conduction type electron-emitting device that has been subjected to the forming treatment is configured to apply a voltage to the above-described conductive thin film 4 and cause a current to flow through the device, thereby causing the above-described electron-emitting portion 5 to emit electrons.

On the other hand, in another surface conduction electron-emitting device as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-235255, a process called an activation process may be applied to the device after forming. . The activation process is
In this step, the element current If and the emission current Ie change significantly.

[0010] The activation step can be performed by repeatedly applying a pulse voltage to the element in an atmosphere containing an organic substance, as in the forming process. With this process,
From the organic substance present in the atmosphere, carbon or a carbon compound is deposited on at least the electron-emitting portion of the device, and the device current If and the emission current Ie are significantly changed, so that better electron-emitting characteristics can be obtained.

An image forming apparatus can be constructed by using an electron source substrate on which a plurality of electron emitting elements as described above are formed and combining it with an image forming member made of a phosphor or the like.

[0012]

However, with the rapid progress of multimedia with the advancement of information in recent years, higher performance is required for image forming apparatuses such as displays. That is, the screen size of the display device is increased, the power consumption is reduced, the definition is increased, the image quality is increased, and the space is saved.

Therefore, in the above-mentioned electron-emitting device, the electron-emitting device to which the electron-emitting device is applied can maintain stable electron emission characteristics with higher efficiency and longer time so that a bright display image can be stably provided. Technology that can be continued is desired.

Here, the efficiency refers to a current (hereinafter, referred to as a device current If) which flows into a vacuum when a voltage is applied to a pair of opposed device electrodes of the surface conduction electron-emitting device. , Emission current Ie).

That is, it is desirable that the device current If be as small as possible and the emission current Ie be as large as possible.

If high-efficiency electron emission characteristics can be stably controlled over a long period of time, for example, in an image forming apparatus using a phosphor as an image forming member, a low-power and bright high-quality image forming apparatus such as a flat TV can be realized.

However, the above-mentioned M.P. In the case of Hartwell's electron-emitting devices, satisfactory electron-emitting characteristics and electron-emitting efficiencies have not always been obtained. The fact is that it is extremely difficult to provide

In other words, for use in such applications, a sufficient emission current Ie can be obtained at a practical voltage (for example, 10 V to 20 V), and the emission current Ie and the device current If do not fluctuate significantly during driving. It is required that the emission current Ie and the device current If do not deteriorate for a long time. The surface conduction electron-emitting device of Hartwell has the following problems.

As shown in FIG. The surface conduction type electron-emitting device of the Hartwell has an electron-emitting portion 5 substantially perpendicular to the voltage application direction.

An object of the present invention is to provide an electron-emitting device having good electron-emitting characteristics and an electron source using the same, and to provide a high-brightness image forming apparatus using the electron-emitting device. It is in.

Another object of the present invention is to provide an electron-emitting device in which the change in electron-emitting characteristics is as small as possible and an electron source using the same, and to provide high brightness using the electron-emitting device for a longer time. An object of the present invention is to provide an image forming apparatus that can be maintained for a long time.

[0022]

The electron-emitting device according to the present invention is characterized in that a pair of electrodes, a conductive film connected to the pair of electrodes and having a gap in a part thereof, are formed on a substrate. A member having carbon as a main component, provided between the portion and the conductive film, and at least one of nickel, iron, and cobalt between the member having carbon as a main component and the substrate. And a metal oxide containing an element.

The metal oxide is preferably at least one oxide selected from the group consisting of nickel oxide, iron oxide, and cobalt oxide. The metal oxide is provided, for example, as a coating on the substrate, and Also includes a fine particle film or an island film. Further, the coating is made of nickel oxide,
It may be a film in which at least one metal oxide of iron oxide and cobalt oxide is contained in a base material mainly composed of silica or the like.

Another feature of the electron-emitting device of the present invention is that a pair of electrodes, a conductive film connected to the pair of electrodes and having a gap in a part thereof, A carbon-containing member provided in connection with the conductive film and having a layered orientation substantially parallel to the substrate surface.

Further, it is preferable that the electron-emitting device is a surface conduction electron-emitting device.

The method of manufacturing an electron-emitting device according to the present invention is characterized in that a metal oxide containing at least one element of nickel, iron and cobalt provided between a pair of electrodes on a substrate is used. A step of forming a conductive film on the containing film, and a step of forming a gap in a part of the conductive film;
Forming a member mainly composed of carbon connected to the conductive film in the gap.

The step of forming a gap in the conductive film is preferably performed by applying a voltage to the conductive film, and a member containing carbon as a main component is provided in the gap. The forming step is preferably performed by applying a voltage to the conductive film in an atmosphere in which a carbon compound is present.

Further, the coating containing the metal oxide is
It may be formed before the formation of the pair of electrodes on the base, or after forming the pair of electrodes on the base,
It may be formed between the pair of electrodes.

Preferably, the coating containing the metal oxide is formed by applying a solution of an organic metal compound containing at least one element of nickel, iron and cobalt to form an organic metal compound film. And a step of heating and baking the organometallic compound film. The step of forming the organometallic compound film includes spin coating,
An aerocoat method, a dipping method, a printing method, an inkjet method, or the like can be used. Further, the formation of the coating containing the metal oxide may be performed by a step of forming a coating containing at least one metal of nickel, iron and cobalt, and a step of oxidizing the coating.

Further, the present invention includes an image forming apparatus such as an electron source and a display device.

The electron source according to the present invention is an electron source that emits electrons in response to an input signal, and includes a plurality of the above-described electron-emitting devices arranged on a substrate. Have multiple rows of electron-emitting devices with
Further, it is characterized by having a modulating means. More preferably, a plurality of electron-emitting devices in which a pair of electrodes of the electron-emitting devices are connected to m X-directional wires and n Y-directional wires that are electrically insulated from each other are arranged on the substrate. It is characterized by the following.

An image forming apparatus according to the present invention is an apparatus for forming an image based on an input signal, and is characterized by comprising at least an image forming member and the above-mentioned electron source.

According to the present invention, an electron-emitting device capable of maintaining stable electron-emitting characteristics for a long time can be realized.

Further, according to the present invention, a stable and good image can be formed for a long time.

In the electron-emitting device according to the present invention, the electron-emitting portion is near the gap of the conductive film. Here, the gap portion is formed so as to bisect the conductive film, but also includes a case where the conductive film is partially connected.

Hereinafter, preferred embodiments of the present invention will be described.

First, the basic configuration of the surface conduction electron-emitting device according to the present invention will be described.

FIGS. 1 (a) and 1 (b) are a plan view and a sectional view, respectively, showing the structure of a basic plane type surface conduction electron-emitting device according to the present invention. FIG. 2 (a),
3B is a plan view and a cross-sectional view schematically showing an enlarged structure near an electron emission portion of the surface conduction electron-emitting device according to the present invention. The basic structure of the device according to the present invention will be described with reference to FIGS.

In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, 5 is an electron emitting portion, and 6 is a metal oxide film.

In FIG. 2, 1 is a substrate, 4 is a conductive thin film, 5 is an electron emitting portion, 6 is a metal oxide film, 10 is a gap formed in the conductive thin film, and 21 is a deposition mainly composed of carbon. The object 22 is a narrower gap formed in a part of the deposit 21.

Examples of the substrate 1 include quartz glass, glass having a reduced impurity content such as Na, blue plate glass, a glass substrate obtained by laminating SiO ₂ formed on a blue plate glass by sputtering or the like, and ceramics such as alumina. .

The material of the opposing element electrodes 2 and 3 may be any material as long as it has conductivity. For example, Ni, Cr, Au, Mo, W, Pt,
Metals or alloys such as Ti, Al, Cu, Pd and Pd, A
g, Au, printed conductors composed of RuO _2, metal or metal oxide such as Pd-Ag and glass, etc., In ₂ O ₃ -S
Examples include a transparent conductor such as nO ₂ and a semiconductor conductor material such as polysilicon.

The element electrode interval L, the element electrode length W, the shape of the conductive thin film 4 and the like are appropriately designed depending on the application form of the element, and for example, in a display device such as a television described later, it corresponds to the screen size. In particular, high-definition televisions require a small pixel size and high definition. Therefore, in order to obtain a sufficient luminance even when the size of the electron-emitting device is limited, it is designed so that a sufficient emission current is obtained.

The distance L between the device electrodes is from several tens nm to several hundred μm.
Yes, photolithography technology that is the basis of the method for manufacturing device electrodes, that is, the performance of the exposure machine and the etching method,
And is set by the voltage applied between the device electrodes,
Preferably, it is from several μm to several tens μm.

The element electrode length W and the film thickness d of the element electrodes 2 and 3 are appropriately determined depending on the resistance value of the electrodes, the connection with the X and Y wirings described above, and the arrangement of a large number of electron sources. It is designed, and usually, the length W of the device electrode is several μm to several hundred μm.
m, and the film thickness d of the device electrodes 2 and 3 is several μm to several μm
m.

In addition to the structure shown in FIG.
The metal oxide film 6, the conductive thin film 4, and the opposing device electrodes 2, 3 in this order.
3, a metal oxide film 6, and a conductive thin film 4 may be laminated in this order.

As the conductive thin film 4, a fine particle film composed of fine particles is preferably used in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of step coverage for the device electrodes 2 and 3, a resistance value between the device electrodes 2 and 3, a forming condition described later, and the like.

In general, the thermal stability of the conductive thin film 4 may dominate the life of the electron emission characteristics, and it is desirable to use a material having a higher melting point as the material of the conductive thin film 4. However, in general, the higher the melting point of the conductive thin film 4 is, the more difficult it is to carry out the energization forming, which will be described later.

Further, an applied voltage (threshold voltage) at which electrons can be emitted depends on the shape of the resulting electron emitting portion.
In some cases, a problem occurs in the electron emission characteristics such as an increase in

In the present invention, the material of the conductive thin film 4 is not particularly required to be a material having a high melting point, and a material / form capable of forming a good electron-emitting portion with a relatively low forming power is selected. Can be.

Examples of materials satisfying the above conditions include Ni,
Preferably, a conductive material such as Au, PdO, Pd, or Pt is formed to have a film thickness having an Rs (sheet resistance) of 10 ² to 10 ⁷ Ω / □. Rs is a value that appears when a resistance R measured in the length direction of a thin film having a thickness t, a width w, and a length 1 is R = Rs (l / w). Then, Rs = ρ / t. The film thickness showing the above-mentioned resistance value is in the range of about 5 nm to 50 nm, and in this film thickness range, the thin film of each material has the form of a fine particle film.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure in a state in which the fine particles are individually dispersed and arranged or in a state in which the fine particles are adjacent to each other or overlap each other (some fine particles are formed). To form an island-like structure as a whole).

The particle size of the fine particles is in the range of several hundred pm to several hundred nm, preferably in the range of 1 nm to 20 nm.

Now, among the materials exemplified above, Pd
O can easily form a thin film by sintering an organic Pd compound in the air, has relatively low electric conductivity because of being a semiconductor, has a wide process margin of film thickness for obtaining the resistance value Rs in the above range, and has an electron emitting portion. Since the metal Pd can be easily reduced after formation or the like, it is a preferable material because the film resistance can be reduced. However, the effects of the present invention are not limited to PdO, and are not limited to the materials exemplified above.

The electron-emitting portion 5 is a high-resistance portion including a gap portion 10 formed in a part of the conductive thin film 4. After passing through an activation step described later, as shown in FIG. Is composed of the deposit 21 mainly composed of Also sediment 2
1 has a gap portion 22 which is narrower than the gap portion 10 formed in the conductive thin film. The gap 22 may also be partially connected.

The deposit 21 mainly composed of carbon is
It is mainly made of graphite-like carbon, but may contain some or all of the elements constituting the conductive thin film 4 and the metal oxide film 6.

The deposit 21 mainly composed of carbon constituting the electron emitting portion 5 is in contact with the metal oxide film 6 formed on the surface of the substrate 1 inside the gap 10 of the conductive thin film 4. In the present invention, the nickel, cobalt and iron elements contained in the metal oxide film 6 exert a catalytic action during the carbon deposition process from the organic substance in the activation step, which will be described in detail later. Graphite-like carbon with good crystallinity oriented in a layered manner with respect to 6 easily deposits.

The metal oxide film 6 is not limited to an oxide of a single metal element selected from nickel oxide, cobalt oxide and iron oxide, but also includes a mixture of these oxides or a plurality of these metal elements. It may be a composite oxide.

According to the present invention, as described above, nickel, cobalt, and iron, which have a catalytic effect on carbon deposition, are disposed at the interface where the electron-emitting portion 5 contacts the substrate. Various forms can be used as the metal oxide film 6.

FIG. 4 shows an example of the form of the metal oxide film 6 which can be preferably used in the present invention.
FIG. 4A shows a case where a continuous film is used as the metal oxide film 6, and FIG. 4B shows a case where a fine particle film or an island film is used.

When heat is applied to the metal oxide film 6 in a state of contact with carbon in a vacuum, the metal oxide film 6 may be reduced to metal.

When the continuous film shown in FIG.
The metal generated by the reduction of the oxide may form a conductive path immediately below the electron-emitting portion 5 in some cases. In such a case, if a voltage is applied between the device electrodes, a leak current flows excessively as the device current If, and the electron emission efficiency is significantly reduced, which is not preferable.

If the vapor pressure of the metal generated by the reduction is high, the metal atoms are desorbed in vacuum (as a result, as shown in FIGS. 3C and 3D, the metal oxide film 6). A groove 7 is formed in the conductive path. This does not cause a problem because the conductive path is not formed. However, when the vapor pressure of the generated metal is low, the metal oxide film 6 is formed by converting the metal oxide into an insulating material such as silica. A mixed oxide mixed with the base material can be preferably used.

On the other hand, as shown in FIG. 4B, when a finely dispersed film or island-like film is used as the metal oxide film 6, the above-described leakage current can be avoided even when reduction occurs. can do. In general, a discretely dispersed fine particle film or island-like film has a larger electrical resistance than a continuous film because there is a space between fine particles or between islands. In particular, when the coverage of the fine particle film, that is, “the area occupied by the fine particles in the film / (the area occupied by the fine particles in the film + the area of the space between the fine particles)” is reduced to about 50% or less, the resistance of the film becomes an index. Since the particle size increases functionally, even if the fine particles constituting the fine particle film are conductive, such a fine particle film effectively becomes an insulating film. Therefore, in the present invention, the film thickness may be considered to be approximately the particle size of the fine particles, but is from several hundred pm to several tens of nm, and the coverage of the fine particle film covering the substrate surface may be set to about 50% or less. .

As described above, the metal oxide film 6 can be preferably used in the form of a continuous film, a fine particle film or an island film, and is used as a mixed film with other oxides or as a composite oxide. be able to.

In general, these oxides are formed on the substrate 1 by using a physical vapor deposition technique such as sputtering. However, as a simpler method, a solution of an organometallic compound is spin-coated, aerodynamically coated. A chemical method of applying an oxide film by coating, dipping, printing, or the like, and drying / baking can be used.

It is to be noted that a film of a metal of nickel, cobalt or iron may be formed in advance by the above-described method, and then heated and fired in an atmosphere containing oxygen to form an oxide.

As described above, according to the present invention, since the deposit in the gap of the conductive thin film constituting the electron emitting portion 5 is made of graphite-like carbon having good orientation and crystallinity, the conductivity and the stability are improved. And stable electron emission characteristics can be obtained for a long time.

Next, a vertical surface conduction electron-emitting device, which is another surface conduction electron-emitting device according to the present invention, will be described.

FIG. 5 is a schematic view showing the structure of a basic vertical surface conduction electron-emitting device.

In FIG. 5, components having the same reference numerals as those in FIG. 1 are the same. 41 is a step formation part. The substrate 1, the device electrodes 2 and 3, the conductive thin film 4, the electron-emitting portion 5, and the metal oxide film 6 are made of the same material as that of the above-mentioned flat surface-conduction type electron-emitting device. Forming part 41
Is S formed by vacuum deposition, printing, sputtering, etc.
The step forming portion 41 is made of an insulating material such as iO _{2, and} the film thickness of the step forming portion 41 corresponds to the device electrode interval L of the flat surface conduction electron-emitting device described above. It is set according to the manufacturing method of the step forming portion, the voltage applied between the device electrodes, and the electric field strength capable of emitting electrons, but is preferably in the range of several tens nm to several μm.

Further, the step forming portion 41 is formed with the metal oxide film 6.
Oxides similar to those described above, that is, oxides of a single metal element selected from nickel oxide, cobalt oxide, and iron oxide, or composite oxides containing a plurality of these metal elements, and insulating materials such as silica. It can also be formed of a mixed oxide with the body. In this case, since the step forming portion 41 itself can be regarded as the metal oxide film 6, it is needless to say that the effects of the present invention can be obtained without forming the metal oxide film 6 again.

The conductive thin film 4 is formed after the formation of the step portion 41, the metal oxide film 6, and the device electrodes 2 and 3, and thus is stacked on the device electrodes 2 and 3. Although the electron emitting portion 5 is shown in a straight line in the step forming portion 41 in FIG. 5, the shape and the position are not limited to this, depending on manufacturing conditions, energization forming conditions and the like.

Various methods are conceivable as a method for manufacturing the electron-emitting device having the electron-emitting portion 5, one example of which is shown in FIG.

Hereinafter, the manufacturing method will be described in order with reference to FIG.
A description will be given based on FIG. 2 and FIG.

1) After sufficiently washing the substrate 1 with a detergent, pure water and an organic solvent, a metal oxide film 6 is formed by a sputtering method or the like (FIG. 6A). The method of forming the metal oxide film 6 is not limited to the sputtering method, and may be formed by an organic metal-based coating material such as another vacuum evaporation method, an electron beam evaporation method, or a CVD method. Alternatively, the metal oxide film 6 can be formed by forming a metal film in advance and then oxidizing the metal film.

2) Subsequently, after the device electrode material is deposited on the substrate 1 on which the metal oxide film 6 has been formed by a vacuum evaporation method, a sputtering method or the like, the device electrodes 2 and 3 are formed by the photolithography technique (FIG. 6 (b)).

3) An organic metal solution is applied and dried between the element electrodes 2 and 3 provided on the insulating substrate 1 on which the metal oxide film 6 is formed, thereby forming an organic metal film. Form. In addition, the organic metal solution is the P
This is a solution of an organometallic compound containing a metal such as d, Ni, Au, or Pt as a main element. Thereafter, the organic metal film is heated and baked, and is patterned by lift-off, etching, or the like to form the conductive thin film 4 (FIG. 6C). Here, the method of applying the organic metal solution has been described. However, the present invention is not limited to this, and a vacuum evaporation method, a sputtering method, a CVD method, or the like.
It may be formed by a method, a dispersion coating method, a dipping method, a spinner method, an ink jet method, or the like.

4) Subsequently, when an energizing process called forming is performed by applying a pulsed voltage or a rising voltage between the device electrodes 2 and 3 by a power supply (not shown), the structure of the conductive thin film 4 is formed. Is formed (FIG. 6D). The conductive thin film 4 is locally destroyed, deformed or deteriorated by the energization treatment, and a portion where the structure is changed (high-resistance portion) is referred to as a gap 10. In this portion, the metal oxide film 6 is partially exposed.

The electrical processing after the forming processing is performed in the measurement and evaluation apparatus shown in FIG. The measurement evaluation device will be described below.

FIG. 7 is a schematic configuration diagram of a measurement and evaluation apparatus for measuring the electron emission characteristics of the device having the configuration shown in FIG. In FIG. 7, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, 5 is an electron emitting portion, and 6 is a metal oxide film. Reference numeral 61 denotes a power supply for applying the element voltage Vf to the element, and 60 denotes a conductive thin film 4 between the element power supplies 2 and 3.
An ammeter for measuring a device current If flowing through the device; 64, an anode electrode for capturing an emission current Ie emitted from an electron emission portion of the device; 63, a high-voltage power supply for applying a voltage to the anode electrode 64; 62 is an electron emitting portion 5 of the device.
This is an ammeter for measuring the emission current Ie emitted from the device.

In measuring the device current If and the emission current Ie of the electron-emitting device, the device currents 2 and 3 are supplied with a power supply 61.
And an ammeter 60, and an anode electrode 64 connected to a power supply 63 and an ammeter 62 is disposed above the electron-emitting device. Further, the electron-emitting device and the anode electrode 64 are installed in a vacuum device, and the vacuum device is provided with devices necessary for a vacuum device such as an exhaust pump (not shown) and a vacuum gauge. Can be measured and evaluated. The exhaust pump is a normal high vacuum system such as a turbo pump or a rotary pump, or a high vacuum system such as a magnetic levitation turbo pump or a dry pump that does not use oil, and an ultra high vacuum system including an ion pump. System. The entire vacuum device and the electron-emitting device can be heated by a heater (not shown).

The voltage of the anode electrode is set to 1 kV to 10 kV.
kV, the distance H between the anode electrode and the electron-emitting device is 2 mm
It was measured in a range of ８8 mm.

In the forming process, there are a case where a pulse having a constant pulse peak value is applied and a case where a voltage pulse is applied while increasing the pulse peak value. First, FIG. 8A shows a voltage waveform in a case where a pulse having a pulse peak value of a constant voltage is applied.

In FIG. 8A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec to 10 m.
sec and T2 are set to 10 μsec to 100 msec, and the peak value of the triangular wave (peak voltage at the time of forming) is appropriately selected.

Next, FIG. 8B shows a voltage waveform when a voltage pulse is applied while increasing the pulse peak value.

In FIG. 8B, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec to 10 m.
sec, T2 is set to 10 μsec to 100 msec, and the peak value of the triangular wave (peak voltage at the time of forming) is increased by, for example, about 0.1 V step.

The forming process ends when the conductive thin film 2 is locally destroyed during the forming pulse.
A voltage that does not deform, for example, a pulse voltage of about 0.1 V is inserted, and the element current is measured to obtain a resistance value.
When the resistance was 1 MΩ or more, the forming was terminated.

When forming the gap described above, the forming process is performed by applying a triangular wave pulse between the electrodes of the device, but the waveform applied between the electrodes of the device is not limited to the triangular wave. A desired waveform such as a rectangular wave may be used, and the peak value, pulse width, pulse interval, and the like are not limited to the values described above. Select an appropriate value according to the above.

5) Next, an activation process is performed on the element for which the forming has been completed. The activation process is performed in an atmosphere containing an organic substance. This atmosphere uses an organic substance remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump. In addition, it can be obtained by introducing an appropriate organic substance into a vacuum once sufficiently evacuated by an ion pump or the like. The preferable pressure of the organic substance at this time differs depending on the above-described application form, the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set according to the case.

Suitable organic substances include alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, nitriles, phenols, carboxyls, sulfonic acids and the like. Organic acids and the like, specifically, methane, ethane, propane such as saturated hydrocarbon represented by C _n H _{2n +2} , ethylene, propylene represented by a composition formula such as C _n H _2n Unsaturated hydrocarbons, benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine,
Ethylamine, phenol, benzonitrile, acetonitrile, formic acid, acetic acid, propionic acid and the like can be used.

By this treatment, carbon is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie change remarkably.

In the present invention, since the metal oxide film 6 is partially exposed at a portion where the conductive thin film 4 is locally broken and deformed by the forming process (that is, the gap portion 10), carbon is removed from the organic substance. During the deposition process, the metal oxide film 6 is catalyzed by the metal elements contained in the metal oxide film 6, that is, iron, cobalt, and nickel.

Therefore, the deposition rate of carbon, that is, the time required for activation is faster than that of other non-catalytic oxide surfaces (eg, silica), and the carbon deposited in the gaps is oriented and crystalline. Has an excellent graphite shape.

The orientation of the deposited carbon is a layer orientation substantially parallel to the surface shape of the metal oxide film 6, but when the surface shape of the metal oxide film 6 is parallel to the substrate surface (FIG. a)), the carbon is more preferably oriented substantially parallel to the substrate surface.

Note that the termination of the activation step is appropriately performed while measuring the device current If and / or the emission current Ie. The pulse width, pulse interval, pulse crest value, and the like can be set as appropriate.

Graphite-like carbon in the present invention refers to those having a complete graphite crystal structure (so-called HOPG), those having crystal grains of about 20 nm and a slightly disordered crystal structure (PG), and those of about 2 nm. Includes those in which the disorder of the crystal structure is further increased (GC), but those containing carbon of 0.35 nm or less (0.335 nm in perfect graphite) as a graphite layer interval are preferable. That is, it can be preferably used even if there is a layer disorder such as a grain boundary between graphite particles.

Although the mechanism of carbon deposition in the surface conduction electron-emitting device according to the present invention is not necessarily clear, a layer parallel to the metal oxide film 6 as a result of the catalytic action of the metal element in the deposition process. Graphitic carbon which is oriented with a structure and has good crystallinity is formed. Since carbon having good orientation and crystallinity is a material having excellent electrical conductivity and thermal stability, it is considered that the electron-emitting device according to the present invention can exhibit stable electron-emitting characteristics for a long time. .

The thickness of the graphite-like carbon is:
The range is preferably 50 nm or less, and more preferably 30 nm or less.

6) In the electron-emitting device thus manufactured,
Preferably, a stabilization step is performed. This step is a step of exhausting the organic substance in the vacuum container. The pressure in the vacuum vessel is preferably 1-3 × 10 ⁻⁷ Torr or less, and more preferably 1 × 1 ⁻⁷ Torr.
^0-8 Torr or less is particularly preferred. It is preferable to use a vacuum exhaust device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum exhaust device such as a sorption pump and an ion pump can be used. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. The heating condition at this time is desirably 80 to 350 ° C., preferably 200 ° C. or more, and it is desirable to perform the heating for as long as possible. However, the heating condition is not particularly limited to this condition. This is performed under conditions appropriately selected according to various conditions.

The atmosphere at the time of driving after performing the stabilization step is preferably the same as the atmosphere at the end of the stabilization treatment, but is not limited to this, as long as the organic substances are sufficiently removed. However, even if the pressure itself slightly increases, sufficiently stable characteristics can be maintained.

By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed.
As a result, the element current If and the emission current Ie are stabilized.

The basic characteristics of the electron-emitting device manufactured by the above-described manufacturing method and to which the present invention can be applied will be described with reference to FIGS.

FIG. 9 shows a typical example of the emission current Ie, the device current If, and the device voltage Vf measured by the measurement and evaluation apparatus shown in FIG. In FIG. 9, since the emission current Ie is significantly smaller than the device current If, the emission current Ie is shown in an arbitrary unit, and each is a linear scale. As is clear from FIG. 9, the electron-emitting device has three properties with respect to the emission current Ie.

First, when an element voltage higher than a certain voltage (called a threshold voltage, Vth in FIG. 9) is applied to the present element, the emission current Ie rapidly increases, while the threshold voltage Vth
At a smaller device voltage, the emission current Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Second, since the emission current Ie depends on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf.

Thirdly, the amount of charge discharged to the anode electrode 64 depends on the time during which the device voltage Vf is applied. That is, the amount of charge captured by the anode electrode 64 can be controlled by the time during which the device voltage Vf is applied.

In FIG. 9, an example in which the element current If monotonically increases with respect to the element voltage Vf (referred to as MI characteristic) is shown by a solid line. The element current If may exhibit a voltage control type negative resistance characteristic (referred to as VCNR characteristic) with respect to the element voltage Vf (not shown). These characteristics can be controlled by controlling the aforementioned steps.

When the characteristics of the surface conduction electron-emitting device described above are used, the electron emission characteristics can be easily controlled in accordance with an input signal. Further, since the electron-emitting device according to the present invention has stable and high-luminance electron emission characteristics for a long time, application to various fields can be expected.

An application example of the electron-emitting device to which the present invention can be applied will be described below.

By arranging a plurality of surface conduction electron-emitting devices according to the present invention on a substrate, for example, an electron source or an image forming apparatus can be constructed.

For the arrangement of the elements on the substrate, for example,
A large number of electron-emitting devices are arranged in parallel, and both ends of each device are connected by wiring. A large number of electron-emitting device rows are arranged (referred to as a row direction). ), A control electrode (called a grid) installed in a space above the electron source to control and drive the electrons (called a ladder type), and n An example is an arrangement in which the Y-directional wiring is disposed via an interlayer insulating layer, and the X-directional wiring and the Y-directional wiring are connected to a pair of device electrodes of the surface conduction electron-emitting device, respectively. Hereinafter, this is referred to as a simple matrix arrangement.

First, the simple matrix arrangement will be described in detail.

According to the characteristics of the above-mentioned three basic characteristics of the surface conduction electron-emitting device according to the present invention, the emission device from the surface conduction electron-emitting device has a threshold voltage higher than the threshold voltage. It can be controlled by the peak value and width of the pulse voltage applied between them. On the other hand, if it is lower than the threshold voltage, almost no emission occurs. According to this characteristic, even when a large number of electron-emitting devices are arranged, if the pulse-like voltage is appropriately applied to each of the devices, the surface-conduction electron-emitting device is selected according to an input signal, and the electron is selected. The amount of release can be controlled.

Hereinafter, the structure of the electron source substrate formed based on this principle will be described with reference to FIG.

The m X-direction wirings 92 are DX1, DX2,.
., DXm, on the substrate 1, a vacuum deposition method, a printing method,
The material, film thickness, wiring width, and the like are designed so that a substantially uniform voltage is supplied to a large number of surface conduction electron-emitting devices by using a conductive metal formed in a desired pattern and formed by a sputtering method or the like. You. An interlayer insulating layer (not shown) is provided between the m X-directional wirings 92 and the n Y-directional wirings 93, and is electrically separated to form a matrix wiring. Positive integer).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The entire area of the substrate 91 on which the X-directional wiring 92 is formed is partially formed in a desired shape. In particular, the X-direction wiring 92 and the Y-direction wiring 9
The film thickness, material, and manufacturing method are appropriately set so as to withstand the potential difference at the intersection of No. 3. The X-direction wiring 92 and the Y-direction wiring 93 are led out as external terminals.

[0118] Immediately below the surface conduction electron-emitting device 94, an oxide of a single metal element selected from nickel oxide, cobalt oxide, and iron oxide, or a composite oxide containing a plurality of these metal elements is used. Is formed on the insulating substrate 1 or the interlayer insulating layer (not shown) so that the above-mentioned film exists.

Further, in the same manner as described above, the opposing electrodes (not shown) of the surface conduction electron-emitting device 94 have m X electrodes.
The directional wiring 92 (DX1, DX2,..., DXm) and the n Y-directional wirings 93 (DY1, DY2,..., DYn) are electrically connected to each other by a connection 95 made of a conductive metal or the like. Things.

Here, m X-directional wires 92 and n Y wires
Some or all of the constituent elements of the conductive metal of the element electrode facing the directional wiring 93 and the connection 95 may be the same or different. These materials are appropriately selected, for example, from the above-described materials for the device electrodes.

As will be described in detail later, a scanning signal for scanning a row of the surface conduction electron-emitting devices 94 arranged in the X direction in accordance with an input signal is applied to the X-direction wiring 92. Is electrically connected to a scanning signal applying means (not shown) for the purpose of illustration, while the Y direction wiring 93 is used to modulate each column of the surface conduction electron-emitting devices 94 arranged in the Y direction according to an input signal. Is electrically connected to a modulation signal generating means (not shown) for applying the above modulation signal.

Further, a driving voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element.

Next, an electron source using the electron source substrate manufactured as described above and an image forming apparatus used for display and the like will be described with reference to FIGS. FIG.
Is a basic configuration diagram of the image forming apparatus, and FIG. 12 is a fluorescent film.

In FIG. 11, reference numeral 91 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 101, a rear plate on which the electron source substrate 91 is fixed; 106, a fluorescent film 104 and a metal back 105 formed on the inner surface of a glass substrate 103; This is the finished face plate. A support frame 102 includes a rear plate 101, a support frame 102, and a face plate 106.
Is coated with frit glass and baked at 400 to 500 ° C. for 10 minutes or more in the air or nitrogen to seal, thereby forming the envelope 108.

In FIG. 11, reference numeral 94 corresponds to the surface conduction electron-emitting portion shown in FIG. 1 or FIG. 92,
Reference numeral 93 denotes an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device. Further, the wiring to these device electrodes may be referred to as a device electrode when the material of the device electrode and the wiring material are the same.

As described above, the envelope 108 includes the face plate 106, the support frame 102, and the rear plate 101. Since the rear plate 101 is provided mainly for the purpose of reinforcing the strength of the substrate 91, In the case where the substrate itself has sufficient strength, the separate rear plate 101 is unnecessary, and the support frame 102 is directly sealed to the substrate 91, and the envelope 108 is enclosed by the face plate 106, the support frame 102, and the substrate 91.
May be configured.

On the other hand, by installing a support (not shown) called a spacer between the face plate 106 and the rear plate 101, the envelope 108 having sufficient strength against atmospheric pressure can be formed. .

FIG. 12 shows a fluorescent film. Fluorescent film 104
Is composed of only a phosphor in the case of monochrome, but is composed of a black conductive material 111 called a black stripe or a black matrix and a phosphor 112 depending on the arrangement of the phosphor in the case of a color phosphor film. The purpose of providing the black stripe and black matrix is
The color separation between the phosphors 112 of the three primary color phosphors required for color display is made black so that color mixing and the like are not noticeable, and a decrease in contrast due to reflection of external light on the phosphor film 104 is suppressed. It is in. The material of the black stripe is not limited to the commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection.

As a method of applying the phosphor on the glass substrate 103, a precipitation method, a printing method, or the like is used regardless of monochrome or color.

Further, a metal back 105 is usually provided on the inner surface side of the fluorescent film 104. The purpose of metal back is
The face plate 1 emits light toward the inner surface side of the phosphor emission.
To improve the brightness by specular reflection toward the 06 side, to act as an electrode for applying the electron beam acceleration voltage, to protect the phosphor from damage due to the collision of negative ions generated in the envelope, etc. is there. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after producing the phosphor film, and then depositing Al by vacuum evaporation or the like.

The face plate 106 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 104 in order to further increase the conductivity of the fluorescent film 104.

When the above-mentioned sealing is performed, in the case of color, since the phosphors of each color must correspond to the electron-emitting devices, sufficient alignment is performed.

The envelope 108 is passed through an exhaust pipe (not shown)
After reducing the degree of vacuum to about 1 × 10 ⁻⁷ Torr, sealing is performed. Further, a getter process may be performed to maintain the degree of vacuum after sealing the envelope 108. This is because the envelope 108 is heated immediately before or after the envelope 108 is sealed by a heating method such as resistance heating or high-frequency heating.
This is a process of heating a getter disposed at a predetermined position (not shown) in the inside to form a deposited film. Getter is usually Ba
Are the main components, and maintain a vacuum degree of, for example, 1 × 10 ^{−5 to} 1 × 10 ⁻⁷ Torr by the adsorption action of the deposited film.

In the image display device of the present invention completed as described above, each of the electron-emitting devices emits electrons by applying a voltage through the external terminals Dox1 to Doxm to Doyn, and emits electrons through the high-voltage terminal 107. An image is displayed by applying a high voltage of several kV or more to the electrode 105 or a transparent electrode (not shown), accelerating the electron beam, causing the electron beam to collide with the fluorescent film 104, and exciting and emitting light.

Next, as shown in FIGS. 20 and 21, a large number of electron-emitting devices arranged in parallel are connected at both ends, and a large number of electron-emitting devices are arranged (referred to as a row direction).
A ladder-like arrangement in which electrons from the electron-emitting devices are controlled and driven by a control electrode (also called a grid) disposed above the electron-emitting devices in a direction (called a column direction) orthogonal to the wiring will be described. .

The ladder-type electron source and the image forming apparatus will be described below with reference to FIGS. 20 and 21.

FIG. 20 is a schematic view showing an example of a ladder-type electron source. In FIG. 20, reference numeral 210 denotes an electron source substrate, and 211 denotes an electron-emitting device. 212, Dx1 to Dxm
Is a common wiring for connecting the electron-emitting devices 211. The plurality of electron-emitting devices 211 are arranged on the substrate 210 in parallel in the X direction (this is called an element row). A plurality of the element rows are arranged to constitute an electron source. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to an element row that wants to emit an electron beam, and a voltage equal to or lower than the electron emission threshold is applied to an element row that does not emit an electron beam. As for the common wirings Dx2 to Dx9 between the element rows, for example, Dx2 and Dx3 can be the same wiring.

FIG. 21 is a schematic diagram showing an example of a panel structure in an image forming apparatus having a ladder-type electron source. 220 is a grid electrode, 221 is a hole through which electrons pass, and 222 is an external terminal made of Dox1, Dox2,..., Doxm. Reference numeral 223 denotes an external terminal made of G1, G2,..., Gn connected to the grid electrode 220;
Reference numeral 224 denotes an electron source substrate in which the common wiring between the element rows is the same wiring. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 11 is whether or not the grid electrode 220 is provided between the electron source substrate 210 and the face plate 186.

In FIG. 21, a grid electrode 220 is provided between a substrate 210 and a face plate 186. The grid electrode 220 is used to modulate the electron beam emitted from the surface conduction electron-emitting device, and to allow the electron beam to pass through a stripe-shaped electrode provided orthogonally to the ladder-shaped element row. , One circular opening 221 is provided for each element. The shape and installation position of the grid are not limited to those shown in FIG. For example, a large number of passage openings may be provided in the form of a mesh as openings, and a grid may be provided around or near the surface conduction electron-emitting device.

The outer container terminal 222 and grid outer terminal 223 are electrically connected to a control circuit (not shown).

In the image forming apparatus of this embodiment, a modulation signal for one line of an image is simultaneously applied to the grid electrode rows in synchronization with sequentially driving (scanning) the element rows one by one. This makes it possible to control the irradiation of each electron beam to the phosphor and display an image one line at a time.

The configuration described above is a schematic configuration required for manufacturing a suitable image forming apparatus used for display and the like, and detailed portions such as materials of each member are limited to the above-described contents. Instead, it is appropriately selected so as to be suitable for the purpose of the image device.

Next, an example of the configuration of a drive circuit for performing television display based on NTSC television signals on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG. .

FIG. 13 is a block diagram showing an example of a driving circuit for performing display in accordance with an NTSC television signal. In FIG. 13, reference numeral 121 denotes a display panel, 122 denotes a scanning signal generation circuit, and 123 denotes timing. Control circuit, 124
Is a shift register. 125 is a line memory, 12
6 is a synchronization signal separation circuit, 127 is a modulation signal generation circuit,
x and Va are DC voltage sources.

The display panel 121 has terminals Dox1 to Dox
m, terminals Doy1 to Doyn, and a high voltage terminal Hv are connected to an external electric circuit. Terminals Dox1 to Doxm are used to sequentially drive electron sources provided in the display panel, that is, a group of surface-conduction electron-emitting devices arranged in a matrix of m rows and n columns in a matrix (row by row). Are applied. To the terminals Dox1 to Doyn, a modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting device in one row selected by the scanning signal is applied. The high-voltage terminal Hv is supplied with a DC voltage of, for example, 10 kV from a DC voltage source Va, which applies sufficient energy to an electron beam emitted from the surface conduction electron-emitting device to excite the phosphor. This is the accelerating voltage to perform.

The scanning signal generating circuit 122 has m switching elements inside (in the drawing, S1 to Sm are schematically shown). Each switching element selects either the output voltage of the DC voltage source Vx or 0 V (ground level), and is electrically connected to the terminals Dox1 to Doxm of the display panel 121. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 123, and can be configured by combining switching elements such as FETs, for example.

In the case of the present embodiment, the DC voltage source Vx uses a drive voltage applied to an element that is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting device. It is set to output a constant voltage that is equal to or lower than the voltage.

The timing control circuit 123 has a function of matching the operation of each section so that an appropriate display is performed based on an externally input image signal. The timing control circuit 123 generates Tscan, Tsft, and Tmry control signals for each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 126.

The synchronizing signal separation circuit 126 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC system television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 126 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience. The DATA signal is input to the shift register 124.

The shift register 124 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and converts the control signal Tsft sent from the timing control circuit 123. (Ie, it can be said that the control signal Tsft is a shift clock of the shift register 124). The data for one line of the image subjected to the serial / parallel conversion (corresponding to drive data for N electron-emitting devices) is output from the shift register 124 as N parallel signals Id1 to Idn.

A line memory 125 is a storage device for storing data for one line of an image for a necessary time only, and a control signal T sent from a timing control circuit 123.
The contents of Id1 to Idn are stored as appropriate according to mry. The stored contents are output as I'd1 to I'dn and input to the modulation signal generator 127.

The modulation signal generator 127 outputs the image data I '
The signal source is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of d1 to I'dn, and its output signal is supplied to the display panel 121 through terminals Doy1 to Doyn.
Is applied to the surface conduction type electron-emitting device in the inside.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie. That is, electron emission has a clear threshold voltage Vth, and electron emission occurs only when a voltage equal to or higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device. From this, when a pulse-like voltage is applied to this element, for example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold is applied, the electron beam is emitted. Is output. At this time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. In addition, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw. Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method of modulating the electron-emitting device according to the input signal.

In implementing the voltage modulation method, the modulation signal generator 127 generates a voltage pulse of a fixed length, and modulates the peak value of the pulse appropriately according to input data. A circuit can be used.

In implementing the pulse width modulation method,
As the modulation signal generator 127, a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data can be used.

The shift register 124 and the line memory 12
5 can be a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is required to convert the output signal DATA of the synchronization signal separation circuit 126 into a digital signal.
An A / D converter may be provided at the output unit 26. In this connection, the circuit used for the modulation signal generator 127 is slightly different depending on whether the output signal of the line memory 125 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 127
For example, a D / A conversion circuit is used, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 127 includes, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. (Comparator) is used. If necessary, an amplifier for amplifying the voltage of the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, for example, an amplification circuit using an operational amplifier or the like can be used as the modulation signal generator 127, and a level shift circuit or the like can be added as necessary. In the case of the pulse width modulation method, for example, a voltage-controlled oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the drive voltage of the surface conduction electron-emitting device can be added as necessary.

In the image display apparatus to which the present invention can be applied, which has such a configuration, by applying a voltage to each of the electron-emitting devices via the external terminals Dox1 to Doxm and Doy1 to Doyn, the electron-emitting device can emit electrons. Occurs. High voltage terminal Hv
A high voltage is applied to the metal back 105 or a transparent electrode (not shown) through the above to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 104 and emit light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. As for the input signal, the NTSC system has been described, but the input signal is not limited to this, and the PAL, SECAM system, etc.
A TV signal composed of a large number of scanning lines (for example,
A high-definition TV system such as the MUSE system can also be adopted.

The image forming apparatus of the present invention can be used not only as a display device for a television broadcast, a display device such as a video conference system or a computer, but also as an image forming device as an optical printer using a photosensitive drum or the like. Can be used.

[0162]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

[Embodiment 1] The basic structure of a surface conduction electron-emitting device according to this embodiment is shown in FIGS.
Are the same as the plan view and the sectional view of FIG. 2 and the enlarged plan view and the sectional view of FIGS.

The method for manufacturing the surface conduction electron-emitting device according to this embodiment is basically the same as that shown in FIG. Less than,
The basic configuration and manufacturing method of the element according to the present embodiment will be described with reference to FIGS.

Hereinafter, the manufacturing method will be described in order with reference to FIG.
A description will be given based on FIG. 2 and FIG.

(Step-a) First, nickel was evaporated on the cleaned quartz substrate 1 by an electron beam evaporation method.
At this time, the film thickness was monitored using a quartz oscillator, and 1 n
The film was formed under the condition of a film thickness of m. Observation of this film with a scanning electron microscope revealed that the film was an island-like film as shown in FIG. 4B in which fine particles having a particle diameter of about 2 nm were dispersed at a coverage of about 40 to 50%. Although an attempt was made to measure the sheet resistance Rs of this film using an apparatus capable of measuring up to 1 MΩ / □, measurement was impossible, and it was found that the film had a sheet resistance of at least 1 MΩ / □.

Next, the substrate 1 on which the nickel fine particle film was formed was baked in air at 500 ° C. for 30 minutes, oxidized, and observed with a scanning electron microscope. Had. As a precautionary measure, the sheet resistance Rs of this film was measured, but it was again impossible to measure, and it was found that the film had a sheet resistance of at least 1 MΩ / □.

Thus, the metal oxide film 6 in the form of a fine particle film was formed on the substrate 1 (FIG. 6A).

On the other hand, in order to clarify the effect of the present invention, on a quartz substrate on which the metal oxide film 6 is not formed,
Thereafter, a surface conduction electron-emitting device was manufactured through the same steps as in this example, and was used as a reference example.

(Step-b) On the substrate 1 on which the metal oxide film 6 has been formed, a pattern to be a gap L between the device electrodes 2 and 3 and a desired device electrode is formed by photoresist (RD-200).
0N manufactured by Hitachi Chemical Co., Ltd.), and 5 nm thick Ti and 100 nm thick Ni were sequentially deposited by electron beam evaporation. Dissolve the photoresist pattern with an organic solvent,
The i / Ti deposited film is lifted off, and the element electrode interval L is 3 μm.
m, the device electrodes 2 and 3 having the device electrode width W of 300 μm were formed (FIG. 6B).

(Step-c) A 100-nm-thick Cr film was
Deposited by vacuum evaporation, corresponding to the shape of the conductive thin film described later
Pattern so as to have an opening, and an organic
Radium compound solution (ccp4230 Okuno Pharmaceutical Co., Ltd.)
) Is spin-coated with a spinner at 300 ° C for 12 minutes
Was heated and baked. Also, the oxidation thus formed
The thickness of the conductive thin film 4 mainly composed of palladium fine particles is 1
0 nm, sheet resistance Rs is 2 × 10 ^FourΩ / □.
In addition, as described above, the fine particle film described here
This is a film in which fine particles of the above are aggregated.

(Step-d) The Cr film and the baked conductive thin film 4 were etched with an acid etchant to form a conductive thin film 4 having a desired pattern (FIG. 6C).

Through the above steps, a metal oxide film 6, device electrodes 2 and 3, and a conductive thin film 4 were formed on the substrate 1.

(Step-e) Next, the device is set in the measurement and evaluation apparatus shown in FIG. 7, evacuated by a vacuum pump, and after reaching a degree of vacuum of 1 × 10 ⁻⁸ Torr, an element voltage Vf is applied to the element. A voltage is applied between the device electrodes 2 and 3 of the device from a power source 61 for
A forming process was performed. The voltage waveform of the forming process is as shown in FIG.

In FIG. 8B, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and in this embodiment, T1 is 1 ms.
ec and T2 are 10 msec, and the peak value of the rectangular wave is 0.
The voltage was raised in steps of 1 V, and a forming process was performed.
During the forming process, a resistance measuring pulse was simultaneously inserted between the forming pulses at a voltage of 0.1 V to measure the resistance. The forming process was terminated when the value measured by the resistance measurement pulse became about 1 MΩ or more, and at the same time, the application of the voltage to the element was terminated.

(Step-f) Subsequently, in order to perform the activation step, benzonitrile was introduced into the vacuum apparatus through a slow leak valve, and the pressure was maintained at 1.0 × 10 ⁻⁶ Torr.
Next, the element subjected to the forming treatment was activated at a peak value of 14 V with the waveform shown in FIG. That is, a pulse voltage was applied between the device electrodes while measuring the device current If in the measurement and evaluation device. Since the If value was almost saturated in about 15 minutes, the energization was stopped, the slow leak valve was closed, and the activation process was completed.

When a similar activation step was performed on the device of the reference example in which the metal oxide film 6 was not formed, If
It took about 30 minutes for the value to reach near saturation.

As described above, the activation time of the device of this example was shorter than that of the device of the reference example.

(Step-g) Subsequently, a stabilizing step is performed. While the vacuum device and the electron-emitting device were heated by the heater and maintained at about 250 ° C., the evacuation of the vacuum device was continued. After 20 hours, the heating by the heater was stopped and the temperature was returned to room temperature, and the pressure in the vacuum apparatus reached about 5 × 10 ⁻¹⁰ Torr.

Subsequently, the electron emission characteristics were measured.

The distance H between the anode 64 and the electron-emitting device was set to 4 mm, and
4 was given a potential of 1 kV. In this state, a rectangular pulse voltage having a peak value of 14 V is applied between the device electrodes 2 and 3 using the power supply 61, and the devices of the device of the present embodiment and the device of the reference example are measured by the ammeter 60 and the ammeter 62. The current If and the emission current Ie were measured, respectively.

The device of this embodiment has a device current If = 7.0.
mA, emission current Ie = 17.5 μA, electron emission efficiency η
(= Ie / If) = 0.25%. In the device of the reference example, the device current If = 4.0 mA, the emission current Ie = 8 μA,
The electron emission efficiency η (= Ie / If) was 0.20%.

Thereafter, electron emission was further continued, and after a certain period of time, the device current If and the emission current Ie were measured again. As a result, in the device of this embodiment, the device current If = 7.
0 mA, emission current Ie = 17.5 μA, electron emission efficiency η
(= Ie / If) = 0.25%, which was not changed, whereas the element of the reference example had an element current If = 2.5 mA,
Emission current Ie = 5 μA, electron emission efficiency η (= Ie / If)
= 0.20%.

From these results, it was found that the device of this example was superior to the device of the reference example in not only the emission current Ie and the electron emission efficiency η but also the stability. .

Further, the device of this example and the device of the reference example manufactured in the above steps were observed with an electron microscope and analyzed for elements.

First, a plane including the electron-emitting portion 5 of the device was observed using a scanning electron microscope. The planar shape of the device of this example was similar to the shape in which a deposit was present on the conductive thin film inside the gap 10 and near the gap 10 of the conductive thin film shown in FIG. . That is, there is a deposit on both sides of the gap 10 formed in the conductive thin film 4, and this deposit is observed in the vicinity of the gap formed in the conductive thin film 4, that is, almost all over the electron emission section 5. . On the other hand, in the device of the reference example, regions having deposits on both sides of the gap formed in the conductive thin film 4 were observed as in the device of the present example, but there were some regions where no deposits were found. . Further, in the deposit 21 in the gap 10 formed in the conductive thin film, a gap 22 narrower than the gap 10 was observed in the device of this embodiment.

Next, deposits near the gaps between the conductive thin films 4 of the device of this embodiment and the device of the reference example were subjected to electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XP).
S), and elemental analysis by Auger electron spectroscopy,
It was confirmed that the deposit mainly consisted of carbon.

Further, the section including the electron emitting portion 5 and the deposit of each device was observed with a transmission electron microscope. In the device of the reference example, a region having a deposit was observed carefully by observing the planar shape with a scanning electron microscope and observed.

As a result, the conductive thin film 4 of the device of this embodiment
2B, there was a deposit similar to the shape shown in FIG. 2B, and a lattice image showing a layered orientation parallel to the substrate surface was observed in the deposit. When the electron beam diffraction of this deposit was measured, about 3.4 ° was obtained as the lattice spacing. Elemental analysis of the vicinity of the interface between the deposit and the substrate by energy dispersive X-ray analysis (EDX analysis) confirmed that Ni element was present on the substrate surface in contact with the deposit. On the other hand, deposits were also found inside the gaps between the conductive thin films 4 of the device of the reference example, but the orientation was more disordered than that of the device of the present example. When the electron beam diffraction of this deposit was measured, the lattice spacing was about 3.8 °.
was gotten.

The lattice spacing of the c-plane of graphite is about 3.3
It is 5 °, which is close to the value obtained with the deposit of the device of this example, and is considered to indicate that the deposit mainly consists of graphite-like carbon having good crystallinity. On the other hand, in the deposit of the device of the reference example, the lattice spacing is very large, which seems to reflect that the crystallinity is low and the structure is disordered.

From these observation results, it was found that in the device of this example, the carbon deposited in the gap 10 of the conductive thin film 4 had good orientation and crystallinity, and contributed to the stability of the electron emission characteristics. Do you get it.

Similar effects were obtained when the metal oxide film 6 was a film formed of fine particles of cobalt oxide and iron oxide in addition to the nickel oxide.

As described above, in this embodiment, stable electron emission with good characteristics was obtained.

[Embodiment 2] Also in this embodiment, the basic structure of the surface conduction electron-emitting device is shown in FIG.
They are the same as the plan view and the cross-sectional view of FIG. 2B, and the enlarged plan view and the cross-sectional view of FIGS. 2A and 2B.

The method for manufacturing the surface conduction electron-emitting device according to this embodiment is basically the same as that shown in FIG. Hereinafter, a basic configuration and a manufacturing method of the element according to the present embodiment will be described with reference to FIGS. 1, 2, and 6.

Hereinafter, the manufacturing method will be described in order with reference to FIG.
A description will be given based on FIG. 2 and FIG.

(Step-a) First, a coating material of cobalt oxide and a coating material of silicon oxide manufactured by SYMETRIC were mixed, and the composition was adjusted in advance so that the component ratio of cobalt oxide after firing was 50 mol%. Spin coating is performed on the cleaned blue glass substrate 1 using the above-described solution, and the substrate is dried at 120 ° C. for 30 minutes.
Pre-baking was performed at 70 ° C. for 30 minutes, and main firing was performed at 550 ° C. for 60 minutes to form a metal oxide film 6 having a thickness of about 80 nm (FIG. 6A). An attempt was made to measure the sheet resistance Rs of the coating 6 containing the metal oxide with an apparatus capable of measuring up to 1 MΩ / □, but it was impossible to measure, and it was found that the coating 6 had a sheet resistance of at least 1 MΩ / □.

Here, in order to clarify the effects of the present invention,
A surface conduction electron-emitting device was manufactured on a blue glass substrate on which a layer corresponding to the metal oxide-containing film 6 was formed of 100% silicon oxide through the same steps as in this example, and was used as a reference example.

(Step-b) Coating 6 Containing Metal Oxide
Is formed on the substrate 1 on which a pattern to be a gap L between the device electrodes 2 and 3 and a desired device electrode is formed by photoresist (R).
D-2000N manufactured by Hitachi Chemical Co., Ltd.), and 5 nm thick Ti and 100 nm thick Ni by electron beam evaporation.
Were sequentially deposited. The photoresist pattern was dissolved in an organic solvent, and the Ni / Ti deposited film was lifted off to form device electrodes 2 and 3 having a device electrode interval L of 3 μm and a device electrode width W of 300 μm (FIG. 6B). ).

(Step-c) A Cr film having a thickness of 100 nm is deposited by vacuum evaporation, patterned so as to have an opening corresponding to the shape of a conductive thin film described later, and an organic palladium compound solution (ccp4230 Okuno Pharmaceutical Co., Ltd.) is formed thereon. Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 12 minutes. The conductive thin film 4 mainly composed of palladium oxide fine particles thus formed has a thickness of 1
0 nm, and the sheet resistance was 2 × 10 ⁴ Ω / □. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated as described above.

(Step-d) The Cr film and the baked conductive thin film 4 were etched with an acid etchant to form a conductive thin film 4 having a desired pattern (FIG. 6C).

Through the above steps, a film 6 containing a metal oxide, device electrodes 2 and 3, and a conductive thin film 4 were formed on the substrate 1.

(Step-e) Next, the apparatus is set in the measurement and evaluation apparatus shown in FIG. 7, evacuated by a vacuum pump, and after reaching a degree of vacuum of 1 × 10 ⁻⁸ Torr, an element voltage Vf is applied to the element. A voltage is applied between the device electrodes 2 and 3 of the device from a power source 61 for
A forming process was performed. The voltage waveform of the forming process is as shown in FIG.

In FIG. 8B, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and in this embodiment, T1 is 1 ms.
ec and T2 are 10 msec, and the peak value of the rectangular wave is 0.
The voltage was raised in steps of 1 V, and a forming process was performed.
During the forming process, a resistance measuring pulse was simultaneously inserted between the forming pulses at a voltage of 0.1 V to measure the resistance. The forming process was terminated when the value measured by the resistance measurement pulse became about 1 MΩ or more, and at the same time, the application of the voltage to the element was terminated.

(Step-f) Subsequently, in order to perform the activation step, benzonitrile was introduced into the vacuum apparatus through a slow leak valve, and the pressure was maintained at 1.0 × 10 ⁻⁶ Torr.
Next, the element subjected to the forming treatment was activated at a peak value of 14 V with the waveform shown in FIG. That is, a pulse voltage was applied between the device electrodes while measuring the device current If in the measurement and evaluation device. Since the If value was almost saturated in about 15 minutes, the energization was stopped, the slow leak valve was closed, and the activation process was completed.

When the same activation step was performed on the device of the reference example in which the film 6 was made of only silicon oxide, it took about 30 minutes for the If value to reach almost saturation.

As described above, the activation time of the device of this example was shorter than that of the device of the reference example.

(Step-g) Subsequently, a stabilizing step is performed. While the vacuum device and the electron-emitting device were heated by the heater and maintained at about 250 ° C., the evacuation of the vacuum device was continued. After 20 hours, the heating by the heater was stopped and the temperature was returned to room temperature, and the pressure in the vacuum apparatus reached about 5 × 10 ⁻¹⁰ Torr.

Subsequently, the electron emission characteristics were measured in the same manner as in Example 1.

The device of this embodiment has a device current If = 5.0.
mA, emission current Ie = 12.5 μA, electron emission efficiency η
(= Ie / If) = 0.25%. In the device of the reference example, the device current If = 3.5 mA, the emission current Ie = 7 μA,
The electron emission efficiency η (= Ie / If) was 0.20%.

Thereafter, the device was further allowed to emit electrons, and after a certain period of time, the device current If and the emission current Ie were measured again. As a result, in the device of this embodiment, the device current If = 5.
0 mA, emission current Ie = 12.5 μA, electron emission efficiency η
(= Ie / If) = 0.25%, which was not changed, whereas the element of the reference example had an element current If = 2.0 mA,
Emission current Ie = 4 μA, electron emission efficiency η (= Ie / If)
= 0.20%.

From these results, it can be seen that the device of the present embodiment is not only excellent in emission current Ie and electron emission efficiency η but also excellent in stability as compared with the device of the reference example. Was.

When the device of this example and the device of the reference example were observed with an electron microscope in the same manner as in Example 1, the device of this example contained a metal oxide immediately below the electron-emitting portion 5. 3 (c) of FIG.
The groove 7 was formed as shown in FIG. When the deposit inside the gap 10 of the conductive thin film 4 was observed in the same manner as in Example 1, carbon having better orientation and crystallinity was deposited than in the device of the reference example, and the electron emission characteristics were improved. And stability.

Further, the same effect was obtained when a coating layer containing nickel oxide or iron oxide was used as the coating layer 6 containing metal oxide instead of the above-mentioned cobalt oxide.

As described above, also in this embodiment, the first embodiment
Similarly, stable electron emission with good characteristics was obtained.

[Embodiment 3] This embodiment is an example of an image forming apparatus in which a large number of surface conduction electron-emitting devices are arranged in a simple matrix.

FIG. 15 is a plan view of a part of the electron source. FIG. 16 is a sectional view taken along the line AA 'in the figure. However, FIG.
5. In FIG. 16, the same symbols indicate the same components. Here, 91 is a substrate, 92 is an X-direction wiring (also referred to as a lower wiring) corresponding to DXm in FIG. 10, 93 is a Y-direction wiring (also referred to as an upper wiring) corresponding to DYn in FIG. Reference numerals 2 and 3 denote device electrodes, 6 denotes a metal oxide film, 151 denotes an interlayer insulating layer, and 152 denotes a contact hole for electrically connecting the device electrode 2 and the lower wiring 92.

Next, the manufacturing method will be specifically described with reference to FIGS.

(Step-a) On a substrate 1 in which a 0.5 mm thick silicon oxide film was formed on a cleaned blue sheet glass by a sputtering method, 5 nm thick Cr and 0.6 mm thick After sequentially laminating Au, the photoresist (A
Z1370 Hoechst Co.) is spin-coated with a spinner and baked, then the photomask image is exposed and developed to form a resist pattern for the lower wiring 92, and the Au / Cr deposited film is wet-etched to a desired shape. Wiring 92
Is formed (FIG. 17A).

(Step-b) Next, an interlayer insulating layer 151 made of a silicon oxide film having a thickness of 1.0 μm is deposited by RF sputtering. Further, a coating 6 containing a metal oxide having a thickness of about 100 nm and a composition ratio of nickel oxide and silicon oxide of about 50 mol% was formed on the interlayer insulating layer 151 by a dual simultaneous sputtering method (FIG. 17).
(B)). Note that the dual simultaneous sputtering method may use a composite target in which _two different targets (in this case, SiO ₂ and NiO) are connected, or may use a target having a separate RF power source for each. . Here, the former method is used, but the latter method is of course possible.

(Step-c) A photoresist pattern for forming a contact hole 152 is formed in the interlayer insulating layer 151 and the film 6 containing a metal oxide deposited in the step-b, and the photoresist pattern is used as a mask to form the interlayer insulating layer 151 and the photoresist pattern. The contact hole 152 is formed by etching the coating 6 containing the metal oxide (FIG. 17C).

(Step-d) Thereafter, a pattern to be a gap L between the device electrode 2 and the device electrode is formed by a photoresist (R
D-2000N manufactured by Hitachi Chemical Co., Ltd.), and 5 nm thick Ti and 0.1 mm thick Ni were sequentially deposited by a vacuum evaporation method. The photoresist pattern is dissolved with an organic solvent, the Ni / Ti deposited film is lifted off, and the device electrode interval L
= 3 μm, and the device electrodes 2 and 3 having the device electrode width W = 0.3 mm were formed. (FIG. 17D).

(Step-e) After forming a photoresist pattern of the upper wiring 93 on the device electrodes 2 and 3, the thickness is 5 nm.
Ti and 0.5 mm thick Au were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form an upper wiring 93 having a desired shape (FIG. 18A).

(Step-f) Cr film 17 having a thickness of 0.1 mm
1 was deposited and patterned by vacuum evaporation, and an organic palladium compound solution (ccp4230 manufactured by Okuno Pharmaceutical Co., Ltd.) was spin-coated thereon with a spinner and heated and baked at 300 ° C. for 10 minutes (FIG. 18B). ). The thus formed conductive thin film 4 mainly composed of palladium oxide fine particles has a thickness of 10 nm and a sheet resistance of 2 nm.
× 10 ⁴ Ω / □.

(Step-g) The Cr film 171 and the fired conductive thin film 4 were etched with an acid etchant and lifted off to form a conductive thin film 4 having a desired pattern (FIG. 18C).

(Step-h) A pattern in which a resist is applied to portions other than the contact hole 152 is formed, and 5 nm thick Ti and 0.5 mm thick Au are formed by vacuum evaporation.
Were sequentially deposited. Unnecessary portions were removed by lift-off to bury the contact holes 152 (FIG. 18D).

Through the above steps, a lower wiring 92, an interlayer insulating layer 151, a film 6 containing a metal oxide, an upper wiring 93, element electrodes 2 and 3, and a conductive thin film 4 were formed on the insulating substrate 1.

Next, an example in which an electron source and a display device are configured using the electron source substrate manufactured as described above will be described with reference to FIGS.

After fixing the substrate 1 on which the element was manufactured as described above on the rear plate 101, a face plate 106 (a fluorescent film 104 and a metal back 105 were formed on the inner surface of the glass substrate 103) was formed 5 mm above the substrate 1. Is arranged via a support frame 102, frit glass is applied to the joint between the face plate 106, the support frame 102, and the rear plate 101, and the frit glass is applied at 400 ° C. in the atmosphere.
It was sealed by baking for a minute. The fixing of the substrate 1 to the rear plate 101 was also performed using frit glass.

In this embodiment, reference numeral 94 in FIG. 11 denotes a surface conduction type electron-emitting device in which an electron-emitting portion is formed on the conductive thin film 4 by a method described later (for example, FIG.
(Corresponding to (b)), and 92 and 93 are element wirings in the X direction and the Y direction, respectively.

The fluorescent film 104 is made of only a phosphor in the case of monochrome, but in this embodiment, the phosphor is formed in a stripe shape, a black stripe is formed first, and each color phosphor is applied to the gap. Then, a fluorescent film 104 was manufactured. As the material for the black stripe, a material mainly containing graphite, which is generally used, was used. Glass substrate 1
A slurry method was used as a method of applying a phosphor to 03.

A metal back 105 is usually provided on the inner side of the fluorescent film 104. The metal back was manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after the fluorescent film was manufactured, and then vacuum-depositing Al.

In the face plate 106, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 104 in order to further increase the conductivity of the fluorescent film 104, but in this embodiment, only a metal back is used. Omitted because sufficient conductivity was obtained.

When the above-mentioned sealing is performed, in the case of color, the phosphors of each color must correspond to the electron-emitting devices.

The atmosphere in the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, terminals outside the container Dox1 to Doxm.
And a voltage was applied between the device electrodes 2 and 3 through Doy1 to Doyn to form the conductive thin film 4 described above.
The voltage waveform of the forming process is the same as that in FIG.

In this embodiment, T1 is 1 msec, and T2 is 10
The process was performed under a vacuum atmosphere of about 1 × 10 ⁻⁵ Torr at msec.

Next, after exhausting was continued until the pressure in the panel reached the level of 10 ^-8 Torr, benzonitrile was introduced into the panel from the exhaust pipe of the panel so that the total pressure became 1 × 10 ^-6 Torr. Introduced and maintained. Outer container terminals Dox1 to Doxm and Doy1
14 through Doyn again between the device electrodes 2 and 3 described above.
The activation process was performed with the peak value of 14 V in the waveform shown in FIG.

As described above, the forming and activating processes were performed, and the electron emitting portions 5 were formed on the above-mentioned conductive thin film 4, whereby a plurality of surface conduction electron-emitting devices 94 were manufactured.

Next, the entire panel was evacuated while being heated to 250 ° C., the temperature was lowered to room temperature, and the inside was set at a pressure of about 10 ⁻⁹ Torr. Then, an exhaust pipe (not shown) was welded by heating with a gas burner. The envelope was sealed.

Finally, in order to maintain the pressure after sealing, a getter treatment was performed by a high-frequency heating method.

In the image display device of the present invention completed as described above, each electron-emitting device has external terminals Dox1 to Dox1.
A scanning signal and a modulation signal are applied to the metal back 105 through Doxm and Doy1 to Doyn, respectively, by applying a scanning signal and a modulation signal from a signal generation unit (not shown). Was accelerated and collided with the fluorescent film 104 to excite and emit light, thereby displaying an image.

The image display device of this example was able to display a good image stably over a long period of time at a luminance (about 150 fL) sufficiently satisfactory as a television.

[Embodiment 4] In this embodiment, an example of a display device configured to display image information provided from various image information sources such as television broadcasting will be described. Display was performed on the image forming apparatus shown in FIG. 11 using the driving circuit shown in FIG. 13 in accordance with an NTSC television signal.

In the present display device, the depth of the display device can be reduced because the display panel using the surface conduction electron-emitting device as an electron beam source can be made thinner. In addition, the display panel using the surface conduction electron-emitting device as the electron beam source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display with good visibility.

The display device of this example was able to display a television image according to an NTSC television signal in a favorable state for a long period of time.

[0246]

As described above, according to the present invention, by forming a metal oxide film such as nickel oxide on a substrate surface, the orientation and crystallinity of a deposit containing carbon as a main component are improved. And an electron-emitting device capable of extracting a stable electron-emitting current for a long time can be provided.
Further, the time of the step of forming the deposit containing carbon as a main component is reduced, and as a result, the manufacturing cost of the electron-emitting device, the electron source using the same, and the image forming apparatus can be reduced.

Further, in an electron source that emits electrons in response to an input signal, a plurality of the above-described electron-emitting devices are arranged on a substrate to form an electron source. Have a plurality of rows of electron-emitting devices connected to the wiring, and further have an arrangement method having a modulating means, or a substrate having m X-directional wirings and n wirings electrically insulated from each other. By providing an electron source in which a plurality of electron-emitting devices in which a pair of device electrodes of the electron-emitting device are connected to the Y-direction wiring are arranged, each electron-emitting device has good electron emission characteristics. An electron source that can be held over time can be provided at low cost.

The image forming apparatus comprises an image forming member and the electron source, and forms an image based on an input signal. Therefore, the stability of electron emission characteristics and the life are improved. In an image forming apparatus serving as an image forming member, a high-quality image forming apparatus, for example, a color flat television can be realized.

[Brief description of the drawings]

FIG. 1 is a view showing a configuration of a basic surface conduction electron-emitting device according to the present invention.

FIG. 2 is an enlarged view showing a configuration of a basic surface conduction electron-emitting device according to the present invention.

FIG. 3 is an enlarged view showing a configuration of a basic surface conduction electron-emitting device according to the present invention.

FIG. 4 is a view for explaining a configuration of a basic surface conduction electron-emitting device according to the present invention.

FIG. 5 is a view showing another embodiment of the basic surface conduction electron-emitting device according to the present invention.

FIG. 6 is a view for explaining a basic manufacturing method of the surface conduction electron-emitting device according to the present invention.

FIG. 7 is a diagram of a measurement and evaluation device used for evaluating the characteristics of the surface conduction electron-emitting device according to the present invention.

FIG. 8 is a diagram illustrating an example of a voltage waveform in a forming process according to the present invention.

FIG. 9 is a diagram showing a typical example of the relationship among the emission current, the device current, and the device voltage of the surface conduction electron-emitting device according to the present invention.

FIG. 10 is a diagram showing a configuration of an electron source substrate according to the present invention.

FIG. 11 is a diagram illustrating a basic configuration of an image forming apparatus according to the present invention.

FIG. 12 is a diagram illustrating a fluorescent film used in the image forming apparatus of FIG. 11;

FIG. 13 is a block diagram of a drive circuit of an example in which the image forming apparatus according to the present invention performs display according to an NTSC television signal.

FIG. 14 is a diagram showing a shape of an activation pulse suitable for the present invention.

FIG. 15 is a diagram illustrating a part of a configuration of an electron source according to a second embodiment of the present invention.

FIG. 16 is a sectional view taken along line AA ′ of FIG.

FIG. 17 is a cross-sectional view for explaining a manufacturing process of the electron source according to the second embodiment of the present invention.

FIG. 18 is a cross-sectional view for explaining a manufacturing process of the electron source according to the second embodiment of the present invention.

FIG. 19 is a diagram showing a configuration of a conventional surface conduction electron-emitting device.

FIG. 20 is a schematic diagram showing an example of an electron source having a ladder-type arrangement.

FIG. 21 is a schematic diagram illustrating an example of a panel structure in an image forming apparatus including a ladder-type arrangement of electron sources.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Device electrode 4 Conductive thin film 5 Electron emission part 6 Metal oxide film 21 Deposit mainly composed of carbon 41 Step formation part 60 Device current If flowing through a conductive thin film between device electrodes 2 and 3 61 A power supply for applying the device voltage Vf to the electron-emitting device 62 An ammeter for measuring the emission current Ie emitted from the electron-emitting portion of the device 63 A voltage is applied to the anode electrode 64 High-voltage power supply 64 Anode electrode 91 Electron source substrate 92 X-direction wiring 93 Y-direction wiring 94 Surface conduction electron-emitting device 95 Connection 101 Rear plate 102 Support frame 103 Glass substrate 104 Fluorescent film 105 Metal back 106 Face plate 107 High-voltage terminal 108 Enclosure 111 Black conductive material 112 Phosphor 121 Display panel 122 Scanning circuit 123 Control circuit 124 shift register 125 a line memory 126 synchronizing signal separation circuit 127 modulation signal generator Vx and Va dc voltage sources 151 interlayer insulating layer 152 contact hole 171 Cr film

Claims (17)

[Claims] 1. A pair of electrodes, a conductive film connected to the pair of electrodes and having a gap in a part thereof, and provided in the gap connected to the conductive film on the base, A member containing carbon as a main component, and a metal oxide containing at least one element of nickel, iron, and cobalt between the member containing carbon as a main component and the base; Electron emitting device. 2. A pair of electrodes, a conductive film connected to the pair of electrodes and having a gap in a part thereof, and a conductive film connected to the conductive film in the gap portion are provided on the base. A member containing carbon having a layered orientation substantially parallel to the substrate surface,
An electron-emitting device comprising: 3. The electron-emitting device according to claim 1, further comprising the metal oxide between the conductive film and the base. 4. The electron-emitting device according to claim 1, wherein the metal oxide is made of at least one of nickel oxide, iron oxide, and cobalt oxide. 5. The electron according to claim 1, wherein the metal oxide is contained in a base material containing silica as a main component, and is disposed between the member containing carbon as a main component and the base. Emission element. 6. The electron emission device according to claim 1, wherein the electron emission device is a surface conduction electron emission device.
3. The electron-emitting device according to item 1. 7. An electron source for emitting electrons in response to an input signal, wherein a plurality of the electron-emitting devices according to claim 1 are arranged on a substrate. Electron source. 8. The electron source according to claim 7, wherein a plurality of electron-emitting devices are arranged in parallel on the base, and the plurality of rows of electron-emitting devices having both ends of each element connected to a wiring are provided. An electron source comprising: a modulation unit. 9. The electron source according to claim 7, wherein a pair of electrodes of the electron-emitting device are provided on the substrate, the m X-directional wires and the n Y-directional wires electrically insulated from each other. An electron source, wherein a plurality of electron-emitting devices are connected. 10. An apparatus for forming an image based on an input signal, comprising at least an image forming member and an image forming member.
An image forming apparatus comprising the electron source according to any one of claims 9 to 9. 11. A step of forming a conductive film on a film provided between a pair of electrodes and containing a metal oxide containing at least one element of nickel, iron, and cobalt on a substrate. And a step of forming a gap in a part of the conductive film, and a step of forming a member containing carbon as a main component connected to the conductive film in the gap portion. Of manufacturing an electron-emitting device. 12. The method according to claim 11, wherein forming the gap in a part of the conductive film includes applying a voltage to the conductive film. 13. The electron-emitting device according to claim 11, wherein the step of forming the member containing carbon as a main component includes a step of applying a voltage to the conductive film in an atmosphere in which a carbon compound exists. Production method. 14. The method according to claim 11, wherein the pair of electrodes are formed after forming the film on the base. 15. The method according to claim 11, wherein the metal oxide is at least one oxide selected from nickel oxide, iron oxide, and cobalt oxide. 16. The method according to claim 11, wherein the coating is a coating in which a metal oxide is contained in a base material mainly composed of silica. 17. The method according to claim 11, wherein the electron-emitting device is a surface conduction electron-emitting device.