JPH1055752A - Electron emission element, electron source, image forming device, and their manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce and stabilize power consumption of an electron emission element after activation process by measuring a current, obtaining a resistance value, terminating foaming when a prescribed resistance is indicated to ensure high resistance, and removing a cut and left part. SOLUTION: After a base body 1 is washed, an element electrode material is laminated by a vacuum evaporation method, and element electrodes 2 and 3 are formed using photolighography technique. Next, an organometal solution is ejected between the element electrodes, heated, and backed, and a conductive film 4 is formed. Then, electric conducting is made between the electrodes, a structural change occurs at a position of the conductive film 4, and the electron emission part 5 is formed. In this electric conducting foaming, a current is measured to apply a voltage to an extent to which the conductive film 4 is not locally destroyed and deformed, a resistance value is obtained, and forming is terminated when a resistance of 1MΩ or more is indicated. After the conductive film 4 has high resistance, hydrogen reduction treatment is performed to remove cut and left part. Thus, the electron emission element obtained by activation process reduces power consumption and is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, an electron source having a large number of such electron-emitting devices, and an image forming apparatus such as a display device or an exposure device using the electron source.
And their production methods.

[0002]

2. Description of the Related Art Heretofore, two types of electron-emitting devices, a thermionic electron-emitting device and a cold cathode electron-emitting device, are known. Field emission devices (hereinafter, referred to as cold cathode electron emission devices)
It is called "FE type". ), Metal / insulating layer / metal type (hereinafter, referred to as
It is called "MIM type". ) And surface conduction electron-emitting devices.

[0003] As an example of the FE type, W. P. Dyke
and W. W. Dolan, "Field Emis
zone ", Advance in Electron
Physics, 8, 89 (1956) or C.I.
A. Spindt, "Physical Proper
ties of thin-filmfield em
issue cathodes withmollyb
denum cones ", J. Appl. Phys.
s. , 47, 5248 (1976).

As an example of the MIM type, C.I. A. Mea
d, “Operation of Tunnel-Emi
session Devices ", J. Appl. Phys.
s. , 32, 646 (1961).

As an example of the surface conduction electron-emitting device,
M. I. Elinson, RadioEng. Elec
Tron Phys. , 10, 1290 (1965).

[0006] The surface conduction electron-emitting device utilizes a phenomenon in which electrons are emitted by passing a current through a small-area thin film formed on an insulating substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using a SnO ₂ thin film by Elinson et al., And a device using an Au thin film [G. Dittmer: "ThinSolid
Films ", 9,317 (1972)] , In 2 O 3
/ SnO ₂ thin film [M. Hartwell a
nd C.I. G. FIG. Fonstad: “IEEE Tran
s. ED Conf. , 519 (1975)], and those based on carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported.

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

In these surface conduction electron-emitting devices, it is general that the electron-emitting portion 5 is formed beforehand by performing an energization process called energization forming on the conductive film 4 before electron emission. That is, the energization forming means that a voltage is applied to both ends of the conductive film 4, and the conductive film 4 is locally destroyed, deformed or deteriorated to change the structure, and the electrons in an electrically high-resistance state are formed. This is a process for forming the emission unit 5. Note that a crack is generated in a part of the conductive film 4 in the electron emitting portion 5, and electrons are emitted from the vicinity of the crack.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be arrayed over a large area because of its simple structure. Therefore, various applications for utilizing this feature are being studied. For example, a charged beam source,
Application to an image forming apparatus such as a display device is exemplified.

Conventionally, as an example in which a large number of surface conduction electron-emitting devices are arrayed, surface conduction electron-emitting devices are arranged in parallel, and both ends (both device electrodes) of each surface conduction electron-emitting device are wired. (Also referred to as a common wiring). An electron source in which rows each connected by a common line (also referred to as a ladder-type arrangement) are provided (for example, JP-A-64-31332, JP-A-1-283737, 2-257552).

In particular, in the case of a display device, a flat panel display device similar to a display device using liquid crystal can be used, and a self-luminous display device that does not require a backlight is used as a surface conduction type electron emission device. There has been proposed a display device in which an electron source in which a number of elements are arranged and a phosphor that emits visible light when irradiated with an electron beam from the electron source are combined (US Pat. No. 5,066,883).

[0012]

With respect to the electron-emitting device used in the above-mentioned electron source, image forming apparatus, etc., there is a demand for more stable electron emission characteristics and improved electron emission efficiency so that a bright display image can be stably provided. Have been.

The above-mentioned electron emission efficiency is, for example, in the case of the above-mentioned surface conduction type electron-emitting device, when a voltage is applied to both ends of the conductive film, a current flowing through this (hereinafter referred to as “device current”). ) And the current emitted into a vacuum (hereinafter referred to as “emission current”). An electron-emitting device having a small device current and a large emission current is desired.

If the electron emission characteristics and efficiency which can be controlled stably are further improved, for example, in an image forming apparatus using a phosphor as an image forming member, a bright and high-quality image forming apparatus with low current can be used. For example, a flat television is realized. Further, as the current is reduced, the cost of a drive circuit and the like constituting the image forming apparatus can be reduced.

When increasing the area of such an image forming apparatus, as one of means for forming a large number of elements over a large area at once, a solution obtained by dissolving a metal complex in water in a bubble jet (BJ) is used. A method of forming a conductive film by applying an aqueous solution for application, using a BJ-type inkjet device as an application device, applying a droplet of the solution between the electrodes, and performing a heating and baking treatment. There is.
It is very effective to manufacture a large number of elements using such a method.

However, in the above-mentioned method, the shape of the droplet immediately after being applied between the electrodes becomes convex, and the conductive film formed by performing the heating and firing step has the end portion closer to the center portion. In some cases, the film thickness may be reduced. When a crack is formed by applying an energizing process (forming process) to such a conductive film, the conductive film may be left uncut at an end portion, and a large leak current may occur. A printing method is also applicable to a large-area process. In this case, however, uncut portions may occur due to the film thickness distribution.

In an electron-emitting device obtained by performing an activation process to be described later on an element having the above-mentioned uncut portion,
An element current due to an ohmic component (current generated according to Ohm's law, the above-described leak current) is generated. When an image forming apparatus is manufactured using electron-emitting devices having such characteristics, there is a problem that power consumption during driving increases. Further, in reality, it is difficult to provide an image forming apparatus having high luminance and excellent operation stability using such an electron-emitting device.

An object of the present invention is to solve the above-mentioned technical problems to be solved, and to provide an electron-emitting device having stable, uniform, and good electron-emitting characteristics and capable of minimizing power consumption during driving. Is to do. Another object of the present invention is to provide an image forming apparatus which uses a plurality of such electron-emitting devices and has high luminance and excellent operation stability.

[0019]

The structure of the present invention to achieve the above object is as follows.

That is, a first aspect of the present invention is a method of manufacturing an electron-emitting device including a conductive film having an electron-emitting portion between a pair of device electrodes formed on a substrate. A step of forming a crack in the conductive film by applying a current to the conductive film, a step of increasing the resistance of a part of the conductive film while detecting a state of the conductive film, Activating the conductive film in an atmosphere including the following.

The first manufacturing method of the present invention further has a feature that “the step of increasing the resistance of a part of the conductive film while detecting the state of the conductive film is performed by the step of increasing the resistance of the conductive film. Includes a step of increasing the resistance of a portion of the metal oxide while detecting a change in the state of the metal oxide constituting at least a part of the metal oxide. ''
That, "Raman spectroscopy is used as a method of detecting the state of the conductive film";"the step of increasing the resistance of a part of the conductive film is a step of aggregating a part of the conductive film; And "the step of aggregating a part of the conductive film includes a heating step or a hydrogen reduction step".

A second aspect of the present invention resides in an electron-emitting device manufactured by the first method of the present invention.

A third aspect of the present invention is a method of manufacturing an electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting devices are manufactured by the above-described first method of the present invention. The present invention is a method for manufacturing an electron source.

A fourth aspect of the present invention is an electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting device is the above-described second electron-emitting device of the present invention. At the source.

The fourth electron source of the present invention further has the following features: "the plurality of electron-emitting devices are wired in a matrix";
It is wired in the form of a ladder. "

According to a fifth aspect of the present invention, there is provided an electron source having a plurality of electron-emitting devices arranged on a substrate, and an image forming member for forming an image by irradiating an electron beam emitted from the electron source. In the method for manufacturing an image forming apparatus, the electron source is manufactured by the third method of the present invention.

Further, a sixth aspect of the present invention is to provide an electron source in which a plurality of electron-emitting devices are arranged on a substrate, and an image forming member for forming an image by irradiating an electron beam emitted from the electron source. In the image forming apparatus, the electron source is the fourth electron source of the present invention.

[0028]

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

The electron-emitting devices to which the present invention can be applied are classified into the cold cathode type electron-emitting devices described above, and are surface conduction type electron-emitting devices.

FIG. 1 is a schematic view showing one configuration example of the surface conduction electron-emitting device of the present invention. FIG.
FIG. 1B is a longitudinal sectional view. In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, and 5 is an electron emitting portion.

Examples of the substrate 1 include quartz glass, glass having a reduced content of impurities such as Na, blue plate glass, a laminate of blue plate glass with SiO ₂ laminated by sputtering, ceramics such as alumina, and a Si substrate. Can be used.

The materials of the opposing device electrodes 2 and 3 are as follows.
General conductor materials can be used, for example, Ni, C
metals or alloys such as r, Au, Mo, W, Pt, Ti, Al, Cu, Pd and Pd, Ag, Au, RuO ₂ , Pd
Metal or metal oxide and printed conductor composed of glass or the like, such as -ag, is appropriately selected from a semiconductor conductive materials such as transparent conductor and polysilicon or the like In ₂ O ₃ -SnO _2.

The element electrode interval L, the element electrode length W, the shape of the conductive film 4 and the like are designed in consideration of the applied form and the like. The element electrode interval L can be preferably in the range of several hundred nm to several hundred μm, more preferably several μm.
m to several tens of μm.

The length W of the device electrode can be in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics. The film thickness d of the device electrodes 2 and 3 can be in the range of several tens nm to several μm.

In addition to the structure shown in FIG.
A configuration in which the conductive film 4 and the opposing element electrodes 2 and 3 are stacked in this order may be adopted.

The main material constituting the conductive film 4 is appropriately selected from metal materials whose oxides are Raman active.

As the conductive film 4, it is preferable to use a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage of the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, a forming condition described later, and the like.
The thickness is preferably in the range of 1 to several hundred nm, more preferably in the range of 1 nm to 50 nm. The resistance value is such that Rs is 10 ² to 10 ⁷ Ω / □. Note that R
s is the amount that appears when the resistance R measured in the length direction of a thin film having a width w and a length 1 is R = Rs (l / w).

The fine particle film described here is a film in which a plurality of fine particles are aggregated. The fine structure thereof is not limited to a state in which the fine particles are individually dispersed and arranged, but also a state in which the fine particles are adjacent to each other or overlapped (some). Particles gather,
(Including the case where an island structure is formed as a whole). The particle size of the fine particles is in the range of several to several hundreds of nm, preferably in the range of 1 to 20 nm.

In the present specification, the term “fine particles” is frequently used, and its meaning will be described.

Small particles are called "fine particles", and smaller ones are called "ultra fine particles". Particles smaller than "ultrafine particles" and having a few hundred atoms or less are widely called "clusters".

However, each boundary is not strict, and changes depending on what kind of property is focused on. Further, “fine particles” and “ultrafine particles” may be collectively referred to as “fine particles”, and the description in this specification is in line with this.

For example, in “Experimental Physics Course 14: Surfaces and Particles” (edited by Kinoshita Yoshio, published by Kyoritsu Shuppan, September 1, 1986), “particles in this paper have diameters of about 2-3 μm to 10 nm. And especially when it is referred to as ultrafine particles, the particle size is about 10 nm to 2-3 n.
It means up to about m. It is not exactly strict because both are collectively written as fine particles, but it is a rough guide. When the number of atoms constituting a particle is two to several tens to several hundreds, it is called a cluster. (Page 195, lines 22 to 26).

In addition, the definition of "ultra-fine particles" in the "Hayashi / Ultra-fine Particle Project" of the New Technology Development Corporation has a lower limit of the particle size, which is as follows.

In the “Ultra Fine Particle Project” of the Creative Science and Technology Promotion System (1981 to 1986), a particle having a particle size (diameter) in the range of about 1 to 100 nm is called an “ultra fine particle”. Then, one ultrafine particle is about 100-
It is an aggregate of about 10 ⁸ atoms. Ultra-fine particles are large to giant particles on an atomic scale. ("Ultra Fine Particles-Creative Science and Technology" Hayashi Tax, Ryoji Ueda, Akira Tazaki
(Edited by Mita Publishing, 1988, page 2, lines 1 to 4) /
"A particle even smaller than an ultrafine particle, that is, a single particle composed of several to several hundred atoms, is usually called a cluster" (ibid., Page 2, lines 12 to 13).

[0045] Based on the general notation as described above,
In the present specification, “fine particles” are an aggregate of a large number of atoms and molecules, and the lower limit of the particle size is several Å to 1 nm, and the upper limit is several μm.
It refers to the degree.

The electron-emitting portion 5 is constituted by a high-resistance crack formed in a part of the conductive film 4. The electron-emitting portion 5 has a thickness, a film quality, a material, and a crack forming technique such as energization forming which will be described later. Depends. In some cases, conductive fine particles having a particle size in the range of several 数 to several tens of nm are present inside the electron-emitting portion 5. The conductive fine particles contain some or all of the elements of the material constituting the conductive film 4. The electron emitting portion 5 and the conductive film 4 in the vicinity thereof may include carbon or a carbon compound.

There are various methods for manufacturing the surface conduction electron-emitting device of the present invention. One example will be described with reference to FIG. In FIG. 2, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

1) The substrate 1 is sufficiently washed with a detergent, pure water, an organic solvent, and the like, and after the element electrode material is deposited by a vacuum deposition method, a sputtering method, or the like, the substrate 1 is deposited on the substrate 1 by using, for example, a photolithography technique. The device electrodes 2 and 3 are formed (FIG. 2
(A)).

2) On the substrate 1 provided with the device electrodes 2 and 3,
Using a BJ-type inkjet device or the like, a droplet of an organic metal solution is ejected between the element electrodes and heated and baked to form the conductive film 4 (FIG. 2B). As the organic metal solution, a solution of an organic compound containing the metal of the material of the conductive film 4 as a main element can be used.

Here, the method of forming the conductive film 4 using the ink jet device has been described, but the method of forming the conductive film 4 is not limited to this, and a printing method or the like may be used.

3) Subsequently, a forming step is performed. As an example of a method of the forming step, a method by an energization process will be described. When electricity is supplied from a power source (not shown) between the device electrodes 2 and 3, an electron-emitting portion 5 having a changed structure is formed at the conductive film 4 (FIG. 2C). FIG. 3 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform.
The method shown in FIG. 3A in which a pulse with a constant pulse crest value is applied continuously and the method shown in FIG. 3B in which a pulse is applied while increasing the pulse crest value are used for this purpose. is there.

First, the case where the pulse peak value is a constant voltage will be described with reference to FIG. T1 in FIG.
And T2 are the pulse width and pulse interval of the voltage waveform. Usually, T1 is 1 μsec to 10 msec, and T2 is 10 μsec to 100 msec.
It is set in the range of m seconds. The peak value of the triangular wave (peak voltage during energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device. Under these conditions,
For example, the voltage is applied for several seconds to several tens minutes. The pulse waveform is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted.

Next, a case where a voltage pulse is applied while increasing the pulse peak value will be described with reference to FIG.
T1 and T2 in FIG. 3B can be the same as those shown in FIG. The peak value of the triangular wave (peak voltage during energization forming) can be increased, for example, by about 0.1 V steps.

The end of the energization forming process can be detected by applying a voltage that does not locally destroy or deform the conductive film 4 during the pulse interval T2, and measuring the current. For example, a current flowing when a voltage of about 0.1 V is applied is measured, a resistance value is obtained, and when a resistance of 1 MΩ or more is indicated, the energization forming can be terminated.

However, in particular, in the case of a conductive film formed by dropping a droplet as described above, an uncut portion is easily generated in a peripheral portion of the film due to the distribution of the film thickness. In order to perform this, it is necessary to apply a high voltage. When a high voltage is applied in the energization forming as described above, the influence on other portions of the conductive film 4 becomes large, and good electron emission characteristics cannot be obtained in many cases. Therefore, in the present invention, even when the resistance value is, for example, 1 KΩ or more and 1 MΩ or less, the application of the voltage is stopped, the reduction treatment is performed in a hydrogen atmosphere or the like, and then the uncut portion which is the source of the ohmic current component is removed. .

As a method for removing the remaining uncut portion,
It is possible to use a method of changing the particle state of the relevant portion and changing to a high-resistance portion. In this case, in order to prevent aggregation of other portions of the conductive film, etc. The remaining uncut portion is removed while detecting the state of the film. The completion of the removal of the uncut portion is performed by detecting a state change of the portion by Raman spectroscopy. This detection method will be specifically described with reference to FIG.

FIG. 4A is a plan view schematically showing the element state after the energization forming. In FIG. 4A, reference numeral 6 denotes a crack region, and reference numeral 7 denotes an uncut portion. FIG. 4 (b)
FIG. 9 is an elevational view schematically showing a state of detecting completion of removal of the uncut portion 7 of the conductive film.

First, in order to increase the resistance of the conductive film 4 and remove the uncut portion 7, the conductive film 4 is subjected to a heat step or a hydrogen reduction step. At the same time, as shown in FIG. 4B, the laser diameter is sufficiently reduced from the laser light source 41 through the prism 42 and the objective lens 43 (paths (1) and (2) in FIG. 7 is irradiated with a laser, and the Raman scattered light image of the uncut portion 7 is taken into the CCD detector 44 through the paths (3) to (4) to (5). The captured image results are processed by the computer 45 to terminate the removal process when the oxide Raman lines present in the uncut portion 7 disappear. The excitation wavelength of the laser to be used is not particularly limited, and an oscillation line of a generally used Ar laser can be used.

As described above, the step of removing the uncut portion 7 is performed while detecting the state of the conductive film, thereby minimizing the influence on other portions of the conductive film 4 and minimizing the influence of the element. The resistance value can be 1 MΩ or more.

4) The element in which a complete crack has been formed through the step of removing the uncut portion is subjected to a process called an activation step.

The activation step can be performed, for example, by repeatedly applying a pulse between the device electrodes 2 and 3 in an atmosphere containing a gas of an organic substance. This atmosphere can be formed by using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump, or is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum. The preferable gas pressure of the organic substance at this time varies depending on the form of the above-mentioned element electrode, the shape of the vacuum vessel, the type of the organic substance, and the like. Suitable organic substances include aliphatic hydrocarbons of alkanes, alkenes, and alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, and organic acids such as phenols, carboxylic acids, and sulfonic acids. Specifically, methane,
Saturated hydrocarbons represented by C _n H _{2n + 2} such as ethane and propane, unsaturated hydrocarbons represented by a composition formula such as C _n H _2n such as ethylene and propylene, benzene, toluene, methanol, ethanol, formaldehyde and acetaldehyde , Acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used. By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie are significantly changed.

The carbon and carbon compound include, for example, graphite (so-called HOPG, PG, GC), and HOPG has a substantially complete graphite crystal structure, PG
Are those with crystal grains of about 20 nm and a slightly disordered crystal structure,
GC refers to a crystal having a crystal grain of about 2 nm and further disorder in the crystal structure. ) And amorphous carbon (refer to amorphous carbon and a mixture of amorphous carbon and the microcrystals of graphite), and the thickness thereof is preferably in the range of 50 nm or less, and 30 n
More preferably, the range is not more than m.

The termination of the activation step can be appropriately determined while measuring the device current If and the emission current Ie.
The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.

5) The electron-emitting device obtained through such a step is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum container. 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 or an ion pump can be used.

In the activation step, when an oil diffusion pump or a rotary pump is used as an exhaust device and an organic gas derived from an oil component generated from the oil diffusion pump or the rotary pump is used, it is necessary to keep the partial pressure of this component as low as possible. is there. The partial pressure of the organic component in the vacuum vessel is preferably 1 × 10 ⁻⁶ Pa or less, more preferably 1 × 10 ⁻⁸ Pa or less, at a partial pressure at which the carbon or carbon compound is not newly deposited. 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 conditions at this time are 80 to 200 ° C, preferably 150 ° C or more,
It is desirable to perform the treatment as long as possible, but the treatment is not particularly limited to this condition, and the treatment is performed under conditions appropriately selected according to various conditions such as the size and shape of the vacuum vessel and the configuration of the electron-emitting device. The pressure in the vacuum vessel needs to be as low as possible, preferably 1 to 3 × 10 ⁻⁵ Pa or less, and more preferably 1 × 10 ⁻⁵ Pa or less.
Particularly preferred is 10 ^-6 Pa or less.

It is preferable that the atmosphere at the time of driving after the stabilization step is performed is the same as the atmosphere at the end of the stabilization treatment, but the present invention is not limited to this. Even if the pressure itself increases somewhat, it is possible to maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, and as a result, the device current If and the emission current Ie
But it stabilizes.

The basic characteristics of the electron-emitting device of the present invention obtained through the above-described steps will be described with reference to FIGS.

FIG. 5 is a schematic diagram showing an example of a vacuum processing apparatus. This vacuum processing apparatus also has a function as a measurement and evaluation apparatus. Also in FIG. 5, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

In FIG. 5, reference numeral 55 denotes a vacuum vessel;
Reference numeral 6 denotes an exhaust pump. An electron-emitting device is provided in the vacuum vessel 55. Reference numeral 51 denotes a power supply for applying a device voltage Vf to the electron-emitting device; 50, an ammeter for measuring a device current If flowing through the conductive film 4 between the device electrodes 2 and 3; An anode electrode for capturing the emission current Ie emitted from the unit 5, a high-voltage power supply 53 for applying a voltage to the anode electrode 54, and a reference numeral 52 for measuring the emission current Ie emitted from the electron emission unit 5. It is an ammeter. As an example, the measurement can be performed with the voltage of the anode electrode 54 in the range of 1 KV to 10 KV and the distance H between the anode electrode 54 and the electron-emitting device in the range of 2 mm to 8 mm.

In the vacuum vessel 55, equipment necessary for measurement in a vacuum atmosphere such as a vacuum gauge (not shown) is provided.
The measurement and evaluation can be performed in a desired vacuum atmosphere.

The exhaust pump 56 is composed of a normal high vacuum system such as a turbo pump and a rotary pump, and an ultrahigh vacuum system such as an ion pump. The entire vacuum processing apparatus provided with the electron-emitting device substrate shown here can be heated by a heater (not shown). Therefore, by using this vacuum processing apparatus, the steps after the energization forming described above can also be performed.

FIG. 6 is a diagram schematically showing the relationship between the emission current Ie and the device current If measured using the vacuum processing apparatus shown in FIG. 5, and the device voltage Vf. In FIG. 6, since the emission current Ie is significantly smaller than the element current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is apparent from FIG. 6, the surface conduction electron-emitting device to which the present invention can be applied has the following three characteristic characteristics regarding the emission current Ie.

First, the emission current Ie of the present device rapidly increases when a device voltage higher than a certain voltage (referred to as a threshold voltage; Vth in FIG. 6) is applied, whereas when the device voltage is lower than the threshold voltage Vth, the emission current Ie increases. 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 monotonically on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf.

Thirdly, the amount of charge discharged by the anode electrode 54 (see FIG. 5) depends on the time during which the device voltage Vf is applied. That is, the amount of charge captured by the anode electrode 54 can be controlled by the time during which the device voltage Vf is applied.

As understood from the above description, the surface conduction electron-emitting device to which the present invention can be applied can easily control the electron emission characteristics according to the input signal. By utilizing this property, it is possible to apply to various fields such as an electron source and an image forming apparatus having a plurality of electron-emitting devices.

FIG. 6 shows an example in which the device current If monotonically increases with respect to the device voltage Vf (MI characteristic).
The element current If may exhibit a voltage-controlled negative resistance characteristic (VCNR characteristic) with respect to the element voltage Vf (not shown).
These properties can be controlled by controlling the steps described above.

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 to which the present invention can be applied on a substrate, for example, an electron source or an image forming apparatus can be configured.

Various arrangements of the electron-emitting devices can be adopted. As an example, each of a large number of electron-emitting devices arranged in parallel is connected at both ends, a large number of rows of electron-emitting devices are arranged (referred to as a row direction), and a direction perpendicular to the wiring (referred to as a column direction). There is a ladder-type arrangement in which electrons from the electron-emitting devices are controlled and driven by control electrodes (also referred to as grids) disposed above the electron-emitting devices. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of the electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. One example is one in which the other of the electrodes of a plurality of electron-emitting devices arranged in the same column is commonly connected to a wiring in the Y direction. This is a so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.

The surface conduction electron-emitting device to which the present invention can be applied has three characteristics as described above. That is,
When the electron emission from the surface conduction electron-emitting device is equal to or higher than the threshold voltage, it can be controlled by the peak value and the width of the pulse voltage applied between the opposing device electrodes. On the other hand, below the threshold voltage, almost no emission occurs. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulse-like voltage is appropriately applied to each of the devices, a surface conduction electron-emitting device is selected according to an input signal, and the amount of electron emission is determined. Can be controlled.

Hereinafter, based on this principle, an electron source substrate obtained by arranging a plurality of electron-emitting devices to which the present invention can be applied will be described with reference to FIG. In FIG. 7, reference numeral 71 denotes an electron source substrate, 72 denotes an X-direction wiring, and 73 denotes a Y-direction wiring.
74 is a surface conduction electron-emitting device, and 75 is a connection.

The m X-direction wirings 72 are Dx1, Dx
2,..., Dxm, and can be formed of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness and width of the wiring are appropriately designed.
The Y-direction wiring 73 is formed of n of Dy1, Dy2,.
It is formed in the same manner as the X-direction wiring 72. These m X-direction wires 72 and n Y-direction wires 7
3, an interlayer insulating layer (not shown) is provided.
Both are electrically separated (m and n are both positive integers).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 71 on which the X-directional wiring 72 is formed. The material and the production method are appropriately set. The X-direction wiring 72 and the Y-direction wiring 73 are respectively drawn out as external terminals.

A pair of device electrodes (not shown) constituting the surface conduction electron-emitting device 74 are connected to m X-direction wires 72 and n Y-direction wires 73 by a connection 75 made of a conductive metal or the like. It is electrically connected.

The material forming the wiring 72 and the wiring 73, the material forming the connection 75, and the material forming the pair of element electrodes may be partially or entirely the same or different from each other. Good. These materials are appropriately selected, for example, from the above-described materials for the device electrodes. When the material forming the element electrode is the same as the wiring material, the wiring connected to the element electrode can also be called an element electrode.

The X-direction wiring 72 is connected to a scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the surface conduction electron-emitting devices 74 arranged in the X direction.
On the other hand, a modulation signal generating means (not shown) for modulating each column of the surface conduction electron-emitting devices 74 arranged in the Y direction according to an input signal is connected to the Y-direction wiring 73. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device.

In the above configuration, individual elements can be selected and driven independently using simple matrix wiring.

An image forming apparatus configured using such an electron source having a simple matrix arrangement will be described with reference to FIGS. 8, 9 and 10. FIG. 8 is a schematic view showing an example of a display panel of the image forming apparatus, and FIG. 9 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG.
FIG. 2 is a block diagram showing an example of a drive circuit for performing display according to an NTSC television signal.

In FIG. 8, reference numeral 71 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 81, a rear plate on which the electron source substrate 71 is fixed; 86, a fluorescent film 84 on the inner surface of a glass substrate 83;
And a face plate on which a metal back 85 and the like are formed. Reference numeral 82 denotes a support frame, and a rear plate 81 and a face plate 86 are connected to the support frame 82 using frit glass or the like. Reference numeral 88 denotes an envelope, which is sealed by firing at a temperature range of 400 to 500 ° C. for 10 minutes or more in the atmosphere or nitrogen, for example.

Reference numeral 74 denotes a surface conduction electron-emitting device as shown in FIG. Reference numerals 72 and 73 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The envelope 88 includes the face plate 86, the support frame 82, and the rear plate 81, as described above. Since the rear plate 81 is provided mainly for the purpose of reinforcing the strength of the substrate 71, if the substrate 71 itself has sufficient strength, the separate rear plate 81 can be unnecessary. That is, the support frame 82 is directly sealed to the substrate 71, and the envelope 8 is formed by the face plate 86, the support frame 82 and the substrate 71.
8 may be configured. On the other hand, by installing a support (not shown) called a spacer between the face plate 86 and the rear plate 81, the envelope 88 having sufficient strength against atmospheric pressure can be configured.

FIG. 9 is a schematic diagram showing a fluorescent film. The fluorescent film 84 can be composed of only a phosphor in the case of monochrome. In the case of a color fluorescent film, a black conductive material 91 called a black stripe (FIG. 9A) or a black matrix (FIG. 9B) or the like and a fluorescent material 92 may be used depending on the arrangement of the fluorescent materials. it can. The purpose of providing a black stripe and black matrix is
In the case of color display, the color separation between the phosphors 92 of the necessary three primary color phosphors is made black to make color mixing less conspicuous, and a decrease in contrast due to reflection of external light on the phosphor film 84 is suppressed. It is in. Black conductive material 91
As the material of, other than a commonly used material containing graphite as a main component, a material having conductivity and low light transmission and reflection can be used.

As a method of applying the phosphor on the glass substrate 83, a precipitation method or a printing method can be adopted regardless of monochrome or color. Usually, a metal back 85 is provided on the inner surface side of the fluorescent film 84. The purpose of providing a metal back is
The light emitted from the phosphor toward the inner surface is converted into a face plate 8.
Improving the brightness by specular reflection on the 6 side,
The purpose is to function as an electrode for applying an electron beam acceleration voltage, and to protect the phosphor from damage due to collision of negative ions generated in the envelope. The metal back can be manufactured by performing a smoothing process (usually called “filming”) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al using vacuum evaporation or the like.

The face plate 86 further has the fluorescent film 8
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 84 in order to increase the conductivity of the phosphor film 84.

When performing the above-mentioned sealing, in the case of color, it is necessary to make each color phosphor correspond to the electron-emitting device, and sufficient alignment is indispensable.

The image forming apparatus shown in FIG. 8 is manufactured, for example, as follows.

Through an exhaust pipe (not shown), the inside of the envelope 88 is evacuated to a degree of vacuum of 10 ^-4 Pa by using a normal vacuum system having a pump system such as a rotary pump or a turbo pump.
A voltage is applied between the device electrodes through the external terminals Dx1 to Dxm and Dy1 to Dyn, and the above-described forming process is performed.

Next, a step of removing the uncut portion which is the source of the above-mentioned ohmic current component is performed. As a guide for ending the removal step, Raman spectroscopy is typically used for only one surface conduction electron-emitting device.

Next, the above-described activation process is performed in a state where the inside of the envelope 88 is at a degree of vacuum of 10 ⁻⁴ Pa.

Then, similarly to the above-described stabilization process, the inside of the envelope 88 is evacuated through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump and a sorption pump, while appropriately heating. After setting the atmosphere of a vacuum degree of about 10 ⁻⁵ Pa to a sufficiently low level of the organic substance, sealing is performed. In order to maintain the degree of vacuum after sealing the envelope 88,
Getter processing can also be performed. This is the envelope 88
Immediately before or after sealing, a getter (not shown) disposed at a predetermined position in the envelope 88 is heated by heating using resistance heating, high-frequency heating, or the like, to form a deposited film. Processing. The getter is usually composed mainly of Ba or the like.
A vacuum degree of ^-5 Pa or more is maintained.

Next, an example of the configuration of a driving 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. . In FIG.
101 is an image display panel, 102 is a scanning circuit, 103 is a control circuit, 104 is a shift register, 105 is a line memory, 106 is a synchronizing signal separation circuit, 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 101 has terminals Dx1 to Dx
m, terminals Dy1 to Dyn, and a high voltage terminal 87 are connected to an external electric circuit. Terminals Dx1 to Dxm sequentially drive electron sources provided in the display panel 101, 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). A scanning signal for performing the scanning is applied. The terminals Dy1 to Dyn include
A modulation signal for controlling an output electron beam of each element of one row of surface conduction electron-emitting devices selected by the scanning signal is applied. The high voltage terminal 87 is supplied with a DC voltage of, for example, 10 K [V] from a DC voltage source Va, which is sufficient to excite the electron beam emitted from the surface conduction electron-emitting device to excite the phosphor. It is an accelerating voltage for applying high energy.

The scanning circuit 102 will be described. The circuit includes m switching elements (S1 to S
m is schematically shown). Each switching element selects either the output voltage of the DC voltage power supply Vx or 0 [V] (ground level),
It is electrically connected to terminals Dx1 to Dxm of the display panel 101. Each of the switching elements S1 to Sm operates based on a control signal Tscan output from the control circuit 103, and can be configured by combining switching elements such as FETs, for example.

In the case of this example, the DC voltage source Vx determines that the drive voltage applied to the unscanned element is equal to or lower than the electron emission threshold voltage based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. It is set to output such a constant voltage.

The control circuit 103 has a function of matching the operation of each unit so that an appropriate display is performed based on an externally input image signal. The control circuit 103 controls the synchronization signal Tsync sent from the synchronization signal separation circuit 106.
, Tscan, Tsft and T
mry control signals are generated.

The synchronizing signal separating circuit 106 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separating (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 106 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 represented as a DATA signal for convenience. This DATA signal is output to the shift register 10
4 is input.

The shift register 104 is for serially / parallel converting the DATA signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 103. (In other words, the control signal Tsft may be rephrased as a shift clock of the shift register 104). Data for one line of serial / parallel converted image (equivalent to drive data for n electron-emitting devices)
Are output from the shift register 104 as n parallel signals Id1 to Idn.

The line memory 105 is a storage device for storing data for one line of an image for a required time, and stores the contents of Id1 to Idn as appropriate according to a control signal Tmry sent from the control circuit 103. The stored contents are output as Id′1 to Id′n and input to the modulation signal generator 107.

The modulation signal generator 107 outputs the image data I
a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of d′ 1 to Id′n;
The output signal is applied to the surface conduction electron-emitting device in the display panel 101 through the terminals Dy1 to Dyn.

As described above, the electron-emitting device of the present invention has the following basic characteristics with respect to the emission current Ie. That is, electron emission has a clear threshold voltage Vth, and Vth
Electron emission occurs only when the above voltage 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 voltage is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold voltage is applied, electrons are not emitted. A beam is output. At that time, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Further, by changing the pulse width Pw, it is possible to control the total amount of charges of the output electron beam.

Therefore, as a method of modulating the electron-emitting device according to the input signal, a voltage modulation method, a pulse width modulation method, or the like can be adopted. When implementing the voltage modulation method, the modulation signal generator 107 generates a voltage pulse of a fixed length, and a voltage modulation circuit capable of appropriately modulating the peak value of the voltage pulse according to input data. Can be used. When performing the pulse width modulation method, the modulation signal generator 107 generates a voltage pulse having a constant peak value, and modulates the width of the voltage pulse appropriately according to input data. A circuit can be used.

The shift register 104 and the line memory 10
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 necessary to convert the output signal DATA of the synchronization signal separation circuit 106 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronization signal separation circuit 106. Just do it. In this connection, the circuit used for the modulation signal generator 107 is slightly different depending on whether the output signal of the line memory 105 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 107 includes:
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 107 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 107, 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 an image forming 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 through terminals Dx1 to Dxm and Dy1 to Dyn outside the container, the electron-emitting devices can emit electrons. Occurs. A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal 87 to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 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. The input signal has been described in the NTSC system. However, the input signal is not limited to this. In addition to the PAL and SECAM systems,
A TV signal composed of more scanning lines than these (for example,
A high-definition TV system such as the MUSE system can also be adopted.

Next, the electron source and the image forming apparatus having the ladder-type arrangement will be described with reference to FIGS. 11 and 12. FIG.

FIG. 11 is a schematic diagram showing an example of a ladder-type electron source. In FIG. 11, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. Reference numeral 112 denotes common wirings D1 to D10 for connecting the electron-emitting devices 111, and these are drawn out as external terminals. A plurality of electron-emitting devices 111 are arranged on the substrate 110 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 the element rows where the electron beam is to be emitted, and a voltage equal to or lower than the electron emission threshold is applied to the element rows where the electron beam is not desired to be emitted. Common wirings D2 to D9 located between the element rows are, for example, D2 and D3, D4 and D5,
D6 and D7, and D8 and D9 may be formed as one and the same wiring.

FIG. 12 is a schematic diagram showing an example of a panel structure in an image forming apparatus provided with a ladder-type electron source. Reference numeral 120 denotes a grid electrode, 121 denotes an opening through which electrons pass, D1 to Dm denote external terminals, and G1 to Gn denote external terminals connected to the grid electrode 120. 1
Reference numeral 10 denotes an electron source substrate in which the common wiring between the element rows is the same wiring. In FIG. 12, the same portions as those shown in FIGS. 8 and 11 are denoted by the same reference numerals as those shown in these drawings. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 8 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.

In FIG. 12, a grid electrode 120 is provided between the substrate 110 and the face plate 86. The grid electrode 120 is for modulating the electron beam emitted from the surface conduction electron-emitting device 111, and allows the electron beam to pass through a stripe-shaped electrode provided orthogonal to the ladder-type element row. Therefore, one circular opening 121 is provided for each element. The shapes and arrangement positions of the grid electrodes are not limited to those shown in FIG. For example, a large number of passage openings may be provided in a mesh shape as openings, and a grid electrode may be provided around or near the surface conduction electron-emitting device.

The external terminals D1 to Dm and the external terminals G1 to Gn 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 image forming apparatus of the present invention described above is a display apparatus for a television broadcast, a video conference system or a computer, or an image forming apparatus as an optical printer using a photosensitive drum or the like. Etc. can also be used.

[0126]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples, and each element within a range in which the object of the present invention is achieved. This also includes those in which substitutions or design changes have been made.

[Embodiment 1] The basic configuration of a surface conduction electron-emitting device according to this embodiment is the same as the plan view and cross-sectional view of FIGS. 1 (a) and 1 (b).

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

Step-a A 0.5 μm thick silicon oxide film is formed on a cleaned blue plate glass by a sputtering method, and this is used as a substrate 1. On such a substrate 1, a photoresist (RD-2000N-41 / 1) having an opening corresponding to the element electrode pattern is provided.
A mask pattern of Hitachi Chemical Co., Ltd.) was formed, and 5 nm thick Ti and 30 nm thick Pt were sequentially deposited by vacuum evaporation. Dissolve the photoresist pattern with an organic solvent,
The Pt / Ti film was lifted off to form device electrodes 2 and 3 (FIG. 2A). The distance L between the device electrodes is 10 μm, and the width W of the device electrode is 300 μm.

Step-b Next, palladium acetate monoethanolamine (hereinafter referred to as "PAME") was used as a conductive film material.
As a result of TG and XD measurement in air, PAME was 170
Decomposed to metal Pd at around ℃, PdO began to be formed at 280 ℃. A solution in which 0.84 g of PAME was dissolved in 12 g of water was used as an aqueous solution for applying BJ (metal concentration: 2.0 wt%). Using a BJ-type ink jet apparatus as a means for applying the solution, droplets were applied six times between element electrodes 2 and 3 prepared in step-a. This at 350 ° C for 10
For 2 minutes, and then palladium oxide fine particles (Pd
A conductive film 4 made of O) was formed (FIG. 2B). The formed conductive film 4 had a diameter of about 120 μm and a thickness of about 10 nm.

Step-c Next, the substrate 1 is placed in the vacuum container 55 of the vacuum processing apparatus shown in FIG.
And exhausted by an exhaust device 56 composed of a rotary pump and a turbo pump.
The degree of vacuum was set to 0 ⁻³ Pa. Thereafter, a voltage is applied between the device electrodes 2 and 3 from the power supply 51 for applying the device voltage Vf, and subsequently, a hydrogen-nitrogen mixed gas of 2% hydrogen is supplied to a pressure of 5.3 × 10 ⁴ Pa. To form the conductive film 4 in a hydrogen atmosphere,
An electron emission portion 5 was formed (FIG. 2C). The voltage waveform of the energization forming process is as shown in FIG.

In this embodiment, T1 in FIG.
Second, T2 was 10 ms, and the peak value (peak voltage) of the triangular wave was 11 V.

The element current If flowing simultaneously with the application of the voltage
However, the device current gradually decreased immediately after the introduction of hydrogen, and immediately after a large amount of current flowed, the device current sharply decreased.
However, the device current If does not become completely zero,
An element current of about 0.05 mA was present. At this point, the application of the voltage was terminated, and the conductive film 4 was left under an atmosphere of hydrogen for 1 hour to undergo a reduction treatment.

Step-d Subsequently, as shown in FIG. 4, the laser diameter is sufficiently reduced from the laser light source 41 through the prism 42 and the objective lens 43, and the end of the conductive film 4 is irradiated with a laser, 4
(3)-(4)-
In the path (5), the conductive film 4 was heated at 200 ° C. while being taken into the CCD detector 44 and monitoring the palladium oxide Raman line (651 cm ^{−1 by} Raman shift).

When the heat treatment was performed for about 90 minutes, the Raman line of palladium oxide completely disappeared, and the heat treatment was stopped. The laser is Ar ion laser 51
Using a 4.5 nm oscillation line, the laser spot diameter is about 1
μm, and the laser power was 0.5 mW on the conductive film 4.

Step-e Next, the inside of the vacuum vessel 55 is evacuated again by the evacuation device 56 composed of a rotary pump and a turbo pump to 2.7 × 1.
The degree of vacuum was set to 0 ⁻³ Pa. After that, a voltage was applied between the device electrodes 2 and 3 from the power supply 51 for applying the device voltage Vf and the activation process was performed. As a result, the device current was substantially 0 before the activation process. If and the emission current Ie are remarkably changed and increased, and the electron emission portion 5 is formed.

The voltage waveform used in the activation process of this embodiment is as shown in FIG. 3A (however, a rectangular wave instead of a triangular wave). In this embodiment, T1 is 0.5 ms, T2
Was set to 10 msec, and the peak value of the rectangular wave (peak voltage at the time of activation) was set to 16V. The time required for the activation treatment was 40 minutes.

The characteristics of the electron-emitting device manufactured as described above were subsequently measured by using the above vacuum processing apparatus. Specifically, the pressure in the vacuum vessel 55 was set to 1.3 × 10 ⁻⁴ Pa, and 1 KV was applied to the anode electrode 54 at a distance of 5 mm above the device for measurement.

The device voltage Vf was applied between the device electrodes 2 and 3, and the device current If and the emission current Ie flowing at that time were measured. As a result, current-voltage characteristics as shown in FIG. 6 were obtained. In this device, the emission current Ie rapidly increases from an element voltage of about 10 V. At an element voltage of 15 V, the element current If becomes 1.2 mA, the emission current Ie becomes 1.2 μA, and the electron emission efficiency η = Ie / If ( %) Was 0.1%. No ohmic component of the device current was observed.

[Example 2] The same process as in Example 1 was carried out up to the step-c to produce an element having a crack in the conductive film, and then the following steps were carried out.

Step-d Evacuation is performed by the exhaust device 56, and the inside of the vacuum container 55 is 2.7 × 1
After setting the degree of vacuum to 0 ⁻³ Pa, hydrogen was supplied to 2.7 × 10 ⁻¹ Pa.
Introduced. Thereafter, as shown in FIG. 4, the laser diameter is sufficiently reduced from the laser light source 41 through the prism 42 and the objective lens 43, and the end of the conductive film 4 is irradiated with a laser, thereby Raman scattering of the end of the conductive film 4. Light image (3)
(4)-(5), the palladium oxide is taken into the CCD detector 44, and the Raman line of palladium oxide (651 by Raman shift)
The conductive film 4 was heated at 200 ° C. while monitoring cm ⁻¹ ).

When the heat treatment was performed for about 30 minutes, the Raman line of palladium oxide completely disappeared, and the heat treatment was stopped. The laser is Ar ion laser 51
Using a 4.5 nm oscillation line, the laser spot diameter is about 1
μm, and the laser power was 0.5 mW on the conductive film 4.

Next, an activation treatment was performed in exactly the same manner as in Step-e of Example 1.

The characteristics of the electron-emitting device manufactured as described above were measured in the same manner as in Example 1. An element voltage Vf is applied between the element electrodes 2 and 3, and an element current If flowing at that time is applied.
When the emission current Ie was measured, current-voltage characteristics as shown in FIG. 6 were obtained. In this device, the emission current Ie rapidly increases from an element voltage of about 10 V. At an element voltage of 14 V, the element current If becomes 1.5 mA, the emission current Ie becomes 1.5 μA, and the electron emission efficiency η = Ie / If.
(%) Was 0.1%. No ohmic component of the device current was observed.

[Example 3] The same process as in Example 2 was performed up to Step-d to produce an element having a crack in the conductive film, and then the following steps were performed.

Step-e After sufficiently evacuating the inside of the vacuum vessel 55 with an ion pump, 2.7 × 10 ^-1 Pa of acetone was introduced. After that, a voltage was applied between the device electrodes 2 and 3 from the power supply 51 for applying the device voltage Vf, and the activation process was performed. As a result, the device current If and the emission current were 0 before the activation process. The current Ie significantly changed and increased, and the electron-emitting portion 5 was formed.

The voltage waveform used in the activation processing of the present embodiment is as shown in FIG. 3A (however, a rectangular wave instead of a triangular wave). In the present embodiment, T1 is 0.5 ms, T2
Was set to 10 msec, and the peak value of the rectangular wave (peak voltage at the time of activation) was set to 16V. The time required for the activation treatment was 40 minutes.

The characteristics of the electron-emitting device manufactured as described above were measured in the same manner as in Example 1. An element voltage Vf is applied between the element electrodes 2 and 3, and an element current If flowing at that time is applied.
When the emission current Ie was measured, current-voltage characteristics as shown in FIG. 6 were obtained. In this device, the emission current Ie rapidly increases from an element voltage of about 10 V. At an element voltage of 14 V, the element current If becomes 1.6 mA, the emission current Ie becomes 1.6 μA, and the electron emission efficiency η = Ie / If.
(%) Was 0.1%. No ohmic component of the device current was observed.

[Embodiment 4] This embodiment is an example in which an image forming apparatus is manufactured using an electron source substrate in which a large number of surface conduction electron-emitting devices are arranged in a simple matrix.

FIG. 13 is a plan view showing a part of an electron source substrate on which a plurality of conductive films are arranged in a matrix. FIG. 14 is a sectional view taken along the line AA ′ in the figure. However, FIGS. 13 and 14
Those denoted by the same reference numerals indicate the same members. Where 7
Reference numeral 1 denotes an electron source substrate, 72 denotes an X-direction wiring (also referred to as a lower wiring) corresponding to Dxm in FIG. 7, 73 denotes a Y-direction wiring (also referred to as an upper wiring) corresponding to Dyn in FIG. 7, 141 denotes an interlayer insulating layer, 142 is a contact hole for electrical connection between the element electrode 2 and the lower wiring 72.

First, a method of manufacturing an electron source substrate according to the present embodiment will be specifically described with reference to FIGS. Steps -a to h described below correspond to (a) to (d) in FIG. 15 and (e) to (g) in FIG.
Corresponding to

Step-a A 5 nm-thick Cr film and a 600 nm-thick Au film were formed by vacuum evaporation on a substrate 71 having a 0.5 μm-thick silicon oxide film formed on a cleaned blue plate glass by a sputtering method. After sequentially laminating, a photoresist (AZ1370 / Hoechst) is spin-coated with a spinner and baked, then a photomask image is exposed and developed to form a lower wiring pattern, and the Au / Cr deposited film is wet-etched. The lower wiring 72 having a desired shape was formed.

Step-b Next, an interlayer insulating layer 141 made of a silicon oxide film having a thickness of 1.0 μm was deposited by RF sputtering.

Step-c Contact hole 1 was formed in the silicon oxide film deposited in step b.
A photoresist pattern for forming 42 was formed, and the interlayer insulating layer 141 was etched using the photoresist pattern as a mask to form a contact hole 142. Etching is CF ₄
And using the H ₂ gas RIE (Reactive Ion
Etching) method.

Step-d After that, a pattern to be a gap between the device electrodes 2 and 3 and the device electrode is formed by a photoresist (RD-2000N-41 / RD).
Hitachi Chemical Co., Ltd.) and a thickness of 5 n
m of Ti and 100 nm of Ni were sequentially deposited. The above photoresist pattern is dissolved in an organic solvent, and Ni / Ti
The deposited film was lifted off to form device electrodes 2 and 3 having a device electrode interval L of 10 μm and a width W of 300 μm.

Step-e After forming a photoresist pattern of the upper wiring 73 on the device electrodes 2 and 3, 5 nm thick Ti and 500 nm thick Au are sequentially deposited by vacuum evaporation, and unnecessary portions are lifted off to remove unnecessary portions. By removing, the upper wiring 73 of a desired shape was formed.

Step-f The aqueous solution used in Example 1 was dropped between the device electrodes 2 and 3 in the same manner as in Example 1 by using a BJ-type ink jet apparatus, and was heated and baked at 350 ° C. for 10 minutes. Thus, the conductive film 4 made of palladium oxide fine particles was formed.

Step-g: A resist pattern was formed in portions other than the contact hole 142, and a 5 nm-thick Ti film and a 500-mm thick film were formed by vacuum evaporation.
nm of Au was sequentially deposited. Unnecessary portions were removed by lift-off to fill the contact holes 142.

By the above steps, the lower wiring 7 is formed on the substrate 71.
2, interlayer insulating layer 141, upper wiring 73, device electrodes 2 and 3,
The conductive film 4 was formed.

Next, an electron source substrate 71 (FIG. 1) in which a plurality of conductive films 4 manufactured as described above are arranged in a matrix.
An image forming apparatus was manufactured using 3). Figure 8 shows the fabrication procedure.
This will be described with reference to FIG.

First, the electron source substrate 71 was fixed on the rear plate 81, and then 5 mm above the electron source substrate 71.
A face plate 86 (formed by forming a fluorescent film 84 and a metal back 85 on the inner surface of a glass substrate 83) is disposed via a support frame 82, and the face plate 86, the support frame 82, and the rear plate 81 are joined together. Frit glass was applied and sealed by baking in air at 430 ° C. for 10 minutes or more (FIG. 8). The fixing of the electron source substrate 71 to the rear plate 81 was also performed with frit glass.

The phosphor film 84 is used to realize color.
A phosphor having a stripe shape (see FIG. 9A) was formed, a black stripe was formed first, and phosphors 92 of the respective colors were applied to gaps by a slurry method to form a phosphor film 84. As a material of the black stripe, a material mainly containing graphite, which is generally used, was used.

Further, a metal back 85 was provided on the inner surface side of the fluorescent film 84. The metal back 85 is manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 84 after the fluorescent film 84 is manufactured, and then performing vacuum deposition of Al.

The face plate 86 is further provided with a fluorescent film 8.
In some cases, a transparent electrode is provided on the outer surface side of the fluorescent film 84 in order to increase the conductivity of the metal back 8.
5 was omitted because sufficient conductivity was obtained.

The atmosphere in the envelope 88 completed as described above is evacuated by a rotary pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, the outer terminals Dx1 to Dx1.
A voltage was applied between the device electrodes of the electron-emitting device through Dxm and Dy1 to Dyn to perform a forming process. In this embodiment, the forming process is performed for each line by connecting the Y-direction wirings in common. The forming was performed under the conditions employed in Example 1.

In the above-described forming process, the device current If did not completely become 0, but the application of the voltage was terminated and the conductive film 4 was subjected to a reduction process by being left for 1 hour in a hydrogen atmosphere.

Subsequently, the end of the conductive film 4 is irradiated with a laser, and the palladium oxide Raman beam (Raman shift is 65 nm).
While monitoring 1 cm ^-1 ), the conductive film 4 was heated to 200 ° C.
Was heated.

When the heat treatment was performed for about 90 minutes, the Raman line of palladium oxide completely disappeared, and the heat treatment was stopped. Detection of the completion of the removal of the uncut portion after the forming was monitored by monitoring only one element.

Next, an activation process was performed in the same manner as in the step-e of the first embodiment, following the above-described forming process.

Thereafter, an exhaust pipe (not shown) was heated and welded at a degree of vacuum of about 1.3 × 10 ⁻³ Pa and sealed off. Finally, gettering was performed by high-frequency heating in order to maintain the degree of vacuum after sealing.

The external terminals Dx1 to Dxm and Dy1 to Dyn and the high voltage terminal 87 of the panel manufactured as described above were connected to necessary driving systems, respectively, to complete an image forming apparatus. Each surface conduction electron-emitting device is provided with an external terminal Dx
1 to Dxm and Dy1 to Dyn, a scanning signal and a modulation signal are respectively applied from a signal generating means (not shown) to emit electrons. The image was displayed by accelerating the beam, colliding with the fluorescent film 84, exciting and emitting light.

The image forming apparatus according to the present embodiment was able to stably display an image with low current and excellent in bright operation stability.

[Comparative Example 1] An element having an element current of about 0.05 mA at the end of the forming in Step-c of Example 1 was left as it was in a hydrogen atmosphere for 1 hour.
The conductive film 4 was subjected to a reduction treatment. Thereafter, the exhaust device 56
After evacuating to reach a degree of vacuum of 2.7 × 10 ⁻³ Pa, a voltage was applied between the device electrodes 2 and 3 from a power supply 51 for applying a device voltage Vf to perform an activation process. However, the device current If, which was substantially 0 before the activation process,
And the emission current Ie changed significantly and increased. The voltage waveform and the peak value used in the activation process in this comparative example are exactly the same as those in the first embodiment.

The device of this comparative example has a device current If of 0.8 mA and an emission current Ie of 0.62 μA at a device voltage of 14 V.
The electron emission efficiency was 0.08%. However, an ohmic component of the device current at a device voltage of 10 V was observed at about 0.1 mA.

In the electron-emitting device manufactured according to this comparative example, the uncut portion generated in the conductive film 4 at the time of forming contributes to the leak component without being cut by the voltage applied at the time of activation. It is presumed.

[Comparative Example 2] An element which had an element current of about 0.05 mA at the end of the forming in Step-c of Example 1 was left as it was in a hydrogen atmosphere for 1 hour.
The conductive film 4 was subjected to a reduction treatment. Thereafter, after sufficiently exhausting with an ion pump, acetone of 2.7 × 10 ^-1 Pa was introduced, and a voltage was applied between the device electrodes 2 and 3 from a power supply 51 for applying a device voltage Vf. When the activation process was performed, the device current If and the emission current Ie, which were substantially 0 before the activation process, were significantly changed and increased, and the electron emission portion 5 was formed. The voltage waveform and the peak value used in the activation process in the comparative example are the same as those in the first embodiment.
Is exactly the same as

In the device of this comparative example, at a device voltage of 14 V, the device current If is 1.1 mA, and the emission current Ie is 0.73 μA.
And the electron emission efficiency was 0.07%. However, an ohmic component of the device current at a device voltage of 10 V was observed at about 0.1 mA.

Also in the electron-emitting device manufactured according to this comparative example, the uncut portion generated in the conductive film 4 at the time of forming contributes to the leak component without being cut by the voltage applied at the time of activation. It is presumed that there is.

[0179]

As described above, according to the present invention, even when a partially uncut portion occurs in the conductive film after forming, the change in the state of the uncut portion is monitored. However, by performing the step of removing the portion, a favorable crack region can be formed while suppressing unnecessary aggregation or the like of the conductive film. As a result, the electron-emitting device obtained through the subsequent activation step can be driven without consuming an element current due to an ohmic component and consuming unnecessary power, and has stable electron-emitting characteristics. .

By arranging a plurality of the electron-emitting devices of the present invention, an electron source having excellent operation stability can be manufactured with high yield.

Further, in the image forming apparatus of the present invention, a bright image having excellent operation stability can be formed at a low current, and, for example, a color flat television is realized.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a surface conduction electron-emitting device which is an example of the electron-emitting device of the present invention.

FIG. 2 is a diagram illustrating an example of a method for manufacturing the electron-emitting device of FIG.

FIG. 3 is a schematic diagram showing an example of a voltage waveform in a current forming process that can be employed in manufacturing the electron-emitting device of the present invention.

FIG. 4 is a schematic view for explaining a step of removing a remaining portion in the method for manufacturing an electron-emitting device according to the present invention.

FIG. 5 is a schematic configuration diagram showing an example of a vacuum processing apparatus (measurement evaluation apparatus) that can be used for manufacturing the electron-emitting device of the present invention.

FIG. 6 shows the emission current I of the surface conduction electron-emitting device of the present invention.
FIG. 6 is a diagram showing a typical example of a relationship between the element voltage e and the element current If and the element voltage Vf.

FIG. 7 is a schematic diagram showing an example of an electron source having a simple matrix arrangement to which the present invention can be applied.

FIG. 8 is a schematic diagram illustrating an example of a display panel of an image forming apparatus to which the present invention can be applied.

FIG. 9 is a schematic diagram illustrating an example of a fluorescent film in a display panel.

FIG. 10 is a block diagram illustrating an example of a drive circuit for performing display on the image forming apparatus in accordance with an NTSC television signal.

FIG. 11 is a schematic diagram showing an example of an electron source having a ladder-type arrangement to which the present invention can be applied.

FIG. 12 is a schematic diagram illustrating an example of a display panel of an image forming apparatus to which the present invention can be applied.

FIG. 13 is a schematic view of an electron source with matrix wiring according to a fourth embodiment.

14 is a schematic cross-sectional view taken along the line A-A 'of FIG.

FIG. 15 is a manufacturing process diagram of the electron source according to the fourth embodiment.

FIG. 16 is a manufacturing process diagram of the electron source according to the fourth embodiment.

FIG. 17 is a plan view of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive film 5 Electron emission part 6 Crack area 7 Uncut part 41 Laser light source 42 Prism 43 Objective lens 44 CCD detector 45 Computer 50 Ammeter for measuring element current If 51 Electron emission A power supply 52 for applying a device voltage Vf to the device 52 An ammeter for measuring an emission current Ie emitted from the electron emission section 5 53 A high-voltage power supply for applying a voltage to the anode electrode 54 Emission from the electron emission section 5 Anode electrode 55 for capturing electrons to be emitted 55 Vacuum container 56 Exhaust pump 71 Electron source substrate 72 X-directional wiring 73 Y-directional wiring 74 Surface conduction electron-emitting device 75 Connection 81 Rear plate 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate 87 High voltage terminal 88 Enclosure 91 Black Electrical material 92 Phosphor 101 Display panel 102 Scanning circuit 103 Control circuit 104 Shift register 105 Line memory 106 Synchronous signal separation circuit 107 Modulation signal generator 110 Electron source substrate 111 Electron emitting element 112 Common wiring for wiring electron emitting element 120 Grid Electrode 121 Opening for passing electrons 141 Interlayer insulating layer 142 Contact hole

Claims (14)

[Claims] 1. A method of manufacturing an electron-emitting device including a conductive film having an electron-emitting portion between a pair of device electrodes formed on a substrate, wherein the step of forming the electron-emitting portion on the conductive film comprises: A step of forming a crack in the conductive film by applying an electric current; a step of increasing the resistance of a part of the conductive film while detecting a state of the conductive film; and a step of forming the conductive film in an atmosphere containing an organic substance. An activation step of applying a current to the conductive film. 2. The step of increasing the resistance of a part of the conductive film while detecting the state of the conductive film includes detecting a change in state of a metal oxide constituting at least a part of the conductive film. The method for manufacturing an electron-emitting device according to claim 1, further comprising a step of increasing the resistance of a portion of the metal oxide. 3. The method for manufacturing an electron-emitting device according to claim 1, wherein Raman spectroscopy is used as a method for detecting the state of the conductive film. 4. The electron according to claim 1, wherein the step of increasing the resistance of a part of the conductive film is a step of aggregating a part of the conductive film. A method for manufacturing an emission element. 5. The method according to claim 4, wherein the step of aggregating a part of the conductive film includes a heating step. 6. The method according to claim 4, wherein the step of aggregating a part of the conductive film includes a hydrogen reduction step. 7. An electron-emitting device manufactured by the method according to claim 1. 8. The electron-emitting device according to claim 7, wherein the electron-emitting device is a surface conduction electron-emitting device. 9. A method for manufacturing an electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting devices are:
A method for manufacturing an electron source, wherein the method is manufactured by the method according to claim 1. 10. An electron source in which a plurality of electron-emitting devices are arranged on a substrate, wherein the electron-emitting devices are arranged on a substrate.
9. An electron source, which is the electron-emitting device according to item 8. 11. The electron source according to claim 10, wherein the plurality of electron-emitting devices are wired in a matrix. 12. The electron source according to claim 10, wherein the plurality of electron-emitting devices are wired in a ladder shape. 13. A method for manufacturing an image forming apparatus, comprising: an electron source having a plurality of electron-emitting devices arranged on a substrate; and an image forming member for forming an image by irradiating an electron beam emitted from the electron source. 10. The method for manufacturing an image forming apparatus according to claim 9, wherein the electron source is manufactured by the method according to claim 9. 14. An image forming apparatus comprising: an electron source having a plurality of electron-emitting devices arranged on a substrate; and an image forming member that forms an image by irradiating an electron beam emitted from the electron source. An image forming apparatus, wherein the electron source is the electron source according to claim 10.