JPH09330648A - Electron emitting element, electron source, image forming device, and manufacture of them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron emitting element having a stable characteristic and high efficiency and display a high-intensity image abundant in operation stability by covering a conductive film constituting the electron emitting element and having an electron emission section with a thermal decomposition product of a metal compound. SOLUTION: An electron emission section 5 is formed with high-resistance cracks formed on a part of a conductive film 4, and it depends on the thickness, nature, material, and manufacture of the conductive film 4. Conductive fine grains may exist in the electron emission section 5. The conductive fine grains contain a part or all of the elements constituting the conductive film 4. The element emission section 5 and the conductive film 4 near it contain carbon or a carbon compound after the specific activating process. A thermal decomposition product 6 of a metal compound is covered with at least the conductive film 4.

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 in which a large number of the electron-emitting devices are arranged, an image forming apparatus such as a display device or an exposure device configured by using the electron source,
And their production methods.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, which are a thermoelectron-emitting device and a cold cathode electron-emitting device. Field emission type (hereinafter, referred to as "FE")
Type ". ), Metal / insulating layer / metal type (hereinafter referred to as “MI
It is called "M 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).

An example of the MIM type is 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 element electrode spacing L in the figure is 0.5 to 1 mm, and W ′ is 0.1 m.
It is set in m.

In these surface conduction electron-emitting devices, it is general that the electron-emitting portion 5 is formed in advance on the conductive film 4 by an energization process called energization forming before the 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. In the electron emitting portion 5, a crack is generated in a part of the conductive film 4, 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 researched. 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 formed in an array, surface conduction electron-emitting devices are arranged in parallel and both ends (both device electrodes) of each surface conduction electron-emitting device are wired. An electron source in which a large number of rows (also referred to as a ladder-type arrangement) in which each of the rows is connected by (also referred to as common wiring) is mentioned (for example, JP-A-64-31332, 1-283749, and JP-A-2-283749). -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 electron emission efficiency means, for example, in the case of the surface conduction electron-emitting device described above, when a voltage is applied across the conductive film, a current (hereinafter referred to as "device current") flowing through the conductive film is called. .) And the current emitted in a vacuum (hereinafter referred to as “emission current”), and 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.

However, the above-mentioned M. In the Hartwell electron-emitting device, satisfactory electron-emitting characteristics and electron-emitting efficiencies have not always been obtained. In fact, it is extremely difficult to provide

When a large number of electron-emitting devices are manufactured on the same substrate, such as an electron source used in an image forming apparatus,
It is desirable that a plurality of electron-emitting devices (for example, one line) can be formed at the same time, but if the forming power per device is large, the number of devices that can be formed at the same time is limited, which is not preferable. In order to reduce the forming power, it is preferable that the resistance value of the conductive film is large. On the other hand, at the time of driving after the completion of the device, it is preferable that the resistance value of the conductive film is small in order to suppress voltage drop or power consumption in the conductive film.

When the resistance value of the conductive film is set to a desired value to satisfy the above requirements, it is usually several to several tens n.
It is necessary to control the film thickness on the order of m, or control the film quality on the structure surface composed of an aggregate of fine particles. However, both of them have problems in controllability at the time of producing a conductive film and subsequent thermal stability and chemical stability.

In view of the above problems, the present invention provides an electron-emitting device capable of realizing good electron-emitting characteristics and long life in a simple manufacturing process, and further, a higher-quality image can be formed. An object is to provide an image forming apparatus.

[0019]

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

That is, the first aspect of the present invention is an electron-emitting device including a conductive film having an electron-emitting portion between a pair of device electrodes provided on a substrate so as to face each other, and at least the conductive film is a metal. An electron-emitting device characterized by being coated with a thermal decomposition product of a compound.

The electron emitting device according to the first aspect of the present invention is further characterized in that "the conductive film contains the same metal element as the metal element of the thermal decomposition product of the metal compound".
“The metal element is Pd”, “the conductive film is a fine particle aggregate”, “the metal compound is
It is any one selected from metallocene, metal carbonyl, and metal acetylacetonate. "" The metal compound has a vapor pressure of 0.1 mTorr at 300 ° C.
Or more ”,“ carbon or / or
And "containing a carbon compound" and "a surface conduction electron-emitting device".

A second aspect of the present invention is the method for manufacturing an electron-emitting device according to the first aspect of the present invention, which comprises at least a step of forming an electron-emitting portion in the conductive film and an atmosphere containing a metal compound gas. A method for manufacturing an electron-emitting device, which comprises heating the substrate below and depositing a thermal decomposition product of a metal compound on at least the conductive film under selective deposition conditions.

A third aspect of the present invention is an electron source which emits electrons in response to an input signal, wherein a plurality of the electron-emitting devices according to the first aspect of the present invention are arranged on the same substrate. It is in the electron source.

The third electron source of the present invention is further characterized in that "a plurality of the electron-emitting devices are arranged in a ladder shape, and both device electrodes of each electron-emitting device are arranged in two rows in parallel. It is connected to the wiring and has modulation means. "
That is, "the plurality of electron-emitting devices are arranged in a matrix, one device electrode of each electron-emitting device is connected to a row wiring, and the other device electrode of each electron-emitting device is connected to the row wiring. “Connected to orthogonal column wiring” is also included.

A fourth aspect of the present invention is the method of manufacturing an electron source according to the third aspect of the present invention, wherein the plurality of electron-emitting devices are manufactured by the second method of the present invention. In the manufacturing method.

A fifth aspect of the present invention is an apparatus for forming an image based on an input signal, wherein the apparatus comprises at least the third electron source of the present invention and an image forming member. Image forming apparatus.

Further, a sixth aspect of the present invention is the method for producing an image forming apparatus according to the fifth aspect of the present invention, wherein the electron source is produced by the fourth aspect of the present invention.

According to the present invention, even when a conductive film capable of forming an electron emitting portion with a relatively low forming power is used, the metal compound is thermally decomposed and formed on the conductive film after forming. Electron emission capable of suppressing the voltage drop and power consumption when driving the device, and maintaining stable electron emission characteristics for a long time by coating the same with a thermal decomposition product having sufficient heat resistance. An element can be realized, and further, an image forming apparatus capable of forming a stable and good image for a long time can be realized.

Further, the deposition of the thermal decomposition product of the metal compound can be carried out under the so-called selective deposition condition in which it is deposited on the conductive material and is hard to deposit on the insulating material. Even when a large number of elements are simultaneously formed on a flexible substrate, a step of removing a deposit attached to a portion requiring insulation property later is unnecessary, so that an image forming apparatus with a large screen is particularly manufactured. The manufacturing process at that time can be simplified.

[0030]

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

The electron-emitting device to which the present invention can be applied is a surface conduction electron-emitting device which is a kind of the cold cathode electron-emitting device as described above.

The basic structure of the surface conduction electron-emitting device to which the present invention can be applied is roughly classified into a planar type and a vertical type.

First, a planar type surface conduction electron-emitting device will be described.

1A and 1B are schematic views showing an example of the structure of a flat surface conduction electron-emitting device according to the present invention. FIG. 1A is a plan view and FIG. 1B is a vertical sectional view. In FIG. 1, 1
Is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, 5 is an electron emitting portion, and 6 is a thermal decomposition product of a metal compound.

Examples of the substrate 1 include quartz glass, glass with 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.
Common 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
It is appropriately selected from a printed conductor composed of a metal such as —Ag or a metal oxide and glass, a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor conductor material such as polysilicon.

The element electrode spacing L, the element electrode length W, the shape of the conductive film 4, etc. are designed in consideration of the applied form. The element electrode spacing L can be preferably in the range of several hundreds nm to several hundreds μm, and more preferably several μm to several tens μm in consideration of the voltage applied between the device electrodes.
Can be in the range of.

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.
It is also possible to have a structure in which the conductive film 4 and the opposing device electrodes 2 and 3 are laminated in this order on top.

As the conductive 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 the step coverage to the element electrodes 2 and 3, the resistance value between the element electrodes 2 and 3, the forming conditions described later, and the like. Usually 0.1n
It is preferably several times several m to several hundreds of nm, and more preferably 1 nm to 50 nm.

In general, the thermal stability of the conductive film 4 is an important parameter that governs the life of electron emission characteristics, and it is desirable to use a material having a higher melting point as the material of the conductive film 4. However, generally, the higher the melting point of the conductive film 4, the more difficult the energization forming described later becomes, and a large amount of electric power is required to form the electron emitting portion. Further, in the electron emission portion obtained as a result, there may occur a problem that an applied voltage (threshold value voltage) capable of emitting electrons increases.

In the present invention, a material having a high melting point is not particularly required as the material of the conductive film 4, and a material / form capable of forming a good electron emitting portion with a relatively low forming power is selected. You can As an example of the material satisfying the above conditions, a conductive material such as Ni, Au, PdO, Pd, or Pt having a film thickness showing a resistance value of Rs of 10 ¹ to 10 ⁷ Ω / □ is preferably used. Rs is the resistance R measured in the length direction of a thin film having a width w and a length l,
= Amount that appears when Rs (l / w) is set. The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure not only in a state in which the fine particles are individually dispersed and arranged, but also in a state in which the fine particles are adjacent to each other or overlap each other (some fine particles may To form an island-like structure as a whole). The particle size of the fine particles is in the range of several Å to several hundred nm, preferably 1 nm.
To 20 nm.

The term "fine particles" is frequently used in this specification, and its meaning will be described.

Small particles are called "fine particles", and particles smaller than this are called "ultrafine particles". It is widely known that particles smaller than "ultrafine particles" and having a number of atoms of about several hundreds or less are called "clusters".

However, each boundary is not strict, and changes depending on what kind of property is focused on for classification. 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 Fine Particles" (edited by Yoshio Kinoshita, published by Kyoritsu Shuppan on September 1, 1986), "the term" fine particles "used in this paper is about 2-3 μm to 10 nm. Up to about 10 nm, especially when referred to as ultrafine particles, the particle size is from about 10 nm to
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 from 2 to several tens to several hundreds, it is called a cluster. (Page 195, lines 22 to 26).

In addition, the definition of "ultrafine particles" in the "Hayashi / ultrafine particle project" of the New Technology Development Corporation has the following lower limit of the particle size.

In the "Ultrafine particle project" (1981-1986) of the Creative Science and Technology Promotion System, particles having a size (diameter) in the range of about 1 to 100 nm are called "ultrafine particles". 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 Shuppan 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).

Based on the above general term,
In the present specification, "fine particles" are aggregates of a large number of atoms and molecules, the lower limit of the particle size is several Å to 1 nm, and the upper limit thereof is several μm.
I will refer to something of a degree.

The electron-emitting portion 5 is constituted by a high-resistance crack formed in a part of the conductive film 4 and depends on the film thickness, film quality and material of the conductive film 4 and a method such as energization forming which will be described later. It will be. Inside the electron emitting portion 5, 1
There may be conductive fine particles having a particle size in the range of nm to several tens of nm. The conductive fine particles contain some or all of the elements of the material forming the conductive film 4. The electron-emitting portion 5 and the conductive film 4 in the vicinity thereof have carbon or a carbon compound when an activation process described later is performed.

The thermal decomposition product 6 of the metal compound covers at least the conductive film 4. This thermal decomposition product 6 is
When the device is driven, the temperature in the vicinity of the electron-emitting portion becomes high due to Joule heat due to the device current, so that it is desirable to have sufficient heat resistance in consideration of the durability of the device.

Next, a vertical type surface conduction electron-emitting device will be described.

FIG. 2 is a schematic view showing a structural example of the vertical surface conduction electron-emitting device of the present invention. The same parts as those shown in FIG. 1 are designated by the same reference numerals as those in FIG. The code is attached. 21 is a step forming part. The substrate 1, the device electrodes 2 and 3, the conductive film 4, the electron emitting portion 5, and the thermal decomposition product 6 of the metal compound may be made of the same materials as in the case of the above-mentioned planar surface conduction electron emitting device. it can. The step forming portion 21 can be made of an insulating material such as SiO ₂ formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The film thickness of the step forming portion 21 corresponds to the device electrode interval L of the flat surface conduction electron-emitting device described above, and is several hundred nm.
To several tens of μm. This film thickness is
Although it is set in consideration of the manufacturing method of the step forming portion and the voltage applied between the element electrodes, the range of several tens nm to several μm is preferable.

The conductive film 4 is laminated on the device electrodes 2 and 3 after the device electrodes 2 and 3 and the step forming portion 21 are formed. The electron-emitting portion 5 is the step forming portion 21 in FIG.
However, depending on manufacturing conditions, forming conditions, and the like, the shape and position are not limited to these.

There are various methods for manufacturing the surface conduction electron-emitting device of the present invention, one example of which will be described with reference to FIG. In FIG. 3, 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 thoroughly washed with a detergent, pure water, an organic solvent, etc., and after the element electrode material is deposited by the vacuum deposition method, the sputtering method, etc., the substrate 1 is deposited on the substrate 1 by, for example, the photolithography technique. The device electrodes 2 and 3 are formed (see FIG.
(A)).

2) On the substrate 1 provided with the device electrodes 2 and 3,
An organometallic solution is applied to form an organometallic film. 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. The organic metal film is heated and baked, and is patterned by lift-off, etching or the like to form the conductive film 4 (FIG. 3).
(B)). Here, the method of applying the organic metal solution has been described as an example, but the method of forming the conductive film 4 is not limited to this, and a vacuum deposition method, a sputtering method, a chemical vapor deposition method,
It is also possible to use a dispersion coating method, a dipping method, a spinner method, or the like.

3) Subsequently, a forming process 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 supply (not shown) between the device electrodes 2 and 3, an electron emitting portion 5 having a changed structure is formed at the portion of the conductive film 4 (FIG. 3C). According to the energization forming, the conductive film 4 is locally formed with a portion having a structural change such as breakage, deformation or alteration. This portion constitutes the electron emission section 5. FIG. 4 shows an example of the voltage waveform of the energization forming.

The voltage waveform is particularly preferably a pulse waveform.
For this purpose, the method shown in FIG. 4 (a) in which a pulse having a constant pulse peak value is continuously applied and the method shown in FIG. 4 (b) in which a pulse is applied while increasing the pulse peak value are used. 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. The peak value of the triangular wave (peak voltage during energization forming) is
It is appropriately selected depending on the form of the surface conduction electron-emitting device. Under such conditions, for example, a 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, the case of applying the voltage pulse while increasing the pulse crest value will be described with reference to FIG.
T1 and T2 in FIG. 4B can be the same as those shown in FIG. 4A. 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 break or deform the conductive film 4 during the pulse interval T2 and measure the current. For example, a current flowing when a voltage of about 0.1 V is applied is measured, and a resistance value is obtained. When a resistance of 1 MΩ or more is indicated, the energization forming is terminated.

4) After the electron emitting portion 5 is formed on the conductive film 4 by energization as described above, when the metal compound gas is introduced onto the substrate while heating the entire substrate, the metal compound gas is thermally decomposed, Thermal decomposition products 6 are deposited (FIG. 3).
(D)). The deposition of such pyrolysis products is carried out under the so-called selective deposition condition in which it is deposited on the conductive material and is difficult to deposit on the insulating material. The manufacturing process is greatly simplified because the process of removing the slag is unnecessary. That is, since the photolithography process is unnecessary, the effect is great especially when an image forming apparatus having a large screen is manufactured.

Examples of the metal compound used in the above step include an alkyl metal, an organometallic complex represented by a metallocene, a benzene complex, an alkene complex, an acetylacetonato complex, a chelate complex represented by a hexafluoroacetonate complex, and a metal. Carbonyl, etc. By decomposing these metal compounds, a metal or a thin film containing a metal as a main component is deposited. The metal complex used in the present invention is preferably one in which a thin film having conductivity is formed by thermal decomposition. The metal compound is sent to the substrate under reduced pressure only by its own vapor or with an inert gas such as hydrogen, nitrogen, or argon. 300 ° C for metal compounds
And preferably has a vapor pressure of 1 mTorr or more,
Further, it is preferably 1 mTorr or more at 250 ° C.

Specifically, Al (CH ₃ ) ₃ , Al (C
_{2 H 5) 3, Co (} C 5 H 5) 2, Fe (C 5 H 5)
_{2, Cr (C 6 H 6} ) 2, Mo (C 6 H 6) 2, Au
(CH ₃ ) ₂ (C ₅ H ₇ O ₂ ), Pt (C ₅ H ₇ O ₂ ) ₂
, Au (CH ₃ ) ₂ (C ₅ HF ₆ O ₂ ), W (CO) ₆
, Mo (CO) _{6 and the} like.

The selective deposition condition means that the film is deposited on the conductor but not on the insulator. In the present invention, it is not deposited on the insulating substrate 1,
The film forming conditions are set so as to deposit on the conductive film 4.
In this case, when a metal compound containing the same metal as the conductive film 4 is used, the metal is likely to be deposited particularly on the conductive film 4.
It is considered that this is because the crystallinity or the lattice constant of the deposit and the underlying layer are the same. Further, since the decomposition temperature is lower than usual, selective deposition is easy.

As described above, it is preferable that the conductive film 4 has a large resistance during forming and a small resistance during subsequent use (driving), but after the thermal decomposition product 6 of the metal compound is formed. By depositing on the conductive film 4, it is possible to satisfy such a requirement.

5) It is preferable that the element on which the thermal decomposition product 6 of the metal compound is deposited after forming is subjected to a treatment called an activation step. By this activation process, the device current If and the emission current Ie can be remarkably changed.

The activation step can be carried out, for example, by repeatedly applying a pulse between the device electrodes 2 and 3 in the same manner as the energization forming 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 alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols,
Examples thereof include organic acids such as carboxylic acid and sulfonic acid, and specifically, C _n H such as methane, ethane, and propane.
Saturated hydrocarbon represented by _{2n + 2,} ethylene, propylene C _n H _2n such unsaturated hydrocarbon represented by composition formula such as benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methyl amine , 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 element from the organic substance existing in the atmosphere, and the element current If and the emission current I
e changes significantly.

Carbon and carbon compounds include, for example, graphite (so-called HOPG, PG, and GC). HOPG is a nearly 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 grain having a size of about 2 nm and further disordered 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 process can be appropriately determined while measuring the device current If and the emission current Ie.
The pulse width, pulse interval, pulse peak value, etc. are set appropriately.

The activation step can also be performed by applying a voltage pulse to the device in the same manner as above in an atmosphere containing a vapor of a metal compound to deposit the metal or its compound. As the metal compound that can be used as the vapor at this time, the same metal compound as that used in the step of depositing the thermal decomposition component can be used.

6) It is preferable that the electron-emitting device obtained through these steps is subjected to a stabilizing 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.

When an oil diffusion pump or a rotary pump is used as an exhaust device in the activation step and an organic gas derived from an oil component generated from this 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 ⁻⁸ Torr or less, more preferably 1 × 10 ⁻¹⁰ Torr 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 condition at this time is 80 to 200 ° C., preferably 150 ° C.
As described above, it is desirable that the treatment is performed 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 ⁻⁷ Torr or less,
Further, the pressure is particularly preferably 1 × 10 ⁻⁸ Torr or less.

It is preferable to maintain the atmosphere at the time of driving after the stabilization process is the atmosphere at the end of the above-mentioned stabilization process, but it is not limited to this, and if the organic substance is sufficiently removed. Even if the pressure itself rises to some extent, 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 to which the present invention is applicable obtained through the above steps will be described with reference to FIGS. 5 and 6.

FIG. 5 is a schematic view showing an example of a vacuum processing apparatus, and this vacuum processing apparatus also has a function as a measurement / 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, 55 is a vacuum container, and
Reference numeral 6 denotes an exhaust pump. An electron-emitting device is provided in the vacuum vessel 55. Further, 51 is a power source for applying a device voltage Vf to the electron-emitting device, 50 is an ammeter for measuring a device current If flowing between the device electrodes 2 and 3, and 54 is emitted from the electron-emitting portion 5 of the device. Is an anode electrode for capturing the emission current Ie, 53 is a high voltage power source for applying a voltage to the anode electrode 54, and 52 is an ammeter for measuring the emission current Ie emitted from the electron emission portion 5. As an example, the voltage of the anode electrode 54 is 1 kV to 1
The measurement can be performed in the range of 0 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 container 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 ultra high 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 above-described energization forming can be performed.

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

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

That is, first, when an element voltage of a certain voltage (referred to as a threshold voltage; Vth in FIG. 6) or more is applied to this element, the emission current Ie rapidly increases, while at the threshold voltage Vth or less, the emission current Ie increases. Almost no Ie is detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie monotonically increases with the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.

Thirdly, the emitted charges trapped in the anode electrode 54 (see FIG. 5) depend on the time for applying the device voltage Vf. 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 can be understood from the above description, the surface-conduction type 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 element current If monotonously increases with respect to the element voltage Vf (hereinafter referred to as “MI characteristic”). However, the element current If is a voltage control type with respect to the element voltage Vf. Negative resistance characteristics (hereinafter referred to as "VCNR characteristics"
Say. ) (Not shown). These properties can be controlled by controlling the steps described above.

Application examples 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 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.

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 below 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 and 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
An interlayer insulating layer (not shown) is provided between
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 a vacuum vapor 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 respectively connected to m X-direction wirings 72 and n Y-direction wirings 73 by connecting wires 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 the same or different in some or all of the constituent elements. Good. These materials are appropriately selected, for example, from the above-mentioned material for the device electrode. 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.

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 is connected to the X-direction wiring 72.
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 the scanning signal and the modulation signal applied to the device.

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

An image forming apparatus constructed by using an electron source having such 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, 71 is an electron source substrate on which a plurality of electron-emitting devices are arranged, 81 is a rear plate on which the electron source substrate 71 is fixed, and 86 is 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.

74 is an 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 is composed of 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 the 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 for applying the phosphor to the glass substrate 83, a precipitation method, a printing method or the like 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.
Improve the brightness by reflecting the light 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 is further provided with a 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 the above-mentioned sealing is performed, in the case of color, it is necessary to associate each color phosphor with the electron-emitting device, and sufficient alignment is indispensable.

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

[0107] Within the envelope 88, similar to the aforementioned stabilization step, while being heated appropriately, ion pump, by an exhaust device not using oil, such as a sorption pump evacuated through an exhaust pipe (not shown), 10 ^- Sealing is performed after an atmosphere of a vacuum degree of about ⁷ Torr with a sufficiently small amount of organic substances. In order to maintain a vacuum degree after the envelope 88 is sealed, a getter process may be performed. This is because 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 immediately before or after the envelope 88 is sealed. This is a process for forming a deposited film. A getter typically contains Ba as a principal component, the adsorption effect of the vapor deposition film, for example, 1 × 10 ^-7
It maintains the degree of vacuum of Torr or more. here,
The steps after the forming process of the surface conduction electron-emitting device can be set appropriately.

Next, a configuration example of a drive circuit for performing television display based on a television signal of the NTSC system on a display panel constructed by using an electron source having 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 sync 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 to connect 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.

Next, 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 non-scanned 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 image signal input from the outside. 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 sync signal separation circuit 106 is a circuit for separating a sync signal component and a luminance signal component from an NTSC 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 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 serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and is based on the control signal Tsft sent from the control circuit 103. The control signal Tsft may be rephrased as the 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 to which the present invention can be applied has the following basic characteristics regarding 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 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 this time, the pulse peak value V
By changing m, the intensity of the output electron beam can be controlled. 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 carrying out the pulse width modulation method, the modulation signal generator 107 uses a pulse width modulation method that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to the 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 sync signal separation circuit 106 into a digital signal. For this, an A / D converter is provided at the output section of the sync signal separation circuit 106. Just go. 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, the modulation signal generator 107 may be an amplifier circuit using, for example, an operational amplifier or the like, and a level shift circuit or the like may be added if 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 forming apparatus to which the present invention having such a structure can be applied, electron emission is performed by applying a voltage to each electron-emitting device via the terminals Dx1 to Dxm and Dy1 to Dyn outside the container. 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 above-mentioned ladder-type electron source and image forming apparatus will be described with reference to FIGS. 11 and 12.

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. For example, the common wirings D2 to D9 located between the element rows may be formed by integrating D2 and D3 into 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 through holes may be provided as openings as meshes, and grid electrodes may be provided around or near the surface conduction electron-emitting device.

The external terminals D1 to Dm and the grid external terminals G1 to Gn are electrically connected to a control circuit (not shown).

In the image forming apparatus of this example, the modulation signals for one image line are simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one column at a time. This makes it possible to control the irradiation of the phosphor with each electron beam and display the image line by line.

The image forming apparatus of the present invention described above is an image forming apparatus as an optical printer including a photosensitive drum or the like in addition to a display device for television broadcasting, a display device such as a television conference system or a computer. Etc. can also be used.

[0131]

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 structure of a basic surface conduction electron-emitting device according to this embodiment is the same as the plan view and the sectional view of FIGS. 1 (a) and 1 (b). In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, 5 is an electron emitting portion, and 6 is a thermal decomposition product of a metal compound.

The method of manufacturing the surface conduction electron-emitting device according to this example is basically the same as that shown in FIG. 3, and the basic steps of the device according to this example will be described below with reference to FIGS. 1 and 3. The various configurations and manufacturing methods will be described in order.

Step-a A silicon oxide film having a thickness of 0.5 μm is formed on the cleaned soda-lime glass by a sputtering method, and this is used as the substrate 1. On this substrate 1, a mask pattern of photoresist (RD-2000N-41 / manufactured by Hitachi Chemical Co., Ltd.) having openings corresponding to the electrode patterns is formed, and Ti of 5 nm in thickness and 100 nm in thickness is formed by a vacuum deposition method. Ni was sequentially deposited. Dissolve the photoresist in an organic solvent and use Ni / Ti
The film was lifted off to form device electrodes 2 and 3 (see FIG. 3).
(A)). Element electrode spacing L is 10 μm, element electrode width W
Is 300 μm.

Step-b A Cr film having a thickness of 100 nm is formed on the above device by a vacuum deposition method, an opening corresponding to the pattern of the conductive film is formed by a photolithography technique, and a Cr mask for forming the conductive film is formed. Was formed. A solution of an organic Pd compound (ccp4230 / Okuno Pharmaceutical Co., Ltd.) was applied thereon using a spinner, and heated and baked at 300 ° C. for 10 minutes to form a conductive film containing PdO as a main component. . The thickness of this film was 10 nm. Subsequently, the Cr mask is removed by wet etching, and the PdO fine particle film is lifted off to form a conductive film 4 having a desired pattern.
Was formed (FIG. 3B). The resistance value of the conductive film 4 is
Rs = 2 × 10 ⁴ Ω / □.

Step-c Next, the substrate 1 is placed in the vacuum container 55 of the vacuum processing apparatus shown in FIG.
Installed in the sample holder (not shown) inside, and exhaust pump 56
The interior of the vacuum container 55 was evacuated to a vacuum degree of 1 × 10 ⁻⁵ Torr. After that, a voltage is applied between the element electrodes 2 and 3 from a power source 51 for applying the element voltage Vf to the element,
Energization forming was performed to form the electron emitting portion 5 (FIG. 3C). The voltage waveform of the energization forming process is shown in Fig. 4.
It is shown in (b).

In this embodiment, T1 in FIG. 4B is set to 1 m.
s and T2 were set to 10 ms, and a triangular wave pulse whose peak value was gradually increased was used. Further, during the forming process, a 0.1 V resistance measurement pulse was inserted within the pause time of the forming pulse, and the forming process was terminated when the resistance value exceeded 1 MΩ. The peak value of the pulse at the end was about 5.0 V in a typical device.

Step-d The substrate 1 after forming is heated to 100 ° C., and W (C
O) ₆ gas was introduced into the vacuum container 55 at 5 mTorr for 5 minutes. As a result, W was deposited on the device electrodes 2 and 3 and the conductive film 4, but W was not deposited on the surface of other insulating substrates (FIG. 3D).

Step-e Subsequently, after the W (CO) ₆ gas was sufficiently exhausted, acetone vapor was introduced into the vacuum chamber 55 at 1 mTorr, and the pulse width was 1 ms between the electrodes of the formed element, and the peak value was 1.
A pulse voltage of 4 V and a frequency of 100 Hz was applied for 20 minutes.

The characteristics of the electron-emitting device manufactured as described above were measured by applying 1 kV to the anode electrode 54 spaced 5 mm above the device. The exhaust device used in the above process is an ultra-high vacuum exhaust device including a sorption pump and an ion pump.

As a result of observing the electron-emitting device after the measurement with a scanning electron microscope, metal deposits were found on the ultrafine particles constituting the conductive film 4 which was found at the beginning. Black deposits were attached to the high potential side of the conductive film 4, which was carbon.

[Example 2] Forming step (step-
The steps up to c) were performed in the same manner using the same material as in Example 1 to fabricate an element having the electron emitting portion 5 in a part of the conductive film 4.

In step-d, the substrate was heated to 150 ° C., and 1 Torr of the organic Pd compound (ccp was placed in a vacuum container).
4230 / Okuno Pharmaceutical Co., Ltd. vapor was introduced for 15 minutes to deposit Pd oxide on the device.

After exhausting the vapor of the organic Pd compound, 1
Pulse width 1 between device electrodes in vacuum of × 10 ^-5 Torr
When an activation process was performed by continuously applying a pulse voltage of ms, a peak value of 15 V, and a frequency of 100 Hz for 30 minutes, the current value flowing between the elements increased to 2.5 mA. A surface conduction electron-emitting device was produced by the above steps, and its electrical characteristics were measured by applying 1 kV to the anode electrode 5 mm apart from the device. In this embodiment, a high vacuum exhaust device including a rotary pump and an oil diffusion pump was used as the exhaust device.

[Embodiment 3] As the substrate and element electrode forming step (step-a), the same steps as in Example 1 were adopted.

Step-b After forming a lift-off Cr film in the same manner as in Example 1,
Au was deposited to a thickness of 2 nm by a vacuum evaporation method. A conductive film of Au was formed by removing the Cr film by etching.
At this time, the resistance value between the device electrodes was 20Ω. Also,
This Au was a so-called island-shaped deposited film deposited in the form of particles.

Step-c The substrate was placed in a vacuum apparatus, and an electron emitting portion was formed in the Au film by the forming process in the same manner as in Example 1.

Step-d The substrate was heated to 120 ° C., and 2 Torr of dimethyl gold acetonate vapor was introduced into the vacuum container to deposit gold on the device.

Thereafter, as an activation treatment, dimethyl gold acetonate vapor was sufficiently exhausted, and a pulse width of 1 was applied between the device electrodes.
A pulse voltage of ms, peak value of 15 V, and frequency of 100 Hz was applied for 30 minutes.

A surface conduction electron-emitting device was produced by the above steps, and its electrical characteristics were measured by applying 1 kV to the anode electrode 5 mm away from the device. The exhaust device used in this embodiment is the same as that in the second embodiment.

[Embodiment 4] As the substrate and device electrode forming step (step-a), the same steps as in Embodiment 1 were adopted.

Step-b After forming a Cr film for lift-off in the same manner as in Example 1,
Mo was deposited by sputtering to a thickness of 3 nm. A Mo conductive film was formed by etching away the Cr film. At this time, the resistance value between the device electrodes was 25Ω.

Step-c The substrate was placed in a vacuum apparatus, and an electron emitting portion was formed on the Mo film by the forming process in the same manner as in Example 1.

Step-d The substrate was heated to 170 ° C., and bisbenzene molybdenum vapor was introduced into the vacuum chamber at 1 Torr for 30 minutes to deposit Mo on the device.

After that, as an activation treatment, bisbenzene molybdenum vapor was sufficiently exhausted, and a pulse width of 1 was applied between the device electrodes.
A pulse voltage of ms, peak value of 15 V, and frequency of 100 Hz was applied for 30 minutes.

A surface conduction electron-emitting device was manufactured by the above steps, and its electrical characteristics were measured by applying 1 kV to the anode electrode 5 mm away from the device.

[Comparative Example] A surface conduction electron-emitting device was manufactured by using the same materials and processes as in Example 2 except that the step-d was omitted, and the electric characteristics thereof were 1 kV on the anode electrode 5 mm away from the device. Was applied and measured.

Table 1 shows the initial measurement results of the device characteristics of Examples 1 to 4 and the comparative example and the measurement results after driving for a certain period of time.

[0159]

[Table 1]

[Embodiment 5] In this embodiment, an image forming apparatus is manufactured using an electron source in which a large number of surface conduction electron-emitting devices are arranged in a simple matrix.

FIG. 13 shows a plan view of a part of a substrate on which a plurality of conductive films are arranged in matrix. In addition, A- in the figure
A sectional view taken along the line A'is shown in FIG. However, the same reference numerals in FIGS. 13 and 14 indicate the same members. Here, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive film, and 6 is a thermal decomposition product of a metal compound. Reference numeral 72 denotes an X-direction wiring (also referred to as a lower wiring) corresponding to Dxm in FIG. 7, and 73 denotes a Y-direction wiring (also referred to as an upper wiring) corresponding to Dyn in FIG.
00 pieces are formed. Reference numeral 141 is an interlayer insulating layer, and 142 is a contact hole for electrically connecting the device electrode 2 and the lower wiring 72.

First, the method of manufacturing the electron source substrate of this embodiment will be specifically described with reference to FIGS. In addition, the steps-a to h described below include (a) to (d) of FIG. 15 and (e) to (h) of FIG. 16, respectively.
Corresponding to.

Step-a Cr was deposited to a thickness of 5 nm and Au was deposited to a thickness of 600 nm by a vacuum deposition method on a substrate 1 in which a silicon oxide film having a thickness of 0.5 μm was formed on a cleaned soda-lime glass by a sputtering method. After sequentially laminating, a photoresist (AZ1370 / Hoechst) is spin-coated with a spinner and baked, and then a photomask image is exposed and developed to form a lower wiring pattern,
The Au / Cr deposited film was wet-etched to form the lower wiring 72 having a desired shape.

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

Step-c Contact hole 1 is 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 this 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 which is to be the gap between the device electrodes 2 and 3 and the device electrode is formed into a photoresist (RD-2000N-41 /
Hitachi Chemical Co., Ltd.) and a thickness of 5 n
m of Ti and 100 nm of Ni were sequentially deposited. The photoresist pattern is dissolved in an organic solvent, the Ni / Ti deposited film is lifted off, and the device electrode interval L is 3 μm and the width W is 3.
The device electrodes 2 and 3 of 00 μm were formed.

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

Step-f Next, a Cr film 161 having a film thickness of 30 nm is deposited by vacuum evaporation and patterned so as to have an opening in the shape of the conductive film 4, and an organic Pd compound solution (ccp-42) is formed thereon.
30) was spin-coated with a spinner and heated and baked at 300 ° C. for 12 minutes to form a conductive film 4 made of PdO fine particles. The thickness of this film was 70 nm.

Step-g The Cr film 161 was wet-etched with an acid etchant and removed together with unnecessary portions of the conductive film 4 made of PdO fine particles to form a conductive film 4 having a desired shape. The resistance value of the conductive film 4 was about Rs = 4 × 10 ⁴ Ω / □.

Step-h: A resist pattern is formed on a portion other than the contact hole 142, and Ti is deposited to a thickness of 5 nm by vacuum vapor deposition, and a thickness of 500 is applied.
nm of Au was sequentially deposited. Unnecessary portions were removed by lift-off to fill the contact holes 142.

Through the above steps, the lower wiring 72, the interlayer insulating layer 141, the upper wiring 73, the device electrode 2, and the insulating substrate 1 are formed on the insulating substrate 1.
3, the conductive film 4 was formed.

Next, an image forming apparatus was manufactured using the substrate 1 (FIG. 13) in which the plurality of conductive films 4 manufactured as described above are arranged in matrix. The manufacturing procedure will be described with reference to FIGS.

Step-i First, the substrate 1 (FIG. 13) on which the plurality of conductive films 4 are matrix-wired is fixed on the rear plate 81, and then the face plate 86 (glass substrate 83) is placed 5 mm above the substrate 1. (A fluorescent film 84 and a metal back 85 are formed on the inner surface of the substrate) via a support frame 82, and frit glass is applied to the joint portion of the face plate 86, the support frame 82, and the rear plate 81, and the atmosphere 10 at 430 ° C
It was sealed by firing for more than a minute (FIG. 8). The fixing of the substrate 1 to the rear plate 81 was also performed with frit glass.

In order to realize color, the fluorescent film 84 is
A fluorescent material having a stripe shape (see FIG. 9A) was formed, a black stripe was first formed, and the fluorescent material 92 of each color was applied to the gap portion by the slurry method to form a fluorescent film 84. As a material for the black stripe, a material which is commonly used and whose main component is graphite was used.

A metal back 85 is 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.

When performing the above-mentioned sealing, in the case of a color, since the phosphors 92 of the respective colors and the electron-emitting devices 74 have to correspond to each other, sufficient alignment is performed.

Step-j The atmosphere in the envelope 88 completed as described above was exhausted to a vacuum degree of about 10 ^-4 Pa by a vacuum pump through an exhaust pipe (not shown). The Y-direction wirings are commonly connected and the forming process is performed for each line. The forming was performed under the conditions employed in Example 1.

Step-k Next, while heating the envelope 88 to 100 ° C. in a constant temperature bath, W
5m Tor of (CO) ₆ gas through an exhaust pipe (not shown)
r introduced.

Step-1 The activation process is carried out. The exhaust pipe of the panel (envelope 88) is connected to an ampoule filled with the activator acetone. Acetone is introduced into the panel and the pressure is 1
The 18V rectangular wave pulse is applied between the device electrodes 2 and 3 by adjusting so as to be mTorr. Pulse width is 100μ
s and the pulse interval was 20 ms.

The activation process was executed line by line. The peak value Va is applied to one X-direction wiring connected to the elements in one row.
A rectangular wave pulse of ct = 18V is applied, and the Y-direction wiring is
Similar to step j, the common electrode is connected. The pulse is changed to a triangular wave every 1 minute, and the device current-device voltage characteristic (If-V
f characteristic) is measured. The value of If at Vf2 = Vact / 2 = 9V is If (Vf2) ≧ If (Vact) /
If 220, the peak value of the rectangular wave pulse for 30 seconds is 19
The voltage is raised to V and then returned to 18 V to continue the activation process.

The device current per device is If (18V)
When ≧ 2 mA was reached, the activation of the row was terminated, the activation processing of the next row was performed, and the same processing was repeated.

Step-m When the activation of all the rows was completed, the valve of the gas introduction device was closed to stop the introduction of acetone, and the entire panel was heated to about 200 ° C. and exhausted for 5 hours.
The fluorescent film 8 is caused to emit electrons by the simple matrix drive.
After making all 4 emit light and confirming that it operates normally,
The exhaust pipe was heat-welded and completely sealed. Finally, the getter (not shown) installed in the panel was flashed by high frequency heating.

The outside-container terminals Dx1 to Dxm and Dy1 to Dyn of the panel manufactured as described above and the high-voltage terminal 87 were respectively connected to necessary drive systems to complete the image forming apparatus. Each surface conduction electron-emitting device is provided with an external terminal Dx
Electrons are emitted by applying a scanning signal and a modulation signal from a signal generating means (not shown) through 1 to Dxm and Dy1 to Dyn, and a high voltage of several kV or more is applied to the metal back 85 through a high voltage terminal 87, thereby An image was displayed by accelerating the beam, colliding it with the fluorescent film 84, and exciting and emitting light.

The image forming apparatus according to the present embodiment was able to stably display an image having high brightness and excellent operation stability.

[0186]

As described above, according to the present invention, it is possible to realize an electron-emitting device having stable electron emission characteristics and high electron emission efficiency.

In addition, in the image forming apparatus of the present invention,
An image with high brightness and excellent operation stability can be formed, and a color flat television can be realized, for example.

[Brief description of drawings]

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

FIG. 2 is a diagram schematically showing a vertical surface conduction electron-emitting device which is an example of the electron-emitting device of the present invention.

FIG. 3 is a diagram illustrating an example of a method for manufacturing the electron-emitting device of FIG.

FIG. 4 is a schematic diagram showing an example of a voltage waveform in an energization forming process that can be adopted when manufacturing the electron-emitting device of 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 of 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 view showing 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 view showing an example of a display panel of an image forming apparatus to which the present invention can be applied.

13 is a schematic diagram of a matrix-wired electron source of Example 5. FIG.

14 is a schematic cross-sectional view taken along the line A-A ′ in FIG.

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

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

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

[Explanation of symbols]

1 Substrate 2, 3 Element Electrode 4 Conductive Film 5 Electron Emission Section 6 Thermal Decomposition Product of Metal Compound 21 Step Forming Section 50 Ammeter for Measuring Element Current If 51 To Apply Element Voltage Vf to Electron Emitting Element Power source 52 for measuring the emission current Ie emitted from the electron emitting portion 5 high voltage power source for applying voltage to the anode electrode 54 anode for trapping electrons emitted from the electron emitting portion 5 Electrode 55 Vacuum container 56 Exhaust pump 71 Electron source substrate 72 X direction wiring 73 Y direction 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 conductive material 92 Phosphor 101 Display panel 102 Scanning circuit 103 Control circuit 04 shift register 105 line memory 106 synchronization signal separation circuit 107 modulation signal generator Vx, Va DC voltage source 110 electron source substrate 111 electron-emitting device 112 common wiring for wiring electron-emitting devices 120 grid electrode 121 for passing electrons Opening 141 Interlayer insulating layer 142 Contact hole 161 Cr film

Claims (15)

[Claims] 1. An electron-emitting device comprising a conductive film having an electron-emitting portion between a pair of device electrodes provided facing each other on a substrate, wherein at least the conductive film is a thermal decomposition product of a metal compound. An electron-emitting device characterized by being covered. 2. The electron emitting device according to claim 1, wherein the conductive film contains the same metal element as the metal element of the thermal decomposition product of the metal compound. 3. The electron-emitting device according to claim 2, wherein the metal element is Pd. 4. The electron-emitting device according to claim 1, wherein the conductive film is an aggregate of fine particles. 5. The electron-emitting device according to claim 1, wherein the metal compound is any one selected from metallocene, metal carbonyl, and metal acetylacetonate. 6. The electron-emitting device according to claim 1, wherein the metal compound has a vapor pressure at 300 ° C. of 0.1 mTorr or more. 7. The electron emitting portion contains carbon and / or a carbon compound.
An electron-emitting device according to any one of 1. 8. The electron-emitting device according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device. 9. The method for manufacturing an electron-emitting device according to claim 1, wherein at least a step of forming an electron-emitting portion in the conductive film, and an atmosphere containing a metal complex gas are used. A method of manufacturing an electron-emitting device, comprising heating the substrate and depositing a thermal decomposition product of a metal compound on at least the conductive film under selective deposition conditions. 10. An electron source which emits electrons in response to an input signal, wherein a plurality of electron-emitting devices according to any one of claims 1 to 8 are arranged on the same substrate. source. 11. A plurality of the electron-emitting devices are arranged in a ladder shape, both device electrodes of each electron-emitting device are connected in parallel to two row wirings, and a modulation means is further provided. The electron source according to claim 10, characterized in that 12. The plurality of electron-emitting devices are arranged in a matrix, one device electrode of each electron-emitting device is connected to a row wiring, and the other device electrode of each electron-emitting device is connected to the row. The electron source according to claim 10, wherein the electron source is connected to a column wiring orthogonal to the wiring. 13. The method for manufacturing an electron source according to claim 10, wherein the plurality of electron-emitting devices are manufactured by the method according to claim 9. . 14. An apparatus for forming an image based on an input signal, wherein the apparatus comprises at least the electron source according to claim 10 and an image forming member. Forming equipment. 15. The method for manufacturing an image forming apparatus according to claim 14, wherein the electron source is manufactured by the method according to claim 13.