JPH1064406A - Electron-emitting element and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the electron-emitting element which enhances efficiency and employs a current quantity correction electrode capable of being easily manufactured, an electron source employing the electron-emitting elements, and the image-forming device wherein the aforesaid efficiency is so determined as to be the ratio of the quantity of electrons arriving at an anode to the quantity of electrons flowing between the emitting elements in the control of electrons emitted in the air by means of surface conductive type electron- emitting elements. SOLUTION: A thin film 14, including an electron-emitting part 16 acting as a resistor, is formed on the element electrodes 12 and 13 of a substrate 11. Electrons emitted from the electron-emitting part 16 by applying drive voltage Vf, follow a locus indicated by an arrow 17. An anode electrode 18 picks up the emitted electrons by means of high voltage Va. A current quantity correcting electrode 1 is formed of conductive thin films, and is floated electrically with respect to the electron-emitting part 16. At this time, since emitting current depends on the element voltage Vf, the quantity of electron emission is thereby controlled by the electrical signals of Vg and Vf.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source and an image forming apparatus such as a display device to which the electron source is applied, and more particularly to a surface conduction electron-emitting device characterized by its structure, an electron source and a display device to which the electron source is applied. And the like.

[0002]

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

[0003] For example, as the FE type, WPDyke & WWDo
lan, "Filed emission" Advances inElectronics & Elec
tron Physics 8 89 (1956) or CASpindt, "Physica
l Properties of thin-film field emission cathodes
with molybdenium cones ", J. Appl. Phys., 47, 5248 (1976)
Etc. have been proposed. As an example of the MIM type, CA
Mead, "The tunnel-emission amplifier, J.Appl.Phys.32
646 (1961) and the like have been proposed. Further, as an example of a surface conduction electron-emitting device (SCE type), MIElinson, Radio
Eng. Electron Phys. 10 (1965) and the like have been proposed. The SCE type utilizes a phenomenon in which an electron is emitted by flowing a current along a small-area thin film formed on a substrate.

As the surface conduction electron-emitting device, a device using a SnO2 thin film by Elinson et al.
By thin film (G. Dittmer, Thin Solid Films 9 317
(1972)), based on In203 / SnO2 thin film (M. Hartwell and
CGFonstad, IEEE Trans.ED Conf 519 (1975)), with carbon thin film (Hisashi Araki et al .: Vacuum, Vol. 26,
No. 1, p. 22 (1983)).

As a typical device configuration of these surface conduction electron-emitting devices, the above-mentioned M.S. FIG. 17 shows the device configuration of the Hartwell.

FIG. 17 is a basic configuration diagram of a surface conduction electron-emitting device as a conventional example.

In FIG. 1, reference numeral 201 denotes an insulating substrate. 202
Denotes a thin film for forming an electron emitting portion, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and which is formed by an energizing process called forming described later.
Is formed. Reference numeral 204 denotes a thin film including an electron-emitting portion. In the figure, L1 is set at 0.5 to 1 mm, and W1 is set at approximately 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion forming thin film 2 is formed before electron emission.
In general, the electron-emitting portion 203 was previously formed by an energization process called forming. That is,
Forming is a process in which a DC voltage or a very slowly increasing voltage, for example, 1 volt, is applied across the electron emitting portion forming thin film 202.
A current of about V / min is applied, and the thin film 202 for forming an electron-emitting portion is applied.
Is locally destroyed, deformed, or altered to form an electron emission portion 203 in an electrically high-resistance state. The electron emitting portion 203 is formed of the thin film 2 for forming an electron emitting portion.
02 has a crack, and electrons are emitted from the vicinity of the crack. Hereinafter, an electron-emitting-portion-forming thin film 202 including an electron-emitting portion 203 formed by forming.
Is referred to as a thin film 204 including an electron-emitting portion. In the surface conduction type electron-emitting device that has been subjected to the above-described forming process, a voltage is applied to the thin film 204 including the above-described electron-emitting portion, and a current is caused to flow through the device to cause the electron-emitting portion 203 to emit electrons. .

The above-described 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 and easy manufacture. Therefore, various applications that make use of this feature are being studied. For example, a charged beam source, a display device, and the like can be given.

As an example in which a large number of surface conduction electron-emitting devices are arranged and formed, an electron is formed by arranging surface conduction electron-emitting devices in parallel, arranging a large number of rows in which both ends of each device are wired and connected. Sources (for example, see
-031332). In particular, in image forming apparatuses such as display apparatuses, flat panel display apparatuses using liquid crystal have recently
Although it has become widespread in place of T, it is not a self-luminous type, and has problems such as having to have a back light source such as a backlight, and the development of a self-luminous type display device has been desired. An image forming apparatus, which is a display device that combines a phosphor that emits visible light with electrons emitted from an electron source having a large number of surface conduction electron-emitting devices, can be manufactured relatively easily even in a large-screen device. This is a self-luminous display device with excellent display quality (for example, USP5066883
Has been proposed).

Conventionally, an element which emits electrons from an electron source constituted by a large number of surface conduction electron-emitting devices and emits light from a phosphor is selected by arranging the above-mentioned many surface conduction electron-emitting devices in parallel. In the direction perpendicular to the row wiring (called the column direction), the control electrode (called the grid) installed in the space between these electron sources and the phosphor and the column direction This is based on an appropriate drive signal to the wiring (as an example, this is proposed in Japanese Patent Application Laid-Open No. 1-2384749). For the purpose of maintaining confidentiality, a vacuum partition using a thin film has already been invented. (As an example of this, JP-A-6-28993 has been proposed).

When the emitted electrons are dominated by a strong electric field in the vicinity of the electron emission portion, the motion is controlled by the electric field, and the motion of the electrons can be controlled by the strength of the electric field. Therefore, a method of arranging a current amount correction electrode above an electron emitting portion and thereby controlling the movement of electrons is well known. Many of them are Spindt-type field emission devices, in which the electric field correction electrode is used to increase the electric field strength and to distort the potential on the surface of the substance by the electric field to emit electrons.

[0013]

However, in the above-mentioned prior art, the electron-emitting device is handled in a vacuum, but the electron-emitting characteristics of the surface-conduction type electron-emitting device in a vacuum are hardly clarified. .

Here, this situation will be described in more detail with reference to FIGS.

FIG. 18 is an explanatory view of an electron emission amount control element as a conventional example.

FIG. 19 is an explanatory diagram relating to a potential distribution and an electron trajectory of a conventional surface conduction electron-emitting device.
In an electron emission device using a surface conduction electron-emitting device, an electron emission portion and an acceleration electrode for pulling electrons are arranged as shown in FIG. 19 and placed in a vacuum. The element voltage Vf between the elements,
A voltage of Va is applied between the element portion and the acceleration electrode. Vf is on the order of about 10 [V], and Va is on the order of about 1 [KV]. At this time, an equipotential surface is formed as schematically shown in FIG. The stripes in the figure are also equipotential surfaces. The bold line indicates the orbit of the emitted electrons. At this time, on the potential surface corresponding to the potential of Vf, as shown in the figure, there is a point xs that intersects with the thin film 204 as the anode. Since the electric field stagnates around this point, the singular point of this electric field is called a stagnation point. In the right direction of the stagnation point in FIG. 19, the electrons obtain an upward force and are sucked up to the anode 206, while on the other hand, between the crack portion of the device and the stagnation point, a downward force is obtained, and the electrons are applied to the anode of the device. Will be dropped. Therefore, whether the electrons emitted from the vicinity of the crack of the device reach the anode 206 or fall to the device anode portion is determined depending on whether the electrons can pass through the stagnation point. As described above, the stagnation point xs plays an important role when using a surface conduction element.

The position of the stagnation point xs from the center of the crack of the element is determined by determining the element voltage as Vf and the potential difference between the anode and the element as Vf.
a, if the distance is H, then xs = Vf × H / (π × Va). As the position of the stagnation point xs is smaller, the electrons can escape out of the stagnation point, and the electrons can reach the anode 206. Therefore, in order to increase the amount of emitted electrons with respect to the amount of current flowing between the elements, this x
Reducing s is an important key.

However, in the above-mentioned conventional surface conduction electron-emitting device, the electric field distribution becomes asymmetrical in the right-left direction in practical use as can be seen from FIG. Compared with the structural symmetry determined by the shape of the electron emitting portion and the shape of the accelerating electrode, this electric field distribution has a very characteristic property, and the electrons are reflected by the bold line in FIG. It will draw a trajectory like that drawn in. Thus, the trajectory of the electrons is asymmetric and complex, and the transverse electric field Vf
The shape changes drastically according to the change of. Thus, the direction of the already emitted electrons has a certain distribution. A grid 2 having a hole at the center as shown in FIG.
05, the position of the hole and the trajectory of the electron generally depends on the configuration of the electric field and current correction electrodes, and is electro-optically complicated. There is a problem in that it becomes a hindrance when trying to electrically compensate for variations between elements and changes over time of the elements, making it impossible to take agile measures. Further, as shown in FIG. 18, the grid 205 having a hole at the center is formed by applying an electric field between the grid 205 and the element to the grid 205 and the anode 20.
When the electric field is larger than the electric field between the electrodes 6, the potential distribution near the hole becomes convex downward, and the electron beam emitted from the element spreads due to the effect of the concave lens due to the bent electric field distribution. Will have a sub-millimeter spread.

Therefore, in the present invention, in controlling electrons emitted into a vacuum by a surface conduction electron-emitting device, the amount of electrons reaching the anode with respect to the amount of current flowing between the devices is referred to as efficiency. It is an object of the present invention to provide an electron-emitting device using a current-amount correction electrode that is easy to manufacture, and an electron source and an image forming apparatus using the same.

[0020]

The above object is achieved by an electron-emitting device having the following features.

That is, in an electron-emitting device provided with electron-emitting means for emitting electrons toward an anode electrode by passing a current through a thin film formed on a substrate, the thin film is thin enough to transmit the emitted electrons. And applying a voltage to the electrode.

The thin-film electrode is positioned on the anode electrode side in parallel with the electron-emitting means by a predetermined distance.

Further, the thin film formed on the substrate is formed so as to straddle two electrodes located on the substrate with a predetermined gap therebetween.

Further, the electron emitting means controls the amount of emitted electrons by changing a voltage applied between two electrodes located on the substrate with a predetermined gap therebetween. .

Further, the voltage applied to the thin-film electrode is fixed, and among the electrons emitted by the electron-emitting means, the transmittance of electrons passing through the thin-film electrode is 5% or more. The thickness of the electrode, which is the thin film, is determined.

Further, it is characterized in that it is placed in a vacuum atmosphere.

Further, the electron emission means is a surface conduction electron emission element.

More preferably, the thin film formed on the substrate is a conductive fine particle which is a resistor, and is formed of a metal or a metal oxide.

The object is achieved by an image forming apparatus having the following features.

That is, a feature is that a plurality of the above-described electron-emitting devices are used.

Further, M horizontal wirings and N vertical wirings electrically insulated from each other are arranged in a matrix, and a predetermined gap is formed on the substrate by the horizontal wirings and the vertical wirings. And two electrodes that are located between the electrodes and the electrode that is the thin film.

[0032]

Embodiments of the present invention will be described below in detail with reference to the drawings.

<Common Embodiment> First, a description will be given of parts common to the respective embodiments described later.

First, the principle of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of an electron emission control device according to an embodiment of the present invention.

FIG. 2 is a top view and a side view of an electron emission portion of the electron emission amount control element according to the embodiment of the present invention.

FIG. 3 is a perspective view of an electron-emitting device according to an embodiment of the present invention.

In each figure, 11 is a substrate, 12 and 13 are device electrodes, and on the device electrodes 12 and 13, a thin film 14 including an electron-emitting portion having a certain resistance is formed. A crack 15 is formed through a forming step (13 is used as an anode). Here, the electrons emitted from the electron emitting portion 16 by applying the driving voltage Vf between the device electrodes 12 and 13 follow the trajectory indicated by the arrow 17 from the vicinity of the stagnation point as shown in FIG. Become. Here, reference numeral 18 denotes an anode electrode, which pulls out emitted electrons by the high voltage Va. Reference numeral 1 denotes a current correction electrode, which is formed of a conductive thin film and is electrically floating at a potential Vg with respect to the electron-emitting portion 16. Numerals 6 and 7 are insulating layers, each having a height h of several micrometers. As shown in FIG. 1, the amount of electron emission can be controlled by electric signals of Vg and Vf. In actual use, Vf, Va, and Vg are 20 V, 1
kV, about 100 V, the substrate 11 and the anode 1
Since the interval H of 8 is about several mm, the electric field applied to the emitted electrons is in the order of 10 5 V / m in the direction perpendicular to the substrate. Further, the distance h between the substrate 11 and the current correction electrode 1 is several micrometers, so that
Of the order of 7 / V / m. For this reason, between the current correction electrode 1 and the substrate 11, the electric field distribution between the electron emission element and the current correction electrode is larger than the electric field between the electron emission element and the anode electrode 18. Further, since the current correction electrode 1 is a conductor between the current correction electrode and the element, the current correction electrode 1 is in a shielded state, and between the current correction electrode and the substrate, the influence of the electric field between the electron-emitting device and the anode electrode 18 is exerted. Is negligible, and the electric field distribution between the electron-emitting device and the current correction electrode becomes dominant.

Therefore, the expression (1) representing the position of the stagnation point xs described in the above-mentioned problem can be replaced by the following expression: xs = Vf × h / (π × Vg) (2) According to the above estimation, it can be seen that is smaller than that of the equation (1). As a result, the amount of electrons dropped and absorbed by the anode substrate of the element decreases, and the amount of electrons reaching the anode increases. That is, the efficiency is improved.

Next, the configuration of the current correction electrode 1 will be described. In FIG. 1, a cavity for changing the trajectory of electrons is provided below the current amount correction electrode 1, and an electron-emitting device is provided below the cavity. The current correction electrode has a thickness that allows electrons to pass therethrough. That is, the voltage V of the current correction electrode
Since g is about 100 V, electrons having energy of about 100 eV are transmitted. That is, 10
For a thin film having a thickness smaller than the mean free path for electrons having an energy of about 0 eV, the electrons are transmitted. For electrons of about 100 eV, there is inelastic scattering due to the Auger effect, and the mean free path is generally short. However, since the emission energy of Auger electrons has an atomic number dependence, it is known that the emission energy is about 50 eV for lithium and about 100 eV for beryllium, and that the emission energy of other metals is lower. (Scanning Electorn Microscopy, Ludwin
g Reimer Springer-Verlag 1986). Therefore,
As a material of the thin film, it is desired not to excite (emit) Auger electrons, and the material must be conductive. Therefore, in consideration of acceleration with electrons of 100 eV or less, beryllium is used as the conductive thin film in the present invention. However, such an Auger effect is ignored depending on the thickness of the thin film (especially, not the average film thickness, but the film thickness may vary as described later, depending on the minimum film thickness). You may. In that case, it is important that the material of the thin film has conductivity, and the range of choice is wide (for example, Ni, Cr, Au, Mo, W, Pt,
Metals or alloys such as Ti, Al, Cu, Pd and Pd,
Metals such as Ag, RuO2, and Pd-Ag, or semiconductors may be used).

In the arrow 17 representing the trajectory of the emission of electrons, the electrode 13 is used as an anode, so that the electrons are pulled by the anode 13 and pass through the current correction electrode 1, which is a portion where the distortion of the electric field is larger. It passes through the tip of the amount correction electrode 1 (see FIG. 19). Therefore, in order to obtain a favorable state in the shape of the cavity 8,
The distance X1 of the cavity from the electron emitting portion 16 to the insulating layer 7 in FIG. 1 is shorter than the distance X2 of the cavity from the electron emitting portion 16 to the insulating layer 6. That is, X1 <X2.

The basic structure of the surface conduction electron-emitting device according to the present invention will be described.

Examples of the substrate 11 include quartz glass, glass in which the content of impurities such as Na is reduced, blue plate glass, a glass substrate obtained by laminating SiO2 on blue plate glass by sputtering or the like, and ceramics such as alumina. Can be The material of the opposing element electrodes 12 and 13 may be any material as long as it has conductivity. For example, Ni, Cr, Au, Mo, W, Pt, Ti,
Metals or alloys such as Al, Cu, Pd and Pd, Ag, R
Examples include a printed conductor composed of a metal such as uO2, Pd-Ag or the like and a metal oxide and glass, a transparent conductor such as In203-SnO2, and a semiconductor conductor material such as polysilicon.

The distance L between the device electrodes 12 and 13 (FIG. 2)
Is hundreds of micrometers to hundreds of angstroms. These values are set according to the photolithography technology, which is the basis of the method for manufacturing the device electrodes, that is, the performance of the exposure machine and the etching method, etc., and the voltage applied between the device electrodes and the electric field intensity capable of emitting electrons. , Preferably from several micrometers to several tens of micrometers. Device electrode length W1 (FIG. 3), film thickness d of device electrodes 12 and 13
Is the resistance value of the electrode, connection with X wiring and Y wiring described later,
It is appropriately designed in consideration of the arrangement problem of a plurality of arranged electron sources. Usually, the device electrode length W1 is several micrometers to several hundred micrometers, and the device electrodes 12 and 13 are used.
Has a film thickness d of several hundred angstroms to several micrometers. In this case, a thin film for forming an electron-emitting portion (hereinafter referred to as a thin film including an electron-emitting portion after the forming process) 14 and device electrodes 12 and 13 are sequentially stacked on the device electrodes 12 and 13. The thickness of the thin film 14 including the electron-emitting portion is preferably from several angstroms to several thousand angstroms, particularly preferably from 10 angstroms to 500 angstroms.
It is set as appropriate according to the step coverage for the electron emitters 2 and 13, the resistance between the electron emitter 16 and the element electrodes 12 and 13, the particle size of the conductive fine particles of the electron emitter 16, the energization processing conditions described later, and the like. Its resistance value is 10 7 than 10 3
Indicates the sheet resistance value of the square ohm / □.

Pd, Ru, Ag, Au, T, Pd, Ru, Ag
i, In, Cu, Cr, Fe, Zn, Sn, Ta, W,
Metals such as Pb, PdO, SnO2, In2O3, Pb
Oxides such as O, Sb2O3, HfB2, ZrB2,
Borides such as LaB6, CeB6, YB4, GdB4,
Carbides such as TiC, ZrC, HfC, TaC, SiC, WC, nitrides such as TiN, ZrN, HfN, Si, G
e, etc., and carbon fine particles. 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 overlapped (island shape). ). The particle size is from several Angstroms to several thousand Angstroms, preferably from 10 Angstroms to 200 Angstroms. The electron emitting portion 16 is preferably made of a plurality of conductive fine particles having a particle size of several Angstroms to several hundred Angstroms, particularly preferably 10 Angstroms to 500 Angstroms. It depends on the production method such as the energization processing conditions described later and is set as appropriate.

The material forming the electron emitting portion 16 is similar to some or all of the elements of the material forming the thin film 14 including the electron emitting portion 16. Various methods can be considered as a method for manufacturing the electron-emitting device. An example is shown in FIG.

FIG. 4 is a view showing a manufacturing process of the electron emission amount control element according to the embodiment of the present invention.

In the figure, reference numeral 14 denotes a thin film for forming an electron emitting portion, for example, a fine particle film. Other numbers correspond to those in FIG. Hereinafter, the description of the manufacturing method in the order of the thin film for forming the electron emitting portion will be sequentially described.

1) After sufficiently washing the substrate 11 with a detergent, pure water and an organic solvent, depositing an element electrode material by a vacuum evaporation method, a sputtering method, or the like, and then depositing the element electrode on the surface of the insulating substrate 11 by photolithography. The electrodes 12 and 13 are formed (FIG. 4A).

2) An organic metal solution is applied between the device electrode 12 and the device electrode 13 provided on the insulating substrate 11 on the insulating substrate on which the device electrodes 12 and 13 are formed, and left standing. Then, an organic metal thin film is formed. Incidentally, the organic metal solution is the above-mentioned Pd, Ru, Ag, Au, Ti, I
This is a solution of an organic compound containing a metal such as n, Cu, Cr, Fe, Zn, Sn, Ta, W, or Pb as a main element. Thereafter, the organic metal thin film is heated and baked, and is patterned by lift-off, etching, or the like, thereby forming the electron-emitting-portion-forming thin film 14 (FIG. 4B). Here, the description has been given of the method of applying the organic metal solution. However, the present invention is not limited to this, and may be formed by a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like.

3) After the configuration, a portion corresponding to the cavity 8 below the current amount correction electrode 1 is patterned, a sacrifice layer 9 is laminated, and thereafter, insulating layers 6 and 7 are deposited to form a current amount correction electrode portion. The beryllium thin film as No. 1 is laminated so as to be connected to a wiring part (not shown) while patterning.
In the present embodiment, the thickness of the beryllium thin film is about several tens nm (FIG. 4C). After the above-described current correction electrode portion is formed, the sacrificial layer 9 is removed by etching to obtain the shape shown in FIG. However, at this time, the film thickness of beryllium also slightly changes due to etching. Therefore, so that the desired thickness after etching,
The film thickness of beryllium to be laminated in the above step 3) is determined in advance. The final thickness is 10 nm at the part where electrons pass.
It is controlled to be less than about.

4) Subsequently, when an energizing process called forming is applied to the device electrodes 12 and 13 by applying a pulsed voltage or a rising voltage by a power supply (not shown) to the element electrodes 12 and 13, the electron emitting portion forming thin film 14 is formed. The electron emitting portion 16 whose structure has been changed is formed at the portion (FIG. 4D). This energization treatment locally destroys the electron-emitting-portion-forming thin film 14,
A portion that has been deformed or altered and has a changed structure is called an electron emitting portion 16. As described above, the electron emission portion 16
Applicants have observed that is composed of conductive fine particles.

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

FIG. 5 is a schematic configuration diagram of a measurement and evaluation apparatus as an embodiment of the present invention.

In the figure, a measurement and evaluation device is a device for measuring the electron emission characteristics of the device having the structure shown in FIG. 1, 11 is a base, 12 and 13 are device electrodes, and 14 is an electron emission portion. The thin film 16 indicates an electron emitting portion. Also, 5
1 is a power supply for applying a device voltage Vf to the device, 52 is an ammeter for measuring a device current If flowing through the thin film 14 including an electron emission portion between the device electrodes 12 and 13, and 18 is an electron emission portion of the device. An anode electrode for capturing the emission current Ie emitted from the electrode 16, a high-voltage power supply 53 for applying a voltage to the anode electrode 18, and an electron emission portion 1 of the device
6 is an ammeter for measuring the emission current Ie emitted from the reference numeral 6. When measuring the electron arrival point, the anode electrode 18 was replaced with an interdigital electrode parallel to the y-axis (FIG. 3), and the electron arrival point distribution in the x-axis direction was measured. Also,
When measuring the three-dimensional electron distribution, a fluorescent plate was placed below the mesh-shaped anode plate, and the brightness distribution of the phosphor was measured. The power supply 55 is a power supply for electrically floating the current correction electrode, and keeps the potential at about 100V. It is needless to say that the amount of emitted electrons (Ie) can be controlled by changing the potential. A control unit for controlling the voltage applied to the current correction electrode is arranged near the element or near the device. In measuring the device current If and the emission current Ie of the electron-emitting device described above, the power supply 51 and the ammeter 52 are connected to the device electrodes 12 and 13, and the power supply 53 and the ammeter 54 are connected above the electron-emitting device. The arranged anode electrode 18 is arranged. The exhaust pump includes a normal high vacuum device system including a turbo pump and a rotary pump, and further includes an ultra-high vacuum device system including an ion pump. The entire vacuum apparatus and the electron source substrate can be heated up to 200 degrees by a heater (not shown). The voltage of the anode electrode 18 is about 1 kV, and the anode electrode 18 and the electron-emitting device 1
The distance H to 6 was measured at about 5 mm.

In the forming process, a voltage pulse was applied while increasing the pulse peak value. Here, FIG. 6 shows a voltage waveform when a voltage pulse is applied while increasing the pulse peak value.

FIG. 6 is a diagram showing voltage pulses applied to the electron emission amount control element according to the embodiment of the present invention.

In the figure, T1 and T2 are the pulse width and pulse interval of the voltage waveform, T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave (at the time of forming). The peak voltage is increased, for example, in steps of about 0.1 V, and 10 −5 to
It was applied under a vacuum atmosphere of about rr. The forming process is completed by measuring the element current at a voltage that does not locally destroy or deform the electron-emitting-portion-forming thin film 14 during the pulse interval T2, for example, a voltage of about 0.1 V, and calculating the resistance value. For example, when a resistance of 1 M ohm or more is indicated, the forming is terminated. The voltage at this time is called a forming voltage VF. When forming the electron-emitting portion described above, the forming process is performed by applying a triangular wave pulse between the electrodes of the device. However, the waveform applied between the electrodes of the device is not limited to the triangular wave, and may be a rectangular wave or the like. A desired waveform may be used, and the peak value, pulse width, pulse interval, and the like are not limited to the above-described values, and may be adjusted according to the resistance value of the electron-emitting device and the like so that the electron-emitting portion is formed well. A desired value may be selected.

5) Next, a process called an activation process is preferably performed on the formed element. The activation treatment is a degree of vacuum of about 10 −4 to 10 −5 torr,
Similar to forming, a process in which the pulse peak value is repeatedly applied with a constant voltage pulse, and the element current If and emission current Ie are significantly changed by depositing carbon and carbon compounds from an organic substance present in a vacuum. This is the process to make it.

While the device current If and the emission current Ie are being measured, for example, when the emission current Ie is saturated, the activation process ends. FIG. 7 shows a time-dependent example of the activation process of the element current If and the emission current Ie.

FIG. 7 is a diagram showing the activation time and the device characteristics of the electron emission amount control device according to the embodiment of the present invention.

The activation process depends on the degree of vacuum, the pulse voltage applied to the device, and the like.
Due to the time dependence of e and the forming process, the state of formation of the film changes near the deformed and altered thin film. In the activation process, carbon and carbon compounds are deposited on a higher potential side than a part of the portion deformed and altered by forming. On the other hand, it is slightly deposited on the low potential side. When observed at a higher magnification, the particles are also deposited around and around the fine particles. Depending on the distance between the opposing device electrodes, carbon and carbon compounds may also be deposited on the device electrodes. The thickness is preferably 500 Å or less, more preferably 300 Å or less. Here, carbon and carbon compound are TEM,
The result of Raman et al. Is graphite (refers to both single and polycrystalline) amorphous carbon (refers to a mixture of amorphous carbon and polycrystalline graphite). Here, the carbon and the carbon compound are graphite (indicating both single and polycrystalline) and amorphous carbon (indicating a mixture of amorphous carbon and polycrystalline graphite) as a result of TEM, Raman and the like.

6) The thus-produced electron-emitting device is driven in a vacuum atmosphere having a degree of vacuum higher than the degree of vacuum subjected to the activation process. The vacuum atmosphere having a degree of vacuum higher than the degree of vacuum subjected to the activation treatment is a degree of vacuum having a degree of vacuum of about 10 −6 or more, more preferably an ultrahigh vacuum system, and carbon and carbon compounds. Is a new degree of vacuum at which almost no deposition occurs.
Therefore, it is possible to control the further deposition of carbon and carbon compounds, and the device current If and the emission current Ie are stabilized at a constant level.

The basic characteristics of the electron-emitting device according to the embodiment of the present invention produced by the above-described device configuration and manufacturing method will be described with reference to FIGS.

FIG. 8 is a diagram showing element characteristics of the electron emission amount control element according to the embodiment of the present invention.

FIG. 8 shows a typical example of the relationship between the emission current Ie, the device current If, and the device voltage Vf measured by the measurement evaluation apparatus shown in FIG. FIG. 8 shows the emission current Ie.
Is significantly smaller than the element current If, and is shown in arbitrary units. As is clear from FIG. 8, the electron-emitting device has the following three characteristics with respect to the emission current Ie.

First, in this device, the emission current Ie sharply increases when an element voltage higher than a certain voltage (referred to as a threshold voltage, Vth in FIG. 8) is applied, whereas the emission current Ie decreases below the threshold voltage Vth. Current Ie is hardly detected. That is, it is a nonlinear element having a clear threshold voltage Vth with respect to the emission current Ie. Second, the emission current Ie is equal to the device voltage V
Since it depends on f, the emission current Ie can be controlled by the element voltage Vf. Third, the emission charge captured by the anode electrode 18 depends on the time during which the device voltage Vf is applied. That is,
The amount of charge captured by the anode electrode 18 is equal to the device voltage Vf
Can be controlled by the application time. On the other hand, the device current If
May exhibit a characteristic that monotonically increases with respect to the element voltage Vf (referred to as MI characteristic) and a voltage-controlled negative resistance (referred to as VCNR characteristic) characteristic.

Since the surface conduction electron-emitting device has the above-described characteristics, that is, the device current If and the emission current Ie have a monotonically increasing characteristic with respect to the device applied voltage, the electron-emitting device according to the present invention can be used in various fields. Applications can be expected.

In a surface conduction electron-emitting device in which conductive fine particles are dispersed in advance, even if a part of the basic manufacturing method of the device structure according to the embodiment of the present invention is changed. Good. The basic configuration and manufacturing method of the surface conduction electron-emitting device have been described above. According to the concept of the present invention, if the surface conduction electron-emitting device has three characteristics, The present invention is not limited thereto, and can be applied to an image forming apparatus such as an electron source and a display device described later. Furthermore, according to the concept of the electron emission amount control element of the present invention, the combined action of the functions of the constituent elements is the most important, and the electron source section may be based on another principle. For example, Spindt or MIM (metal / insulator / metal) elements may be used. In that case, the cavity below the electrode thin film for correcting the amount of current need not necessarily have the asymmetry as described above.

Next, an electron source and an image forming apparatus according to an embodiment of the present invention will be described.

By arranging a plurality of the aforementioned electron-emitting devices on a substrate, an electron source or an image forming apparatus can be constructed. As a substrate-type arrangement, for example, there is a method of arranging a large number of surface conduction electron-emitting devices in parallel and connecting both ends of each device by wiring as described in the conventional example. In this method, a large number of rows of electron-emitting devices are arranged (referred to as a row direction),
An array method in which electrons are controlled and driven by a control electrode (called a grid) provided in a space above the electron source in a direction orthogonal to the wiring (called a column direction), and m
On the X-directional wirings, n Y-directional wirings are provided via an insulating layer, and the X-directional wirings and the Y-directional wirings are respectively applied to a pair of device electrodes of the surface conduction electron-emitting device and the current amount correction electrode. There is an array method that connects directional wiring (hereafter,
Called a simple matrix arrangement). The simple matrix will be described below.

According to the above three characteristics of the surface conduction electron-emitting device, when the electron emitted from the surface conduction electron-emitting device is equal to or higher than the threshold voltage Vth, the pulse-like voltage applied between the opposing device electrodes is increased. Is controlled by the crest value and the width. On the other hand, it is hardly emitted below the threshold voltage Vth. Therefore, even when a large number of electron-emitting devices are arranged, if the 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 controlled. You can do it. Hereinafter, the structure of a substrate serving as an electron source based on this principle will be described with reference to FIG.

FIG. 9 is a configuration diagram of a substrate as an electron source according to an embodiment of the present invention.

In the figure, m X-directional wires 102 are DX
1, DX2,. . DXm is formed on the insulating substrate 101 by a vacuum deposition method, a printing method, a sputtering method, or the like.
The X-direction wiring 102 is made of a conductive metal or the like having a desired pattern, and is made of a material, a film thickness, and a wiring so that substantially equal voltages are respectively supplied to a large number of surface conduction elements and current correction electrodes. The width is set. The Y-direction wiring 103 is
DY1, DY2. . It is composed of n wirings DYn and is formed in the same manner as the X-directional wiring 102. These m X
An interlayer insulating layer (not shown) is provided between the directional wiring 102 and the n Y-directional wirings 103 to form a matrix wiring in a state of being electrically separated (m and n are both positive integers). . The interlayer insulating layer (not shown) is made of SiO2 or the like formed by a vacuum evaporation method, a printing method, a sputtering method, or the like, and has a desired shape on the entire surface or a part of the insulating substrate 101 on which the X-direction wiring 102 is formed. The thickness, material, and manufacturing method are appropriately set so as to be able to withstand the potential difference at the intersection of the X-direction wiring 102 and the Y-direction wiring 103, in particular. The X-direction wiring 102 and the Y-direction wiring 103 are respectively drawn out as external terminals. Further, in the same manner as described above, the opposing electrode (not shown) of the surface conduction electron-emitting device 104 and the electrode (not shown) of the current amount correction electrode are connected to the m X-direction wirings 102 and n.
A Y-directional wiring 103, a connection 105 made of a conductive metal or the like formed by a vacuum evaporation method, a printing method, a sputtering method, or the like;
And 106 are electrically connected. Here, some or all of the constituent elements of the conductive metal of the element electrode facing the m X-directional wirings 102, the n Y-directional wirings 103, the connection 105, and the wiring 106 are the same. May also be different from each other, and Ni, C
metals or alloys such as r, Au, Mo, W, Pt, Ti, Al, Cu, Pd and Pd, Ag, RuO2, Pd-Ag
And a printed conductor composed of a metal or metal oxide and glass, a transparent conductor such as In203-SnO2, and a semiconductor conductor material such as polysilicon. The surface conduction electron-emitting device may be formed on either the insulating substrate 101 or an insulating layer (not shown). Also,
The X-direction wiring 102 connects the odd-numbered wiring to the surface conduction electron-emitting device 104 and the even-numbered wiring to the current-amount correction electrode. All the Y-direction wirings 103 are connected to the surface conduction electron-emitting device 104.

As will be described in more detail later, the X-direction wiring 10
In the odd-numbered part 2, scanning signal applying means (not shown) for applying a scanning signal for scanning a row of the surface conduction electron-emitting devices 104 arranged in the direction of the X-direction wiring 102 according to an input signal is provided. It is electrically connected. On the other hand, the Y-direction wiring 103 generates a modulation signal (not shown) for applying a modulation signal for modulating each of the rows of the surface conduction electron-emitting devices 104 arranged in the Y direction in accordance with an input signal. The means are electrically connected. Further, the driving voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element. Further, control means for controlling the current amount correction electrode thin films arranged in the X direction in accordance with an input signal is electrically connected to the even-numbered portion of the X-direction wiring 102. When a surface conduction electron-emitting device is used as the electron-emitting portion, it is not necessary to control the amount of emitted electrons by controlling the potential of the current correction electrode. In the present embodiment, the potential of the current correction electrode is constant in the order of several minutes. However, the amount of emitted electrons is controlled by the potential of the current correction electrode, and thereby the luminance is greatly changed according to the image signal. Is also good. In the present embodiment, the potential is changed on a very slow time scale (several hours) in accordance with the change in the device current, in order to suppress the overall variation of the electron emission portion due to the change with time.

Although not performed in this embodiment,
The variation of each element may be corrected by the voltage of the current correction electrode. At this time, regardless of the presence or absence of an image signal, the current amount correction electrode of the corresponding element is set to a predetermined potential, so that the element potential sends a signal ignoring the variation of the element.

Next, an image forming apparatus using the electron source created as described above will be described with reference to FIGS.

FIG. 10 is a basic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

In the drawing, reference numeral 111 denotes an electron source substrate on which an electron-emitting device is manufactured as described above, and 112 denotes an electron source substrate 1
11 is a rear plate on which the glass substrate 1 is fixed.
A face plate 117 having a fluorescent film 115, a metal pack 116, etc. formed on the inner surface of a support plate 117 is a support frame. The rear plate 112, the support frame 117, and the face plate 113 are coated with frit glass or the like, and are exposed to air or nitrogen. Inside, the envelope 118 is formed by baking at 400 to 500 degrees for 10 minutes or more to adhere. Reference numeral 119 corresponds to the electron emission unit in FIG. Reference numerals 102 and 103 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device (similar to FIG. 9). Further, the wiring to these device electrodes may be referred to as a device electrode when the material of the device electrode and the wiring material are the same. The envelope 118 includes the face plate 113, the support frame 117, and the rear plate 112 as described above. However, since the rear plate 112 is provided mainly for the purpose of reinforcing the strength of the substrate 111,
If the substrate 111 itself has sufficient strength, the separate rear plate 112 is unnecessary, and the support frame 1
17, the face plate 113, the support frame 11
7. The envelope 118 may be constituted by the substrate 111.

FIG. 11 is a diagram showing a fluorescent film of an image forming apparatus as an embodiment of the present invention.

In the drawing, the fluorescent film 115 is composed of only a fluorescent substance in the case of a monochrome, but in the case of a color fluorescent film,
Depending on the arrangement of the phosphors, (a) a black conductive material 121 called a black stripe or (b) a black matrix or the like
And the phosphor 122. The purpose of providing a black stripe or a black matrix is to make color mixing and the like inconspicuous by blackening a painted portion between the phosphors of the three primary color phosphors required for color display,
Then, it is to suppress a decrease in contrast due to diplomatic reflection in the fluorescent film 115. The material of the black stripe is not limited to the commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection. The method of applying the phosphor on the glass substrate 114 is monochrome,
A precipitation method or a printing method is used regardless of the color. Also,
Usually, a metal back 116 is provided on the inner surface side of the fluorescent film 115. The purpose of the metal back 116 is as follows.・ Improving the luminance by reflecting the light toward the inner surface side of the light emitted from the phosphor toward the face plate 113 side ・ Working as an electrode for applying an electron beam acceleration voltage ・ In the envelope 118 This is to protect the phosphor from damage caused by the collision of the generated negative ions. This metal back 1
No. 16 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 115 after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like. The face plate 113 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 115 in order to further increase the conductivity of the fluorescent film 115. When performing the above-described sealing, in the case of color display, it is necessary to make the phosphors of each color correspond to the electron-emitting devices, and thus it is necessary to perform sufficient alignment. The envelope 118 is sealed at a degree of vacuum of about 10 −6 Torr through an exhaust pipe (not shown). In addition, through an exhaust pipe (not shown), for example, in a normal vacuum system such as a rotary pump or a turbo pump as a pump system, in a degree of vacuum of about 10 −6 Torr,
Odd-numbered Dx1 to Dxm and Dy1 of terminals outside the container
A voltage was applied between the device electrodes 102 and 103 through Dyn to perform the above-described forming, and then an activation process was performed to form an electron emission portion 119 to manufacture an electron emission device. Then bake at 80-150 degrees for 3-15
While performing for a time, for example, the system is switched to an ultrahigh vacuum apparatus system which is a pump system such as an ion pump. The switching of the ultra-high vacuum system and the baking are performed to satisfy the monotonically increasing characteristics (MI characteristics) of the device current If and the emission current Ie of the surface conduction electron-emitting device described above. It is not limited. Further, a getter process may be performed in order to maintain the degree of vacuum after the envelope 118 is sealed. This is because the getter arranged at a predetermined position (not shown) in the envelope 188 is heated immediately before or after the envelope 118 is sealed or by heating such as resistance heating or high-frequency heating. This is a process of forming a deposited film by heating. The getter usually contains Ba or the like as a main component, and maintains a vacuum degree of, for example, 10 −5 or 10 −7 Torr by the adsorption action of the deposited film.

In the image display device according to the embodiment of the present invention completed as described above, each electron-emitting device emits electrons by applying a voltage through terminals Dx1 to Dxm and Dy1 to Dyn outside the container. A high voltage of several kV or more is applied to the metal back 116 or a transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam, collide with the fluorescent film 115, and excite and emit light to display an image. Is what you do. The above-described configuration is a schematic configuration necessary for manufacturing an image forming apparatus suitable for use in display and the like. For example, detailed parts such as materials of each member are not limited to the above-described contents. Appropriate selection is made to suit the application.

Hereinafter, each embodiment will be described in more detail.

<First Embodiment> The basic structure of an electron emission amount control element according to the present embodiment and a method of manufacturing the same are described below.
This is the same as FIGS. Therefore, the description of the overlapping part will be omitted.

Hereinafter, with reference to FIGS. 1 to 6, a basic structure and a manufacturing method of the device according to the present embodiment will be described.

As shown in FIG. 1, the amount of electron emission can be controlled by electric signals Vg and Vf. However, in the present embodiment, the on / off control of the emission of electrons is performed only at Vf as described in the common embodiment, utilizing the characteristics of the surface conduction electron-emitting device, and Vg is 80 V Fixed to. Further, the distance H was fixed at 5 mm, the distance h was fixed at 8 μm, Va was fixed at 1 KV, and Vf was made variable from 0 V to 20 V.
Therefore, in the cavity 8 below the correction electrode 1, the correction electrode 1
Is dominant. Therefore, the stagnation point is about 0.6 μm according to the equation (2). Also,
The distribution of the electron beam orbit in the x direction on the thin film is the maximum Vf
In the above, the expression (3) represents (where ＾ represents a multiplier).

X0 = h × ((Vf ＾ −5) / Vg) ＾ (1/2) + xs With respect to x0 given by Expression (3), it is empirical that x0 is within the interval of [0, x0]. Is known to.

In this embodiment, x0 is 2.1
In this case, X1 was set to 2 μm, and X2 was set to 4 μm so that the transmission position was the center.

Hereinafter, the steps of manufacturing the electron emission amount control element according to the present embodiment will be sequentially described.

[Step A] A desired pattern of device electrodes 12 and 13 is formed of photoresist on a substrate 11 in which a 0.5-μm-thick silicon oxide film is formed on a cleaned blue plate glass by sputtering. Ti having a thickness of 50 angstroms and Ni having a thickness of 1000 angstroms were sequentially deposited by an evaporation method. The photoresist pattern was dissolved with an organic solvent, and the Ni / Ti deposited film was lifted off to form device electrodes 12 and 13. The element electrode interval L was 2 microns, and the element electrode width W1 was 30 microns.

[Step B] Subsequently, the inter-element electrode gap L
Using a mask having an opening in the vicinity thereof, a Cr film having a thickness of 1000 Å is deposited and patterned thereon by vacuum evaporation, and organic Pd is spin-coated thereon by a spinner, and heated and baked at 300 ° C. for 10 minutes. Did. Here, W2 was 20 microns. Also,
The film thickness of the thus formed electron-emitting-portion-forming thin film mainly composed of palladium oxide fine particles (hereinafter referred to as a thin film including an electron-emitting portion after a forming step described later) 14 is 100.
Angstrom, sheet resistance is 2 × 10 4 Ω /
It was □. The fine particle film described here is, as described above, a film in which a plurality of fine particles are gathered, and as a fine structure, not only a state in which the fine particles are individually dispersed and arranged, but also the fine particles are adjacent to each other or It refers to a film in an overlapped state (including an island shape), and the particle size refers to the diameter of fine particles whose particle shape can be recognized in the above state.

[Step C] The Cr film and the fired electron emitting portion forming thin film 14 were etched with an acid etchant to form a desired pattern. Through the above steps, the substrate 11
Element electrodes 12 and 13 and thin film 14 for forming electron-emitting portions are formed thereon.
Etc. were formed.

[Step D] After the formation of the current amount correction electrode, the insulating layer 3 under the current amount correction electrode is patterned and laminated by 8 μm. Thereafter, similarly, insulating layers 8 and 9 having a height of 8 μm are formed, and the average film thickness is about 30 nm so as to be connected to a wiring part (not shown) while patterning a beryllium film as a current correction electrode part. It is laminated so that it becomes. Then, after the current amount correction electrode portion in FIG. 4C is formed, the sacrificial layer 9 is removed by etching to obtain the shape of FIG. 4D. At this time, the thickness of beryllium also changes due to the etching. Since the change appears largely in the center of the film, X1, X
2 was determined. It is difficult to measure this film thickness,
It is considered that the thickness of a portion through which electrons pass due to the decrease in the film thickness becomes thinner than that of the laminated structure, and includes a portion having several to several tens of nanometers. As a result, the electrons easily pass through the beryllium thin film serving as the current correction electrode 1.

[Step E] Next, the apparatus is set in the measurement and evaluation apparatus shown in FIG.
After reaching the degree of vacuum of orr, a voltage is applied between the element electrodes 12 and 13 of two of the three elements from the power supply 31 for applying the element voltage Vf to the elements, and the energization processing (forming processing) is performed. went. FIG. 6 shows a voltage waveform of the forming process. In FIG. 6, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this embodiment, T1 is 1 millisecond, T2 is 10 milliseconds, and the peak value of the rectangular wave (the peak voltage at the time of forming) is 0. .1V step up,
A forming process was performed. During the forming process, a resistance measuring pulse was simultaneously inserted between T2 at a voltage of 0.1 V to measure the resistance. Note that the forming process was terminated when the measured value of the resistance measurement pulse became about 1 M ohm or more, and at the same time, the application of the voltage to the element was terminated. The forming voltage VF of the device was 5.0 V.

[Step F] Subsequently, a rectangular wave having a pulse width T1 was applied to the formed element at the same cycle as T2 in Step D described above to perform an activation processing. Here, the peak value of the rectangular wave was set to 14V. That is, a high resistance activation process was performed. At this time, the degree of vacuum in the measurement / evaluation apparatus in FIG. 5 was 1.5 × 10 −5 torr. About 30
The activation process was completed in minutes. In this manner, the electron emitting section 16
Was formed to produce an electron-emitting device. In the emission amount control type electron-emitting device according to the present embodiment prepared as described above, the position of the stagnation point is changed by changing the potential of the current amount correction electrode as shown in FIG. Is changing.

Under such conditions, the ratio between the device current and the amount of electrons reaching the anode varies greatly. When this ratio is fixed at Vf, in the region of VgH >> Vah,
It is empirically represented by equation (3) (where ＾ represents a multiplier).

R0 × (Vg × H / (Va × h)) ＾ (1/2) Equation (3) r0 represents the electron transmittance of the thin film. Therefore, assuming that the current amount of the same element and the electron-emitting device in which the correction electrode is not provided is 1, the electron-emitting device with the current-amount correction electrode of the present embodiment is five times as large. However, r0 was set to 10%.

If the basic concept of the present invention is followed,
The combined action of the functions of the components is the most important, and does not particularly depend on the specific configuration of the current correction electrode, the specific configuration of the electron source, and the specific manufacturing method thereof. The material of the thin film of the current correction electrode is not limited to beryllium. Further, the electron source may be based on another principle. For example, Spindt or MIM (metal / insulator / metal) elements may be used.

<Second Embodiment> This is an example of an image forming apparatus in which a plurality of surface conduction electron-emitting devices are arranged in a simple matrix. The basic configuration of the electron emission amount control element in the present embodiment is the same as in FIGS. Therefore, the description of the overlapping part will be omitted. This embodiment will be described below mainly with reference to FIG.
This will be described with reference to FIGS.

FIG. 12 is a plan view of an electron source according to a second embodiment of the present invention.

FIG. 13 is a sectional view taken along the line AA ′ of the electron source according to the second embodiment of the present invention.

FIG. 14 and FIG. 15 are views showing a manufacturing process of the electron source according to the second embodiment of the present invention.

In each figure, 11 is a substrate, and 102 is FIG.
, An X-direction wiring corresponding to Dxn (also referred to as a lower wiring), 103 a Y-direction wiring corresponding to Dyn in FIG. 9 (also referred to as an upper wiring), 14 a thin film including an electron-emitting portion, and 12 and 13 element electrodes. , 151 are interlayer insulating layers, and 152 is a device electrode 12 and an odd-numbered wiring 10.
2 is a contact hole for electrical connection with the second. The element electrode 13 is electrically connected to the odd-numbered wiring 103. Reference numeral 163 in FIG. 13 denotes a contact hole for electrically connecting the even-numbered wiring 102 in the X direction and the thin film 1 of the current correction electrode. Further, reference numeral 164 in FIG. 13 denotes an insulator layer for providing a cavity below the current amount correction electrode.

Next, the manufacturing method will be specifically described in the order of steps.

[Step A] A 50-Å thick Cr film and a 6000-Å thick Cr film were formed on a substrate 11 in which a 0.5 μm thick silicon oxide film was formed on a cleaned blue plate glass by a sputtering method. After sequentially laminating Au, a photoresist is spin-coated with a spinner and baked, and then a photomask image is exposed and developed.
A resist pattern for the lower wiring 102 is formed, and Au / Cr
The deposited film is wet-etched to form the lower wiring 102 having a desired shape (FIG. 14A).

[Step B] Next, an interlayer insulating layer 151 made of a silicon oxide film having a thickness of 1.0 μm is deposited by RF sputtering (FIG. 14B).

[Step C] A photoresist pattern for forming the contact hole 152 is formed in the silicon oxide film deposited in the step B, and the photoresist pattern is used as a mask to form the insulating layer 151.
Is etched to form a contact hole 152.
Here, the etching is performed by RIE using CF4 and H2 gas.
(Re-active Ion Etching) method (FIG. 14 (c)).

[Step D] Thereafter, a pattern to be a gap between the device electrode 12 and the device electrode is formed by photoresist, and a 50 Å thick T is formed by vacuum evaporation.
i, Ni having a thickness of 1000 Å was sequentially deposited. The photoresist pattern is dissolved in an organic solvent and Ni /
The Ti deposited film was lifted off to form device electrodes 12 and 13. The shape of the gap was the same as that of the above-described embodiment (FIG. 14D). [Step E] After forming a photoresist pattern of the upper wiring 103 on the device electrodes 12 and 13, 50 angstrom thick Ti and 5000 angstrom thick Au are sequentially deposited by vacuum deposition, and unnecessary portions are lifted off to remove unnecessary portions. After removal, the upper wiring 103 having a desired shape was formed (FIG. 15E).

[Step F] Next, in order to form a thin film for forming an electron emitting portion, a Cr film 161 having a thickness of 1000 Å is deposited by vacuum evaporation using a metal mask.
Patterning was performed, and organic Pd was spin-coated with a spinner and heated and baked at 300 ° C. for 10 minutes.
The thickness of the thus formed electron-emitting-portion-forming thin film 14 mainly composed of fine particles of palladium oxide is 10 μm.
0 angstrom, sheet resistance 5 × 10 4 Ω
/ □. The fine particle film described here is, as described above, a film in which a plurality of fine particles are gathered, and as a fine structure, not only a state in which the fine particles are individually dispersed and arranged, but also the fine particles are adjacent to each other or A film in an overlapped state (including an island shape) is referred to, and the particle size refers to a diameter of a fine particle whose particle shape can be recognized in the above state (FIG. 15).
(F)).

[Step G] A desired pattern was formed by etching the Cr film 161 and the fired thin film for forming an electron emission portion with an acid etchant. Contact hole 152
A pattern is formed such that a resist is applied to portions other than the portion, and 50 Å thick Ti,
5000 Å thick Au was sequentially deposited.
Unnecessary portions were removed by lift-off to bury the contact holes 152 (FIG. 15G).

[Step H] The portion corresponding to the cavity and the portion corresponding to the contact hole are patterned, the sacrificial layer 9 is laminated, and then the insulating layer 164 is laminated.
The height of each layer is 8 microns.
Thereafter, similarly to the first embodiment, the beryllium thin film 1 as the current amount correction electrode portion is laminated while being patterned. Thereafter, the sacrifice layer 9 is removed by etching to form a cavity. Then, the contact hole 152 was buried (FIG. 15H).

Next, an example in which a display device is formed using the electron sources formed as described above will be described with reference to FIGS.

After fixing a substrate 111 on which a plurality of planar surface conduction electron-emitting devices are formed on a rear plate 112,
The face plate 113 is placed 5 mm above the substrate 111.
(A fluorescent film 115 and a metal back 116 are formed on the inner surface of a glass substrate 114)
7, the face plate 113, the support frame 11
7. A frit glass is applied to the joint of the rear plate 112, and 400 ° C. to 500 ° C. in air or nitrogen atmosphere.
It sealed by baking at ℃ for 10 minutes or more. The fixing of the substrate 111 to the rear plate 112 was also performed with frit glass. The fluorescent film 115 is composed of only a phosphor in the case of monochrome, but in the present embodiment, a stripe-shaped phosphor is adopted, a black stripe is formed first, and a phosphor of each color is applied to a gap between the phosphors. The film 115 was formed. As a material for the black stripe, a material mainly containing graphite, which is generally widely used, was used. A slurry method was used as a method for applying the phosphor on the glass substrate 114. Further, a metal back 116 is provided on the inner surface side of the fluorescent film 115.
Provided. The metal back 116 was produced by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after producing the phosphor film, and then performing vacuum deposition of Al. The face plate 113 further includes a fluorescent film 115.
In some cases, a transparent electrode (not shown) is provided on the outer surface side of the fluorescent film 115 in order to increase the conductivity of the phosphor film 115. However, in the present embodiment, a sufficient conductivity was obtained only by using a metal back, so that the description was omitted. When the above-mentioned sealing is performed, in the case of color, the phosphors of each color must correspond to the electron-emitting devices, so that sufficient alignment is performed. The atmosphere in the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, electrons are emitted through terminals Dx1 to Dxm and Dy1 to Dyn outside the container. By applying a voltage between the electrodes of the device and performing a forming process, an electron-emitting portion 119 was formed. The voltage waveform of the forming process is the same as in FIG. In this embodiment, T1 is set to 1 millisecond and T2 is set to 10 milliseconds, and the process is performed in a vacuum atmosphere of about 1 × 10 −5 torr. The electron emitting portion 119 thus formed was in a state in which fine particles mainly composed of palladium element were dispersed and arranged, and the average particle diameter of the fine particles was 30 angstroms. Next, a high resistance activation process was performed while measuring the element current If and the emission current Ie with a rectangular wave (wave height 14 V) having the same T1 and T2 as the forming at a degree of vacuum of 2 × 10 −5 power. . Next, the air was evacuated to a degree of vacuum of about 10 −6 torr, and an exhaust pipe (not shown) was heated by a gas burner to seal the envelope and seal the envelope. Finally, in order to maintain the degree of vacuum after sealing, getter processing was performed by a high-frequency heating method.

In the image display device of the present embodiment completed as described above, each of the electron-emitting devices is provided with an external terminal Dx
The electron emission is controlled by applying a scanning signal and a modulation signal from 1 to Dxm and Dy1 to Dyn respectively from a signal generation means (not shown), and a number is applied to the metal back 119 through a high voltage terminal Hv shown in FIG. A high voltage of kV or more is applied to accelerate the electron beam, and the fluorescent film 115
Then, the image was displayed by exciting and emitting light.
The voltage control signal of the current correction electrode was applied from a signal generating means (not shown) to correct the change with time of the element and to improve the efficiency.

The thus-formed electron emission amount control element in the image forming apparatus of the present embodiment changes the emission amount by setting the potential of the current amount correction electrode to a desired value, thereby increasing the efficiency of the element. Can be formed.

<Third Embodiment> In this embodiment, a display panel using the above-described surface conduction electron-emitting device as an electron beam source is provided with various image information sources such as a television broadcast. FIG. 16 shows an example of a display device configured to display provided image information.
This will be described with reference to FIG.

FIG. 16 is a diagram showing a basic configuration of a display device according to a third embodiment of the present invention.

In the figure, 1700 is a display panel, 1
701 is a display panel driving circuit, 1702 is a display panel controller, 1703 is a multiplexer, 1704 is a decoder, 1705 is an input / output interface circuit, 1706 is a CPU, 1707 is an image generation circuit, 1708, 1709 and 1710 are image memory interface circuits, 1711 is an image input interface circuit, 1712 and 1713 are TV signal receiving circuits, and 1714 is an input unit. When the present display device receives a signal including both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information that is not directly related to features are omitted.

Hereinafter, the function of each section will be described along the flow of the image signal.

First, the TV signal receiving circuit 1713 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication.
The type of TV signal to be received is not particularly limited,
For example, various systems such as the NTSC system, the PAL system, and the SECAM system may be used. A TV signal (for example, a so-called high-definition TV including the MUSE system) composed of a larger number of scanning lines than the above can take advantage of the display panel of the present embodiment suitable for a large area and a large number of pixels. It is a suitable signal source. The TV signal received by the TV signal receiving circuit 1713 is output to the decoder 1704. T
The V signal receiving circuit 1712 is a circuit for receiving a TV image signal transmitted using a wired transmission system such as a coaxial table or an optical fiber. As with the TV signal receiving circuit 1713, the type of the TV signal to be received is not particularly limited.
The signal is also output to the decoder 1704. The image input interface circuit 1711 is a circuit for receiving an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is output to the decoder 1704. The image memory interface circuit 1710 is a circuit for taking in an image signal stored in a video tape recorder (hereinafter abbreviated as VTR).
704. Image memory interface circuit 1709 This is a circuit for taking in an image signal stored in a video disk. The taken image signal is output to a decoder 1704. The image memory interface circuit 1708, like a so-called still image disk,
A circuit for capturing an image signal from a device that stores still image data. The captured still image data is input to a decoder 1704. The input / output interface circuit 1705 is a circuit for connecting the present display device to an external computer, a computer network, or an output device such as a printer. In addition to inputting and outputting image data and character / graphic information, the CPU 1706 included in the display device may be used in some cases.
It is also possible to input and output control signals and numerical data between the device and the outside. The image generation circuit 1707 includes image data and character / graphic information input from outside via the input / output interface circuit 1705, or a CPU.
A circuit for generating display image data based on the image data and character / graphic information output from 1706. Inside this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory storing an image pattern corresponding to a character code, a processor for performing image processing, etc. And other circuits necessary for generating an image. The display image data generated by this circuit is output to the decoder 1704, but may be output to an external computer network or printer via the input / output interface circuit 1705 in some cases. The CPU 1706 mainly performs operation control of the display device and operations related to generation, selection, and editing of a display image. For example, a control signal is output to the multiplexer 1703, and image signals to be displayed on the display panel are appropriately selected or combined. At that time, a control signal is generated for the display panel controller 1702 in accordance with the image signal to be displayed, and the screen display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines on one screen, and the like are determined. The operation of the display device is appropriately controlled. Also, image data and character / graphic information are directly output to the image generation circuit 1707, or an external computer or memory is accessed via the input / output interface circuit 1705 to input image data or character / graphic information. I do. The CPU 1706 may, of course, be involved in work for other purposes. For example,
It may be directly related to the function of generating and processing information, such as a personal computer or a word processor. Alternatively, it may be connected to an external computer network via the input / output interface circuit 1705 as described above, and work such as numerical calculation may be performed in cooperation with an external device. The input unit 1714 is connected to the CPU 170
6 is for the user to input commands, programs, or data. For example, in addition to a keyboard and a mouse, various input devices such as a joystick, a barcode reader, and a voice recognition device can be used. is there.
In addition, the decoder 1704 is connected to the above 1707 to 171.
This is a circuit for inversely converting various image signals input from 3 into three primary color signals, or luminance signals and I signals and Q signals. The decoder 1704 preferably includes an image memory (indicated by a broken line in the figure). This is for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of a still image. Alternatively, in cooperation with the image generation circuit 1707 and the CPU 1706, image thinning, interpolation, enlargement,
This is because there is an advantage that image processing and editing including reduction and composition can be easily performed. The multiplexer 1703 selects a display image appropriately based on a control signal input from the CPU 1706. That is, the multiplexer 1703 is connected to the decoder 1704.
A desired image signal is selected from the inversely-converted image signals input from, and output to the drive circuit 1701. In that case, by switching and selecting an image signal within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. . The display panel controller 1702 is a circuit for controlling the operation of the drive circuit 1701 based on a control signal input from the CPU 1706. First, for example, a signal for controlling an operation sequence of a power supply (not shown) for driving a display panel is output to the drive circuit 1701 as one related to a basic operation of the display panel. In addition, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlaced or non-interlaced) is output to the drive circuit 1701 as related to the display panel driving method. In some cases, a control signal related to image quality adjustment such as luminance, contrast, color tone, and sharpness of a display image may be output to the drive circuit 1701. A driving circuit 1701 is a circuit for generating a driving signal to be applied to the display panel 1700, and includes an image signal input from the multiplexer 1703 and a display panel controller 1
It operates based on a control signal input from the 702.

The function of each unit has been described above. With the configuration illustrated in FIG. 16, in the display device of this embodiment, image information input from various image information sources can be displayed on the display panel 1700. It is. That is,
Various image signals including television broadcasts are inversely converted by a decoder 1704, appropriately selected by a multiplexer 1703, and input to a drive circuit 1701. On the other hand, the display controller 1702
Generates a control signal for controlling the operation of the driving circuit 1701 according to the image signal to be displayed. Drive circuit 1701
Applies a drive signal to the display panel 1700 based on the above-described image signal and control signal. Thus, an image is displayed on display panel 1700.
These series of operations are totally controlled by the CPU 1706. In the present display device, the decoder 1
An image memory built in the 704 and an image generation circuit 1707
And not only display the selection from the information,
For image information to be displayed, for example, image processing such as enlargement, reduction, rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, and synthesis, erasure, connection, replacement, and insertion It is also possible to perform image editing such as. Although not particularly described in the description of the present embodiment, a dedicated circuit for processing and editing audio information at the same time as the above-described image processing and image editing may be provided.

Therefore, the display device of this embodiment is
TV broadcast display equipment, video conference terminal equipment,
It can combine the functions of image editing equipment that handles still images and moving images, computer terminal equipment, word processors and other terminal equipment for business use, game machines, etc. in a single unit, and is extremely suitable for industrial or consumer use. Wide application range. FIG. 16 shows only an example of a configuration of a display device using a display panel using a surface conduction electron-emitting device as an electron beam source, and it goes without saying that the present invention is not limited to this. For example, a circuit related to a function that is not necessary for the purpose of use among the components in FIG. 16 may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present display device is applied to a videophone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present display device, in particular, it is easy to reduce the thickness of a display panel using a surface conduction electron-emitting device as an electron beam source, so that the depth of the display device can be reduced. Furthermore, the display panel using a surface conduction electron-emitting device as an electron beam source is easy to enlarge the screen, and has high brightness and excellent viewing angle characteristics, so that a realistic and powerful image can be easily viewed. It is possible to display well.

The present invention may be applied to a system including a plurality of devices such as a host computer, an interface, and a printer, or may be applied to an apparatus including a single device. Needless to say, the present invention can be applied to a case where the present invention is implemented by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to a system or an apparatus, the system or the apparatus operates in a predetermined manner.

[0125]

As described above, according to the present invention,
The surface conduction electron-emitting device using the current correction electrode, which is easy to manufacture, has realized high efficiency of the amount of electrons reaching the anode in controlling electrons emitted in vacuum.

Further, the image forming apparatus constituted by the electron source of the present invention is applied to an image forming apparatus having stable and controlled electron emission characteristics, for example, an image forming apparatus using a phosphor as an image forming member. Can realize provision of a bright, high-quality color flat television with low current.

[0127]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electron emission amount control element as an embodiment of the present invention.

FIG. 2 is a top view and a side view of an electron emission portion of the electron emission amount control element according to the embodiment of the present invention.

FIG. 3 is a perspective view of an electron-emitting device as an embodiment of the present invention.

FIG. 4 is a diagram showing a manufacturing process of the electron emission amount control element as the embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a measurement and evaluation device as an embodiment of the present invention.

FIG. 6 is a diagram illustrating voltage pulses applied to an electron emission amount control element according to an embodiment of the present invention.

FIG. 7 is a diagram showing an activation time and an element characteristic of an electron emission amount control element as an embodiment of the present invention.

FIG. 8 is a diagram showing element characteristics of an electron emission amount control element as an embodiment of the present invention.

FIG. 9 is a configuration diagram of a substrate as an electron source according to an embodiment of the present invention.

FIG. 10 is a basic configuration diagram of an image forming apparatus as an embodiment of the present invention.

FIG. 11 is a diagram showing a fluorescent film of the image forming apparatus as an embodiment of the present invention.

FIG. 12 is a plan view of an electron source according to a second embodiment of the present invention.

FIG. 13 shows an electron source A- according to a second embodiment of the present invention.
It is A 'sectional drawing.

FIG. 14 is a diagram illustrating a manufacturing process of the electron source according to the second embodiment of the present invention.

FIG. 15 is a diagram illustrating a manufacturing process of the electron source according to the second embodiment of the present invention.

FIG. 16 is a basic configuration diagram of a display device according to a third embodiment of the present invention.

FIG. 17 is a basic configuration diagram of a surface conduction electron-emitting device as a conventional example.

FIG. 18 is an explanatory diagram of an electron emission amount control element as a conventional example.

FIG. 19 is a diagram illustrating a potential distribution and an electron trajectory of a surface conduction electron-emitting device as a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Current correction electrode 3 Insulator layer 6, 7 Insulator layer 8 Cavity part 9 Sacrifice layer 11 Substrate 12, 13 Element electrode 14 Thin film including electron emission part 15 Crack 16 Electron emission part 17 Trace of emitted electron 18 Anode electrode 51 , 55 power supply 52, 54 ammeter 53 high-voltage power supply 101 insulating substrate 102 X-directional wiring 103 Y-directional wiring 104 surface conduction electron-emitting device 105 connection 106 wiring 111 electron source substrate 112 rear plate 113 faceplate 114 glass substrate 115 fluorescent film 116 Metal Back 117 Support Frame 118 Envelope 119 Electron Emitting Part 121 Black Conductor 122 Phosphor 151 151 Insulating Layer 152 Contact Hole 161 Cr Film 163 Contact Hole 164 Insulating Layer 201 Insulating Substrate 202 Thin Film for Electron Emitting Part 203 Electron Emission part 2 4 Thin film including electron-emitting section 1700 Display panel 1701 Drive circuit 1702 Display panel controller 1703 Multiplexer 1704 Decoder 1705 Input / output interface circuit 1706 CPU 1707 Image generation circuit 1708, 1709, 1710 Image memory interface circuit 1711 Image input interface circuit 1712, 1713 TV Signal receiving circuit 1714 Input section

Claims (10)

[Claims] 1. An electron-emitting device having an electron-emitting means for emitting electrons toward an anode electrode by passing a current through a thin film formed on a substrate, wherein the thin film is thin enough to transmit the emitted electrons. An electron-emitting device, wherein a voltage is applied to the electrode. 2. The electron-emitting device according to claim 1, wherein the electrode, which is the thin film, is located parallel to the anode electrode by a predetermined distance from the electron-emitting means. 3. The electron emission device according to claim 1, wherein the thin film formed on the substrate is formed so as to straddle two electrodes located on the substrate with a predetermined gap therebetween. element. 4. The electron emission means controls the amount of emitted electrons by changing a voltage applied between two electrodes located on the substrate with a predetermined gap therebetween. The electron-emitting device according to claim 2. 5. The method according to claim 1, wherein a voltage applied to the thin-film electrode is fixed, and a transmittance of electrons transmitted through the thin-film electrode among the electrons emitted by the electron-emitting means is 5% or more. 2. The electron-emitting device according to claim 1, wherein the thickness of the thin film electrode is determined. 6. The electron-emitting device according to claim 1, wherein the electron-emitting device is placed in a vacuum atmosphere. 7. The electron-emitting device according to claim 1, wherein said electron-emitting device is a surface conduction electron-emitting device. 8. The electron-emitting device according to claim 1, wherein the thin film formed on the substrate is a conductive fine particle serving as a resistor, and is made of a metal or a metal oxide. 9. An image forming apparatus comprising a plurality of the electron-emitting devices according to claim 1. 10. A method in which M horizontal wirings and N vertical wirings electrically insulated from each other are arranged in a matrix, and a predetermined gap is formed on the substrate by the horizontal wirings and the vertical wirings. The image forming apparatus according to claim 9, wherein two electrodes positioned through the thin film and an electrode that is the thin film are generated.