JP2003109488A - Electron emission element, electron source, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron emission element, an electron source, an image display device, and an image forming device capable of forming a converged electron beam with high definition writing capability, at higher response and itself produced easily, and facilitating the manufacture. SOLUTION: This electron emission element is so formed that a cathode electrode 2, a first insulating layer 4, a second insulating layer 5, and a gate electrode 6 are stacked on a substrate 1, and is provided with a plurality of through holes 7 formed from the gate electrode 6 to the first insulating layer 4 and the second insulating layer 5, transports electron from the cathode electrode 2 toward an electron emission layer 3 disposed on the cathode electrode 2, and emits the electron from the electron emission layer 3. This device is characterized in that the thickness of the first insulating layer 4 and the second insulating layer 5 is thinner than the distance between the cathode electrode 2 and the gate electrode 6, at least, in the whole part or a part of an opening region 9 where the through hole 7 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device that emits electrons by applying a voltage, an electron source and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, which are a thermoelectron-emitting device and a cold cathode electron-emitting device. The cold cathode electron emission device includes a field emission type (hereinafter referred to as “FE type”), a metal / insulating layer / metal type (hereinafter referred to as “MIM type”), a surface conduction type electron emission device, and the like.

As an example of the FE type, W. P. Dyke &
W. W. Dolan, "Field Emissio
n ", Advance in Electron Ph
ysics, 8, 89 (1956) or C.I. A. Sp
indt, "PHYSICAL Properties"
of thin-film field emissi
on cathodes with mollybden
ium cones ”, J. Appl. Phys., 4
The one disclosed in 7, 5248 (1976) is known.

An example of the MIM type is C.I. A. Mea
d, "Operation of Tunnel-Em
"Ission Devices", J. Apply. P
hys. , 32,646 (1961) and the like are known.

Further, in a recent example, Toshiaki,
Kusunoki "Fluctuation-free"
electron emission from n
on-formed metal-insulator
-Metal (MIM) cathodes Fabri
cated by low current Anod
ic oxidation ", Jpn. J. Appl.
Phys. vol. 32 (1993) pp. L169
5, Mutsumi Suzuki et al "An
MIM-Cathode Array for Cat
hode luminescent display
s ", IDW'96, (1996) pp. 529 and the like have been studied.

[0006] As an example of the surface conduction type, as reported by Elinson (MI Elinson Radio Eng. E.
electron Phys. , 10 (1965)) and the like. In this surface conduction electron-emitting device, electrons are emitted by passing a current through a thin film of a small area formed on a substrate in parallel to the film surface. It utilizes the phenomenon. As the surface conduction type element, one using the SnO ₂ thin film described in Ellison's report, one using an Au thin film, (G. Dittmer. Thin Solid F
ilms, 9, 317 (1972)), In ₂ O ₃ / Sn
O ₂ thin film (M. Hartwell and
C. G. Fonstad, IEEE Trans. ED
Conf. , 519 (1983)) and the like have been reported.

[0007]

In the image forming apparatus, the phosphor (anode electrode) arranged facing the electron-emitting device is made to collide with the electron emitted from the electron-emitting device so that the phosphor emits the light. However, in a high-definition image forming apparatus, it is necessary to converge an electron orbit, reduce the size of an electron-emitting device, reduce a driving voltage, and have a highly reliable method of manufacturing an electron-emitting device.

In the FE type electron emitting device, as shown in FIG. 16, the Spindt type is widely known, but since the tip of the electron emitting portion has a sharp tip structure, it is difficult to converge the electron beam. It has been difficult to realize a high definition image forming apparatus. FIG. 16 is a schematic diagram showing a conventional electron-emitting device.

In addition, in the Spindt type electron-emitting device, an element structure in which a focusing electrode for focusing the electron beam is provided has been proposed, but there are problems such as the complexity of the element structure and the manufacturing method.

On the other hand, in the electron-emitting device described in US Pat. No. 6,204,597, as shown in FIGS. 17 and 18, two insulating layers between the gate electrode and the cathode electrode are laminated, and the insulating layers are separated. An element structure has been proposed in which the electron beam is converged by changing the relative permittivity (ε) of the layer. 17 and 18 are schematic views showing a conventional electron-emitting device.

In this case, the potential distribution is determined by the relative permittivity ratio and the thickness of each insulating layer. For example, when the relative permittivity ratio is designed to be 4, SiO ₂ (ε = 4) on one side. When it is used, it is necessary to set ε = 16 on the other side, and a material having a large relative dielectric constant is required. As a result, the parasitic capacitance between the gate electrode and the cathode electrode is increased, and the response speed of the device is rapidly deteriorated. Further, since it is necessary to select two kinds of insulating materials, there are restrictions on the materials and non-adaptation to the element manufacturing process.

In US Pat. No. 5,404,070, etc., FIG.
As shown in FIG. 20 and FIG. 20, there has been proposed a structure in which the insulating layer between the gate electrode and the cathode electrode is removed for the purpose of reducing the parasitic capacitance. For example, in FIG. In the structure, the electrons emitted from directly under the gate electrode are absorbed by the gate electrode, which causes a decrease in electron emission efficiency and an increase in power consumption, and it is difficult to realize a high-definition image forming apparatus. 19 and 20 are schematic diagrams showing a conventional electron-emitting device.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to form a focused electron beam, which enables high-definition and high-speed response.
An object of the present invention is to provide an electron-emitting device, an electron source and an image forming apparatus which can be easily manufactured.

[0014]

In order to achieve the above object, an electron-emitting device according to the present invention comprises a cathode electrode arranged on a substrate and an insulating member arranged on the cathode electrode and having a plurality of openings. A layer, a gate electrode disposed on the insulating layer, the gate electrode having a plurality of through holes disposed on the plurality of openings of the insulating layer, and at least the cathode electrode located in the opening of the insulating layer. An electron-emitting device having an electron-emitting layer arranged, wherein the gate electrode side end of the plurality of openings arranged in the insulating layer and the cathode electrode in the plurality of openings arranged in the gate electrode. It is characterized in that there is a gap between the side end.

Further, in the electron-emitting device according to the present invention, the insulating layer and the gate electrode are connected to each other in a region of the gate electrode outside a region where the plurality of openings are arranged. Is characterized by.

Further, the electron emitting device according to the present invention is characterized in that the electron emitting layer is disposed between the cathode electrode and the insulating layer.

Further, the electron source according to the present invention is an electron source in which a plurality of electron emitting devices are arranged, and the electron emitting device is the electron emitting device.

Further, the image forming apparatus according to the present invention is an image forming apparatus having an electron source and a phosphor, and the electron source is the electron source.

Further, in the electron-emitting device according to the present invention, the cathode electrode arranged on the substrate, the insulating layer arranged on the cathode electrode, the gate electrode arranged on the insulating layer, and the gate electrode. To at least the insulating layer and a plurality of through holes, and an electron emitting layer disposed on the cathode electrode located at least in the through hole, which is at least the through hole. The thickness of the insulating layer is smaller than the distance between the cathode electrode and the gate electrode in all or a part of the opening region where the hole is formed.

Further, the electron-emitting device according to the present invention is characterized in that the electron-emitting layer is laminated between the cathode electrode and the insulating layer.

Further, the electron-emitting device according to the present invention is characterized in that the electron-emitting layer is arranged only in the through hole.

Further, in the electron-emitting device according to the present invention, the electron-emitting layer is directly connected to the cathode electrode in a region where electrons are emitted, and the cathode is provided through the insulating layer in a region where electrons are not emitted. It is characterized in that it is connected to electrodes.

Further, the electron-emitting device according to the present invention is characterized in that the cathode electrode surface of the portion in contact with the through hole is below the cathode electrode surface of the other portion.

Further, in the electron-emitting device according to the present invention, an insulating layer having the same thickness as the distance between the cathode electrode and the gate electrode is arranged at a constant interval between the cathode electrode and the gate electrode. It is characterized by

The electron-emitting device according to the present invention is characterized in that the electron-emitting layer contains carbon as a main component.

Further, the electron-emitting device according to the present invention is characterized in that the electron-emitting layer has a positive bandgap.

The electron-emitting device according to the present invention is characterized in that the electron-emitting layer is a diamond-like carbon film or an amorphous carbon film.

Further, in the electron-emitting device according to the present invention, the electron-emitting layer is connected to the cathode electrode through the catalytic conductive layer, the electron-emitting layer contains carbon as a main component, and the tip thereof is It is characterized by having a conical shape or a pyramidal shape.

Further, in the electron-emitting device according to the present invention, the cathode electrode and the gate electrode are laminated on the substrate, and the first insulating layer and the second insulating layer are provided between the cathode electrode and the gate electrode. And has a plurality of through holes formed from the gate electrode to at least the insulating layer, and transports electrons from the cathode electrode to an electron emission layer arranged on the cathode electrode. An electron-emitting device that emits electrons from an emission layer, characterized in that the second insulating layer is not formed at least in all or part of an opening region in which the through hole is formed.

Further, the electron source according to the present invention is characterized in that a plurality of the above-mentioned electron-emitting devices are arranged.

The electron source according to the present invention is characterized in that the plurality of electron-emitting devices are arranged in matrix.

Further, the image forming apparatus according to the present invention has an anode electrode for capturing electrons emitted from the electron-emitting device, and an image forming member arranged on the anode electrode for forming an image. And

The image forming apparatus according to the present invention is characterized in that the image forming member is a phosphor.

Here, the opening region means a portion where the through hole is formed in the electron-emitting device, and includes not only the surface of the electron-emitting device but also the region inside the electron-emitting device.

The through-hole means a portion in which the insulating layer and the electrode do not exist inside. However, when the electron-emitting layer is formed only inside the through-hole, the portion including the electron-emitting layer is removed. To become a through hole.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However,
The dimensions, materials, and components of the components described in this embodiment
The shape and the relative arrangement thereof are not intended to limit the scope of the present invention thereto unless otherwise specified.

Further, in the following drawings, the same reference numerals are given to the members described in the drawings used in the above description of the prior art and the members similar to the members described in the above-mentioned drawings.
Further, the description of the embodiment of the electron-emitting device according to the present invention described below also serves as the description of the embodiment of the electron source and the image forming apparatus according to the present invention.

1 to 3 are schematic views showing an example of a structure and a manufacturing method of an embodiment of an electron-emitting device according to the present invention and a principle explanation of the electron-emitting device according to the present invention.

First, with reference to FIGS. 1 to 3, the overall structure and manufacturing method of an electron-emitting device according to an embodiment of the present invention will be described.

FIG. 1 is a schematic view ((a) is a schematic sectional view, (b) is a schematic plan view) of an electron-emitting device according to an embodiment of the present invention, and FIG. FIG. 9 is a schematic diagram of an electron-emitting device when an example of driving the emission device is shown and wiring is performed in a state in which a voltage can be applied. 3A to 3D are manufacturing process diagrams of the electron-emitting device according to the embodiment of the present invention.

The electron-emitting device according to this embodiment is roughly composed of a cathode electrode 2 arranged on a substrate 1, an electron-emitting layer 3, a first insulating layer 4, a second insulating layer 5, and a gate. It is composed of an electrode 6, a through hole 7, an opening region 9 in which the through hole 7 is formed, and an anode electrode 8 (FIG. 2) arranged so as to face these.

An example of the method of manufacturing the electron-emitting device of the present invention will be described. The surface of the device is thoroughly cleaned in advance, such as quartz glass, glass with a reduced content of impurities such as Na, soda-lime glass, and silicon substrate. SiO by sputtering method
_The cathode electrode 2 is formed on an insulating substrate 1 made of a laminated body of ₂ and ceramics such as alumina.

The cathode electrode 2 is generally conductive and is formed by a general vacuum film forming technique such as a vapor deposition method or a sputtering method, or a photolithography technique.

The material of the cathode electrode 2 is, for example, Be,
Mg, Ti, Zr, Hf, V, Nb, Mo, W, Al,
Metal or alloy material such as Cu, Ni, Cr, Au, Pt, Pd, TiC, ZrC, HfC, TaC, SiC, W
Carbides such as C, HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ ,
YB _4, GdB borides such as _4, TiN, ZrN, nitrides such as HfN, Si, a semiconductor such as Ge, is appropriately selected from carbon.

The thickness of the cathode electrode 2 is set in the range of several tens of nm to several hundreds of μm, preferably several hundreds of n.
It is selected in the range of m to several μm.

Next, an electron emission layer 3 is deposited subsequent to the cathode electrode 2. Further, a first insulating layer 4 is deposited on the electron emission layer 3. The first insulating layer 4 is formed by a general vacuum film forming method such as a sputtering method, and the thickness thereof is set in the range of several nm to several μm, preferably several tens nm to several hundreds. selected from the nm range.

Next, a second insulating layer 5 is deposited on the first insulating layer 4. The second insulating layer 5 is formed by a general vacuum film forming method such as a sputtering method, and the thickness thereof is set in the range of several nm to several μm, preferably several tens nm to several hundreds. selected from the nm range. The material selected is selected from the materials different from those of the first insulating layer 4.

Further, a gate electrode 6 is deposited on the second insulating layer 5. The gate electrode 6 is the cathode electrode 2
It has electrical conductivity like the above, and is formed by a general vacuum film forming technique such as a vapor deposition method and a sputtering method, and a photolithography technique. The material of the gate electrode 6 is, for example, B
e, Mg, Ti, Zr, Hf, V, Nb, Mo, W, A
1, metal such as Cu, Ni, Cr, Au, Pt, Pd, or alloy material, TiC, ZrC, HfC, TaC, Si
Carbides such as C and WC, HfB ₂ , ZrB ₂ , LaB ₆ , C
borides such as eB ₆ , YB ₄ , GdB ₄ , TiN, ZrN,
It is appropriately selected from nitrides such as HfN, semiconductors such as Si and Ge, and carbon.

The thickness of the gate electrode 6 is several tens of n.
It is set in the range of m to several μm, and is preferably selected in the range of several tens nm to several hundreds nm.

Next, by the photolithography technique,
A part of the first insulating layer 4, the second insulating layer 5 and the gate electrode 6 is removed from the substrate 1 by an etching process, and a through hole 7 is formed so that the electron emission layer 3 is exposed. This etching process may be stopped on the electron emission layer 3 or may be stopped after a part of the electron emission layer 3 is etched.

The through hole 7 formed in this step may be a hole type, a slit type or the like, and an appropriate shape is selected depending on the required beam shape, driving voltage and the like.

The size of the through hole depends on the required beam size,
The size is selected from the optimum range depending on the driving voltage and the like, and the size thereof is selected from the range of several nm to several tens μm.

Next, an etching process is performed to further remove the second insulating layer 5 in the region including the plurality of through holes 7. This step requires a condition that only the second insulating layer 5 is removed without etching the first insulating layer 4.

For example, an etching step using a solution such as a hydrofluoric acid solution may be mentioned, but in addition to this, conditions under which isotropic etching can be performed using plasma may be selected. Further, by setting the etching conditions optimally in the step of opening the gate electrode, it is possible to omit the sidewall etching step of the insulating layer in the step of opening the gate electrode described above.

Here, in order to realize a high-definition electron-emitting device, an element structure capable of controlling an electron beam and converging the beam is necessary. When a voltage was applied to the device to drive the device, some of the electrons proceeded according to the electric field due to the electric field formed in the vicinity of the electron emitting portion, and it was difficult to converge the electron beam.

The present invention solves the above problems and realizes a high-definition electron-emitting device. The electron emission mechanism of the electron-emitting device of the present invention will be described in detail below with reference to FIGS. FIG. 4 is a diagram showing electron trajectories of an embodiment of the electron-emitting device of the present invention.

FIG. 4 shows a state in which electrons are emitted in a vacuum when the electron-emitting device of the present invention is actually driven.

In the electron-emitting device of the present invention, as shown in FIG. 4, a region α exists near the through hole 7.

This region α is a region in which a vacuum layer having a relative permittivity (ε0) of 1 and a first insulating layer 4 having a relative permittivity (ε1) larger than 1 are laminated. .

Due to the electrical characteristics, the potential distribution is biased to a region having a small relative permittivity, so that the equipotential surface is dense in the vacuum region. As a result, a downwardly convex potential surface is formed in the region β directly above the electron emission layer 3 in the through hole 7, and the electrons emitted from the electron emission layer 3 are converged in one direction.

For the above-mentioned reason, the electron beam converging effect is optimum at the ratio (ε1 / ε0) of the relative permittivity (ε1) of the first insulating layer 4 and the relative permittivity of vacuum (ε0 = 1). The value can be designed. For example, when SiO ₂ is used as the first insulating layer 4, the ratio is (ε1 / ε0 = 4).

As a result, as shown in FIG. 5A, the size of the electron beam when the electron-emitting device of the present invention is actually driven is shown. FIG. 5 is a diagram showing a result of an electron beam and an input signal and an output signal of the embodiment of the electron emitting device of the present invention.

On the other hand, in the conventional device structure in which two insulating layers are laminated as shown in FIGS. 17 and 18, when the same beam converging effect as described above is to be obtained, the second insulating layer 5 is used.
When SiO ₂ (ε2 = 4) is used as the insulating material, it is necessary to select an insulating material having a relative dielectric constant (ε1 = 16) as the first insulating layer 4.

As a result, as shown in FIG. 5B, in the conventional two-layer insulating layer structure, signal delay occurs due to an increase in parasitic capacitance, and a high-definition electron-emitting device cannot be realized.

In the electron emitting device of the present invention, as shown in FIG. 6, the electron emitting layer 3 may extend over both the cathode electrode 2 and the first insulating layer 4.
FIG. 6 is a diagram showing an example of the configuration of the embodiment of the electron-emitting device of the present invention.

In the case of this element structure, as a manufacturing method, the step of forming the through hole 7 and removing the second insulating layer 5 and then forming the electron emitting layer 3 can be performed.

In this case, since electrons are not transported from the cathode electrode 2 to the electron emission layer 3 on the first insulating layer 4, no electrons are emitted into the vacuum. Compared with the device structure in which electrons are emitted from the entire surface of the electron emission layer 3 in FIG. 20, electrons colliding with the gate electrode 6 can be suppressed and electron emission efficiency can be improved.

Further, as shown in FIGS. 7 and 8, when the cathode electrode is partially dug in the through hole region, a higher electron converging effect is obtained in the electron emitting portion, and a high-definition electron is obtained. An emission element can be realized. Figure 7
FIG. 8 is a diagram showing an example of the configuration of the embodiment of the electron-emitting device of the present invention, and FIG. 8 is a diagram showing how the electron-emitting device having the device structure shown in FIG. 7 is driven.

Further, as shown in FIG. 9, by increasing the thickness of the insulating layer 5 other than the vicinity of the through hole 7, the parasitic capacitance can be further reduced and a high speed response can be realized. FIG. 9 is a diagram showing an example of the configuration of the embodiment of the electron-emitting device of the present invention.

Further, as shown in FIG. 10, the device strength can be improved by supporting the second insulating layer 5 between the cathode electrode and the gate electrode at a constant interval. FIG. 10 is a diagram showing an example of the configuration of the embodiment of the electron-emitting device of the present invention.

Further, as shown in FIG. 11, by using a needle-shaped material for the electron emission layer 3, the driving voltage can be reduced. FIG. 11 is a diagram showing an example of the configuration of the embodiment of the electron-emitting device of the present invention.

In the electron-emitting device of the present invention, a general conductor or semiconductor may be used, but diamond or diamond-like carbon, which is known as a low field electron-emitting material,
Amorphous carbon or the like is desirable.

Further, when a material having a sharp tip such as carbon nanotubes or graphite nanofibers is used as the electron emission layer as shown in FIG. 11, the carbon nanotubes or graphite nanofibers are not shown to have a catalytic property so as to grow. There is a structure in which a conductive layer is arranged, and a material having a sharp tip such as the carbon nanotube or graphite nanofiber is selectively used as the electron emission layer on the catalytic conductive layer. The sharp structure of the tip here may be a cone shape or a pyramid shape.

Next, an example used in the image forming apparatus will be described. FIG. 12 is a schematic diagram in which the embodiments of the electron-emitting device of the present invention are arranged in a matrix.

An image forming apparatus obtained by arranging a plurality of electron-emitting devices to which the present invention is applicable will be described with reference to FIG. In FIG. 13, 1111 is an electron source substrate,
Reference numeral 1112 is an X-direction wiring, and 1113 is a Y-direction wiring.
Reference numeral 1114 is the electron-emitting device of the present invention. FIG. 13 is a schematic diagram in which an image forming apparatus is formed by using the embodiment of the electron emitting device of the present invention.

In FIG. 13, reference numeral 1121 is a rear plate, 1122 is a side wall, and 1127 is an envelope.

In FIG. 13, m X-direction wirings 1112 are provided.
, DXm, and are made of an aluminum-based wiring material having a thickness of about 1 μm and a width of 300 μm formed by a vapor deposition method. The wiring material, film thickness, and width are appropriately designed. The Y-direction wiring 1113 has a thickness of 0.5.
μm, width 100 μm, DY1, DY2. ． It is composed of n DYn wirings and is formed similarly to the X-direction wiring 1112.

Between the m X-direction wirings 1112 and the n Y-direction wirings 1113, a thickness not shown is about 1 μm.
Is provided to electrically separate the two (m and n are both positive integers).

The interlayer insulating layer (not shown) is an insulating layer formed by a sputtering method or the like. For example, the X-direction wiring 11
12 is formed on the entire surface or a part of the electron source substrate 1111 in a desired shape, and in particular, the film thickness, material and manufacturing method are set so as to withstand the potential difference at the intersection of the X-direction wiring 1112 and the Y-direction wiring 1113. Is set appropriately. X-direction wiring 111
2 and the Y-direction wiring 1113 are drawn out as external terminals.

A pair of electrodes (not shown) constituting the electron-emitting device 1114 of the present invention are electrically connected by m X-direction wirings 1112 and n Y-direction wirings 1113.

A scanning signal applying means (not shown) for applying a scanning signal for selecting the row of the electron-emitting devices 1114 of the present invention arranged in the X direction is connected to the X-direction wiring 1112.

On the other hand, the Y-direction wiring 1113 is connected to a modulation signal generating means (not shown) for modulating each column of the electron-emitting devices 1114 of the present invention arranged in the Y-direction according to an input signal.

The drive voltage applied to each electron-emitting device is
It is supplied as a difference voltage between the scanning signal and the modulation signal applied to the element. In the present invention, the Y-direction wiring has a high potential,
The X-direction wiring was connected so as to have a low potential. By connecting in this way, a beam converging effect can be obtained.

According to the above arrangement, individual elements can be selected and driven independently by using simple matrix wiring.

It is possible to form a display panel of an image forming apparatus configured by using an electron source having such a simple matrix arrangement.

In the image forming apparatus using the electron-emitting device of the present invention, the phosphor is aligned and arranged above the device in consideration of the emitted electron orbit.

The fluorescent film used in the panel of the present case will be described with reference to FIG. FIG. 14 is a schematic diagram showing an example of the phosphor used in the image forming apparatus of the present invention. In the case of a color fluorescent film, it is composed of a black conductive material 141 called a black stripe shown in FIG. 14A or a black matrix shown in FIG.

In the case of color display, the purpose of providing the black stripes and the black matrix is to make the mixed portions between the phosphors 142 of the three primary color phosphors necessary to be black so as to make the color mixture inconspicuous and to prevent the external color of the phosphors 142. The reduction in contrast due to light reflection was suppressed.

As the material for the black stripe, a material containing graphite as a main component, which is usually used in this embodiment, was used.

In FIG. 13, the fluorescent film 1 on the substrate 1123
A metal back 1125 is usually provided on the inner surface side of 124.

The metal back 1125 is formed after the fluorescent film is formed.
The inner surface of the fluorescent film was smoothed (usually called “filming”), and then Al was deposited by vacuum deposition or the like.

On the face plate 1126, a transparent electrode (not shown) is provided on the outer surface side of the fluorescent film 1124 in order to further increase the conductivity of the fluorescent film 1124.

When the above-mentioned sealing is performed, in the case of color, it is necessary to associate each color phosphor with the electron-emitting device.
Sufficient alignment is essential. In the present embodiment, the corresponding phosphor is arranged directly above the electron source.

Next, the scanning circuit of the image forming apparatus of the present invention will be described with reference to FIG. FIG. 15 is a schematic view of an image forming apparatus formed by using the electron-emitting device of the present invention.

The circuit is provided with M switching elements therein (schematically shown by S1 to Sm in the figure).

Each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level), and is electrically connected to the terminals Dx1 to Dxm of the display panel 1301.

Each switching element 130 of S1 to Sm
2 is a control signal Tscan output from the control circuit 1303
), And can be configured by combining switching elements such as FETs.

In the case of the present example, the DC voltage source Vx has a driving voltage applied to an unscanned element based on the characteristics (electron emission threshold voltage) of the electron-emitter element of the present invention, and the electron emission threshold value is applied. It is set to output a constant voltage that is less than or equal to the value voltage.

The control circuit 1303 has a function of matching the operation of each unit so that an appropriate display is performed based on an image signal input from the outside.

The control circuit 1303 uses the sync signal separation circuit 1
Based on the synchronization signal Tsync sent from 306, control signals Tscan, Tsft, and Tmry are generated for each unit.

The sync signal separation circuit 1306 is a circuit for separating a sync signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured.

The sync signal separated by the sync signal separation circuit 1306 is composed of a vertical sync signal and a horizontal sync signal, but it is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. The DATA signal is input to the shift register 1304.

The shift register 1304 is for serially / parallel-converting the DATA signals serially input in time series for each line of the image, and is based on the control signal Tsft sent from the control circuit 1303. The control signal Tsft can be said to be the shift clock of the shift register 1304.

The serial / parallel converted image data for one line (corresponding to drive data for N electron emission elements) is output from the shift register 1304 as N parallel signals Id1 to Idn.

The line memory 1305 is a storage device for storing data for one line of an image for a required time, and stores the contents of Id1 to Idn as appropriate in accordance with the control signal Tmry sent from the control circuit 1303. The stored contents are output as Id′1 to Id′n and input to the modulation signal generator 1307.

The modulation signal generator 1307 outputs the image data I
a signal source for appropriately driving and modulating each of the electron-electron emitting devices of the present invention according to each of d′ 1 to Id′n,
The output signal is applied to the electron-emitting device of the present invention in the display panel 1301 through the terminals Dox1 and Doyn.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie. That is, a clear threshold voltage Vth is required for electron emission.
Therefore, electron emission occurs only when a voltage higher than Vth is applied.

For voltages above the electron emission threshold,
The emission current also changes according to the change in the voltage applied to the element.

From this, when a pulsed voltage is applied to this device, for example, no electron emission occurs even if a voltage below the electron emission threshold is applied, but when a voltage above the electron emission threshold is applied. An electron beam is output.

At this time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm.

Further, by changing the pulse width Pw, it is possible to control the total amount of charges of the electron beam output.

Therefore, as a method of modulating the electron-emitting device according to the input signal, a voltage modulation method, a pulse width modulation method or the like can be adopted.

When carrying out the voltage modulation method, the modulation signal generator 1307 is a voltage modulation method that generates a voltage pulse of a constant length and appropriately modulates the peak value of the pulse according to the input data. A circuit can be used.

When implementing the pulse width modulation method,
As the modulation signal generator 1307, it is possible to use a circuit of a pulse width modulation system that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data.

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

When the digital signal type is used, it is necessary to convert the output signal DATA of the sync signal separation circuit 1306 into a digital signal.
An A / D converter may be provided at the output section of 6.

In relation to this, the circuit used for the modulation signal generator 1307 is slightly different depending on whether the output signal of the line memory 1305 is a digital signal or an analog signal.

That is, in the case of the voltage modulation method using a digital signal, for example, a D / A conversion circuit is used for the modulation signal generator 1307, and an amplification circuit or the like is added if necessary.

In the case of the pulse width modulation method, the modulation signal generator 1307 compares, for example, a high-speed oscillator and a counter for counting the number of waves output by the oscillator and the output value of the counter with the output value of the memory. A circuit is used that is a combination of comparators.

If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator to the drive voltage of the electron-electron-emitting device of the present invention can be added.

In the case of the voltage modulation method using an analog signal, the modulation signal generator 1307 can adopt an amplifier circuit using an operational amplifier, for example, and a level shift circuit or the like can be added if necessary.

In the case of the pulse width modulation method, for example, a voltage control type oscillation circuit (VCO) can be adopted, and an amplifier for amplifying the voltage up to the driving voltage of the electron electron-emitting device of the present invention is added if necessary. You can also

The configuration of the image forming apparatus described here is an example of the image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention.

As for the input signal, the NTSC system is mentioned, but the input signal is not limited to this, and PAL,
In addition to the SECAM system and the like, a TV signal (for example, a high-definition TV including the MUSE system) system including a large number of scanning lines can be adopted.

Further, in addition to the display device, it can also be used as an image forming device as an optical printer constituted by using a photosensitive drum or the like.

[0126]

EXAMPLES Examples of the present invention will be described in more detail below. (Embodiment 1) FIG. 1 shows an example of a sectional view and a plan view of an electron-emitting device manufactured according to this embodiment, and FIG. 3 shows an example of a method for manufacturing an electron-emitting device of the present invention. The manufacturing process of the electron-emitting device of this embodiment will be described in detail below.

Quartz was used for the substrate 1, and after sufficient cleaning, a cathode electrode 2 having a thickness of 300 was formed by sputtering.
After depositing Ti with a thickness of nm, a diamond-like carbon film was deposited with a thickness of 80 nm as the electron emission layer 3 by the CVD method.

Next, SiNx is deposited as a first insulating layer 4 on the diamond-like carbon film by a CVD method to a thickness of 100.
nm deposition, followed by 3 SiO ₂ as a second insulating layer 5.
Then, the gate electrode 6 was deposited to a thickness of 100 nm by the sputtering method.

In the laminated substrate formed as described above, 104 through holes of φ0.5 μm are formed in the gate electrode 6 by dry etching by photolithography and RIE, and then SiO ₂ and SiNx are sequentially formed by RIE. Etching was carried out and stopped on the electron emission layer 3. Then, SiO ₂ was etched using buffered hydrofluoric acid to remove the SiO ₂ in the region including the through hole 7.

The electron-emitting device manufactured as described above is placed in a vacuum container, and a pulse voltage of 15 V is applied between the gate electrode 6 and the cathode electrode 2 to the upper part of the electron-emitting device.
Phosphors to which a voltage of 5 kV was applied were arranged at a distance of mm.

As a result, an electron beam converged to 38 μm was obtained.

(Example 2) Using glass as a substrate, thoroughly washing, and then depositing Ti with a thickness of 300 nm as a cathode electrode by a sputtering method, and then depositing SiNx as a first insulating layer with a thickness of 100 nm by a CVD method Then, SiO ₂ is deposited to a thickness of 300 nm as a second insulating layer, and further,
As a gate electrode, Ta was deposited to a thickness of 100 nm by a sputtering method.

On the laminated substrate formed as described above, 104 φ0.5 μm through holes were formed in the gate electrode by dry etching by photolithography and RIE, and then SiO ₂ and SiNx were sequentially formed by RIE. Etched and stopped on cathode electrode 2. The etching process here was stopped when the cathode electrode was dug in a concave shape of 50 nm.

After that, buffered hydrofluoric acid was used to remove Si.
O ₂ was etched to remove SiO ₂ in the area including the through holes.

Next, as an electron emission layer, a diamond-like carbon film was deposited only on the cathode electrode, and the electron emission characteristics were evaluated in a vacuum container.

As a result, an electron beam focused to 34 μm was obtained.

Example 3 Using the same laminated substrate as in Example 2, diamond-like carbon was deposited as an electron emission layer so as to cover the cathode electrode and the first insulating layer,
The electron emission characteristics were evaluated in a vacuum container.

As a result, an electron beam of 34 μm was obtained, and high efficiency could be realized without emitting electrons from diamond-like carbon on the first insulating layer.

Example 4 In this example, the structure of the electron-emitting device shown in FIG. 11 will be described. After using glass for the substrate 1 and performing sufficient cleaning, after depositing Ti with a thickness of 300 nm as the cathode electrode 2 by the sputtering method,
The first insulating layer 4 is made of SiNx 100 by the CVD method.
nm deposition, followed by 3 SiO ₂ as a second insulating layer 5.
Then, the gate electrode 6 was deposited to a thickness of 100 nm by the sputtering method.

On the laminated substrate formed as described above, 104 through holes 7 of φ0.5 μm are formed in the gate electrode 6 by dry etching by photolithography and RIE, and then SiO ₂ and SiNx are sequentially formed. RIE
Etched by and stopped on the cathode electrode 2. Then, SiO ₂ was etched using buffered hydrofluoric acid to remove the SiO ₂ in the region including the through hole 7.

Next, after depositing 8 nm of PdO as a catalyst on the surface of the cathode electrode 2 of the above-mentioned laminated substrate, CVD is performed.
Carbon nanotubes were grown using the method and evaluated in a vacuum vessel.

As a result, the gate electrode 6 and the cathode electrode 2
The voltage between them was reduced to 12 V, and an electron beam converged to 38 μm was obtained.

(Embodiment 5) Another crystal diamond film was formed as an electron emission layer on a laminated substrate in which the same through holes as in Embodiment 3 were formed.

The electron-emitting device manufactured as described above was placed in a vacuum container, and a pulse voltage of 14 V was applied between the gate electrode and the cathode electrode by 1 mm above the electron-emitting device.
Phosphors to which a voltage of 5 kV was applied were arranged at a distance of.

As a result, an electron beam converged to 38 μm was obtained. A converged electron beam can also be obtained by using an amorphous carbon film as the electron emission layer.

(Embodiment 6) In this embodiment, the structure of the electron-emitting device shown in FIG. 10 will be described. After using quartz for the substrate 1 and performing sufficient cleaning, after depositing Ti with a thickness of 300 nm as the cathode electrode 2 by the sputtering method,
As the electron emission layer 3, a diamond-like carbon film having a thickness of 80 nm was deposited by using the CVD method.

Next, 100 nm of SiNx was deposited as a first insulating layer 4 on the diamond-like carbon film by the CVD method.
nm deposition, followed by 3 SiO ₂ as a second insulating layer 5.
Then, the gate electrode 6 was deposited to a thickness of 100 nm by the sputtering method.

On the laminated substrate formed as described above, 104 φ0.5 μm through holes 7 were formed in the gate electrode 6 by dry etching by photolithography and RIE.

However, in this case, the above-mentioned 104 through-hole groups were separated by 5 μm to form three regions. Then, Si
O ₂ and SiNx were sequentially etched by RIE and stopped on the electron emission layer 3.

After that, buffered hydrofluoric acid was used to remove Si.
O ₂ is etched to form SiO _{2 in a} region including the through hole 7.
Was removed. As a result, Si between the through holes
The O ₂ layer remained unremoved, increasing the strength of the device.

The electron-emitting device manufactured as described above is placed in a vacuum container, and a pulse voltage of 15 V is applied between the gate electrode 6 and the cathode electrode 2 to the upper part of the electron-emitting device.
Phosphors to which a voltage of 5 kV was applied were arranged at a distance of mm.

As a result, an electron beam converged to 50 μm was obtained.

(Embodiment 7) In Embodiments 1 to 5, the same result is obtained even if an N-type silicon substrate is used as the substrate.

(Embodiment 8) An image forming apparatus in which the elements of Embodiments 1 to 7 were individually used and arranged in a 100 × 100 MTX pattern was manufactured. As an example, the case of using the element of Example 1 will be described.

Wiring was performed by connecting the X wiring to the cathode electrode 2 and the Y wiring to the gate electrode 5 as shown in FIG. The electron-emitting device has 104 through holes as one pixel,
It was arranged at a pitch of 30 μm in width and 100 μm in length. Phosphors were aligned and arranged on the upper part of the element at positions separated by 1 mm. A voltage of 5 kV was applied to the phosphor.

The input signal was driven by using a circuit as shown in FIG. As a result, a high-definition image forming apparatus could be formed.

[0157]

As described above, according to the present invention,
A cathode electrode, an electron emission layer, an insulating layer arranged on the substrate,
A gate electrode and a structure in which the thickness of the insulating layer is thinner than the distance between the cathode electrode and the gate electrode makes it possible to change the potential distribution in the vicinity of the electron emission layer, and Can converge.

By applying the electron-emitting device having the above structure, the electron source and the image forming apparatus can be improved in performance.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an electron-emitting device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of driving an electron-emitting device of the present invention.

FIG. 3 is a manufacturing process diagram of the electron-emitting device according to the embodiment of the present invention.

FIG. 4 is a diagram showing electron trajectories of an embodiment of an electron-emitting device of the present invention.

FIG. 5 is a diagram showing a result of an electron beam and an input signal and an output signal of the embodiment of the electron emitting device of the present invention.

FIG. 6 is a diagram showing an example of a configuration of an embodiment of an electron-emitting device of the present invention.

FIG. 7 is a diagram showing an example of a configuration of an embodiment of an electron-emitting device of the present invention.

FIG. 8 is a diagram showing how an electron-emitting device having the device structure shown in FIG. 7 is driven.

FIG. 9 is a diagram showing an example of a configuration of an embodiment of an electron-emitting device of the present invention.

FIG. 10 is a diagram showing an example of a configuration of an embodiment of an electron-emitting device of the present invention.

FIG. 11 is a diagram showing an example of a configuration of an embodiment of an electron-emitting device of the present invention.

FIG. 12 is a schematic view in which embodiments of the electron-emitting device of the present invention are arranged in a matrix.

FIG. 13 is a diagram showing an embodiment of the electron-emitting device of the present invention,
It is a schematic diagram which formed the image forming apparatus.

FIG. 14 is a schematic diagram showing an example of a phosphor used in the image forming apparatus of the present invention.

FIG. 15 is a schematic diagram in which an image forming apparatus is formed by using the electron-emitting device of the present invention.

FIG. 16 is a schematic view showing a conventional electron-emitting device.

FIG. 17 is a schematic view showing a conventional electron-emitting device.

FIG. 18 is a schematic view showing a conventional electron-emitting device.

FIG. 19 is a schematic view showing a conventional electron-emitting device.

FIG. 20 is a schematic view showing a conventional electron-emitting device.

[Explanation of symbols]

1 substrate 2 cathode electrode 3 Electron emission layer 4 First insulating layer 5 Second insulating layer 6 Gate electrode 7 through holes 8 Anode electrode (phosphor) 9 Opening area 141 black conductive material 142 phosphor 1111 Electron source substrate 1112 X-direction wiring 1113 Y-direction wiring 1114 Electron-emitting device 1121 rear plate 1122 side wall 1123 substrate 1124 fluorescent film 1125 metal back 1126 Face plate 1127 envelope 1301 display panel 1302 switching element 1303 control circuit 1304 shift register 1305 line memory 1306 Sync signal separation circuit 1307 Modulation signal generator

Claims (20)

[Claims] 1. A cathode electrode arranged on a substrate, an insulating layer arranged on the cathode electrode and having a plurality of openings, and arranged on the insulating layer, each on a plurality of openings of the insulating layer. An electron-emitting device having a gate electrode having a plurality of through-holes arranged in the insulating layer, and an electron-emitting layer arranged at least on the cathode electrode located in the opening of the insulating layer, wherein the electron-emitting device is arranged in the insulating layer. An electron-emitting device characterized in that a gap is formed between the end of the plurality of openings formed on the side of the gate electrode and the end of the plurality of openings arranged on the gate electrode on the side of the cathode electrode. 2. The insulating layer and the gate electrode are connected to each other in a region of the gate electrode outside a region in which the plurality of openings are arranged. Electron-emitting device. 3. The electron-emitting device according to claim 1, wherein the electron-emitting layer is disposed between the cathode electrode and the insulating layer. 4. An electron source in which a plurality of electron-emitting devices are arranged, wherein the electron-emitting device is the electron-emitting device according to claim 1 or 2. 5. An image forming apparatus having an electron source and a phosphor, wherein the electron source is the electron source according to claim 4. 6. A cathode electrode arranged on a substrate, an insulating layer arranged on the cathode electrode, a gate electrode arranged on the insulating layer, and formed from the gate electrode to at least the insulating layer. An electron emission layer having a plurality of through holes formed therein, and an electron emission layer disposed on the cathode electrode located at least in the through hole, wherein at least the entire opening region in which the through holes are formed. Alternatively, in part, the thickness of the insulating layer is thinner than the distance between the cathode electrode and the gate electrode. 7. The electron-emitting device according to claim 6, wherein the electron-emitting layer is laminated between the cathode electrode and the insulating layer. 8. The electron emitting device according to claim 6, wherein the electron emitting layer is provided only in the through hole. 9. The electron emission layer is directly connected to the cathode electrode in a region that emits electrons, and is connected to the cathode electrode through the insulating layer in a region that does not emit electrons. The electron-emitting device according to claim 6. 10. The electron emission according to claim 6, wherein the cathode electrode surface of the portion in contact with the through hole is lower than the cathode electrode surface of the other portion. element. 11. The insulating layer having the same thickness as the distance between the cathode electrode and the gate electrode is arranged at a constant interval between the cathode electrode and the gate electrode. The electron-emitting device according to any one of 6 to 10. 12. The electron emitting device according to claim 6, wherein the electron emitting layer contains carbon as a main component. 13. The electron-emitting device according to claim 6, wherein the electron-emitting layer has a positive bandgap. 14. The electron-emitting device according to claim 6, wherein the electron-emitting layer is a diamond-like carbon film or an amorphous carbon film. 15. The electron emission layer is connected to the cathode electrode via a catalytic conductive layer, the electron emission layer contains carbon as a main component, and its tip has a conical shape or a pyramidal shape. The electron-emitting device according to any one of claims 6 to 14, which is characterized. 16. A cathode electrode and a gate electrode are laminated on a substrate, and a first insulating layer and a second insulating layer are laminated between the cathode electrode and the gate electrode. Electron emission having a plurality of through holes formed at least over the insulating layer, transporting electrons from the cathode electrode toward the electron emission layer arranged on the cathode electrode and emitting electrons from the electron emission layer An electron-emitting device, wherein the second insulating layer is not formed in at least all or part of the opening region in which the through hole is formed. 17. An electron source comprising a plurality of electron-emitting devices according to claim 6 arranged therein. 18. The electron source according to claim 17, wherein the plurality of electron-emitting devices are arranged in matrix. 19. An anode electrode for supplementing electrons emitted from the electron-emitting device according to claim 6, and an image forming member arranged on the anode electrode for forming an image. An image forming apparatus having. 20. The image forming apparatus according to claim 19, wherein the image forming member is a phosphor.