JP2002231124A - Cold cathode field electron emission element and cold cathode field electron emission display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold cathode field electron emission element having focus poles capable of surely having an electron collection effect on a plurality of field emission elements even with a simple structure. SOLUTION: This cold cathode field emission element comprises (A) a support body 10, (B) a cathode electrode 11 formed on the support body 10 and extending in a first direction, (C) a gate electrode 13 disposed above the cathode electrode 11 and extending in a second direction, (D) a hole part 14A provided in the area of the gate electrode 13 overlapped with the cathode electrode 11, (E) an electron emission part 15 disposed at the bottom part of the hole part, and (F) a focus electrode 30. The focus electrode 30 extends in the second direction, and disposed between the gate electrode 13 and the gate electrode 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cold cathode field emission device and a cold cathode field emission display.

[0002]

2. Description of the Related Art In the field of display devices used for television receivers and information terminal equipment, the conventional mainstream cathode ray tubes (C
RT) to a flat-panel (flat panel) display device that can meet the demands for thinner, lighter, larger screen, and higher definition. As such a flat display device, a liquid crystal display device (LCD), an electroluminescence display device (ELD), a plasma display device (PD)
P), a cold cathode field emission display (FED: field emission display). Among them, liquid crystal display devices are widely used as display devices for information terminal equipment, but there are still problems in high brightness and large size for application to stationary television receivers. . On the other hand, a cold cathode field emission display device is a cold cathode field emission device (hereinafter, referred to as a field emission device) capable of emitting electrons from a solid into a vacuum based on a quantum tunnel effect without using thermal excitation. (Which may be referred to as an element), and has attracted attention in terms of high luminance and low power consumption.

FIG. 47 shows a configuration example of a cold cathode field emission display device (hereinafter, may be referred to as a display device) provided with a field emission element. The illustrated field emission device has a conical electron emission portion, a so-called Spindt.
This is a type of device called a field emission device. The field emission device includes a cathode electrode 11 formed on a support 10, an insulating layer 12 formed on the support 10 and the cathode electrode 11, a gate electrode 13 formed on the insulating layer 12, It comprises a hole 14A provided in the electrode 13, an opening 14B provided in the insulating layer 12, and a conical electron emitting portion 15 formed on the cathode electrode 11 located at the bottom of the opening 14B. . Generally, the cathode electrode 11 and the gate electrode 13 are formed such that the projected images of these two electrodes are formed in a stripe shape in a direction orthogonal to each other, and a region (1) where the projected images of these two electrodes overlap.
This corresponds to a pixel area. Usually, a plurality of field emission elements are arranged in this area (hereinafter, referred to as an overlap area). Further, such overlapping areas are usually arranged in a two-dimensional matrix in an effective area (area functioning as an actual display portion) of the cathode panel CP.

On the other hand, the anode panel AP is
And a phosphor layer 22 formed on a substrate 20 and having a predetermined pattern, and an anode electrode 23 formed thereon. One pixel is composed of a group of field emission elements arranged in an overlapping region of the cathode electrode 11 and the gate electrode 13 on the cathode panel side, and a phosphor layer 22 on the anode panel side facing the group of these field emission elements. It is configured. In the effective area, such pixels are arranged, for example, in the order of several hundred thousand to several million.
Note that a black matrix 21 is formed on the substrate 20 between the phosphor layers 22.

Anode panel AP and cathode panel CP
Are arranged so that the field emission element and the phosphor layer 22 face each other, and are joined at a peripheral portion via a frame (not shown), whereby a display device can be manufactured.
A through hole (not shown) for evacuation is provided in the ineffective area surrounding the effective area and a peripheral circuit for selecting a pixel is formed.
A chip tube (not shown) sealed after vacuum evacuation is connected to the through hole. That is,
The space surrounded by the anode panel AP, the cathode panel CP, and the frame is a vacuum.

In such a display device, electrons are emitted from the electron emitting section 15 at a certain divergence angle (see FIG. 48). Therefore, depending on the size of the pixel (the size of the phosphor layer), all of the electrons emitted from the electron emitting portion 15 do not collide with the phosphor layer 22 located in the region facing the electron emitting portion 15 and the display is performed. There is a problem that the luminance efficiency with respect to the power consumption of the entire device is reduced, and the electron emission part 15 emits electrons from the phosphor layer 2 constituting an adjacent pixel.
As a result, a problem arises that optical crosstalk occurs. These problems become more remarkable as the pixels become smaller with the refinement of the display device.

As a means for solving these problems, a technique of providing a focus electrode (converging electrode) above a gate electrode is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-82213,
Alternatively, it is known from the abstract of the 1994 Fall Meeting of the Japan Society of Applied Physics, 21p-ZQ-5 (hereinafter referred to as Document 1).

The focus electrode plays a role as an electron converging lens from the viewpoint of electron optics. A voltage lower than the voltage applied to the gate electrode is applied to the focus electrode, and the resulting potential difference causes the equipotential surface in the vicinity of the space through which the electrons pass to be curved, thereby converging the trajectories of the electrons.

The focus electrode disclosed in Japanese Patent Application Laid-Open No. 9-82213 surrounds one or a plurality of field emission elements and is located on a plane closer to the anode electrode than a plane including the tip of the electron emission portion. Are located. Further, an insulating film is formed to separate the electron emitting portion from the focus electrode, and the focus electrode is formed on the top surface and the side surface of the insulating film.

Further, in the field emission device disclosed in Document 1, a ring-shaped gate electrode is formed on the insulating layer so as to surround one electron emitting portion, and further on the insulating layer outside the gate electrode. A ring-shaped focus electrode is formed.

[0011]

SUMMARY OF THE INVENTION Japanese Patent Application Laid-Open No. 9-82213
In the focus electrode disclosed in Japanese Patent Application Laid-Open Publication No. H10-107, when a focus electrode is arranged around one electron emission portion, the number of electron emission portions that can be provided in the display device is limited. Also,
Since it is necessary to make the thickness of the insulating film for forming the focus electrode somewhat thicker than the thickness of the insulating layer, CV
There is a problem that it takes a long time to form the insulating film by the D method, the sputtering method, or the like, and the manufacturing throughput of the display device is reduced. Further, when the material forming the insulating film is different from the material forming the insulating layer, in the heating step in manufacturing the display device, stress is generated in the insulating layer or the insulating film due to a difference in the coefficient of thermal expansion, and the worst case occurs. In this case, the display device may be damaged. Alternatively, depending on the material of the insulating film, the heating temperature in the heating step may be limited. In addition, when electrons collide with the insulating film emitted from the electron emitting portion, the insulating film is damaged or the insulating film is charged, so that the equipotential surface near the insulating film is distorted, and the trajectory of electrons changes. There is also a possibility that discharge may occur due to such a problem or charging of the insulating film.

Also, when the technique disclosed in Document 1 is applied, it is necessary to arrange a focus electrode around one electron emitting portion, and the number of electron emitting portions that can be provided in a display device is limited. receive.

Accordingly, an object of the present invention is to provide a focus electrode which can avoid the above-mentioned various problems and can surely exert an electron focusing effect on a plurality of field emission devices despite having a simple structure. Cold cathode field emission device,
Another object of the present invention is to provide a cold cathode field emission display device incorporating such a cold cathode field emission device.

[0014]

According to a first aspect of the present invention, there is provided a cold-cathode field emission device which is formed on (A) a support and (B) a support. , First
(C) a gate electrode disposed above the cathode electrode and extending in a second direction different from the first direction, and (D) a gate electrode overlapping the cathode electrode. A cold cathode field emission device including: a hole provided; (E) an electron emission portion disposed at the bottom of the hole; and (F) a focus electrode. 2 and is disposed between the gate electrodes.

The first object of the present invention for achieving the above object is as follows.
The cold cathode field emission display according to the aspect, the cathode panel on which the cold cathode field emission device is formed, and the anode panel on which the anode electrode and the phosphor layer are formed,
The phosphor layer and the cold cathode field emission device are arranged so as to face each other, and the cathode panel and the anode are joined at a peripheral portion.
A support; (B) a cathode electrode formed on the support and extending in a first direction; and (C) a gate disposed above the cathode electrode and extending in a second direction different from the first direction. An electrode, (D) a hole provided in a region of the gate electrode overlapping the cathode electrode, (E) an electron-emitting portion provided at the bottom of the hole, and (F) a focus electrode. A cold cathode field emission display, wherein the focus electrode extends in a second direction and is disposed between the gate electrodes.

A cold cathode field emission device or a cold cathode field emission display according to the first embodiment of the present invention (hereinafter, referred to as a cold cathode field emission device).
In the field emission device or the display device according to the first aspect of the present invention), it is preferable that the focus electrode and the gate electrode are substantially on the same plane. Here, the term “substantially the same plane” means that the planes do not have to be strictly the same plane. This includes the case where the insulating film is present, or the structure where an insulating film is formed below the focus electrode as described later.

The field emission device or the display device according to the first aspect of the present invention further comprises a second focus electrode, wherein the second focus electrode extends in the first direction and has a cathode. It is also possible to adopt a configuration that is provided above the region between the electrode and the cathode electrode. That is, in such a configuration, the projected image in which the projected images of the focus electrode and the second focus electrode are combined has a cross-girder shape. Overlap.

The second object of the present invention for achieving the above object is as follows.
The cold cathode field emission device according to the aspect (A) is provided on a support, (B) a cathode electrode formed on the support and extending in a first direction, and (C) disposed above the cathode electrode. ,
A gate electrode extending in a second direction different from the first direction; (D) a hole provided in a region of the gate electrode overlapping the cathode electrode; and (E) an electron provided at the bottom of the hole. A cold cathode field emission device comprising: an emission unit; and (F) a focus electrode, wherein the focus electrode extends in a first direction and extends above a region between the cathode electrodes. It is characterized by being provided.

The second object of the present invention for achieving the above object.
The cold cathode field emission display according to the aspect, the cathode panel on which the cold cathode field emission device is formed, and the anode panel on which the anode electrode and the phosphor layer are formed,
The phosphor layer and the cold cathode field emission device are arranged so as to face each other, and the cathode panel and the anode are joined at a peripheral portion.
A support; (B) a cathode electrode formed on the support and extending in a first direction; and (C) a gate disposed above the cathode electrode and extending in a second direction different from the first direction. An electrode, (D) a hole provided in a region of the gate electrode overlapping with the cathode electrode, (E) an electron-emitting portion provided at the bottom of the hole, and (F) a focus electrode. A cold cathode field emission display, wherein the focus electrode extends in a first direction and is disposed above a region between the cathode electrodes.

A cold cathode field emission device or a cold cathode field emission display (hereinafter, referred to as a cold cathode field emission device) according to a second embodiment of the present invention.
(Referred to as a field emission device or a display device according to the second aspect of the present invention), the focus electrode and the gate electrode are preferably substantially on the same plane. Here, the term “substantially the same plane” means that the focus electrode occupies an extent to which an insulating film for preventing a short circuit between the focus electrode and the gate electrode is formed between the focus electrode and the gate electrode. This means that a configuration in which a gap exists between the plane and the virtual plane occupied by the gate electrode is included.

In the field emission device or the display device according to the second aspect of the present invention, it is desirable that the cathode electrode, the gate electrode, and the focus electrode have a planar shape in a stripe shape, but are not limited to such a planar shape. is not.

The first or second embodiment of the present invention
Field emission device or display device according to
Are sometimes simply referred to as the present invention).
Is the voltage V applied to the focus electrode_FTo the second
When a focus electrode is provided, the second focus electrode
Applied voltage V_F2), The voltage V applied to the gate electrode _G
Need to be lower than That is, the following equation (2-
It is necessary to satisfy 1) and (2-2).

[0023] [Equation _{2] V F <V G (} 2-1) V F2 <V G (2-2)

The voltage applied to the gate electrode may be a constant value or a variable value depending on the configuration of the display device. Also, the voltage applied to the focus electrode may be a constant value or a variable value depending on the configuration of the display device. When the variable these voltages, the voltage V _G applied to the gate electrode and its minimum value, the voltage V _F applied to the focus electrode or the second focus electrode, when the F _F2 and its maximum value, It suffices to satisfy Expressions (2-1) and (2-2). Here, the voltage applied to the gate electrode is a positive value, and the voltage applied to the focus electrode is a positive value, 0, as long as the following expressions (1) and (2-1) are satisfied. The voltage applied to the second focus electrode can be a positive value, 0 volt, or a negative value as long as the expression (2-2) is satisfied. .
Incidentally, the voltage F _F2 applied to the voltage V _F and the second focus electrode applied to the focus electrode may be different even in the same.

Each of the focus electrodes may be connected to a focus electrode drive circuit, or each of the focus electrodes may be integrated into one, that is, one in shape, or electrically connected to each other. In this state, it may be connected to the focus electrode drive circuit. The same applies to the second focus electrode. Further, the focus electrode and the second focus electrode are formed into one shape, or
In a state where they are electrically connected to each other, they may be connected to the focus electrode drive circuit, or the focus electrodes and the second focus electrode may be connected to different focus electrode drive circuits.

In the field emission device or the display device according to the first aspect of the present invention, (a) an insulating layer is formed on the support and the cathode electrode, and (b) the insulating layer is formed on the insulating layer.
A structure in which a gate electrode and a focus electrode are formed, (c) an opening communicating with a hole provided in the gate electrode is provided in the insulating layer, and (d) an electron emission portion is located at the bottom of the opening. It can be.

In this case, in the field emission device or the display device according to the first embodiment of the present invention, it is desirable that the gate electrode and the focus electrode have a planar shape in the form of a stripe, but are not limited to such a planar shape. is not. And, furthermore, in this case, the insulating layer is made of SiO ₂ based materials, distance L _GL between the gate electrode and the focus electrode (unit: m), a voltage applied to the gate electrode V _G (unit: Volts) and the voltage applied to the focus electrode as V _F (unit: volts), the following equation (1)
Is preferably satisfied. Thus, it is possible to reliably prevent the occurrence of creeping discharge along the surface of the insulating layer between the focus electrode and the gate electrode.

[Equation 3] (V _G -V _F ) / L _GF <7 × 10 ⁷ (V / m) (1)

As described above, the voltage applied to the gate electrode may be a constant value or a variable value depending on the configuration of the display device. Further, the voltage applied to the focus electrode also depends on the configuration of the display device.
It may be a constant value or a variable value. These voltage when the variable is set to its maximum value a voltage V _G applied to the gate electrode in equation (1),
When the voltage V _F applied to the focus electrode is set to the minimum value, it is only necessary to satisfy Expression (1).

On the other hand, in the field emission device or the display device according to the second aspect of the present invention, (a) an insulating layer is formed on the support and the cathode electrode, and (b) an insulating layer is formed on the insulating layer. A gate electrode is formed, (c) a focus electrode is formed on the insulating layer via an insulating film, and (d) an opening communicating with a hole provided in the gate electrode is provided in the insulating layer. (E) The electron emission portion may be located at the bottom of the opening. In the field emission device or the display device according to the second aspect of the present invention, (a) an insulating layer is alternatively formed on the support and the cathode electrode, and (b) an insulating layer is formed on the insulating layer. A focus electrode is formed; (c) a gate electrode is formed on the insulating layer via an insulating film; and (d) the insulating film and the insulating layer communicate with a hole provided in the gate electrode. An opening is provided, (e)
A configuration in which the electron-emitting portion is located at the bottom of the opening may be employed.

In the case where the second focus electrode is provided in the field emission device or the display device according to the first aspect of the present invention, the focus electrode and the focus electrode in the field emission device or the display device according to the second aspect of the present invention are provided. A similar configuration can be used. Alternatively, a grid-shaped insulating film may be formed over the gate electrode and the insulating layer, and the focus electrode and the second focus electrode may be formed over the insulating film.

In the field emission device or the display device according to the second aspect of the present invention, or in the first aspect of the present invention,
In the case where the second focus electrode is provided in the field emission device or the display device according to the above aspect, as long as insulation between the gate electrode and these focus electrodes can be ensured, the width of these focus electrodes and the thickness of the insulating film are provided. The nature is essentially arbitrary. However, it is preferable that the insulating film be as thin as possible from the viewpoint of shortening the film formation time.

In these cases, a configuration in which the electron-emitting portion is provided on a portion of the cathode electrode located at the bottom of the opening (for convenience, referred to as a first configuration) can be adopted, or The cathode electrode located at the bottom of the opening may have a configuration corresponding to the electron emission portion (for convenience, referred to as a second configuration), or the cathode electrode located at the bottom of the opening. May be configured such that the edge of the opening provided in the device corresponds to the electron-emitting portion (for convenience, referred to as a third configuration).

As the field emission device having the first configuration,
Spindt type (a field emission element in which a conical electron emission portion is provided on a portion of the cathode electrode located at the bottom of the opening), crown type (a crown-shaped electron emission portion is located at the bottom of the opening) (A field emission device provided on a portion of a cathode electrode which is provided above) and a flat type (a field emission device provided on a portion of a cathode electrode where a substantially flat electron emission portion is located at the bottom of an opening). be able to. Further, as the field emission device having the second configuration, a flat field emission device that emits electrons from a flat cathode electrode surface, and a crater-type field emission device that emits electrons from a projection on the surface of the cathode electrode having unevenness. Emission elements can be mentioned. Furthermore,
An edge-type field emission device can be given as a field emission device having the third configuration.

As a material for forming a gate electrode in a field emission device having the first structure, the second structure or the third structure, or as a material for forming a focus electrode or a second focus electrode, tungsten ( W), niobium (Nb), tantalum (Ta), titanium (Ti), molybdenum (Mo), chromium (Cr), aluminum (Al), copper (Cu), gold (Au), silver (A)
g), nickel (Ni), cobalt (Co), zirconium (Zr), iron (Fe), platinum (Pt) and zinc (Z
n) at least one metal selected from the group consisting of: n) alloys or compounds containing these metal elements (eg, nitrides such as TiN, WSi ₂ , MoSi ₂ , TiSi
₂ , silicide such as TaSi ₂ ); or silicon (S
semiconductors such as i); and conductive metal oxides such as ITO (indium tin oxide), indium oxide, and zinc oxide. Note that the focus electrode or the second focus electrode may be made of zirconium (Zr), titanium (Ti), a zirconium-aluminum alloy, a zirconium-vanadium-aluminum alloy, a zirconium-vanadium-iron alloy, a mixture of zirconium powder and graphite powder,
Alternatively, it may be made of a so-called non-evaporable material that exhibits a gettering function while maintaining a solid state in a vacuum layer, such as magnesium. To manufacture a gate electrode, a focus electrode, and a second focus electrode, CVD
A thin film composed of the above-mentioned constituent materials by a known thin film forming technique such as a method, a sputtering method, an evaporation method, an ion plating method, an electrolytic plating method, an electroless plating method, a screen printing method, a laser ablation method, and a sol-gel method. Is formed on an insulating layer or an insulating film. When the thin film is formed over the entire surface of the insulating layer or the insulating film, the thin film is patterned using a known patterning technique to form a gate electrode, a focus electrode, and a second focus electrode having a desired planar shape. . After the formation of the gate electrode having a desired planar shape, a hole may be formed in the gate electrode, or the hole may be formed in the gate electrode simultaneously with the formation of the gate electrode having the desired planar shape. In addition, if a resist pattern is formed in advance on an insulating layer or an insulating film before a thin film is formed, a gate electrode, a focus electrode,
The formation of the second focus electrode is possible. Further, if evaporation is performed using a mask having an opening corresponding to the shape of the gate electrode, the focus electrode, or the second focus electrode, or screen printing is performed using a screen having such an opening, patterning after film formation can be performed. Becomes unnecessary. The material forming the gate electrode and the material forming the focus electrode or the second focus electrode can be the same material, the same kind of material, or different materials. Further, the gate electrode and the focus electrode can be formed at the same time, or can be formed in different steps, depending on these structures. Furthermore, the focus electrode and the second focus electrode can be formed at the same time, or can be formed in different steps, depending on these configurations.

In the field emission device having the first structure including the Spindt-type field emission device, the materials constituting the electron emission portion include tungsten, tungsten alloy, molybdenum, molybdenum alloy, titanium, titanium alloy, niobium, and the like. At least one material selected from the group consisting of niobium alloy, tantalum, tantalum alloy, chromium and chromium alloy, and silicon containing impurities (polysilicon or amorphous silicon) can be given.

In the field emission device having the first structure composed of the crown type field emission device, the material constituting the electron emission portion may be conductive particles or a combination of the conductive particles and a binder. it can. As conductive particles, carbon-based materials such as graphite; tungsten (W);
Niobium (Nb), tantalum (Ta), titanium (Ti),
Refractory metals such as molybdenum (Mo) and chromium (Cr);
Alternatively, a transparent conductive material such as ITO (indium tin oxide) can be used. As the binder, for example, glass such as water glass or a general-purpose resin can be used. General-purpose resins include thermoplastic resins such as vinyl chloride resin, polyolefin resin, polyamide resin, cellulose ester resin, and fluorine resin, and thermosetting resins such as epoxy resin, acrylic resin, and polyester resin. Can be exemplified. In order to improve the electron emission efficiency, it is preferable that the particle size of the conductive particles is sufficiently smaller than the size of the electron emission portion. The shape of the conductive particles is not particularly limited, such as a sphere, a polyhedron, a plate, a needle, a column, and an irregular shape. However, it is preferable that the shape is such that the exposed portions of the conductive particles can be sharp projections. Conductive particles having different sizes and shapes may be mixed and used.

In the field emission device having the first configuration of the flat field emission device, the electron emission portion is made of a material having a work function Φ smaller than that of the cathode electrode. Preferably, the material to be selected is determined based on the work function of the material constituting the cathode electrode, the potential difference between the gate electrode and the cathode electrode, the required magnitude of the emitted electron current density, and the like. do it. As a typical material forming the cathode electrode in the field emission device, tungsten (Φ = 4.
55 eV), niobium (Φ = 4.02 to 4.87 eV),
Molybdenum (Φ = 4.53-4.95 eV), aluminum (Φ = 4.28 eV), copper (Φ = 4.6 eV), tantalum (Φ = 4.3 eV), chromium (Φ = 4.5 eV)
V) and silicon (Φ = 4.9 eV). The electron emitting portion preferably has a work function Φ smaller than these materials, and the value is approximately 3 eV.
The following is preferred. Such materials include carbon (Φ <1 eV), cesium (Φ = 2.14 eV), La
B ₆ (Φ = 2.66 to 2.76 eV), BaO (Φ =
1.6 to 2.7 eV), SrO (Φ = 1.25 to 1.6)
eV), Y ₂ O ₃ (Φ = 2.0 eV), CaO (Φ = 1.
6 to 1.86 eV), BaS (Φ = 2.05 eV), T
iN (Φ = 2.92 eV), ZrN (Φ = 2.92 eV)
V). It is more preferable that the electron emission portion is made of a material having a work function Φ of 2 eV or less. Note that the material forming the electron emitting portion does not necessarily need to have conductivity.

Particularly preferred constituent materials of the electron-emitting portion include carbon, more specifically, diamond, especially amorphous diamond. When the electron emitting portion is made of amorphous diamond, 5 × 1
At 0 ⁷ V / m or less of the electric field strength, can be obtained current density of emitted electrons required for the display device. Further, since the amorphous diamond is an electric resistor, the emission electron current obtained from each electron emission portion can be made uniform, and thus, it is possible to suppress the variation in brightness when incorporated into a display device. Further, since amorphous diamond has extremely high resistance to a sputtering action by ions of residual gas in the display device, the life of the field emission device can be extended.

Alternatively, in the field emission device having the first configuration including the flat field emission device, the secondary electron gain δ of such a material may be used as a material forming the electron emission portion.
Is the secondary electron gain δ of the conductive material forming the cathode electrode
It may be appropriately selected from materials that are larger than the above.
That is, silver (Ag), aluminum (Al), gold (A
u), cobalt (Co), copper (Cu), molybdenum (M
o), niobium (Nb), nickel (Ni), platinum (P
t), metals such as tantalum (Ta), tungsten (W) and zirconium (Zr); semiconductors such as silicon (Si) and germanium (Ge); inorganic simple substances such as carbon and diamond; and aluminum oxide (Al ₂ O ₃₎ ), Barium oxide (BaO), beryllium oxide (BeO), calcium oxide (CaO), magnesium oxide (MgO), tin oxide (SnO ₂ ), barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ), etc. It can be appropriately selected from the compounds. Note that the material forming the electron emitting portion does not necessarily need to have conductivity.

In a field emission device having the second configuration (a flat field emission device or a crater type field emission device) or a field emission device having a third configuration (edge type field emission device), electron emission is performed. As materials constituting the cathode electrode corresponding to the portion, tungsten (W), tantalum (Ta), niobium (Nb), titanium (Ti), molybdenum (Mo), chromium (Cr), aluminum (A)
l), metals such as copper (Cu), gold (Au), silver (Ag),
Alternatively, examples thereof include alloys and compounds thereof (for example, nitrides such as TiN, and silicides such as WSi ₂ , MoSi ₂ , TiSi ₂ , and TaSi ₂ ), semiconductors such as diamond, and carbon thin films. The thickness of such a cathode electrode is approximately 0.05 to 0.5 μm, preferably 0.1 to 0.5 μm.
It is desirable that the thickness be in the range of 1 to 0.3 μm, but it is not limited to such a range. Examples of the method for forming the cathode electrode include a vapor deposition method such as an electron beam vapor deposition method and a hot filament vapor deposition method, a sputtering method, a combination of a CVD method, an ion plating method and an etching method, a screen printing method, and a plating method. . According to the screen printing method or the plating method, it is possible to directly form a striped cathode electrode.

Alternatively, the light emitting device comprises a second structure (a flat field emission device or a crater type field emission device), a field emission device having a third structure (edge type field emission device), or a flat field emission device. In the field emission device having the first configuration, the cathode electrode and the electron emission portion are
It can also be formed using a conductive paste in which conductive fine particles are dispersed. As the conductive fine particles, graphite powder; barium oxide powder, strontium oxide powder,
Graphite powder mixed with at least one of metal powders; diamond particles or diamond-like carbon powder containing impurities such as nitrogen, phosphorus, boron, and triazole; carbon nanotube powder; (Sr, Ba,
Ca) CO ₃ powder; and silicon carbide powder. In particular, it is preferable to select graphite powder as the conductive fine particles from the viewpoint of reduction of the threshold electric field and durability of the electron emitting portion. The shape of the conductive fine particles
In addition to a spherical shape and a scale-like shape, an arbitrary regular shape or an irregular shape can be adopted. Also, the particle size of the conductive fine particles may be smaller than the thickness or pattern width of the cathode electrode or the electron emitting portion. The smaller the particle size, the more the number of emitted electrons per unit area can be increased. However, if the particle size is too small, the conductivity of the cathode electrode and the electron emitting portion may be deteriorated. Therefore, the preferable range of the particle size is approximately 0.01 to 4.0 μm.
m. Such conductive fine particles are mixed with a glass component or other suitable binder to prepare a conductive paste, a desired pattern is formed by a screen printing method using the conductive paste, and then the pattern is fired to emit electrons. A cathode electrode and an electron-emitting portion functioning as a portion can be formed. Alternatively, a cathode electrode or an electron-emitting portion functioning as an electron-emitting portion can be formed by a combination of a spin coating method and an etching technique or a lift-off method.

Further, in the field emission device having the first configuration including the Spindt-type field emission device and the crown-type field emission device, the cathode electrode is made of tungsten (W), niobium (Nb), or niobium (Nb). Tantalum (T
a), metals such as molybdenum (Mo), chromium (Cr), aluminum (Al), and copper (Cu); alloys or compounds containing these metal elements (for example, nitrides such as TiN, WSi ₂ , MoSi ₂ , A silicide such as TiSi ₂ or TaSi ₂ ); a semiconductor such as silicon (Si);
TO (indium tin oxide) can be exemplified.
Examples of the method for forming the cathode electrode include a vapor deposition method such as an electron beam vapor deposition method and a hot filament vapor deposition method, a sputtering method, a combination of a CVD method, an ion plating method and an etching method, a screen printing method, a plating method, and a lift-off method. be able to. According to the screen printing method or the plating method, it is possible to directly form a striped cathode electrode.

The constituent material of the anode electrode may be appropriately selected depending on the structure of the display device. That is, when the display device is a transmissive type (the anode panel corresponds to the display surface) and the anode electrode and the phosphor layer are laminated on the substrate in this order, the substrate is not replaced with the anode electrode. The material itself must be transparent, ITO (indium tin oxide)
And the like. On the other hand, when the display device is a reflection type (a cathode panel corresponds to a display surface), and when a phosphor layer and an anode electrode are laminated on a substrate in this order even when the display device is a transmission type, In addition to ITO, the materials described above in connection with the cathode electrode and the gate electrode can be appropriately selected and used.

As the phosphor constituting the phosphor layer, a phosphor for fast electron excitation or a phosphor for slow electron excitation can be used. When the display device is a monochromatic display device, the phosphor layer does not have to be particularly patterned. In the case where the display device is a color display device, phosphor layers corresponding to the three primary colors of red (R), green (G), and blue (B) patterned in stripes or dots may be alternately arranged. preferable. The gap between the patterned phosphor layers may be filled with a black matrix for the purpose of improving the contrast of the display screen.

As an example of the configuration of the anode electrode and the phosphor layer,
(1) An anode electrode is formed on a substrate, and a phosphor layer is formed on the anode electrode. (2) A phosphor layer is formed on the substrate, and an anode electrode is formed on the phosphor layer. Configuration. In the configuration of (1), a so-called metal back film that is electrically connected to the anode electrode may be formed on the phosphor layer. In the configuration of (2), a metal back film may be formed on the anode electrode.

The fact that the projected image of the gate electrode extending in the second direction and the projected image of the cathode electrode extending in the first direction extend in a direction orthogonal to each other can simplify the structure of the field emission device or the display device. Preferred from a viewpoint. Note that an electron emission portion (one or a plurality of field emission elements) is provided in an overlapping area where the projected images of the cathode electrode and the gate electrode overlap (corresponding to an area for one pixel or an area for one subpixel). Usually, such an overlapping area is within the effective area of the cathode panel (the area functioning as an actual display screen),
They are arranged in a dimensional matrix.

In the field emission device having the first to third configurations, the planar shape of the opening (shape when the opening is cut by a virtual plane parallel to the surface of the support) is circular, elliptical, Any shape such as a rectangle, a polygon, a rounded rectangle, and a rounded polygon can be used. The opening can be formed by, for example, isotropic etching, or a combination of anisotropic etching and isotropic etching.
One hole is provided in the gate electrode, one opening communicating with one hole provided in the gate electrode is provided in the insulating layer, and one or a plurality of electrons are provided in the opening provided in the insulating layer. An emission portion may be provided, a plurality of holes may be provided in the gate electrode, one opening communicating with the plurality of holes provided in the gate electrode may be provided in the insulating layer, and the opening may be provided in the insulating layer. One or a plurality of electron-emitting portions may be provided in one opening.

As a constituent material of the insulating layer and the insulating film, SiO 2
₂ , BPSG, PSG, BSG, AsSG, PbSG,
SiO ₂ materials such as SiON, SOG (spin-on glass), low melting point glass, glass paste, SiN,
Insulating resins such as polyimide can be used alone or in appropriate combination. Known processes such as a CVD method, a coating method, a sputtering method, and a screen printing method can be used for forming the insulating layer and the insulating film. It is preferable to form the insulating layer and the insulating film from the same material from the viewpoint of avoiding the occurrence of a problem due to a difference in thermal expansion coefficient during various heat treatments.

A resistor layer may be provided between the cathode electrode and the electron emission section. Alternatively, when the surface of the cathode electrode or its edge portion corresponds to the electron emission portion,
The cathode electrode may have a three-layer structure including a conductive material layer, a resistor layer, and an electron emission layer corresponding to an electron emission portion. By providing the resistor layer, the operation of the field emission device can be stabilized, and the electron emission characteristics can be made uniform. Examples of the material forming the resistor layer include a carbon-based material such as silicon carbide (SiC), a semiconductor material such as SiN and amorphous silicon, and a high-melting metal oxide such as ruthenium oxide (RuO ₂ ), tantalum oxide, and tantalum nitride. be able to. Examples of the method for forming the resistor layer include a sputtering method, a CVD method, and a screen printing method. The resistance value may be approximately 1 × 10 ⁵ to 1 × 10 ⁷ Ω, preferably several MΩ.

The support constituting the cathode panel or the substrate constituting the anode panel only needs to have at least the surface made of an insulating member, and is a glass substrate, a glass substrate having an insulating material layer formed on the surface, a quartz substrate. A quartz substrate having an insulating material layer formed on its surface; and a semiconductor substrate having an insulating material layer formed on its surface.

When the cathode panel and the anode panel are joined at the peripheral portion, the joining may be performed using an adhesive layer, or a frame made of an insulating rigid material such as glass or ceramic and an adhesive layer may be used in combination. You may go.
When the frame and the adhesive layer are used together, by appropriately selecting the height of the frame, the facing distance between the cathode panel and the anode panel is set longer than when using only the adhesive layer. It is possible to In addition, as a constituent material of the adhesive layer, frit glass is generally used, but a so-called low melting point metal material having a melting point of about 120 to 400 ° C. may be used. Examples of such low melting point metal materials include In (indium: melting point: 157 ° C.); indium-gold based low melting point alloy; Sn ₈₀ Ag ₂₀ (melting point: 220 to 370 ° C.);
n ₉₅ Cu ₅ (melting point 227 to 370 ° C) such as tin (Sn)
High-temperature solder: Pb _97.5 Ag _2.5 (melting point 304 ° C),
Pb _94.5 Ag _5.5 (melting point 304-365 ° C), Pb
Lead (Pb) such as _97.5 Ag _1.5 Sn _1.0 (melting point 309 ° C)
-Based high-temperature solder; zinc (Zn) -based high-temperature solder such as Zn ₉₅ Al ₅ (melting point 380 ° C.); Sn ₅ Pb ₉₅ (melting point 300 to
314 ° C.), Sn ₂ Pb ₉₈ (melting point 316-322 ° C.), etc .; tin-lead based solder; Au ₈₈ Ga ₁₂ (melting point 38
Brazing filler metal such as 1 ° C) (All subscripts above represent atomic%)
Can be exemplified.

When the cathode panel, the anode panel and the frame are joined together, the three may be joined simultaneously,
Alternatively, one of the cathode panel and the anode panel may be joined to the frame in the first stage, and the other of the cathode panel and the anode panel may be joined to the frame in the second stage. If the three-member simultaneous bonding and the bonding in the second stage are performed in a high vacuum atmosphere, the space surrounded by the cathode panel, the anode panel, the frame, and the adhesive layer is evacuated simultaneously with the bonding. Alternatively, after the three members have been joined, the space surrounded by the cathode panel, the anode panel, the frame, and the adhesive layer can be evacuated to a vacuum. When evacuation is performed after the bonding, the pressure of the atmosphere at the time of the bonding may be either normal pressure or reduced pressure. The gas constituting the atmosphere may be air, nitrogen gas, or group 0 of the periodic table. May be an inert gas containing a gas belonging to (for example, Ar gas).

When evacuation is performed after the bonding, the evacuation can be performed through a chip tube previously connected to the cathode panel and / or the anode panel. The chip tube is typically configured using a glass tube, and includes a cathode panel and / or
Alternatively, frit glass or the above-mentioned low melting point metal material is used to join the periphery of the penetrating portion provided in the ineffective area of the anode panel, and after the space reaches a predetermined degree of vacuum, it is sealed off by heat fusion. Note that if the entire display device is once heated and then cooled before the sealing is performed, the residual gas can be released into the space, and the residual gas can be removed to the outside of the space by exhaustion, which is preferable. is there.

In the present invention, the focus electrode extends in the second direction and is provided between the gate electrodes, or alternatively, extends in the first direction and is connected to the cathode electrode. Since it is arranged above the region between the cathode electrodes, the structure of the field emission device can be simplified, and a plurality of field emission devices arranged along the second direction or the first direction Can have a convergence effect on the electrons emitted from. Furthermore, in the field emission device or the display device according to the first aspect of the present invention,
For example, since the gate electrode and the focus electrode can be formed at the same time, the number of manufacturing steps of the field emission device and the display device does not increase. On the other hand, in the field emission device or the display device according to the second aspect of the present invention, for example, an insulating film may be formed between the gate electrode and the focus electrode to prevent a short circuit. The manufacturing process of the device does not increase significantly.

[0056]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments of the invention (abbreviated as embodiments).

Embodiment 1 Embodiment 1 relates to a field emission device and a display device according to the first aspect of the present invention. FIG. 1 is a schematic partial exploded perspective view of the display device according to the first embodiment, FIG. 2 is a schematic partial end view, and FIG. 3 is a schematic partial end view of a field emission device. .

The field emission device according to the first embodiment is a field emission device having a first structure composed of a so-called Spindt-type field emission device.
And a first direction (a direction parallel to the plane of FIG. 3)
A cathode electrode 11 extending to the cathode electrode;
, A gate electrode 13 extending in a second direction (a direction perpendicular to the plane of FIG. 3) different from the first direction;
(D) a hole 14A provided in a region of the gate electrode 13 overlapping the cathode electrode 11, (E) a conical electron emitting portion 15 provided at the bottom of the hole 14A, and (F) a focus electrode. 30. Then, (a) the insulating layer 12 is formed on the support 10 and the cathode electrode 11, (b) the gate electrode 13 and the focus electrode 30 are formed on the insulating layer 12, and (c) the insulating layer 12 is formed on the insulating layer 12. The opening 14B communicating with the hole 14A provided in the gate electrode 13 is provided, and (d) the electron emitting portion 15 is located at the bottom of the opening 14B. That is, the conical electron emitting portion 15
Is provided on the portion of the cathode electrode 11 located at the bottom of the opening 14B.

In the field emission device of the first embodiment,
The focus electrode 30 extends in the second direction (the direction perpendicular to the plane of FIG. 3), and is disposed between the gate electrodes 13 and on the insulating layer 12. That is,
The focus electrode 30 and the gate electrode 13 are on the same plane. In the field emission device according to the first embodiment, the gate electrode 13 and the focus electrode 30 have a stripe shape in plan view. That is, these electrodes 13, 30
Are parallel and straight.

The insulating layer 12 is made of SiO_TwoSystem material (specific
Contains SiO_Two), The gate electrode 13 and the focus
The distance between the electrodes 30 is L_GL(Unit: m), gate
The voltage applied to the electrodes is V_G(Unit: volt), four
The voltage applied to the cas electrode is V_F(Unit: volts)
Then, the following expression (1) is satisfied. In particular,
V _GIs 50 volts, V_F0 volts, L_GFWith 20 μm
did. The width of the gate electrode 13 is 100 μm,
The width of the electrode 30 was 110 μm.

[Equation 4] (V _G -V _F ) / L _GF <7 × 10 ⁷ (V / m) (1)

The cathode electrode 11 and the gate electrode 13
Means that the projected images of these two electrodes are each formed in a stripe shape in a direction orthogonal to each other, and the projected images of these two electrodes overlap (corresponding to a region for one pixel).
, A plurality of field emission devices are arranged. Further, such overlapping areas are usually arranged in a two-dimensional matrix in an effective area (area functioning as an actual display portion) of the cathode panel CP.

On the other hand, the anode panel AP is
And a phosphor layer 22 (red light emitting phosphor layer 22R, green light emitting phosphor layer 22G, blue light emitting phosphor layer 22B) formed on the substrate 20 and having a predetermined pattern. (Not shown) and an anode electrode 23 formed thereon. One pixel is composed of a group of field emission elements arranged in an overlapping region of the cathode electrode 11 and the gate electrode 13 on the cathode panel side, and a phosphor layer 22 on the anode panel side facing the group of these field emission elements. It is configured. In the effective area, such pixels are arranged, for example, in the order of several hundred thousand to several million. Note that a black matrix 21 is formed on the substrate 20 between the phosphor layers 22.

Anode panel AP and cathode panel CP
Are arranged so that the field emission element and the phosphor layer 22 face each other, and are joined at a peripheral portion via a frame (not shown), whereby a display device can be manufactured.
A through-hole (not shown) for evacuation is provided in an ineffective area surrounding the effective area and a peripheral circuit for selecting a pixel is formed. The connected tip tube (not shown) is connected. That is, the space surrounded by the anode panel AP, the cathode panel CP, and the frame is in a vacuum.

The cathode electrode 11 has a relative negative voltage (0
Volts) is applied from the cathode electrode driving circuit 24, a relatively positive voltage V _G is applied from the gate electrode driving circuit 25 to the gate electrode 13, higher positive voltage than the gate electrode 13 to the anode electrode 23 ( For example, several kilovolts) is applied from the acceleration power supply 26. Further, a voltage V _F that satisfies Expressions (1) and (2-1) is applied to the focus electrode 30 from the focus electrode drive circuit 27. When displaying on such a display device, for example,
A scanning signal is inputted to the cathode electrode 11 from the cathode electrode driving circuit 24, and the gate electrode driving circuit 2 is inputted to the gate electrode 13.
5 to input a video signal. Due to an electric field generated when a voltage is applied between the cathode electrode 11 and the gate electrode 13, electrons are emitted from the electron emitting portion 15 based on the quantum tunnel effect, and the electrons are attracted to the anode electrode 23, and the fluorescent layer 22 Collide with As a result, the phosphor layer 22
Are excited to emit light, and a desired image can be obtained.
That is, the operation of the display device is basically controlled by the voltage applied to the gate electrode 13 and the voltage applied to the electron emission unit 15 through the cathode electrode 11.

[0066] The V _G 50 volts, the V _F 0 volt, L _GF
FIG. 4 shows a simulation result of what electric field is formed by the gate electrode 13 and the focus electrode 30 when the width of the gate electrode 13 is 100 μm and the width of the focus electrode 30 is 110 μm. Show. In the space above the region between the gate electrode 13 and the focus electrode 30, the equipotential surface is distorted by the influence of the focus electrode 30 and emits from the electron emission portion 15 (not shown in FIG. 4). Then, electrons passing through the gate electrode 13 and traveling upward of the focus electrode 30 are affected by the focus electrode 30, and the
It can be seen that it has been returned to above 3. That is, it can be seen that the focus electrode 30 exerts a convergence effect on electrons.

The outline of the method of manufacturing the Spindt-type field emission device which is the field emission device of the first embodiment will be described below with reference to FIGS. 5 and 6 which are schematic partial end views of a support and the like. I do. In the following description, the hole 14A provided in the gate electrode 13 and the opening 1A provided in the insulating layer will be described.
4B may be collectively referred to as an opening 114.

The manufacturing method of the Spindt-type field emission device is basically a method of forming the conical electron emitting portion 15 by vertical vapor deposition of a metal material. That is, the hole 14A
However, the amount of vapor deposition particles that reach the bottom of the opening 14B is gradually reduced by utilizing the shielding effect of the overhang-like deposit formed near the hole 14A. , Electron emitting portion 15 which is a conical deposit
Are formed in a self-aligned manner. Here, a method of forming a release layer 17 on the gate electrode 13 in advance to facilitate removal of unnecessary overhang-like deposits will be described.

[Step-100] First, a striped cathode electrode 11 made of niobium (Nb) is formed on a support 10 made of, for example, glass, and then an insulating layer 12 made of SiO ₂ is formed on the entire surface. , Tungsten (W)
A gate electrode 13 and a focus electrode 30 are formed on the insulating layer 12. The formation of the gate electrode 13 and the focus electrode 30 can be performed based on, for example, a sputtering method, a lithography technique, and a dry etching technique.

[Step-110] Next, the gate electrode 13,
A resist layer 16 functioning as an etching mask is formed on the focus electrode 30 and the insulating layer 12 by a lithography technique (see FIG. 5A). Then RI
Gate electrode 13 by E (reactive ion etching) method
A hole 14A is formed in the insulating layer 12 and an opening 14A is formed in the insulating layer 12.
Form B. The cathode electrode 11 is provided at the bottom of the opening 14B.
Is exposed. After that, the resist layer 16 is removed by an ashing technique. Thus, the structure shown in FIG. 5B can be obtained.

[Step-120] Next, the electron-emitting portion 15 is formed on the cathode electrode 11 exposed at the bottom of the opening 14B. Specifically, first, the release layer 17 is formed by obliquely depositing aluminum. At this time, by selecting a sufficiently large incident angle of the vapor deposition particles with respect to the normal line of the support 10, almost no aluminum is deposited on the bottom of the opening 14 </ b> B, and the gate electrode 13, the focus electrode 30, and the insulating layer 12 are formed. The release layer 17 can be formed on the substrate. The release layer 17 protrudes in an eaves shape from the opening end of the hole 14A, thereby forming the hole 14A.
Is substantially reduced in diameter (see FIG. 5C).

[Step-130] Next, for example, molybdenum (Mo) is vertically deposited on the entire surface. At this time, as shown in FIG. 6A, as the conductive material layer 18 made of molybdenum having an overhang shape grows on the release layer 17, the substantial diameter of the hole 14A is gradually reduced. Therefore, vapor deposition particles contributing to deposition at the bottom of the opening 14B are gradually limited to those passing near the center of the hole 14A. As a result, a conical deposit is formed at the bottom of the opening 14B, and the conical deposit made of molybdenum becomes the electron emission portion 15.

[Step-140] Thereafter, the release layer 17 is formed on the insulating layer 1 by an electrochemical process and a wet process.
2. The insulating layer 12, the conductive material layer 18 above the focus electrode 30 and the gate electrode 13 is selectively removed by peeling off from the surfaces of the focus electrode 30 and the gate electrode 13. As a result, as shown in FIG. 6B, the conical electron emitting portion 15 can be left on the cathode electrode 11 located at the bottom of the opening 14B. After that, the insulating layer 12 is isotropically etched to form a hole 14 provided in the gate electrode 13.
It is preferable to expose the end of A (see FIG. 6C). The isotropic etching can be performed by dry etching using radicals as a main etching species, such as chemical dry etching, or wet etching using an etchant. As an etching solution, for example, a 49% hydrofluoric acid aqueous solution and pure water 1:10
A 0 (volume ratio) mixture can be used.

[Step-150] Thereafter, the display device is assembled. Specifically, the anode panel AP and the cathode panel CP are arranged such that the phosphor layer 22 and the field emission device face each other, and the anode panel AP and the cathode panel CP (more specifically, the substrate 20 and the support 10) at the peripheral portion via a frame (not shown). At the time of joining, frit glass is applied to a joint portion between the frame body and the anode panel AP and a joint portion between the frame body and the cathode panel CP, and the anode panel AP, the cathode panel CP, and the frame are bonded together and pre-baked. After the frit glass is dried, the main firing is performed at about 450 ° C. for 10 to 30 minutes. Thereafter, the space surrounded by the anode panel AP, the cathode panel CP, the frame, and the frit glass is evacuated through a through-hole (not shown) and a chip tube, and when the pressure in the space reaches about 10 ⁻⁴ Pa. To seal off the tip tube (not shown) by heating and melting. Thus, the space surrounded by the anode panel AP, the cathode panel CP, and the frame can be evacuated. After that, wiring to necessary external circuits is performed to complete the display device. Thus, the display device shown in FIG. 2 can be obtained.

An example of a method for manufacturing the anode panel AP is as follows.
This will be described below with reference to FIG. First, a luminescent crystal particle composition is prepared. For this purpose, for example, a dispersant is dispersed in pure water, and the mixture is stirred for 1 minute at 3000 rpm using a homomixer. Next, the luminescent crystal particles are put into pure water in which a dispersant is dispersed, and 50
Stir at 00 rpm for 5 minutes. Then, for example,
Add polyvinyl alcohol and ammonium bichromate, stir well and filter.

In the manufacture of the anode panel AP, the photosensitive film 40 is formed on the entire surface of the substrate 20 made of, for example, glass.
Is formed (applied). Then, the photosensitive film 40 formed on the substrate 20 is exposed by exposure light emitted from an exposure light source (not shown) and passing through an opening 44 provided in the mask 43 to form a photosensitive region 41 ( (See FIG. 46A). Thereafter, the photosensitive film 40 is developed and selectively removed to leave the remaining photosensitive film (the photosensitive film after exposure and development) 42 on the substrate 20 (see FIG. 46B). Next, a carbon agent (carbon slurry) is applied to the entire surface, dried and baked, and then the remaining portion 42 of the photosensitive film and the carbon agent thereon are removed by a lift-off method, so that the carbon on the exposed substrate 20 is removed. A black matrix 21 made of an agent is formed, and at the same time, the remaining portion 42 of the photosensitive film is removed (see FIG. 46C). Then, on the exposed substrate 20, each of the red, green, and blue phosphor layers 2
2 (see FIG. 46D). Specifically, a luminescent crystal particle composition prepared from each luminescent crystal particle (phosphor particle) is used. For example, a red photosensitive luminescent crystal particle composition (phosphor slurry) is applied to the entire surface. Coating, exposing and developing, then applying a green photosensitive luminescent crystal particle composition (phosphor slurry) over the entire surface, exposing and developing, and further, a blue photosensitive luminescent crystal particle composition (Phosphor slurry) may be applied to the entire surface, exposed and developed.
Then, an anode electrode 23 is formed on the phosphor layer 22 and the black matrix 21 by forming an aluminum thin film having a thickness of about 0.07 μm by a sputtering method. Thus, the anode panel AP can be obtained. Note that the phosphor layer 22 can also be formed by a screen printing method or the like.

(Embodiment 2) Embodiment 2 is a modification of Embodiment 1. FIG. 7 is a schematic partial perspective view of the cathode panel in the display device according to the second embodiment. The field emission device or the display device according to the second embodiment further includes a second focus electrode 32. The second focus electrode 32 extends in the second direction, that is, extends in parallel with the cathode electrode 11, and is disposed above a region between the cathode electrodes 11. In the second embodiment, the second focus electrode 32 is formed on the insulating layer 12, the gate electrode 13, and the focus electrode 30 via the insulating film 31, whereby the gate electrode 13 and the second focus electrode are formed. 32 can be prevented. The projected image obtained by synthesizing the projected image of the focus electrode 30 and the projected image of the second focus electrode 32 has a cross-girder shape.

The insulating film 31 and the second focus electrode 32 in the field emission device of the second embodiment are different from those of the first embodiment.
Between [Step-100] and [Step-110] of the method for manufacturing the field emission device described above, an insulating film 31 made of SiO _{2 having} a thickness of about _LGF satisfying the above-mentioned equation (1) is formed on the entire surface. After the film formation, a second conductive layer for focus electrode formation made of chromium (Cr) is formed on the insulating film 31 by a sputtering method, and then the second conductive layer for focus electrode formation and the insulating film 31 are striped. It can be obtained by patterning in a shape.

FIG. 8 shows a modification of the field emission device of the second embodiment. In this field emission device, a grid-shaped insulating film 33 is formed on the gate electrode 13 and the insulating layer 12, and the focus electrode 30 and the second focus electrode 32 are formed integrally on the insulating film 33. ing. As a result, the gate electrode 13 and the second focus electrode 32
Can be prevented from short-circuiting. Focus electrode 30
Is combined with the projected image of the second focus electrode 32 in a grid shape, and the projected image of the cathode electrode 11 and the projected image of the gate electrode 13 overlap in the middle of the grid.

In this modification of the second embodiment, the insulating film 33 and the focus electrode 3 in the field emission device are used.
0, the second focus electrode 32 is obtained by forming the above-described formula (1) on the entire surface after forming the stripe-shaped gate electrode 13 in the [Step-100] of the method for manufacturing the field emission device of the first embodiment. An insulating film 33 made of SiO _{2 having} a thickness of about _LGF which is satisfactory is formed, and a conductive layer for forming a focus electrode made of chromium (Cr) is formed on the insulating film 33 by a sputtering method. It can be obtained by patterning the conductive layer for electrode formation and the insulating film 33 in a grid pattern.

Embodiment 3 Embodiment 3 relates to a field emission device and a display device according to the second aspect of the present invention. FIG. 9 is a schematic partial perspective view of the cathode panel in the display device according to the third embodiment. The display device according to the third embodiment has the same configuration as that shown in FIG. 2 except for the focus electrode, and thus a detailed description is omitted.

The field emission device according to the third embodiment is also a field emission device having a first configuration composed of a so-called Spindt-type field emission device.
A cathode electrode 11 formed thereon and extending in a first direction;
(C) a gate electrode 13 disposed above the cathode electrode 11 and extending in a second direction different from the first direction;
(D) A hole 14A provided in a region of the gate electrode 13 overlapping the cathode electrode 11, (E) an electron emission portion 15 provided at the bottom of the hole 14A, and (F) a focus electrode 35. Have been. Then, (a) on the support member 10 and the cathode electrode 11, an insulating layer 1 made of SiO ₂
2 is formed, and (b) a gate electrode 13 is formed on the insulating layer 12.
Is formed, and (c) a focus electrode 35 is formed on the insulating layer 12 via an insulating film 34 made of SiO ₂ .
(D) The insulating layer 12 is provided with an opening 14B communicating with the hole 14A provided in the gate electrode 13, and (e) the electron emitting portion 15 is located at the bottom of the opening 14B. That is,
The conical electron emission section 15 is provided on a portion of the cathode electrode 11 located at the bottom of the opening 14B.

In the field emission device of the third embodiment,
The focus electrode 35 extends in the first direction and is provided above a region between the cathode electrodes 11. That is, the focus electrode 35 and the gate electrode 13 are substantially on the same plane. In the field emission device according to the third embodiment, the cathode electrode 11, the gate electrode 13, and the focus electrode 30 have a stripe shape in plan view. That is, both sides of these electrodes 11, 13, 30 are parallel and linear.

The cathode electrode 11 and the gate electrode 13
Means that the projected images of these two electrodes are each formed in a stripe shape in a direction orthogonal to each other, and the projected images of these two electrodes overlap (corresponding to a region for one pixel).
Usually, a plurality of field emission devices are arranged. Further, such overlapping areas are usually arranged in a two-dimensional matrix in the effective area of the cathode panel CP.

The insulating film 34 and the focus electrode 35 in the field emission device of the third embodiment are formed after the stripe-shaped gate electrode 13 is formed in [Step-100] of the method of manufacturing the field emission device of the first embodiment. Then, on the entire surface, an insulating film 34 of SiO _{2 having} a thickness of about _LGF satisfying the above formula (1) is formed, and then a focus electrode forming conductive layer of chromium (Cr) is formed by sputtering. After being formed on the insulating film 34, the conductive layer for forming a focus electrode and the insulating film 34 can be obtained by patterning in a stripe shape.

In the field emission device described in the third embodiment, the vertical positional relationship between gate electrode 13 and focus electrode 35 may be reversed. That is, (a) the insulating layer 12 is formed on the support 10 and the cathode electrode 11, (b) the focus electrode 35 is formed on the insulating layer 12, and (c) the focus electrode 35 is formed on the insulating layer 12 and the focus electrode 35. In addition, a gate electrode 13 is formed via an insulating film 34,
(D) The gate electrode 13 is formed on the insulating film 34 and the insulating layer 12.
An opening 14B communicating with the hole 14A provided in the opening 14B is provided, and (e) the electron emitting portion may be located at the bottom of the opening 14B.

(Embodiment 4) In the following embodiments, structures of various field emission devices and a method of manufacturing the same will be described. In the drawings referred to below, illustration of a focus electrode is omitted. Further, based on the example of forming the focus electrode described in Embodiment 1,
Hereinafter, the second embodiment or the third embodiment will be described.
Needless to say, the focus electrode described in (1) can be formed.

Embodiment 4 relates to a field emission device having a first configuration composed of a crown type field emission device. FIG. 11A is a schematic partial end view of a field emission device including a crown-type field emission device, and FIG. 11B is a schematic perspective view in which a part is cut away. The crown-type field emission device includes a cathode electrode 11 formed on a support 10, an insulating layer 12 formed on the support 10 and the cathode electrode 11, a gate electrode 13 formed on the insulating layer 12, An opening 114 penetrates through the gate electrode 13 and the insulating layer 12 and a crown-type electron emitting portion 15A provided on the cathode electrode 11 located at the bottom of the opening 14B.

Hereinafter, a method for manufacturing a crown type field emission device will be described with reference to FIGS.

[Step-400] First, a striped cathode electrode 11 is formed on a support 10 made of, for example, glass. Note that the cathode electrode 11 extends in the left-right direction of the drawing. The striped cathode electrode 11
For example, after forming an ITO film over the entire surface to a thickness of about 0.2 μm on the support 10 by a sputtering method,
It can be formed by patterning an O film. The cathode electrode 11 may be a single material layer, or may be formed by laminating a plurality of material layers. For example, the surface layer of the cathode electrode 11 can be made of a material having a higher electrical resistivity than the rest in order to suppress the variation in the electron emission characteristics of each electron emission portion formed in a later step. Note that such a configuration of the cathode electrode can be applied to a cathode electrode of another field emission device. Next, an insulating layer 12 is formed on the support 10 and the cathode electrode 11. Here, as an example, a glass paste is screen-printed on the entire surface to a thickness of about 3 μm. Next, moisture and a solvent contained in the insulating layer 12 are removed,
Further, in order to flatten the insulating layer 12, for example, two-stage baking such as temporary baking at 100 ° C. for 10 minutes and main baking at 500 ° C. for 20 minutes are performed. Instead of the screen printing using the glass paste as described above, an SiO ₂ film may be formed by, for example, a plasma CVD method.

Next, a gate electrode 13 and a focus electrode in the form of stripes are formed on the insulating layer 12. The gate electrode 13 and the focus electrode extend in a direction perpendicular to the plane of the drawing. That is, the direction in which the projected images of the gate electrode 13 and the focus electrode extend is 90 degrees with the direction in which the projected image of the striped cathode electrode 11 extends.

[Step-410] Next, [Step-110]
The gate electrode 13 and the insulating layer 12 are
The gate electrode 13 and the insulating layer 1
2, an opening 114 is formed, and the cathode electrode 11 is exposed at the bottom of the opening 14B. The diameter of the opening 114 is about 2
５０50 μm.

[Step-420] Next, the gate electrode 13
Above, on the focus electrode, on the insulating layer 12, and in the opening 11
A release layer 51 is formed on the side wall surface of No. 4 (FIG. 10A).
reference). In order to form the release layer 51, for example, a photoresist material may be applied to the entire surface by spin coating, and patterning may be performed to remove only a part of the bottom of the opening 14B. At this point, opening 1
The substantial diameter of 14 is reduced to about 1-20 μm.

[Step-430] Next, as shown in FIG. 10B, a conductive composition layer 52 made of a composition material is formed on the entire surface. The composition raw material used here contains, for example, 60% by weight of graphite particles having an average particle size of about 0.1 μm as conductive particles, and 40% by weight of No. 4 water glass as a binder. This composition raw material is, for example, 1400 rpm,
Spin coating is performed on the entire surface for 10 seconds. Opening 14
The surface of the conductive composition layer 52 in B rises along the side wall surface of the opening 14B due to the surface tension of the composition raw material, and becomes concave toward the center of the opening 14B. Thereafter, calcination for removing moisture contained in the conductive composition layer 52 is performed, for example, at 400 ° C. for 30 minutes in the air.

In the composition raw materials, the binder is (1)
It may itself be a dispersion medium of conductive particles,
(2) The conductive particles may be coated, or (3) a dispersion medium of the conductive particles may be formed by being dispersed or dissolved in an appropriate solvent. A typical example of the case (3) is water glass, which is described in Japanese Industrial Standard (JIS) K140.
Nos. 1 to 4 specified in No. 8 or equivalents thereof can be used. Nos. 1 to 4 are four-grade grades based on the difference in the number of moles (about 2 to 4 moles) of silicon oxide (SiO ₂ ) with respect to 1 mole of sodium oxide (Na ₂ O) as a constituent of water glass. , Each greatly differ in viscosity. Therefore, when using water glass in the lift-off process, various conditions such as the type and content of the conductive particles dispersed in the water glass, affinity with the release layer 51, and the aspect ratio of the opening 114 are taken into consideration. It is preferable to select the best grade of water glass or to prepare and use water glass equivalent to these grades.

Since the binder is generally inferior in conductivity, if the content of the binder is too large relative to the content of the conductive particles in the composition raw material, the electric resistance value of the electron emitting portion 15A to be formed increases, There is a risk that electron emission will not be performed smoothly. Therefore, for example, in the case of a composition raw material obtained by dispersing carbon-based material particles as conductive particles in water glass, for example, the ratio of the carbon-based material particles to the total weight of the composition raw material is determined by the ratio of the electron emission portion 15A. It is preferable to select approximately 30 to 95% by weight in consideration of characteristics such as the electric resistance value, the viscosity of the composition raw material, and the adhesiveness between the conductive particles. By selecting the ratio of the carbon-based material particles within such a range, it is possible to sufficiently lower the electric resistance of the electron-emitting portion 15A to be formed and to maintain good adhesion between the carbon-based material particles. . However, when the alumina particles are mixed with the carbon-based material particles as the conductive particles, the adhesiveness between the conductive particles tends to decrease. Therefore, the carbon-based material particles may be adjusted according to the content of the alumina particles. Is preferably increased, and particularly preferably 60% by weight or more. The composition raw material may contain a dispersant for stabilizing the dispersed state of the conductive particles, and additives such as a pH adjuster, a drying agent, a curing agent, and a preservative. A composition raw material obtained by dispersing a powder in which conductive particles are covered with a coating of a binder (binder) in an appropriate dispersion medium may be used.

As an example, when the diameter of the crown-shaped electron-emitting portion 15A is approximately 1 to 20 μm and carbon-based material particles are used as the conductive particles, the particle diameter of the carbon-based material particles is approximately 0.1 μm to 1 μm. It is preferable to set the range. By selecting the particle diameter of the carbon-based material particles in such a range, sufficiently high mechanical strength is provided at the edge of the crown-shaped electron emission portion 15A, and the adhesion of the electron emission portion 15A to the cathode electrode 11 is improved. It will be good.

[Step-440] Next, as shown in FIG. 10C, the release layer 51 is removed. Peeling is 2% by weight
In sodium hydroxide aqueous solution for 30 seconds. At this time, the peeling may be performed while applying ultrasonic vibration. Thereby, together with the release layer 51, the release layer 5
1 is removed, and the opening 1 is removed.
Only the portion of the conductive composition layer 52 on the cathode electrode 11 exposed at the bottom of 4B is left. The remaining portion becomes the electron emission portion 15A. The shape of the electron-emitting portion 15A has a crown-like shape with its surface depressed toward the center of the opening 14B. The state at the end of [Step-440] is
As shown in FIG. FIG. 11B is a schematic perspective view showing a part of the field emission device, and FIG.
FIG. 3B is a schematic partial end view along line AA of FIG. In FIG. 11B, a part of the insulating layer 12 and the gate electrode 13 is cut away so that the entire electron emitting portion 15A can be seen. In one electron emission region, 5 to 10
It is sufficient to provide about 0 electron emitting portions 15A. The binder exposed on the surface of the electron-emitting portion 15A may be removed by etching so that the conductive particles are reliably exposed on the surface of the electron-emitting portion 15A.

[Step-450] Next, the electron emitting portion 15A
Is fired. Baking is performed in dry air at 400 ° C., 30
Perform under the condition of minutes. In addition, what is necessary is just to select a baking temperature according to the kind of binder contained in a composition raw material. For example,
When the binder is an inorganic material such as water glass,
The heat treatment may be performed at a temperature at which the inorganic material can be fired. When the binder is a thermosetting resin, the heat treatment may be performed at a temperature at which the thermosetting resin can be cured. However, in order to maintain the adhesion between the conductive particles, it is preferable to perform the heat treatment at a temperature at which the thermosetting resin does not excessively decompose or carbonize. Regardless of which binder is used, the heat treatment temperature depends on the gate electrode, focus electrode, cathode electrode,
It is necessary that the temperature be such that no damage or defects occur in the insulating layer.
The heat treatment atmosphere should be an inert gas atmosphere so that the electrical resistivity of the gate electrode, focus electrode, and cathode electrode does not increase due to oxidation, or defects and damage do not occur in the gate electrode and the cathode electrode. preferable. When a thermoplastic resin is used as a binder, heat treatment may not be required.

(Embodiment 5) Embodiment 5 relates to a field emission device having a first configuration composed of a flat field emission device. FIG. 12C shows a schematic partial cross-sectional view of the field emission device of the fifth embodiment. The flat field emission device includes a cathode electrode 11 formed on a support 10 made of, for example, glass, the support 10 and the cathode electrode 11.
The insulating layer 12 formed thereon, the gate electrode 13 and the focus electrode formed on the insulating layer 12, the opening 114 penetrating the gate electrode 13 and the insulating layer 12, and the cathode electrode located at the bottom of the opening 14B. 11 comprises a flat electron-emitting portion 15B. Here, the electron-emitting portion 15B is formed on the striped cathode electrode 11 extending in the direction perpendicular to the paper surface of FIG. Further, the gate electrode 13 and the focus electrode extend in the left-right direction on the paper of FIG. Cathode electrode 1
1. The gate electrode 13 and the focus electrode are made of chrome (C
r). The electron emitting portion 15B is specifically formed of a thin layer made of graphite powder. Also,
In order to stabilize the operation of the field emission device and to make the electron emission characteristics uniform, an S
A resistor layer 60 made of iC is provided. In the flat field emission device shown in FIG. 12C, the resistor layer 60 and the electron emission portion 15B are formed over the entire surface of the cathode electrode 11, but such a structure is adopted. It is not limited, but the point is that at least the opening 14B
It is sufficient that the electron emitting portion 15B is provided at the bottom of the substrate.

Hereinafter, a method of manufacturing the flat field emission device according to the fifth embodiment will be described with reference to FIG. 12 which is a schematic partial cross-sectional view of a support and the like.

[Step-500] First, on the support 10,
After a cathode electrode conductive material layer made of chromium (Cr) is formed by a sputtering method, the cathode electrode conductive material layer is patterned based on a lithography technique and a dry etching technique. Thus, the striped cathode electrode 11 can be formed on the support 10 (see FIG. 12A). The cathode electrode 11 is
It extends in the direction perpendicular to the paper surface of FIG.

[Step-510] Next, the cathode electrode 11
An electron emitting portion 15B is formed on the upper portion. Specifically, first, a resistor layer 60 made of SiC is formed on the entire surface by a sputtering method, and then an electron emission portion 15B made of a graphite powder paint is formed on the resistor layer 60 by a spin coating method. Then, the electron emission section 15B is dried.
Thereafter, the electron-emitting portion 15B and the resistor layer 60 are patterned according to a known method (see FIG. 12B).
Electrons are emitted from the electron emitting portion 15B.

[Step-520] Next, the insulating layer 12 is formed on the entire surface.
To form Specifically, the electron-emitting portion 15B and the support
10 on, for example, SiO 2 by sputtering._TwoFrom
Is formed. The insulating layer 12 is made of glass
Screen printing of paste, SiO _TwoLayer C
It can also be formed based on the method of forming by the VD method.
You. Thereafter, the stripe-shaped gate electrode 13 and the
A scum electrode is formed on the insulating layer 12.

[Step-530] Next, [Step-110]
The gate electrode 13 and the insulating layer 12 are formed based on the same method as described above.
An opening 114 is formed at the bottom, and the electron-emitting portion 15B is exposed at the bottom of the opening 14B. Thereafter, a heat treatment is performed at 400 ° C. for 30 minutes in order to remove the organic solvent in the electron emitting portion 15B. After that, it is preferable that the insulating layer 12 is isotropically etched to expose the end of the hole 14A of the gate electrode 13. Thus, the field emission device shown in FIG. 12C can be obtained.

(Embodiment 6) Embodiment 6 is a modification of the field emission device of Embodiment 5. FIG. 13C is a schematic partial cross-sectional view of the flat field emission device according to the sixth embodiment. In the flat field emission device shown in FIG. 13C, the structure of the electron emitting portion 15B is slightly different from that of the flat field emission device of the fifth embodiment shown in FIG. Hereinafter, a method for manufacturing the flat field emission device according to the sixth embodiment will be described with reference to FIG. 13 which is a schematic partial cross-sectional view of a support and the like.

[Step-600] First, a conductive material layer for a cathode electrode is formed on the support 10. Specifically, after a resist material layer (not shown) is formed on the entire surface of the support 10, the resist material layer where the cathode electrode is to be formed is removed. Thereafter, a cathode electrode conductive material layer made of chromium (Cr) is formed on the entire surface by a sputtering method. Further, a resistor layer 60 made of SiC is formed on the entire surface by a sputtering method, and then a graphite powder coating layer is formed on the resistor layer 60 by a spin coating method, and the graphite powder coating layer is dried. Thereafter, when the resist material layer is removed using a stripping solution, the cathode electrode conductive material layer, the resistor layer 60 and the graphite powder paint layer formed on the resist material layer are also removed. Thus, based on the so-called lift-off method, the cathode electrode 11,
A structure in which the resistor layer 60 and the electron emitting portion 15B (electron emitting layer) are stacked can be obtained (see FIG. 13A).

[Step-610] Next, the insulating layer 12 is formed on the entire surface.
Is formed, a gate electrode 13 and a focus electrode in the form of stripes are formed on the insulating layer 12 (FIG. 13B).
reference). Thereafter, based on the same method as in [Step-110], an opening 114 is formed in the gate electrode 13 and the insulating layer 12, thereby exposing the electron-emitting portion 15B at the bottom of the opening 14B ((C in FIG. 13). )reference). afterwards,
It is preferable that the insulating layer 12 is isotropically etched to expose the end of the hole 14A of the gate electrode 13. Electrons are emitted from the electron emission portion 15B provided on the surface of the cathode electrode 11 exposed at the bottom of the opening 14B.

Embodiment 7 Embodiment 7 also relates to a flat field emission device. FIG. 15B is a schematic partial end view of the flat field emission device according to the seventh embodiment. In the flat type field emission device according to the seventh embodiment, the electron emission portion 15C is formed of a carbon thin film formed based on a CVD method.

It is preferable to form the electron emission portion from a carbon thin film because the work function of carbon (C) is low and a high emission electron current can be achieved. In order to emit electrons from the carbon thin film, the carbon thin film may be placed in an appropriate electric field (for example, an electric field having an intensity of about 10 ⁶ volt / m).

When a resist material is used as an etching mask and plasma etching of a carbon thin film such as a diamond thin film is performed using oxygen gas,
As a reaction by-product in the etching reaction system, (C
A carbon-based polymer such as an (H _x ) -based or (CF _x ) -based polymer is generated as a deposition material. Generally, when a depositable substance is generated in an etching reaction system in plasma etching,
This deposited substance is deposited on the side wall surface of the resist material having a low ion incidence probability or on the processed end surface of the object to be etched to form a so-called side wall protective film. Contribute. However, when an oxygen gas is used as an etching gas, the sidewall protective film made of a carbon-based polymer is immediately removed by the oxygen gas even if formed. Also,
When oxygen gas is used as an etching gas,
The consumption of resist material is also severe. For these reasons, in the conventional oxygen plasma processing of a diamond thin film,
The dimensional conversion difference between the diamond thin film and the mask is large, and anisotropic processing is often difficult.

In order to solve such a problem, for example, a configuration is adopted in which a carbon thin film selective growth region is formed on the surface of the cathode electrode, and an electron emitting portion made of a carbon thin film is formed on the carbon thin film selective growth region. I just need. That is, Embodiment 7
In the manufacture of the flat field emission device, a cathode electrode is formed on a support, a carbon thin film selective growth region is formed on the surface of the cathode electrode, and then a carbon thin film (electron emission region) is formed on the carbon thin film selective growth region. (Corresponding to a part).
The step of forming a carbon thin film selective growth region on the surface of the cathode electrode is referred to as a carbon thin film selective growth region forming step.

Here, the carbon thin film selective growth region is preferably a portion of the cathode electrode on which metal particles are adhered on the surface or a portion of the cathode electrode on which a metal thin film is formed on the surface. In order to further secure the selective growth of the carbon thin film in the carbon thin film selective growth region, sulfur (S), boron (B)
Or it is desirable that phosphorus (P) is attached, and these substances are considered to act as a kind of catalyst,
Thereby, the selective growth of the carbon thin film can be further improved. The carbon thin film selective growth region may be formed on the surface of the portion of the cathode electrode located at the bottom of the opening. May be formed to extend to the surface of the portion. The carbon thin film selective growth region may be formed on the entire surface of the portion of the cathode electrode located at the bottom of the opening, or may be formed partially.

In the carbon thin film selective growth region forming step, the surface of the portion of the cathode electrode where the carbon thin film selective growth region is to be formed (hereinafter, may be simply referred to as the surface of the cathode electrode).
And a step of forming a metal thin film on the surface, thereby selectively growing a carbon thin film comprising a portion of the cathode electrode having the metal particles attached to the surface or the metal thin film formed on the surface. Preferably, an area is obtained.
In this case, in order to further ensure the selective growth of the carbon thin film in the carbon thin film selective growth region, sulfur (S), boron (B) or phosphorus (P) is added to the surface of the carbon thin film selective growth region. It is desirable that the carbon thin film be adhered, so that the selective growth of the carbon thin film can be further improved. As a method of attaching sulfur, boron or phosphorus to the surface of the carbon thin film selective growth region, for example, a compound layer made of a compound containing sulfur, boron or phosphorus is formed on the surface of the carbon thin film selective growth region, and then, for example, heating is performed. By subjecting the compound layer to treatment, the compound constituting the compound layer is decomposed to leave sulfur, boron, or phosphorus on the surface of the carbon thin film selective growth region. Examples of compounds containing sulfur include thionaphthene, thiophthene, and thiophene. Examples of the compound containing boron include triphenylboron. Examples of the phosphorus-containing compound include triphenylphosphine.

Alternatively, in order to further ensure the selective growth of the carbon thin film in the carbon thin film selective growth region,
After attaching metal particles to the surface of the cathode electrode or forming a metal thin film, it is desirable to remove metal oxide (so-called natural oxide film) on the surface of the metal particles or the surface of the metal thin film. The removal of metal oxide on the surface of metal particles or the surface of a metal thin film can be performed, for example, by a microwave plasma method in a hydrogen gas atmosphere, a trans-coupled plasma method, an inductively-coupled plasma method, an electron cyclotron resonance plasma method, an RF plasma method, or the like. It is preferable to perform the plasma reduction process based on the above, a sputtering process in an argon gas atmosphere, or a cleaning process using an acid or a base such as hydrofluoric acid. In the case where a step of adhering sulfur, boron or phosphorus to the surface of the carbon thin film selective growth region, or a step of removing metal oxide on the surface of the metal particles or the surface of the metal thin film, an opening is formed in the insulating layer. It is preferable to perform these steps after the provision and before the formation of the carbon thin film on the carbon thin film selective growth region.

As a method of attaching metal particles to the surface of the cathode electrode in order to obtain the carbon thin film selective growth region, for example, a region other than the cathode electrode region where the carbon thin film selective growth region is to be formed is made of an appropriate material (for example, After forming a layer composed of a solvent and metal particles on the surface of the portion of the cathode electrode where the carbon thin film selective growth region is to be formed in a state covered with the mask layer), a method of removing the solvent and leaving the metal particles is given. Can be. Alternatively, as a step of attaching metal particles to the surface of the cathode electrode, for example, in a state where a region other than the region of the cathode electrode where the carbon thin film selective growth region is to be formed is covered with an appropriate material (for example, a mask layer), After the metal compound particles containing metal atoms constituting the metal particles are attached to the surface of the cathode electrode, the metal compound particles are decomposed by heating, thereby comprising a portion of the cathode electrode with the metal particles attached to the surface. A method for obtaining a carbon thin film selective growth region can be mentioned. In this case, specifically, a method of forming a layer comprising a solvent and metal compound particles on the surface of the portion of the cathode electrode where the carbon thin film selective growth region is to be formed, and then removing the solvent to leave the metal compound particles is exemplified. can do. The metal compound particles include a metal halide constituting the metal particles (e.g., iodide, chloride,
It is preferable to be made of at least one material selected from the group consisting of bromide, etc.), oxides, hydroxides and organometallics. In these methods, at an appropriate stage, a material (for example, a mask layer) covering a region other than the region of the cathode electrode where the carbon thin film selective growth region is to be formed is removed.

As a method for forming a metal thin film on the surface of the cathode electrode in order to obtain a carbon thin film selective growth region, for example, a region other than the cathode electrode region where the carbon thin film selective growth region is to be formed is coated with an appropriate material. Plating method such as electrolytic plating method and electroless plating method in the state, MOCV
Known methods such as a CVD method (chemical vapor deposition method) including the D method and a physical vapor deposition method (PVD method, Physical Vapor Deposition method) can be used. Examples of physical vapor deposition methods include (a) electron beam heating, resistance heating, various vacuum evaporation methods such as flash evaporation, (b) plasma evaporation, (c) two-electrode sputtering, DC sputtering, Various sputtering methods such as direct current magnetron sputtering method, high frequency sputtering method, magnetron sputtering method, ion beam sputtering method, bias sputtering method, etc., (d) DC (direct current)
, An RF method, a multi-cathode method, an activation reaction method, an electric field vapor deposition method, a high-frequency ion plating method, a reactive ion plating method and the like.

Here, the metal particles or metal thin films are made of molybdenum (Mo), nickel (Ni), titanium (T
i), chromium (Cr), cobalt (Co), tungsten (W), zirconium (Zr), tantalum (Ta),
Iron (Fe), copper (Cu), platinum (Pt) and zinc (Z
Preferably, it is composed of at least one metal selected from the group consisting of n).

Examples of the carbon thin film include a graphite thin film, an amorphous carbon thin film, a diamond-like carbon thin film, and a fullerene thin film. As a method of forming a carbon thin film, a microwave plasma method, a trans-coupled plasma method, an inductively-coupled plasma method, an electron cyclotron resonance plasma method, a CVD method based on an RF plasma method, etc., and a CVD method using a parallel plate type CVD apparatus are used. Examples can be given. The form of the carbon thin film includes not only a thin film but also carbon whiskers and carbon nanotubes (including hollow and solid).

The structure of the cathode electrode may be a single-layer structure of a conductive material layer, a lower conductive material layer, a resistor layer formed on the lower conductive material layer, and a resistor layer formed on the resistor layer. It is also possible to adopt a three-layer structure of the upper conductive material layer formed. In the latter case, a carbon thin film selective growth region is formed on the surface of the upper conductive material layer. Thus, by providing the resistor layer, the electron emission characteristics in the electron emission portion can be made uniform.

Hereinafter, an example of a method of manufacturing the flat field emission device according to the seventh embodiment will be described with reference to FIGS. 14 and 15, which are schematic partial end views of a support and the like.

[Step-700] First, a conductive material layer for a cathode electrode is formed on a support 10 made of, for example, glass, and then the conductive material layer for a cathode electrode is patterned based on a well-known lithography technique and RIE method. As a result, the striped cathode electrode 11 is
0. The striped cathode electrode 11
It extends in the horizontal direction of the drawing. Cathode electrode 11
Consists of a chromium (Cr) layer having a thickness of about 0.2 μm formed by, for example, a sputtering method.

[Step-710] Thereafter, the insulating layer 1 is formed on the entire surface, specifically, on the support 10 and the cathode electrode 11.
Form 2

[Step-720] Next, after forming the gate electrode 13 and the focus electrode in the form of stripes on the insulating layer 12, an opening is formed in the gate electrode 13 and the insulating layer 12 by the same method as in [Step-110]. Forming a portion 114;
The cathode electrode 11 is exposed at the bottom of the opening 14B (see FIG. 14A). Striped gate electrode 1
The reference numeral 3 and the focus electrode extend in the direction perpendicular to the plane of the drawing. The planar shape of the opening 114 is, for example, 1 μm to 3 μm in diameter.
It is a circle of 0 μm. For example, one to 3,000 openings 114 may be formed in a region (electron emission region) for one pixel.

[Step-730] Next, the electron emitting portion 15C is placed on the cathode electrode 11 exposed at the bottom of the opening 14B.
To form Specifically, first, the carbon thin film selective growth region 70 is formed on the surface of the cathode electrode 11 located at the bottom of the opening 14B. For this purpose, first, a mask layer 71 in which the surface of the cathode electrode 11 is exposed is formed at the center of the bottom of the opening 14B (see FIG. 14B). Specifically, after a resist material layer is formed on the entire surface including the inside of the opening 114 by a spin coating method, holes are formed in the resist material layer located at the center of the bottom of the opening 14B based on lithography technology. By forming, the mask layer 71
Can be obtained. The mask layer 71 includes a portion of the cathode electrode 11 located at the bottom of the opening 14B,
4, the gate electrode 13, the focus electrode, and the insulating layer 12. Thereby, in the next step, a carbon thin film selective growth region is formed on the surface of the cathode electrode 11 located at the center of the bottom of the opening 14B, but the cathode electrode 11 and the gate electrode 13 are short-circuited by metal particles. Can be reliably prevented.

Next, metal particles are deposited on the mask layer 71 including the exposed surface of the cathode electrode 11. Specifically, a solution in which nickel (Ni) fine particles are dispersed in a polysiloxane solution (isopropyl alcohol is used as a solvent) is applied to the entire surface by spin coating to form a cathode thin film selective growth region 70. Electrode 11
A layer composed of a solvent and metal particles is formed on the surface of the portion.
Thereafter, the mask layer 71 is removed, the solvent is removed by heating to about 400 ° C., and the metal particles 72 are left on the exposed surface of the cathode electrode 11, whereby the carbon thin film selective growth region 70 can be obtained. (See FIG. 15A). The polysiloxane is exposed on the exposed cathode electrode 1.
1 has a function of fixing the metal particles 72 to the surface (so-called adhesive function).

[Step-740] Thereafter, a carbon thin film 73 having a thickness of about 0.2 μm is formed on the carbon thin film selective growth region 70 to obtain the electron emitting portion 15C. This state is shown in FIG. The conditions for forming the carbon thin film 73 based on the microwave plasma CVD method are exemplified in Table 1 below.

[Table 1] [Film formation conditions for carbon thin film] Gas used: CH ₄ / H ₂ = 100/10 SCCM Pressure: 1.3 × 10 ³ Pa Microwave power: 500 W (13.56 MHz) Film formation temperature: 500 ゜ C

After the cathode electrode 11 is formed, a carbon thin film selective growth region 70 is formed on the cathode electrode 11 based on, for example, a lift-off method.
10], [Step-720], and [Step-740].

(Eighth Embodiment) An eighth embodiment relates to a field emission device having a second structure composed of a flat field emission device. FIG. 16C is a schematic partial cross-sectional view of the planar field emission device according to the eighth embodiment. This flat-type field emission device includes a stripe-shaped cathode electrode 11 formed on a support 10 made of, for example, glass, and a support 10.
And an insulating layer 12 formed on the cathode electrode 11, a stripe-shaped gate electrode 13 and a focus electrode formed on the insulating layer 12, and the gate electrode 13 and the insulating layer 12; Consists of an exposed opening 114. The cathode electrode 11 extends in the direction perpendicular to the plane of FIG. 16C, and the gate electrode 13 and the focus electrode extend in the horizontal direction of the plane of FIG. 16C. The cathode electrode 11 is made of chromium (Cr), and the insulating layer 12 is made of SiO ₂ . Here, the portion of the cathode electrode 11 exposed at the bottom of the opening 14B is the electron-emitting portion 1
5D.

Hereinafter, a method of manufacturing the flat field emission device according to the eighth embodiment will be described with reference to FIG. 16, which is a schematic partial cross-sectional view of a support and the like.

[Step-800] First, the cathode electrode 11 functioning as the electron-emitting portion 15D is formed on the support. Specifically, after a cathode electrode conductive material layer made of chromium (Cr) is formed on the support 10 by a sputtering method, the cathode electrode conductive material layer is patterned based on a lithography technique and a dry etching technique. Thereby, the stripe-shaped cathode electrode 11 is formed.
Can be formed on the support 10 (see FIG. 16A). The cathode electrode 11 extends in a direction perpendicular to the plane of the paper of FIG.

[Step-810] Next, an insulating layer 12 made of SiO ₂ is formed on the support 10 and the cathode electrode 11 by, eg, CVD. Note that the insulating layer 12 can also be formed from a glass paste based on a screen printing method.

[Step-820] Thereafter, a gate electrode 13 and a focus electrode in the form of stripes are formed on the insulating layer 12 (see FIG. 16B). The gate electrode 13 and the focus electrode extend in the left-right direction on the paper of FIG. For example, the gate electrode 13 and the focus electrode in a stripe shape can be directly formed on the insulating layer 12 by a screen printing method.

[Step-830] Next, [Step-110]
The gate electrode 13 and the insulating layer 12 are formed based on the same method as described above.
An opening 114 is formed at the bottom, and the cathode electrode 11 functioning as the electron-emitting portion 15D is exposed at the bottom of the opening 14B (see FIG. 16C). After that, it is preferable that the insulating layer 12 is isotropically etched to expose the end of the hole 14A of the gate electrode 13.

Ninth Embodiment A field emission device according to a ninth embodiment is a modification of the field emission device according to the eighth embodiment. Embodiment 9 showing a schematic partial cross-sectional view in FIG.
Is different from the planar field emission device of the eighth embodiment shown in FIG.
The point is that minute uneven portions 11A are formed on the surface (corresponding to the electron emission portion) of the cathode electrode 11 exposed at the bottom of 4B. Such a flat field emission device according to the ninth embodiment can be manufactured by the following manufacturing method.

[Step-900] First, [Step-800]
To [Step-820], a stripe-shaped cathode electrode 11 is formed on the support 10 and an insulating layer 12 is formed on the entire surface. Form on top. That is, a tungsten layer having a thickness of about 0.2 μm is formed on a support 10 made of, for example, glass by a sputtering method, and the tungsten layer is patterned in a stripe shape according to a normal procedure to form a cathode electrode 11. I do. Next, an insulating layer 12 is formed on the support 10 and the cathode electrode 11. The insulating layer 12 can be formed by a CVD method using TEOS (tetraethoxysilane) as a source gas. Further, a gate electrode 13 and a focus electrode are formed on the insulating layer 12. The state in which the process up to this point has been completed is substantially the same as that shown in FIG.

[Step-910] [Step-830]
In the same manner as described above, an opening is formed in the gate electrode 13 and the insulating layer 12.
114 is formed, and the cathode electrode 1 is formed at the bottom of the opening 14B.
Expose 1 Then, it is exposed at the bottom of the opening 14B.
A minute uneven portion 11A is formed on the cathode electrode 11
I do. When forming the minute uneven portion 11A, etching is performed.
SF as gas ₆To form the cathode electrode 11
The etching rate of the grain boundary is lower than the etching rate of the tungsten crystal grain.
RIE by setting conditions such that the chining speed is faster
Dry etching based on the method is performed. As a result, the tongue
Small irregularities with dimensions almost reflecting the crystal grain size of stainless steel
The portion 11A can be formed.

In the configuration of the flat field emission device according to the ninth embodiment, a large electric field is applied from the gate electrode 13 to the minute uneven portion 11A of the cathode electrode 11, more specifically, the convex portion of the minute uneven portion 11A. Is added. At this time, since the electric field concentrated on the convex portion is larger than when the surface of the cathode electrode 11 is smooth, electrons are efficiently emitted from the convex portion by the quantum tunnel effect. Therefore, compared to the flat field emission device according to the eighth embodiment in which the smooth cathode electrode 11 is simply exposed at the bottom of the opening 14B, an improvement in luminance when incorporated in a display device can be expected. Therefore, according to the planar field emission device of the ninth embodiment shown in FIG.
Even if the potential difference between the two is relatively small, a sufficient emission electron current density can be obtained, and a high luminance display device can be achieved. Alternatively, the gate voltage required to achieve the same luminance may be low, so that low power consumption can be achieved.

The opening is formed by etching the insulating layer 12 and then the minute uneven portion 11A is formed in the cathode electrode 11 based on the anisotropic etching technique. Thereby, it is also possible to form the minute uneven portions 11A at the same time. That is, when the insulating layer 12 is etched, anisotropic etching conditions under which a certain degree of ion sputtering action can be expected are adopted, and the etching is continued even after the opening 14B having the vertical wall is formed. Part 14B
The minute uneven portion 11A can be formed in the portion of the cathode electrode 11 exposed at the bottom of the substrate. After that, isotropic etching of the insulating layer 12 may be performed.

In the same step as [Step-900], after forming a cathode conductive material layer made of tungsten on the support 10 by a sputtering method,
After patterning the conductive material layer for a cathode electrode based on a lithography technique and a dry etching technique, and then forming minute irregularities 11A on the surface of the conductive material layer for a cathode electrode, [Step-810] to [Step-830] By performing similar steps, a field emission device similar to that shown in FIG. 17A can be manufactured.

Alternatively, in the same step as in [Step-900], a cathode conductive material layer made of tungsten is formed on the support 10 by a sputtering method, and then formed on the surface of the cathode electrode conductive material layer. Small irregularities 1
After forming 1A and then patterning the cathode electrode conductive material layer based on the lithography technique and the dry etching technique, [Step-810] to [Step-830]
By performing the same steps as in (A) of FIG.
A field emission device similar to that shown in FIG.

FIG. 17B shows a modification of the field emission device shown in FIG. In the field emission device shown in FIG. 17B, the average height position of the tip of the minute uneven portion 11A is closer to the support 10 than the lower surface position of the insulating layer 12 (that is, the height is lower). Is). To form such a field emission device, the duration of the dry etching in [Step-910] may be extended. According to such a configuration, the electric field intensity near the center of the opening 14B can be further increased.

FIG. 18 shows a flat field emission device in which a coating layer 11B is formed on the surface of the cathode electrode 11 corresponding to the electron emission portion (more specifically, on at least the minute uneven portion 11A).

The coating layer 11B is preferably made of a material having a work function Φ smaller than that of the material forming the cathode electrode 11. The material to be selected depends on the work of the material forming the cathode electrode 11. It may be determined based on the function, the potential difference between the gate electrode 13 and the cathode electrode 11, the required magnitude of the emitted electron current density, and the like.
As a constituent material of the coating layer 11B, amorphous diamond can be exemplified. When the coating layer 11B is formed using amorphous diamond, 5 × 10
An emission electron current density required for a display device can be obtained at an electric field strength of ⁷ V / m or less.

The thickness of the coating layer 11B is
Should be selected to reflect the This is because the concave portion of the minute uneven portion 11A is buried by the coating layer 11B, and the surface of the electron emission portion is smoothed.
This is because the meaning of providing is lost. Therefore, depending on the size of the minute uneven portion 11A, for example, when the minute uneven portion 11A is formed by reflecting the crystal grain size of the electron-emitting portion, the thickness of the coating layer 11B is set to about 30 to 100 nm. Is preferably selected. When the average height position of the tip portion of the minute uneven portion 11A is lower than the lower surface position of the insulating layer 12, strictly speaking, the average height position of the tip portion of the coating layer 11B is set to the lower surface position of the insulating layer 12. It is more preferable that the temperature is lower than the above.

More specifically, after [Step-810], a coating layer 11B made of amorphous diamond may be formed on the entire surface by, eg, CVD. In addition, the coating layer 11B
Is also deposited on a resist layer (not shown) formed on the gate electrode 13 and the insulating layer 12, but this deposited portion is removed at the same time when the resist layer is removed. The coating layer 11B can be formed based on a CVD method using, for example, a CH ₄ / H ₂ mixed gas or a CO / H ₂ mixed gas as a raw material gas. The layer 11B is formed.

Alternatively, in the same step as [Step-800], a cathode conductive material layer made of tungsten is formed on the support 10 by a sputtering method, and then the cathode is formed based on a lithography technique and a dry etching technique. The conductive material layer for the electrode is patterned, and then the fine irregularities 11 are formed on the surface of the conductive material layer for the cathode electrode.
After forming A and then forming the coating layer 11B, by performing the same steps as [Step-810] to [Step-830], the field emission device shown in FIG. 18 can also be manufactured.

Alternatively, in the same step as in [Step-800], a cathode conductive material layer made of tungsten is formed on the support 10 by a sputtering method, and then formed on the surface of the cathode electrode conductive material layer. Small irregularities 1
After forming 1A and then forming the covering layer 11B, the covering layer 11B and the conductive material layer for the cathode electrode are patterned based on the lithography technique and the dry etching technique, and then [Step-810] to [Step-830]. By performing similar steps, the field emission device shown in FIG. 18 can be manufactured.

Alternatively, as the material constituting the coating layer, a material may be appropriately selected such that the secondary electron gain δ of such a material is larger than the secondary electron gain δ of the conductive material constituting the cathode electrode. it can.

Incidentally, the electron emission portion 15D (the surface of the cathode electrode 11) of the flat field emission device shown in FIG.
May be formed with a coating layer. In this case, [Step-8]
30], the coating layer 11B may be formed on the surface of the cathode electrode 11 exposed at the bottom of the opening 14B.
After forming a cathode electrode conductive material layer thereon, forming a coating layer 11B on the cathode electrode conductive material layer,
Based on lithography technology and dry etching technology,
These layers may be patterned.

(Embodiment 10) Embodiment 10 relates to a field emission device having a second configuration composed of a crater type field emission device. FIG. 22B is a schematic partial cross-sectional view of the crater type field emission device according to the tenth embodiment. In the crater type field emission device of the tenth embodiment, a cathode electrode 111 having a plurality of raised portions 111A for emitting electrons and a concave portion 111B surrounded by each raised portion 111A is provided on a support 10. I have. Note that FIG. 21B is a schematic perspective view in which the insulating layer 12 and the gate electrode 13 have been removed.

The shape of the concave portion is not particularly limited, but typically forms a substantially spherical surface. This is because a sphere is used in the method for manufacturing the crater type field emission device, and the concave portion 111B is used.
Is formed to reflect a part of the shape of the sphere. Therefore, when the concave portion 111B forms a substantially spherical surface, the raised portion 111A surrounding the concave portion 111B has an annular shape. In this case, the concave portion 111B and the raised portion 111A have a shape like a crater or a caldera as a whole. Since the raised portion 111A is a portion that emits electrons, it is particularly preferable that the tip portion 111C is sharp from the viewpoint of increasing the electron emission efficiency. Tip 11 of ridge 111A
Even if the profile of 1C has irregular irregularities,
Alternatively, it may be smooth. The arrangement of the protrusions 111A within one pixel may be regular or random. In addition, the concave portion 111B may be surrounded by a raised portion 111A continuous along the circumferential direction of the concave portion 111B, or in some cases, may be surrounded by a discontinuous raised portion 111A along the circumferential direction of the concave portion 111B. You may.

In such a method of manufacturing a crater-type field emission device, the step of forming a striped cathode electrode on a support is, more specifically, a step of supporting the striped cathode electrode covering a plurality of spheres. Forming on the body, removing the sphere, removing the portion of the cathode electrode covering the sphere, and thereby, a plurality of ridges emitting electrons, surrounded by each ridge, and the sphere Forming a cathode electrode having a concave portion reflecting a part of the shape of the cathode electrode.

It is preferable to remove the sphere by a change in the state of the sphere and / or a chemical change. Here, the state change and / or chemical change of the sphere means a change such as expansion, sublimation, foaming, gas generation, decomposition, combustion, and carbonization, or a combination thereof. For example, if the sphere is made of an organic material, it is more preferable to remove the sphere by burning it. It should be noted that the removal of the sphere and the removal of the portion of the cathode electrode covering the sphere need not necessarily occur simultaneously. For example, when a part of the sphere remains after removing the part of the cathode electrode covering the sphere, the remaining sphere may be removed later.

In particular, when the sphere is made of an organic material, when the sphere is burned, for example, carbon monoxide, carbon dioxide, and water vapor are generated, the pressure in the closed space near the sphere increases, and the cathode electrode near the sphere is Explodes when a certain pressure limit is exceeded. Due to the force of the rupture, the portion of the cathode electrode covering the sphere is scattered to form a raised portion and a concave portion, and the sphere is removed. At this time, since the initial process of burning the sphere proceeds in the closed space, a part of the sphere may be carbonized. It is preferable that the thickness of the portion of the cathode electrode covering the sphere be thin enough to be scattered by bursting.

In the crater-type field emission device according to Embodiment 12 to be described later, the sphere can be removed by a change in the state and / or a chemical change of the sphere. Sometimes it is easier to do so. Here, the external force is a physical force such as a blowing pressure of air or an inert gas, a blowing pressure of a cleaning liquid, a magnetic attraction force, an electrostatic force, a centrifugal force, or the like. In the twelfth embodiment, unlike the crater-type field emission device according to the tenth embodiment, there is no need to scatter the cathode electrode in a portion that covers the sphere, so that there is an advantage that a residue of the cathode electrode hardly occurs. .

The sphere used in the crater-type field emission device according to the twelfth embodiment described later has at least a surface made of a material having a higher interfacial tension (surface tension) than the interfacial tension (surface tension) of the material forming the cathode electrode. Preferably, it is configured. In the crater-type field emission device according to Embodiment 12, at least the surface of the sphere only needs to satisfy this condition regarding interfacial tension. In other words, the portion having an interfacial tension higher than the interfacial tension of the cathode electrode may be only the surface of the sphere or the whole, and the surface of the sphere and / or the entire constituent material may be inorganic. Any of a material, an organic material, or a combination of an inorganic material and an organic material may be used. In the crater-type field emission device according to the twelfth embodiment, when the cathode electrode and the like are made of a normal metal-based material, the surface of the metal-based material has a hydroxyl group derived from adsorbed moisture, and the surface of the insulating layer has Is generally in a state of high hydrophilicity, in which a hydroxyl group derived from a dangling bond of an Si—O bond and adsorbed moisture is present. Therefore, it is particularly effective to use a sphere having a hydrophobic surface treatment layer. As a constituent material of the hydrophobic surface treatment layer, a fluorine-based resin such as polytetrafluoroethylene can be used. When the sphere has a hydrophobic surface treatment layer, the inside of the hydrophobic surface treatment layer is referred to as a core material, and the core material is made of a polymer material other than glass, ceramics, and fluororesin. Any of these may be used.

The organic material constituting the sphere is not particularly limited, but a general-purpose polymer material is preferable. However, in the case of a polymer material having an extremely high degree of polymerization or an extremely large content of multiple bonds, the combustion temperature becomes too high, and the cathode electrode may be adversely affected when the sphere is removed by combustion. Therefore, it is preferable to select a polymer material that can be burned or carbonized at a temperature at which there is no risk of adversely affecting these materials. Representative polymer materials include styrene, urethane, acrylic, vinyl, divinylbenzene, melamine, formaldehyde, and polymethylene homopolymers and copolymers. Alternatively, a fixed-type sphere having an adhesive force may be used as the sphere in order to secure a reliable arrangement on the support. As the fixed type sphere, a sphere made of an acrylic resin can be exemplified.

Alternatively, for example, a heat-expandable microsphere encapsulated with vinylidene chloride-acrylonitrile copolymer as an outer shell, isobutane as a foam material, and encapsulated can be used as a sphere. In the crater-type field emission device of the tenth embodiment, when such a heat-expandable microsphere is used and the heat-expandable microsphere is heated, the polymer of the outer shell is softened, and the contained isobutane is gasified and expanded. As a result, a true sphere hollow body having a particle size of about four times as much as that before the expansion is formed. As a result, in the crater-type field emission device of the tenth embodiment, a raised portion for emitting electrons and a concave portion surrounded by the raised portion and reflecting a part of the shape of a sphere are formed on the cathode electrode. Can be. Incidentally, the expansion of the heat-expandable microspheres due to heating is also referred to in the present specification.
Included in the concept of sphere removal. Thereafter, the thermal expansion type microspheres may be removed using an appropriate solvent.

In the crater-type field emission device according to the tenth embodiment, after a plurality of spheres are arranged on a support, a cathode electrode covering the spheres may be formed. In this case, or in Embodiment 1 described later,
In the crater-type field emission device of No. 2, as a method of disposing a plurality of spheres on the support, a dry method of scattering the spheres on the support can be used. For example, in the field of manufacturing a liquid crystal display device, a technique of spraying spacers for maintaining a constant panel interval can be applied to the spraying of spheres. Specifically, a so-called spray gun that sprays a sphere from a nozzle with compressed gas can be used.
When the sphere is ejected from the nozzle, the sphere may be dispersed in a volatile solvent. Alternatively, the spheres can be sprinkled using an apparatus or method commonly used in the field of electrostatic powder coating. For example, using a corona discharge, a sphere negatively charged by an electrostatic powder spray gun can be sprayed toward a grounded support. Since the sphere used is very small as described later, when the sphere is sprayed on the support, it adheres to the surface of the support by, for example, electrostatic force, and does not easily fall off the support in the subsequent steps. After arranging a plurality of spheres on the support, if the spheres are pressurized, overlapping of the plurality of spheres on the support can be eliminated, and the spheres can be densely arranged in a single layer on the support. it can.

Alternatively, like a crater-type field emission device in Embodiment 11 described later, a composition layer composed of a composition in which a sphere and a cathode electrode material are dispersed in a dispersion medium is formed on a support. Thus, after disposing a plurality of spheres on the support and covering the spheres with the cathode electrode made of the cathode electrode material, the dispersion medium can be removed. The composition may be in the form of a slurry or a paste, and the composition and viscosity of the dispersion medium may be appropriately selected according to the desired properties. As a method for forming the composition layer on the support, a screen printing method is suitable. Typically, the cathode electrode material is preferably fine particles whose sedimentation speed in the dispersion medium is lower than that of a sphere. Examples of a material constituting such fine particles include carbon, barium, strontium, and iron. After removing the dispersion medium, the cathode electrode is fired if necessary. Examples of the method for forming the composition layer on the support include a spraying method, a dropping method, a spin coating method, and a screen printing method. In addition, while the sphere is arranged, the sphere is covered with a cathode electrode made of a cathode electrode material,
Depending on the method of forming the composition layer, it is necessary to pattern the cathode electrode.

Alternatively, in a twelfth embodiment to be described later, a composition layer composed of a composition obtained by dispersing spheres in a dispersion medium is formed on a support. After placing the sphere, the dispersion medium can be removed. The composition may be in the form of a slurry or a paste, and the composition and viscosity of the dispersion medium may be appropriately selected according to the desired properties. Typically, an organic solvent such as isopropyl alcohol is used as a dispersion medium, and the dispersion medium can be removed by evaporation. Examples of the method for forming the composition layer on the support include a spraying method, a dropping method, a spin coating method, and a screen printing method.

The gate electrode and the cathode electrode extend in directions different from each other (for example, the angle formed by the projected image of the striped gate electrode and the projected image of the striped cathode electrode is 90 degrees). It is patterned in a stripe shape, and electrons are emitted from the ridge located in the electron emission region. Therefore, the raised portion only needs to be present only in the electron emission region in terms of function. However, even if the protrusions and recesses exist in a region other than the electron emission region, such protrusions and recesses do not perform any function of emitting electrons while being covered with the insulating layer. Therefore, no problem occurs even if the sphere is arranged on the entire surface.

The diameter of the sphere should form a desired opening diameter, concave portion diameter, display screen size, number of pixels, size of electron emission region, and one pixel of a display device using a field emission element. The selection can be made according to the number of field emission devices, but is preferably selected in the range of 0.1 to 10 μm. For example, a sphere commercially available as a spacer for a liquid crystal display device has a good particle size distribution of 1 to 3%, and it is preferable to use this. Ideally, the shape of the sphere is a true sphere, but it need not necessarily be a true sphere. It is preferable to arrange spheres on the support at a density of about 100 to 5000 spheres / mm ² . For example, when spheres are arranged on the support at a density of about 1000 / mm ² , for example, the size of the electron emission region is assumed to be 0.5 mm × 0.2 mm
In this case, about 100 spheres exist in the electron emission region, and about 100 ridges are formed.
If such a number of protrusions are formed in one electron emission region, the variation in the diameter of the concave portion due to the variation in the particle size distribution and the sphericity of the sphere is almost averaged, and in practice,
The emission electron current density and luminance per pixel (or one sub-pixel) are substantially uniform.

The crater type field emission device according to the tenth embodiment or the eleventh and the first embodiments described later.
In the crater-type field emission device of No. 2, part of the shape of the sphere is reflected in the shape of the concave portion forming the electron-emitting portion. The profile of the tip of the protruding portion may have irregular irregularities or may be smooth. Since the tip is formed by breaking the cathode electrode, the tip of the raised portion is likely to have an irregular shape. When the tip is sharpened to the ridge due to the breakage, the tip can function as a highly efficient electron-emitting portion, which is advantageous. In the crater-type field emission device according to the tenth or eleventh embodiment, each of the raised portions surrounding the concave portion has a substantially annular shape. Present.

The arrangement of the ridges on the support may be regular or random, depending on the arrangement of the spheres. When the above-mentioned dry method or wet method is adopted,
The arrangement of the ridges on the support is random.

Embodiment 10 or Embodiment 11,
In the crater-type field emission device according to the twelfth embodiment, an opening is formed in the insulating layer after the formation of the insulating layer. After the opening is formed, the protective layer may be removed. Chromium can be exemplified as a material forming the protective layer.

A method of manufacturing the crater type field emission device according to the tenth embodiment will be described below with reference to FIGS. 19 to 22. FIGS. 19 (A), 20 (A), and 21
(A) is a schematic partial end view, FIG. 22 (A) and (B) are schematic partial cross-sectional views, FIG. 19 (B), FIG. 20 (B) and FIG. (B) of FIG.
FIG. 22 (A), FIG. 20 (A) and FIG. 21 (A) are partial perspective views schematically showing a wider range.

[Step-1000] First, a plurality of spheres 80
Is formed on the support 10. Specifically, first, a support 1 made of, for example, glass is used.
The sphere 80 is arranged on the entire surface on the zero. The sphere 80 is made of, for example, a polymethylene-based polymer material and has an average diameter of about 5 mm.
μm, particle size distribution less than 1%. Approximately 1000 spheres / mm were placed on the support 10 using a spray gun.
Place randomly at a density of ² . Spraying using a spray gun may be either a method of spraying a sphere mixed with a volatile solvent or a method of spraying it from a nozzle in a powder state. The placed sphere 80 is supported by the support 1 by electrostatic force.
It is held above zero. This state is shown in FIGS. 19A and 19B.

[Step-1010] Next, the cathode electrode 111 is formed on the sphere 80 and the support 10. FIGS. 20A and 20B show a state in which the cathode electrode 111 is formed. The cathode electrode 111 can be formed, for example, by screen-printing a carbon paste in a stripe shape. At this time, since the sphere 80 is disposed on the entire surface of the support 10, the sphere 80 has a cathode electrode 111 as shown in FIG.
There are, of course, some that are not coated with. Next, the cathode electrode 111 is dried at, for example, 150 ° C. in order to remove moisture and a solvent contained in the cathode electrode 111 and to flatten the cathode electrode 111. At this temperature, the sphere 80 undergoes no state change and / or chemical change.
Instead of the screen printing using the carbon paste as described above, a cathode electrode conductive material layer constituting the cathode electrode 111 is formed on the entire surface, and the cathode electrode conductive material layer is formed by a usual lithography technique and dry etching. The stripe-shaped cathode electrode 111 can also be formed by patterning using a technique. When the lithography technique is applied, the resist material layer is usually formed by a spin coating method, but if the rotation speed of the support 10 during spin coating is about 500 rpm and the rotation time is about several seconds, the sphere 80 falls off. It can be held on the support body 10 without being displaced.

[Step-1020] Next, by removing the sphere 80, the cathode electrode 1 coated with the sphere 80 is removed.
A cathode electrode 111 having a plurality of raised portions 111A that emit electrons and a concave portion 111B that is surrounded by each raised portion 111A and reflects a part of the shape of the sphere 80 is removed. Form. This state is shown in FIGS. 21A and 21B. Specifically, the cathode electrode 1
The sphere 80 is burned by heating at about 530 ° C., also serving as firing of 11. With the burning of the sphere 80, the pressure in the closed space in which the sphere 80 was trapped increases,
When the portion of the cathode electrode 111 covering the sphere 80 exceeds a certain withstand pressure limit, it is ruptured and removed. as a result,
A raised portion 111A and a concave portion 111B are formed in a part of the cathode electrode 111 formed on the support 10.
When a part of the sphere remains as a residue after the sphere is removed, it depends on the material constituting the sphere to be used.
The residue may be removed using an appropriate cleaning solution.

[Step-1030] Thereafter, the insulating layer 12 is formed on the cathode electrode 111 and the support 10. Specifically, for example, a glass paste is screen-printed on the entire surface to a thickness of about 5 μm. Next, the insulating layer 12 is dried at, for example, 150 ° C. in order to remove moisture and a solvent contained in the insulating layer 12 and to planarize the insulating layer 12. Instead of screen printing using a glass paste as described above, an SiO ₂ film may be formed by, for example, a plasma CVD method.

[Step-1040] Next, a stripe-shaped gate electrode 13 and a focus electrode are formed on the insulating layer 12 (see FIG. 22A). The direction in which the projected images of the striped gate electrode 13 and the focus electrode extend is at an angle of 90 degrees with the direction in which the projected images of the striped cathode electrode 111 extend.

[Step-1050] Thereafter, the gate electrode 1
3 and the projection image of the cathode electrode 111 overlap with each other, the opening 11 is formed in the gate electrode 13 and the insulating layer 12 based on the same method as in [Step-110].
4, thereby exposing a plurality of ridges 111A and recesses 111B at the bottom of the opening 14B. Note that it is preferable to perform etching under a condition that a sufficiently high etching selectivity with respect to the cathode electrode 111 can be secured.
Alternatively, it is preferable to form a protection layer made of, for example, chromium after forming the protruding portion 111A and remove the protection layer after forming the opening 114. Thus, the field emission device shown in FIG. 22B can be obtained.

(Eleventh Embodiment) The eleventh embodiment is a modification of the crater type field emission device described in the tenth embodiment. The method of manufacturing the crater-type field emission device according to the eleventh embodiment will be described with reference to FIG. 23. Forming a composition layer 81 made of a composition dispersed on a support 10; a plurality of spheres 80 are arranged on the support 10; and the spheres are covered with a cathode electrode 111 made of a cathode electrode material. After that, the step of removing the dispersion medium, that is, the point of the wet method,
This is different from the method of manufacturing the crater type field emission device of the tenth embodiment.

[Step-1100] First, a plurality of spheres 80 are arranged on the support 10. Specifically, a composition layer 81 made of a composition obtained by dispersing a sphere 80 and a cathode electrode material 81B in a dispersion medium 81A is formed on the support 10. That is, for example, a sphere 80 made of a polymethylene-based polymer material having an average diameter of about 5 μm and an average diameter of about 0.0
A composition formed by dispersing 5 μm carbon particles as a cathode electrode material 81B in a dispersion medium 81A is screen-printed in stripes on a support 10 to form a composition layer 81. FIG. 23A shows a state immediately after the formation of the composition layer 81.

[Step-1110] In the composition layer 81 held by the support 10, the spheres 80 will soon settle down and be disposed on the support 10, and the spheres 80 will be removed from the support 1.
The cathode electrode material 81B is settled on 0, and the cathode electrode 111 made of the cathode electrode material 81B is formed. Thereby, the plurality of spheres 80 are arranged on the support 10 and the cathode electrode 111 made of the cathode electrode material is formed.
Can cover the sphere 80. This state is shown in FIG.
3 (B).

[Step-1120] Thereafter, the dispersion medium 81A
Is removed, for example, by evaporation. This state is shown in FIG.

[Step-1130] Next, Embodiment 1
By performing the same steps as [Step-1020] to [Step-1050] in Step 0, a field emission device similar to that shown in FIG. 22B can be completed.

Twelfth Embodiment A twelfth embodiment is also a modification of the method of manufacturing the crater type field emission device of the tenth embodiment. In the method for manufacturing a crater-type field emission device according to the twelfth embodiment, the step of forming a striped cathode electrode on a support is, more specifically, a step of arranging a plurality of spheres on the support, A plurality of ridges for emitting a sphere, and a recess surrounded by each ridge and reflecting a part of the shape of the sphere, and each of the ridges is formed around the sphere by a cathode electrode. And a step of removing the sphere. The arrangement of the plurality of spheres on the support is performed by scattering the spheres. The sphere has a hydrophobic surface treatment layer. Hereinafter, a method for manufacturing such a field emission device will be described with reference to FIG.

[Step-1200] First, a plurality of spheres 180 are arranged on the support. Specifically, a plurality of spheres 180 are arranged on the entire surface of the support 10 made of glass. The sphere 180 is formed by coating a core material 180A made of, for example, a divinylbenzene polymer material with a surface treatment layer 180B made of a polytetrafluoroethylene resin, and has an average diameter of about 5 μm and a particle size distribution of less than 1%. . The spheres 180 are randomly arranged on the support 10 at a density of about 1000 / mm ² using a spray gun. The placed sphere 180 is adsorbed on the support 10 by electrostatic force. FIG. 24A shows a state in which the processes up to this point have been completed.

[Step-1210] Next, a plurality of raised portions 111A for emitting electrons, and each of the raised portions 111A are surrounded by the raised portions 111A.
And a recess 111B reflecting a part of the shape of the sphere 180
And a cathode electrode 111 in which each protruding portion 111 </ b> A is formed around the sphere 180 is provided on the support 10.
Specifically, in the same manner as described in the tenth embodiment, for example, a carbon paste is screen-printed in a stripe shape, but in the twelfth embodiment, the surface of the sphere 180 is made hydrophobic by the surface treatment layer 180B. Sphere 1
The carbon paste screen-printed on 80 is immediately flipped and dropped, and is deposited around the sphere 180 to form a raised portion 111A. Tip 11 of ridge 111A
1C is not as sharp as in the case of the crater type field emission device of the tenth embodiment. The portion of the cathode electrode 111 that has entered between the sphere 180 and the support 10 is
1B. In FIG. 24B, the cathode electrode 111
Although a gap is present between the sphere 180 and the sphere 180, the cathode electrode 111 may be in contact with the sphere 180. Thereafter, the cathode electrode 111 is dried at, for example, 150 ° C. FIG. 24B shows a state in which the processes up to this point have been completed.

[Step-1220] Next, by applying an external force to the sphere 180, the sphere 180
Is removed. As a specific removing method, cleaning and blowing of compressed gas can be mentioned. FIG. 24C shows a state in which the processes up to this point have been completed. The removal of the sphere can be based on the state change and / or the chemical change of the sphere, and more specifically, for example, the sphere can be removed by combustion.

[Step-1230] Then, the embodiment 1
By performing [Step-1030] to [Step-1050] of Step 0, a field emission device substantially similar to that shown in FIG. 22B can be obtained.

(Thirteenth Embodiment) A thirteenth embodiment relates to a field emission device having a third structure composed of an edge type field emission device. FIG. 25A is a schematic partial cross-sectional view of the edge-type field emission device. The edge type field emission device includes a stripe-shaped cathode electrode 211 formed on a support 10, a support 10 and a cathode electrode 211.
An insulating layer 12 is formed on the insulating layer 12, a gate electrode 13 and a focus electrode are formed in a stripe shape on the insulating layer 12, and an opening 114 is provided in the gate electrode 13 and the insulating layer 12. An edge 211A of the cathode electrode 211 is exposed at the bottom of the opening 14B. By applying a voltage to the cathode electrode 211 and the gate electrode 13, the edge portion 2 of the cathode electrode 211 is
Electrons are emitted from 11A.

As shown in FIG. 25B, a recess 10A may be formed in the support 10 below the cathode electrode 211 in the opening 114. Alternatively, as shown in a schematic partial cross-sectional view of FIG.
The first gate electrode 13A formed thereon and the support 10
And an interlayer insulating layer 12A formed on the first gate electrode 13A, a cathode electrode 211 formed on the interlayer insulating layer 12A, an interlayer insulating layer 12A and the cathode electrode 211.
And the second gate electrode 13B formed on the insulating layer 12B. The opening 114 is formed in the second gate electrode 13.
B, the insulating layer 12B, the cathode electrode 211, and the interlayer insulating layer 12A. An edge portion 211A of the cathode electrode 211 is exposed on a side wall of the opening 114. The cathode electrode 211, the first gate electrode 13A, the second
By applying a voltage to the gate electrode 13B, the edge portion 21 of the cathode electrode 211 corresponding to the electron-emitting portion is formed.
Electrons are emitted from 1A.

For example, a method of manufacturing the edge type field emission device shown in FIG. 25C will be described below with reference to FIG. 26 which is a schematic partial end view of a support or the like.

[Step-1300] First, a tungsten film having a thickness of about 0.2 μm is formed on a support 10 made of, for example, glass by a sputtering method, and is subjected to a photolithography technique and a dry etching technique according to a usual procedure. This tungsten film is patterned to form a first gate electrode 13A. Next, on the entire surface, SiO ₂
After forming a 0.3 μm-thick interlayer insulating layer 12A made of tungsten, a striped cathode electrode 211 made of tungsten is formed on the interlayer insulating layer 12A (see FIG. 26A).

[Step-1310] Thereafter, an insulating layer 12B made of, for example, SiO ₂ and having a thickness of 0.7 μm is formed on the entire surface. (FIG. 2)
6 (B)).

[Step-1320] Next, [Step-11]
0], the second gate electrode 13B is anisotropically etched by, eg, RIE to form a hole. Next, the insulating layer 12B exposed at the bottom of the hole is isotropically etched to form an opening 14B. Since the insulating layer 12B is formed using SiO ₂ , wet etching using a buffered hydrofluoric acid aqueous solution is performed. The wall surface of the opening 14B formed in the insulating layer 12B recedes from the opening end surface of the hole formed in the second gate electrode 13B, and the amount of retreat at this time can be controlled by the length of the etching time. it can. Here, the lower end of the opening 14B formed in the insulating layer 12B corresponds to the second gate electrode 13B.
The wet etching is performed until the hole formed in the hole is retracted from the opening end surface.

Next, the cathode electrode 211 exposed at the bottom of the opening 14B is dry-etched under the condition that ions are used as main etching species. In dry etching using ions as a main etching species, charged particles can be accelerated by applying a bias voltage to an object to be etched or by using an interaction between a plasma and a magnetic field.
Generally, anisotropic etching proceeds, and the processed surface of the object to be etched becomes a vertical wall. However, in this step, there are some incident components having an angle other than perpendicular also in the main etching species in the plasma, and the oblique incident components also occur due to scattering at the end of the opening 14B. In the exposed surface of the cathode electrode 211, the main etching species is also incident with a certain probability to a region that should be blocked by the opening 14B and should not reach ions. At this time, the main etching species having a smaller incident angle with respect to the normal line of the support 10 have a higher incidence probability, and the main etching species having a larger incident angle have a lower incidence probability.

Therefore, although the position of the upper end of the opening formed in the cathode electrode 211 is almost aligned with the lower end of the opening 14B formed in the insulating layer 12B, the position of the lower end of the opening formed in the cathode electrode 211 is small. The position of the portion protrudes from its upper end. That is, the cathode electrode 21
The thickness of the one edge portion 211A becomes thinner toward the front end portion in the protruding direction, and the edge portion 211A is sharpened. For example, by using a SF ₆ as an etching gas, it is possible to perform a good machining of the cathode electrode 211.

Next, the interlayer insulating layer 12A exposed at the bottom of the opening formed in the cathode electrode 211 is isotropically etched to form an opening in the interlayer insulating layer 12A.
14 is completed. Here, wet etching using a buffered hydrofluoric acid aqueous solution is performed. The wall surface of the opening formed in interlayer insulating layer 12A is recessed from the lower end of the opening formed in cathode electrode 211. The amount of retreat at this time can be controlled by the length of the etching time. Opening 1
When the first resist layer is removed after the completion of FIG. 14, FIG.
(C) can be obtained.

(Embodiment 14) Embodiment 14 relates to a modification of the method for manufacturing a Spindt-type field emission device described in Embodiment 1. A modification of the Spindt-type field emission device of the fourteenth embodiment will be described below with reference to FIGS. 27 to 30 which are schematic partial end views of a support and the like. The emission element is basically manufactured based on the following steps. (A) Stripe-shaped cathode electrode 11 on support 10
(B) forming the insulating layer 12 on the support 10 including the cathode electrode 11 (c) forming the striped gate electrode 13 and the focus electrode on the insulating layer 12 (d) bottom Opening 114 in which cathode electrode 11 is exposed
(E) a step of forming a conductive material layer 91 for forming an electron-emitting portion over the entire surface including the inside of the opening 114; Conductive material layer 91
(G) forming a mask material layer 92 on the conductive material layer 91 so as to cover the region of the mask material layer 92. (g) The etching rate of the conductive material layer 91 in the direction perpendicular to the support 10 The conductive material layer 91 and the mask material layer 92 are etched under anisotropic etching conditions in which the etching rate in the direction perpendicular to the
1, the electron emitting portion 15 having a conical tip.
Step of Forming E on Cathode Electrode 11 Exposed in Opening 14B

[Step-1400] First, a cathode electrode 1 made of chromium (Cr) is formed on a support 10 having a SiO ₂ layer having a thickness of about 0.6 μm formed on a glass substrate, for example.
1 is provided. Specifically, a cathode conductive material layer made of chromium is deposited on the support 10 by, for example, a sputtering method or a CVD method, and the cathode conductive material layer is patterned to form a plurality of cathode electrodes 11. Can be formed. Cathode electrode 11
Is 50 μm, for example, and the space between the cathode electrodes is, for example, 30 μm. Thereafter, SiO _{2 is} deposited on the support 10 including the cathode electrode 11 by plasma CVD using TEOS (tetraethoxysilane) as a source gas.
Is formed. The thickness of the insulating layer 12 is about 1 μm. Next, the projected image extends in the direction orthogonal to the projected image of the cathode electrode 11 over the entire surface on the insulating layer 12 and is a stripe-shaped gate electrode 13 extending parallel to each other.
And forming a focus electrode.

Next, the cathode electrode 11 and the gate electrode 13
In the electron emission region which is an overlap region with the above, that is, in one pixel region, an opening 114 penetrating through the gate electrode 13 and the insulating layer 12 is formed based on the same method as in [Step-110] (FIG. 27). (A)). The planar shape of the opening 114 is, for example, a circle having a diameter of 0.3 μm. Usually, about several hundred to one thousand openings 114 are formed in one pixel region.

[Step-1410] Next, the adhesion layer 9 is formed on the entire surface.
0 is formed by a sputtering method (see FIG. 27B). The adhesion layer 90 is formed of a conductive material formed entirely on the exposed surface of the insulating layer 12 where the gate electrode 13 is not formed and the insulating layer 12 exposed on the side wall surface of the opening 114 in the next step. This layer is provided to increase the adhesion between the layer 91 and the layer 91. Assuming that the conductive material layer 91 is formed of tungsten, the adhesion layer 90 made of tungsten is used.
Is formed to a thickness of 0.07 μm by a DC sputtering method.

[Step-1420] Next, over the entire surface including the inside of the opening 114, a conductive material layer 91 for forming an electron emitting portion made of tungsten having a thickness of about 0.6 μm is reduced with hydrogen reduction pressure C.
It is formed by a VD method (see FIG. 28A). On the surface of the conductive material layer 91 on which the film is formed, a concave portion 91A reflecting a step between the upper end surface and the bottom surface of the opening 114 is formed.

[Step-1430] Next, a mask material layer 92 is formed so as to shield the region of the conductive material layer 91 (specifically, the concave portion 91A) located at the center of the opening 114. Specifically, first, a thickness of 0.
A 35 μm resist material is formed as a mask material layer 92 on the conductive material layer 91 (see FIG. 28B). The mask material layer 92 absorbs the concave portions 91A of the conductive material layer 91 and has a substantially flat surface. Next, the mask material layer 92 is etched by RIE using an oxygen-based gas. This etching is completed when the flat surface of the conductive material layer 91 is exposed. Thereby, the concave portions 91 of the conductive material layer 91 are formed.
The mask material layer 92 remains so that A is buried flat (see FIG. 29A).

[Step-1440] Next, the conductive material layer 91
And the mask material layer 92 and the adhesion layer 90 are etched to form a conical electron emission portion 15E (FIG. 29B).
reference). The etching of these layers is performed under anisotropic etching conditions in which the etching rate of the conductive material layer 91 is higher than the etching rate of the mask material layer 92. The etching conditions are illustrated in Table 2 below.

[Table 2] [Etching conditions for conductive material layer 91 etc.] SF ₆ flow rate: 150 SCCM O ₂ flow rate: 30 SCCM Ar flow rate: 90 SCCM Pressure: 35 Pa RF power: 0.7 kW (13.56 MHz)

[Step-1450] Thereafter, the insulating layer 12 is formed inside the opening 14B under isotropic etching conditions.
30 is completed, the field emission device shown in FIG. 30 is completed. The isotropic etching may be the same as that described in [Step-140].

Here, the mechanism for forming the electron-emitting portion 15E in [Step-1440] will be described with reference to FIG. FIG. 31A is a schematic diagram showing how the surface profile of the object to be etched changes at regular intervals as the etching proceeds.
FIG. 1B is a graph showing the relationship between the etching time and the thickness of the object to be etched at the center of the opening 114. The thickness of the mask material layer in the center of the opening 114 h _p, the height of the electron-emitting portion 15E at the center of the opening 114 and h _e.

Under the etching conditions shown in Table 2, the etching rate of the conductive material layer 91 is naturally higher than the etching rate of the mask material layer 92 made of the resist material.
In a region where the mask material layer 92 does not exist, the conductive material layer 9
1 immediately starts to be etched, and the surface of the object to be etched quickly descends. On the other hand, in the region where the mask material layer 92 exists, the etching of the conductive material layer 91 thereunder does not start unless the mask material layer 92 is first removed. rate of decrease in the thickness of the object to be etched is slow (h _p decreasing segment), the first time when the mask material layer 92 is lost,
Rate of decrease in the thickness of the object to be etched is similar to the nonexistent areas of the mask material layer 92 faster (h _e decreasing segment). h _e
The start time of the decreasing section is the latest at the center of the opening 114 where the mask material layer 92 has the maximum thickness, and the mask material layer 9
2 toward the periphery of the thin opening 114. Thus, a conical electron emitting portion 15E is formed.

The ratio of the etching rate of the conductive material layer 91 to the etching rate of the mask material layer 92 made of the resist material will be referred to as “resist selectivity”.
The fact that the selectivity with respect to the resist is an important factor in determining the height and shape of the electron-emitting portion 15E will be described with reference to FIG. FIG. 32A shows the case where the resist selectivity is relatively small, FIG. 32C shows the case where the resist selectivity is relatively large, and FIG. In this case, the shape of the electron-emitting portion 15E is shown. The larger the selectivity with respect to the resist, the more the mask material layer 92
Since the film thickness of the conductive material layer 91 is more severe than that of the electron emission portion 15, it can be seen that the electron emitting portion 15E is higher and sharper. The resist selectivity decreases as the ratio of O ₂ flow to SF ₆ flow increases. Also, when using an etching apparatus that can change the incident energy of ions by using a substrate bias, it is possible to increase the RF bias power or reduce the frequency of the AC power supply for bias application to select the resist. The ratio can be reduced.
The value of the resist selectivity is selected to be 1.5 or more, preferably 2 or more, and more preferably 3 or more.

In the above-described etching, it is naturally necessary to ensure a high selectivity with respect to the gate electrode 13, focus electrode and cathode electrode 11, but there is no problem at all under the conditions shown in Table 2. This is because the material constituting the gate electrode 13, the focus electrode, and the cathode electrode 11 is hardly etched by the fluorine-based etching species, and an etching selectivity of about 10 or more can be obtained under the above conditions.

(Embodiment 15) A method of manufacturing a Spindt-type field emission device according to Embodiment 15 is described in Embodiment 1.
14 is a modification of the manufacturing method of the Spindt-type field emission device of FIG. In the manufacturing method according to the fifteenth embodiment, the region of the conductive material layer shielded by the mask material layer can be made narrower than in the manufacturing method according to the fourteenth embodiment. That is, in the manufacturing method of the Spindt-type field emission device according to the fifteenth embodiment, the columnar portion and the enlarged portion communicating with the upper end of the columnar portion reflect the step between the upper end surface and the bottom surface of the opening. A substantially funnel-shaped recess is formed on the surface of the conductive material layer, and in step (f), after forming a mask material layer on the entire surface of the conductive material layer, the mask material layer and the conductive material layer are formed on the surface of the support. By removing the mask material in a plane parallel to the surface, a mask material layer is left on the columnar portion.

Hereinafter, a method for manufacturing a Spindt-type field emission device according to Embodiment 15 will be described with reference to FIGS. 33 to 35 which are schematic partial end views of a support and the like.

[Step-1500] First, the cathode electrode 11 is formed on the support 10. The cathode electrode 11 is formed, for example, by a DC sputtering method using a TiN layer (having a thickness of 0.1 nm).
1 μm), a Ti layer (5 nm in thickness), an Al—Cu layer (0.4 μm in thickness), a Ti layer (5 nm in thickness), a TiN layer (0.02 μm in thickness), and a Ti layer (0.02 μm). The stacked films can be formed by sequentially stacking to form a stacked film and subsequently patterning the stacked film. In the drawing, the cathode electrode 11 is represented by a single layer. Next, an insulating layer 12 having a thickness of 0.7 μm is formed on the support 10 and the cathode electrode 11 by TEO.
It is formed based on a plasma CVD method using S (tetraethoxysilane) as a source gas. Next, a gate electrode 13 and a focus electrode are formed on the insulating layer 12.

Further, an etching stopper layer 93 made of, for example, SiO ₂ and having a thickness of 0.2 μm is formed on the entire surface. The etching stop layer 93 is not an indispensable member for the function of the field emission device, and serves to protect the gate electrode 13 when the conductive material layer 91 is etched in a later step. still,
The gate electrode 1 for the etching conditions of the conductive material layer 91
If 3 can have a sufficiently high etching resistance, the etching stop layer 93 may be omitted. Then, R
Etching stop layer 93, gate electrode 1 by IE method
3. An opening 114 penetrating the insulating layer 12 and exposing the cathode electrode 11 at the bottom is formed based on the same method as in [Step-110]. Thus, the state shown in FIG. 33A is obtained.

[Step-1510] Next, an adhesion layer 90 made of, for example, tungsten having a thickness of 0.03 μm is formed on the entire surface including the inside of the opening 114. Next, the opening 114
A conductive material layer 91 for forming an electron emission portion is formed on the entire surface including the inside (see FIG. 33B). However, Embodiment 15
The thickness of the conductive material layer 91 is selected so that a concave portion 91A deeper than the concave portion 91A described in the manufacturing method of the fourteenth embodiment is formed on the surface. That is, by appropriately setting the thickness of the conductive material layer 91, the columnar portion 91 </ b> B and the enlarged portion communicating with the upper end of the columnar portion 91 </ b> B, reflecting the step between the upper end surface and the bottom surface of the opening 114. A substantially funnel-shaped recess 91 </ b> A made of the conductive material 91 </ b> C can be formed on the surface of the conductive material layer 91.

[Step-1520] Next, the conductive material layer 91
Over the entire surface, for example, by electroless plating, a thickness of about 0.5
A mask material layer 92 made of μm copper (Cu) is formed (see FIG. 34A). The electroless plating conditions are illustrated in Table 3 below.

[0214] [Table 3] Plating liquid: copper sulfate _{(CuSO 4 · 5H 2 O)} 7g / liter Formalin (37% HCHO) 20ml / l sodium hydroxide (NaOH) 10 g / l sodium potassium tartrate 20 g / l plating bath temperature ： 50 ℃

[Step-1530] Thereafter, the mask material layer 92 and the conductive material layer 91 are removed in a plane parallel to the surface of the support 10 so that the mask material layer 92 is left on the columnar portion 91B ( FIG. 34 (B)). This removal can be performed by, for example, a chemical mechanical polishing method (CMP method).

[Step-1540] Next, the conductive material layer 91
The conductive material layer 91, the mask material layer 92, and the adhesion layer 90 are etched under anisotropic etching conditions in which the etching rate of the adhesion layer 90 is higher than the etching rate of the mask material layer 92. As a result, an electron-emitting portion 15E having a conical shape is formed in the opening 114 (see FIG. 35A). If the mask material layer 92 remains at the tip of the electron emitting portion 15E, the mask material layer 92 can be removed by wet etching using a dilute hydrofluoric acid aqueous solution.

[Step-1550] Next, when the side wall surface of the opening 14B provided in the insulating layer 12 inside the opening 14B is receded under isotropic etching conditions, FIG.
(B) is completed. The isotropic etching may be the same as that described in the manufacturing method of the fourteenth embodiment.

Incidentally, in the electron emitting portion 15E formed by the manufacturing method of the fifteenth embodiment, the fourteenth embodiment
A sharper conical shape is achieved as compared with the electron-emitting portion 15E formed by the manufacturing method of (1). This is due to the difference between the shape of the mask material layer 92 and the ratio of the etching rate of the conductive material layer 91 to the etching rate of the mask material layer 92. This difference will be described with reference to FIG. FIG. 36 is a diagram showing how the surface profile of the object to be etched changes at regular intervals, and FIG.
6A shows a case where a mask material layer 92 made of copper is used, and FIG. 36B shows a case where a mask material layer 92 made of a resist material is used. For simplicity, it is assumed that the etching rate of the conductive material layer 91 is equal to the etching rate of the adhesion layer 90, and the illustration of the adhesion layer 90 is omitted in FIG.

When the mask material layer 92 made of copper is used (see FIG. 36A), the etching rate of the mask material layer 92 is sufficiently lower than the etching rate of the conductive material layer 91. The mask material layer 92 does not disappear inside, and therefore, the electron emitting portion 1 having a sharp tip portion
5E can be formed. On the other hand, when the mask material layer 92 made of a resist material is used (see FIG. 36B), the etching rate of the mask material layer 92 is not so slow as compared with the etching rate of the conductive material layer 91. In addition, the mask material layer 92 tends to disappear during the etching, so that the conical shape of the electron emission portion 15E after the mask material layer has disappeared tends to be blunt.

[0220] The mask material layer 9 remaining in the columnar portion 91B is formed.
2 has an advantage that the shape of the electron-emitting portion 15E is hard to change even if the depth of the columnar portion 91B slightly changes.
That is, the depth of the columnar portion 91B can change due to the thickness of the conductive material layer 91 and variations in step coverage.
Since the width of the columnar portion 91B is substantially constant irrespective of the depth, the width of the mask material layer 92 is also substantially constant, and there is no great difference in the shape of the finally formed electron emitting portion 15E. On the other hand, in the mask material layer 92 remaining in the concave portion 91A, the width of the mask material layer also changes depending on whether the concave portion 91A is shallow or deep, so that the concave portion 91A is shallow and the thickness of the mask material layer 92 is small. The thinner the thinner, the earlier the blunting of the conical shape of the electron emitting portion 15E starts. The electron emission efficiency of the field emission device is determined by the potential difference between the gate electrode and the cathode electrode, the distance between the gate electrode and the cathode electrode, the work function of the constituent materials of the electron emission portion, and the tip of the electron emission portion. It also changes depending on the shape. Therefore, it is preferable to select the shape of the mask material layer and the etching rate as described above as necessary.

(Embodiment 16) The method of manufacturing a Spindt-type field emission device of the embodiment 16 is a modification of the method of manufacturing a Spindt-type field emission device of the embodiment 15. In the method for manufacturing a Spindt-type field emission device according to the sixteenth embodiment, in the step (e), the column is communicated with the upper end of the column, reflecting the step between the upper end surface and the bottom surface of the opening. A substantially funnel-shaped concave portion including an enlarged portion is formed on the surface of the conductive material layer, and in step (f), a mask material layer is formed on the entire surface of the conductive material layer, and then the mask material on the conductive material layer and in the enlarged portion is formed. By removing the layer, a mask material layer is left on the columnar portion. Hereinafter, a method for manufacturing a Spindt-type field emission device according to Embodiment 16 will be described with reference to FIGS. 37 and 38 which are schematic partial end views of a support and the like.

[Step-1600] First, FIG.
Embodiment 15 up to the formation of the mask material layer 92 shown in FIG.
After performing [Step-1500] to [Step-1520], only the mask material layer 92 on the conductive material layer 91 and in the enlarged portion 91C is removed, so that the mask material layer 92 is formed on the columnar portion 91B. Leave (see FIG. 37A). At this time, for example, by performing wet etching using a diluted hydrofluoric acid aqueous solution, the conductive material layer 9 made of tungsten is formed.
1 can be selectively removed without removing the mask material layer 92 made of copper. Although the height of the mask material layer 92 remaining in the columnar portion 91B depends on the etching time, this etching time is not so long as the portion of the mask material layer 92 buried in the enlarged portion 91C is sufficiently removed. Does not require strictness. This is because the discussion regarding the height of the mask material layer 92 is substantially the same as the discussion regarding the shallow depth of the columnar portion 91B described above with reference to FIG. This is because the shape of the formed electron-emitting portion 15E is not significantly affected.

[Step-1610] Next, the conductive material layer 91
The etching of the mask material layer 92 and the adhesion layer 90 is performed in the same manner as in the method of manufacturing the Spindt-type field emission device of the fifteenth embodiment, and the electron emission portion 15E as shown in FIG.
To form This electron emitting portion 15E is provided as shown in FIG.
Of course, the whole may have a conical shape as shown in FIG. 37. However, FIG. 37B shows a modification in which only the tip portion has a conical shape. Such a shape can occur when the height of the mask material layer 92 embedded in the columnar portion 91B is low or the etching rate of the mask material layer 92 is relatively high. No problem.

[Step-1620] After that, when the side wall surface of the opening 14B provided in the insulating layer 12 inside the opening 14B is receded under isotropic etching conditions, FIG.
8 is completed. The isotropic etching may be the same as that described in [Step-140].

(Embodiment 17) The manufacturing method of the Spindt-type field emission device of the embodiment 17 is a modification of the method of manufacturing the Spindt-type field emission device of the embodiment 14. FIG. 39 is a schematic partial end view of the Spindt-type field emission device according to the seventeenth embodiment. The manufacturing method of the Spindt-type field emission device of the seventeenth embodiment is different from the manufacturing method of the Spindt-type field emission device of the fourteenth embodiment in that
It is characterized by comprising a base 94 and a conical electron emitting portion 15E stacked on the base 94. Here, the base 9
4 and the electron-emitting portion 15E are made of different conductive materials. Specifically, the base 94 is a member for adjusting the distance between the electron emitting portion 15E and the end of the hole 14A of the gate electrode 13, and has a function as a resistor layer. It is composed of a polysilicon layer containing impurities. The electron emission portion 15E is made of tungsten, and has a conical shape, more specifically, a conical shape.
Note that an adhesion layer 90 made of TiN is formed between the base 94 and the electron-emitting portion 15E. In addition, the adhesion layer 90
Are not essential components for the function of the electron-emitting portion, but are formed for manufacturing reasons. The opening 114 is formed by digging the insulating layer 12 from immediately below the gate electrode 13 to the upper end of the base 94.

Hereinafter, a method for manufacturing the Spindt-type field emission device of the seventeenth embodiment will be described with reference to FIGS. 40 to 42 which are schematic partial end views of a support and the like.

[Step-1700] First, the steps up to the formation of the opening 114 are performed in the same manner as in [Step-1400] of the fourteenth embodiment. Subsequently, a conductive material layer 94A for forming a base is formed on the entire surface including the inside of the opening 114. Conductive material layer 94A
Functions also as a resistor layer, is composed of a polysilicon layer, and can be formed by a plasma CVD method.
Next, a flattening layer 95 made of a resist material is formed on the entire surface by spin coating so that the surface is substantially flat (see FIG. 40A). Next, both layers are etched under the condition that the etching rates of the planarization layer 95 and the conductive material layer 94A are substantially equal to each other, and the bottom of the opening 114 is filled with the base 94 having a flat upper surface (see FIG. 40B). ). Etching can be performed by an RIE method using an etching gas containing a chlorine-based gas and an oxygen-based gas. Since the etching is performed after the surface of the conductive material layer 94A is once flattened by the flattening layer 95, the upper surface of the base 94 becomes flat.

[Step-1710] Next, the adhesion layer 90 is formed on the entire surface including the remaining portion of the opening 114, and the opening 1
A conductive material layer 91 for forming an electron-emitting portion is formed on the entire surface including the remaining portion 14 and the remaining portion of the opening 114 is filled with the conductive material layer 91 (see FIG. 41A). The adhesion layer 90 is made of Ti having a thickness of 0.07 μm formed by a sputtering method.
The conductive material layer 91 is an N layer, and is a 0.6 μm thick tungsten layer formed by a low pressure CVD method. On the surface of the conductive material layer 91, a recess 91A is formed reflecting the step between the upper end surface and the bottom surface of the opening 114.

[Step-1720] Next, the conductive material layer 91
A mask material layer 92 made of a resist material is formed on the entire surface by spin coating so that the surface is substantially flat (see FIG. 41B). The mask material layer 92 has a flat surface by absorbing the concave portions 91A on the surface of the conductive material layer 91. Next, the mask material layer 92 is etched by an RIE method using an oxygen-based gas (see FIG. 42A). This etching ends when the flat surface of the conductive material layer 91 is exposed. As a result, the mask material layer 92 is left flat in the concave portions 91A of the conductive material layer 91, and the mask material layer 92 is formed so as to shield the region of the conductive material layer 91 located at the center of the opening 114. I have.

[Step-1730] Next, Embodiment 14
In the same manner as in [Step-1440], the conductive material layer 91,
When both the mask material layer 92 and the adhesion layer 90 are etched, the electron emission portion 15E and the adhesion layer 90 having a conical shape corresponding to the magnitude of the resist selectivity are formed based on the mechanism described above, and the electron emission portion is completed. ((B) of FIG. 42)
reference). After that, the insulating layer 1 is formed inside the opening 14B.
When the side wall surface of the opening 14B provided in 2 is retracted,
The field emission device shown in FIG. 39 can be obtained.

(Embodiment 18) The manufacturing method of the Spindt-type field emission device of the embodiment 18 is a modification of the method of manufacturing the Spindt-type field emission device of the embodiment 15. FIG. 44B is a schematic partial end view of the Spindt-type field emission device of the eighteenth embodiment. The difference between the Spindt-type field emission device of the eighteenth embodiment and the Spindt-type field emission device of the fifteenth embodiment is that the electron-emitting portion has a base 94 and a base portion similar to the Spindt-type field emission device of the seventeenth embodiment. 94
And a conical electron emitting portion 15E stacked on the upper portion. Here, the base 94 and the electron emitting portion 15E
And different conductive materials. In particular,
The base 94 is a member for adjusting the distance between the electron-emitting portion 15E and the end of the hole 14A of the gate electrode 13, and has a function as a resistor layer, and is made of poly-containing impurity. It is composed of a silicon layer. Electron emission unit 1
5E is made of tungsten and has a conical shape, more specifically, a conical shape. Note that an adhesion layer 90 made of TiN is formed between the base 94 and the electron-emitting portion 15E. Note that the adhesion layer 90 is not an essential component for the function of the electron-emitting portion, but is formed for manufacturing reasons. The insulating layer 12 is formed just below the gate electrode 13 from the base 94.
The opening 114
Are formed.

Hereinafter, a method of manufacturing the Spindt-type field emission device according to the eighteenth embodiment will be described with reference to FIGS. 43 and 44 which are schematic partial end views of a support and the like.

[Step-1800] First, the steps up to the formation of the opening 114 are performed in the same manner as in [Step-1400] of the fourteenth embodiment. Next, a conductive material layer for forming a base is formed on the entire surface including the inside of the opening 114, and the conductive material layer is etched, so that the base 94 filling the bottom of the opening 114 is formed.
Can be formed. Although the illustrated base 94 has a flattened surface, the surface may be concave. The base 94 having a flattened surface can be formed by the same process as [Step-1700] in the seventeenth embodiment. Further, the adhesive layer 90 and the conductive material layer 9 for forming an electron emission portion are formed on the entire surface including the remaining portion of the opening 114.
1 are sequentially formed. At this time, a substantially funnel-shaped concave portion 91A composed of a columnar portion 91B reflecting a step between the upper end surface and the bottom surface of the remaining portion of the opening 114 and an enlarged portion 91C communicating with the upper end of the columnar portion 91B is formed of a conductive material layer. The thickness of the conductive material layer 91 is selected so as to be generated on the surface of the conductive material layer 91. next,
A mask material layer 92 is formed over the conductive material layer 91. This mask material layer 92 is formed using, for example, copper. FIG.
3 (A) shows a state in which the process up to this point has been completed.

[Step-1810] Next, the mask material layer 9
2 and the conductive material layer 91 are removed in a plane parallel to the surface of the support 10 to leave the mask material layer 92 on the columnar portion 91B (see FIG. 43B). This removal
Similarly to [Step-1530], the chemical mechanical polishing method (C
MP method).

[Step-1820] Next, the conductive material layer 91
When the mask material layer 92 and the adhesion layer 90 are etched, the electron emission portion 15E having a conical shape corresponding to the magnitude of the resist selectivity is formed based on the mechanism described above.
The etching of these layers is performed according to the [Step-
1540]. Electron emission unit 15
An electron emission portion is formed by E and the base 94, and the adhesion layer 90 remaining between the electron emission portion 15E and the base 94. Of course, the electron emitting portion may have a conical shape as a whole. However, FIG. . This shape is such that the height of the mask material layer 92 buried in the columnar portion 91B is low or the height of the mask material layer 9 is small.
2, which may occur when the etching rate is relatively high, but does not hinder the function as the electron emitting portion.

[Step-1830] Thereafter, the side wall surface of the insulating layer 12 is retreated inside the opening 14B under isotropic etching conditions, whereby the field emission device shown in FIG. 44B is completed. . The isotropic etching conditions may be the same as those described in the manufacturing method of the fourteenth embodiment.

(Embodiment 19) The method for manufacturing a Spindt-type field emission device according to the nineteenth embodiment is a modification of the method for manufacturing a Spindt-type field emission device according to the sixteenth embodiment. The difference between the Spindt-type field emission device of the nineteenth embodiment and the Spindt-type field emission device of the sixteenth embodiment is that
Similarly to the Spindt-type field emission device of the seventeenth embodiment, the base 94 and the conical electron emission portion 1 stacked on the base 94
5E. Hereinafter, a method of manufacturing the Spindt-type field emission device according to the nineteenth embodiment will be described with reference to FIG. 45 which is a schematic partial end view of a support and the like.

[Step-1900] The steps up to the formation of the mask material layer 92 are performed in the same manner as in [Step-1800] of the eighteenth embodiment. Thereafter, only the mask material layer 92 on the conductive material layer 91 and in the enlarged portion 91C is removed, so that the columnar portion 91 is removed.
The mask material layer 92 is left in B (see FIG. 45). For example, wet etching using a dilute hydrofluoric acid aqueous solution is performed without removing the conductive material layer 91 made of tungsten.
Only the mask material layer 92 made of copper can be selectively removed. After this, the conductive material layer 91 and the mask material layer 9
2 and the process of isotropically etching the insulating layer 12, etc., can all be performed in the same manner as in the manufacturing method of the Spindt-type field emission device of the eighteenth embodiment.

As described above, the present invention has been described based on the embodiments of the present invention, but the present invention is not limited to these. The structures, configurations, and manufacturing methods of the anode panel, the cathode panel, and the display device described in the embodiment of the invention are merely examples, and can be appropriately changed.

Further, various materials used in the manufacture of the field emission device are also examples, and can be changed as appropriate. In the field emission device, one electron emission portion corresponds to one hole portion provided in the gate electrode. However, depending on the structure of the field emission device, a plurality of holes are provided in one hole portion. It is also possible to adopt a form in which the electron emitting portions correspond, or a form in which one electron emitting portion corresponds to a plurality of holes.

The planar shape of the gate electrode and the focus electrode is not limited to the stripe shape. For example, the width of the gate electrode in the overlap region where the projected images of the cathode electrode and the gate electrode overlap, and the width of the focus electrode in the vicinity of the overlap region may be increased.

The gate electrode and the focus electrode in the field emission device and the display device according to the first embodiment of the present invention are formed of a band-shaped or sheet-shaped metal foil having a hole, and the gate electrode is formed on a support. The support portion and the focus electrode support portion are formed, and the metal foil is in contact with the top surface of the gate electrode support portion and the focus electrode support portion, and the hole provided in the gate electrode is positioned above the electron emission portion. In this case, a metal foil may be stretched.
In this case, one electron emitting portion may be formed below the plurality of holes formed in the metal foil, or one electron emitting portion may be formed below the one hole formed in the metal foil. May be formed. Note that various electron-emitting portions in the field emission device having the first to third configurations can be applied as the electron-emitting portion.

The electron emission region can be constituted by a field emission element commonly called a surface conduction type field emission element. This surface conduction type field emission device is, for example, tin oxide (SnO ₂ ), gold (Au), indium oxide (In ₂ O ₃ ) / tin oxide (SnO ₂ ), carbon, palladium oxide (SnO ₂ ) on a support made of glass. A pair of electrodes formed of a conductive material such as PdO), having a small area, and arranged at a predetermined interval (gap) are formed in a matrix. A carbon thin film is formed on each electrode. Then, a row-direction wiring is connected to one electrode of the pair of electrodes, and a column-direction wiring is connected to the other electrode of the pair of electrodes. When a voltage is applied to the pair of electrodes, an electric field is applied to the carbon thin films facing each other across the gap, and electrons are emitted from the carbon thin films. By causing such electrons to collide with the phosphor layer on the anode panel,
The phosphor layer is excited to emit light, and a desired image can be obtained.

[0244]

According to the present invention, the structure of the field emission device can be simplified, the electrons emitted from the plurality of field emission devices can be converged, and so-called optical crosstalk occurs. As a result, the luminance efficiency per power consumption of the display device can be increased. Furthermore, in the field emission device or the display device according to the first aspect of the present invention, for example, since the gate electrode and the focus electrode can be formed at the same time, the manufacturing process of the field emission device or the display device is reduced. Does not increase. On the other hand, in the field emission device or the display device according to the second aspect of the present invention, for example, an insulating film for preventing short circuit may be formed between the gate electrode and the focus electrode. The manufacturing process of the device does not increase significantly.

Further, since there is no need to form a focus electrode above the gate electrode, abnormal discharge does not occur between the anode electrode and the focus electrode. Moreover,
Unlike a conventional field emission device, since a thick insulating film does not exist near the trajectory of electrons emitted from the hole provided in the gate electrode, electrons do not collide with the insulating film and the insulating film is not charged. As a result, the electron trajectory is not distorted, abnormal discharge does not occur, and damage to the insulating film due to collision of electrons does not occur.

Furthermore, since the area of the portion of the cathode panel exposed to the space is smaller than that of the conventional cold cathode field emission display, the amount of gas adsorbed on the portion of the cathode panel is reduced. I can do it. As a result, the amount of gas adsorbed on the electron-emitting portion is reduced, the deterioration of the field-emitting device can be suppressed, the life of the field-emitting device can be extended, and the threshold value at which the field-emitting device emits electrons can be obtained. Voltage can be reduced, and power consumption of the display device can be reduced. In addition, the electron emission characteristics from the field emission device are made uniform. Further, the withstand voltage between the cathode electrode or the gate electrode and the anode electrode is improved, so that the voltage applied to the anode electrode can be increased. As a result, it is possible to suppress the luminance degradation of the phosphor layer, achieve high luminance, and reduce gas emission from the phosphor layer due to accelerated electron collision, thereby extending the life of the display device. Can be planned.

As a result, a cold cathode field emission display having high reliability, long life, and low power consumption can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic partial exploded perspective view of a cold cathode field emission display according to a first embodiment of the present invention.

FIG. 2 is a schematic partial end view of the cold cathode field emission display according to the first embodiment of the invention;

FIG. 3 is a schematic partial end view of the cold cathode field emission device according to the first embodiment of the invention;

[4] 50 volts V _G, the V _F 0 V, the L _GF 2
When the width of the gate electrode was set to 100 μm and the width of the focus electrode was set to 110 μm, the equipotential surface and the electron were obtained. 5 is a graph showing the locus of the trajectory.

FIG. 5 is a schematic partial end view of a support and the like for explaining a method for manufacturing a Spindt-type cold cathode field emission device.

FIG. 6 is a schematic partial end view of a support and the like for explaining a method of manufacturing the Spindt-type cold cathode field emission device following FIG. 5;

FIG. 7 is a schematic partial perspective view of a cathode panel in a cold cathode field emission display according to Embodiment 2 of the present invention.

FIG. 8 is a schematic partial perspective view of a cathode panel in a modification of the cold cathode field emission display according to the second embodiment of the invention;

FIG. 9 is a schematic partial perspective view of a cathode panel in a cold cathode field emission display according to Embodiment 3 of the present invention.

FIG. 10 is a schematic partial end view of a support and the like for describing a method of manufacturing a crown-type cold cathode field emission device according to Embodiment 4 of the present invention.

FIG. 11 is a schematic partial end view of a support and the like for explaining a method of manufacturing the crown-type cold cathode field emission device according to the fourth embodiment of the invention, following FIG. 10;

FIG. 12 is a schematic partial cross-sectional view of a support and the like for describing a method of manufacturing a flat cold cathode field emission device according to Embodiment 5 of the present invention.

FIG. 13 is a schematic partial cross-sectional view of a support and the like for describing a method of manufacturing a flat cold cathode field emission device according to Embodiment 6 of the present invention.

FIG. 14 is a schematic partial end view of a support and the like for describing a method of manufacturing a flat cold cathode field emission device according to Embodiment 7 of the present invention.

FIG. 15 is a schematic partial end view of a support and the like for explaining the method of manufacturing the flat cold cathode field emission device of the seventh embodiment, following FIG. 15;

FIG. 16 is a schematic partial cross-sectional view of a support and the like for describing a method of manufacturing a flat-type cold cathode field emission device according to Embodiment 8 of the present invention.

FIG. 17 is a schematic partial cross-sectional view of a flat-type cold cathode field emission device according to Embodiment 9 of the present invention.

FIG. 18 is a schematic partial cross-sectional view of a modification of the flat-type cold cathode field emission device according to the ninth embodiment of the invention.

FIG. 19 is a schematic partial end view and a partial perspective view of a support and the like for describing a method for manufacturing a crater-type cold cathode field emission device according to Embodiment 10 of the present invention.

20 is a schematic partial end view of a support and the like for explaining a method of manufacturing the crater-type cold cathode field emission device according to Embodiment 10 of the present invention, following FIG. 19;
It is a partial perspective view.

FIG. 21 is a schematic partial end view of a support and the like for explaining a method of manufacturing the crater-type cold cathode field emission device according to Embodiment 10 of the present invention, following FIG. 20,
It is a partial perspective view.

FIG. 22 is a schematic partial cross-sectional view of a support and the like for explaining the method for manufacturing the crater-type cold cathode field emission device according to Embodiment 10 of the present invention, following FIG. 21;

FIG. 23 is a schematic partial cross-sectional view of a support and the like for describing a method for manufacturing a crater-type cold cathode field emission device according to Embodiment 11 of the present invention.

FIG. 24 is a schematic partial cross-sectional view of a support and the like for describing a method for manufacturing a crater-type cold cathode field emission device according to Embodiment 12 of the present invention.

FIG. 25 is a schematic partial sectional view of an edge-type cold cathode field emission device.

FIG. 26 is a schematic partial end view of a support and the like for explaining a method of manufacturing an edge-type cold cathode field emission device.

FIG. 27 is a schematic partial end view of a support and the like for describing a method for manufacturing a Spindt-type cold cathode field emission device according to Embodiment 14 of the present invention;

FIG. 28 is a schematic partial end view of a support and the like for explaining the method for manufacturing the Spindt-type cold cathode field emission device of the fourteenth embodiment of the invention, following FIG. 27;

FIG. 29 is a schematic partial end view of the support and the like for explaining the method for manufacturing the Spindt-type cold cathode field emission device according to the fourteenth embodiment of the invention, following FIG. 28;

FIG. 30 is a schematic partial end view of the support and the like for explaining the method for manufacturing the Spindt-type cold cathode field emission device according to the fourteenth embodiment of the invention, following FIG. 29;

FIG. 31 is a view for explaining a mechanism for forming a conical electron emitting portion.

FIG. 32 is a diagram schematically showing a relationship between a resist selectivity and the height and shape of an electron-emitting portion.

FIG. 33 is a schematic partial end view of a support and the like for describing a method for manufacturing a Spindt-type cold cathode field emission device according to Embodiment 15 of the present invention;

FIG. 34 is a schematic partial end view of a support and the like for illustrating a method for manufacturing a Spindt-type cold cathode field emission device according to Embodiment 15 of the present invention, following FIG. 33;

FIG. 35 is a schematic partial end view of the support and the like for illustrating the method for manufacturing the Spindt-type cold cathode field emission device according to the fifteenth embodiment of the present invention, following FIG. 34;

FIG. 36 is a diagram showing how the surface profile of an object to be etched changes at regular intervals.

FIG. 37 is a schematic partial end view of a support and the like for describing a method of manufacturing a Spindt-type cold cathode field emission device according to Embodiment 16 of the present invention.

FIG. 38 is a schematic partial end view of a support and the like for describing a Spindt-type cold cathode field emission device according to Embodiment 16 of the invention, following FIG. 37;

FIG. 39 is a schematic partial end view of a Spindt-type cold cathode field emission device obtained by the method for manufacturing a Spindt-type cold cathode field emission device according to Embodiment 17 of the present invention;

FIG. 40 is a schematic partial end view of a support and the like for describing a method for manufacturing a Spindt-type cold cathode field emission device according to Embodiment 17 of the present invention;

FIG. 41 is a schematic partial end view of the support and the like for explaining the method for manufacturing the Spindt-type cold cathode field emission device of the seventeenth embodiment of the invention, following FIG. 40;

FIG. 42 is a schematic partial end view of the support and the like for explaining the method for manufacturing the Spindt-type cold cathode field emission device according to the seventeenth embodiment of the invention, following FIG. 41;

FIG. 43 is a schematic partial end view of a support and the like for describing a method of manufacturing a Spindt-type cold cathode field emission device according to Embodiment 18 of the present invention;

FIG. 44 is a schematic partial end view of a support and the like for explaining the method for manufacturing the Spindt-type cold cathode field emission device according to the eighteenth embodiment of the invention, following FIG. 43;

FIG. 45 is a schematic partial end view of a support and the like for describing a method for manufacturing a Spindt-type cold cathode field emission device according to Embodiment 19 of the present invention;

FIG. 46 is a schematic partial cross-sectional view of a substrate and the like for describing a method for manufacturing an anode panel in the cold cathode field emission display according to the first embodiment of the present invention;

FIG. 47 is a schematic partial end view of a conventional cold cathode field emission display.

FIG. 48 is a view schematically showing a state in which electrons are emitted from an electron emission portion constituting a conventional cold cathode field emission device at a certain divergence angle.

[Explanation of symbols]

CP: cathode panel, AP: anode panel, 10: support, 11, 111, 211 ... cathode electrode, 111A ... ridge, 111B ... recess, 111C ... tip Part, 11A ... minute uneven part,
11B: coating layer, 12, 12A, 12B: insulating layer, 13, 13A, 13B: gate electrode, 14A
..Hole portions, 14B, 114 ... opening portions, 15, 15
A, 15B, 15C, 15D, 15E: electron emission portion, 16: resist layer, 17: release layer, 18
..Conductive material layer, 20 substrate, 21 black matrix, 22R, 22G, 22B phosphor layer, 23 anode electrode, 24 cathode electrode drive circuit, 25 ... Gate electrode drive circuits 26
..Acceleration power supply, 27 ... focus electrode drive circuit, 3
0, 35 ... Focus electrode, 31, 33, 34 ...
.Insulating film, 32... Second focus electrode, 40.
・ Photosensitive film, 41: photosensitive area, 42: remainder of photosensitive film (photosensitive film after exposure and development), 43 ...
Mask, 44 ... opening, 51 ... release layer, 52 ...
-Conductive composition layer, 60 ... resistor layer, 70 ... carbon thin film selective growth area, 71 ... mask layer, 72 ...
Metal particles, 73: carbon thin film, 80, 180: sphere, 81: composition layer, 81A: dispersion medium, 81B
... cathode electrode material, 180A ... core material, 180
B: surface treatment layer, 90: adhesion layer, 91: conductive material layer, 91A: concave portion, 91B: columnar portion, 9
1C: enlarged portion, 92: mask material layer, 93 ...
Etching stop layer, 94: base, 94A: conductive material layer, 95: flattening layer

Claims (18)

[Claims] 1. A support, (B) a cathode electrode formed on the support and extending in a first direction, and (C) a cathode electrode disposed above the cathode electrode, wherein the first direction is A gate electrode extending in a different second direction; (D) a hole provided in a region of the gate electrode overlapping the cathode electrode; (E) an electron emission portion provided at a bottom of the hole; A) a cold cathode field emission device comprising a focus electrode, wherein the focus electrode extends in the second direction and is disposed between the gate electrodes. Cold cathode field emission device. 2. The cold cathode field emission device according to claim 1, wherein the focus electrode and the gate electrode are substantially on the same plane. (A) an insulating layer is formed on the support and the cathode electrode; (b) a gate electrode and a focus electrode are formed on the insulating layer; and (c) the insulating layer has 3. The cold cathode field emission device according to claim 2, wherein an opening communicating with the hole provided in the gate electrode is provided, and (d) the electron emission portion is located at the bottom of the opening. 4. The cold cathode field emission device according to claim 3, wherein the electron-emitting portion is provided on a portion of the cathode electrode located at the bottom of the opening. 5. The cold cathode field emission device according to claim 3, wherein a portion of the cathode electrode located at the bottom of the opening corresponds to an electron emission portion. 6. The cold cathode field emission device according to claim 3, wherein an edge portion of the opening provided at a portion of the cathode electrode located at the bottom of the opening corresponds to an electron emission portion. 7. The cold cathode field emission device according to claim 3, wherein the planar shape of the gate electrode and the focus electrode is a stripe shape. 8. The insulating layer is made of a SiO ₂ material, the distance between the gate electrode and the focus electrode is L _GL (unit: m), and the voltage applied to the gate electrode is V _G (unit:
Volts), voltage V _F (unit applied to the focus electrode: when the bolt), a cold cathode field emission device according to claim 7, characterized by satisfying the equation (1) below. [Number _{1] (V G -V F)} / L GF <7 × 10 7 (V / m) (1) 9. A semiconductor device further comprising a second focus electrode, wherein the second focus electrode extends in a first direction, and
2. The cold cathode field emission device according to claim 1, wherein the cold cathode field emission device is provided above a region between the cathode electrodes. (A) a support; (B) a cathode electrode formed on the support and extending in a first direction; and (C) a cathode electrode provided above the cathode electrode, wherein the first direction is A gate electrode extending in a different second direction; (D) a hole provided in a region of the gate electrode overlapping the cathode electrode; (E) an electron emission portion provided at a bottom of the hole; A) a cold cathode field emission device comprising a focus electrode, wherein the focus electrode extends in a first direction and is disposed above a region between the cathode electrodes. A cold cathode field emission device characterized by the following. 11. The cold cathode field emission device according to claim 10, wherein the focus electrode and the gate electrode are substantially on the same plane. 12. (a) On a support and a cathode electrode,
An insulating layer is formed; (b) a gate electrode is formed on the insulating layer; (c) a focus electrode is formed on the insulating layer via an insulating film; The cold cathode field emission device according to claim 11, wherein an opening communicating with the hole provided in the gate electrode is provided, and (e) the electron emission portion is located at the bottom of the opening. 13. The cold cathode field emission device according to claim 12, wherein the electron emission portion is provided on a portion of the cathode electrode located at the bottom of the opening. 14. A device according to claim 1, wherein a portion of the cathode electrode located at the bottom of the opening corresponds to an electron emitting portion.
3. The cold cathode field emission device according to item 2. 15. The cold cathode field emission device according to claim 12, wherein an edge of the opening provided at a portion of the cathode electrode located at the bottom of the opening corresponds to an electron emission portion. 16. The cold cathode field emission device according to claim 10, wherein a planar shape of the cathode electrode, the gate electrode, and the focus electrode is a stripe shape. 17. A cathode panel on which a cold cathode field emission device is formed and an anode panel on which an anode electrode and a phosphor layer are formed such that the phosphor layer and the cold cathode field emission device face each other. A cathode panel and an anode are joined at a peripheral portion, and a cold cathode field emission device is formed on the support; and (B) a cathode electrode formed on the support and extending in a first direction. (C) a gate electrode provided above the cathode electrode and extending in a second direction different from the first direction; and (D) a hole provided in a region of the gate electrode overlapping the cathode electrode. (E) a cold cathode field emission display comprising: an electron emission portion disposed at the bottom of the hole; and (F) a focus electrode, wherein the focus electrode extends in a second direction. And gate power A cold cathode field emission display, characterized in that disposed between the gate electrode. 18. A cathode panel on which a cold cathode field emission device is formed and an anode panel on which an anode electrode and a phosphor layer are formed such that the phosphor layer and the cold cathode field emission device face each other. A cathode panel and an anode are joined at a peripheral portion, and a cold cathode field emission device is formed on the support; and (B) a cathode electrode formed on the support and extending in a first direction. (C) a gate electrode provided above the cathode electrode and extending in a second direction different from the first direction; and (D) a hole provided in a region of the gate electrode overlapping the cathode electrode. (E) a cold cathode field emission display comprising: an electron emission portion disposed at the bottom of the hole; and (F) a focus electrode, wherein the focus electrode extends in a first direction. And cathode Cold cathode field emission display, characterized in that disposed above the region between the electrode and the cathode electrode.