JPH0896704A - Particulate emitting device, field emission type device and manufacture of these devices - Google Patents

Abstract

PURPOSE: To homogenize an emission current quantity, so that high accuracy can be attained, by providing a fine hole inserted through a gate electrode and an insulating layer, and providing in this fine hole a thin film consisting of a particulate emitting substance of work function smaller than the material of a cathode electrode. CONSTITUTION: A cathode electrode 13 and a gate electrode 14 are opposed through an insulating layer 15. Many fine holes 20, inserted through the gate electrode 14 and the insulating layer 15, are formed to provide in each fine hole 20 a thin film 16 consisting of a particulate emitting substance of work function smaller than a constitutional material of the cathode electrode 13. When voltage is applied across the cathode electrode line 13 and gate electrode line 14, prescribed voltage is applied to the thin film 16 in each fine hole 20 in a corresponding picture element region, to emit an electron (e) from the thin film 16. Here is formed an equipotential surface Em almost flat in the fine hole 20 along a surface of the thin film 16. The emitted electron (e) is advanced orthogonal to the equipotential surface Em, not so deflecting a track, to arrive at a prescribed phosphor through a vacuum part 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle emission device (for example, an electron emission source suitable for use in an ultra-thin display device), a field emission device (for example, a display device including the electron emission source). And the manufacturing methods thereof.

[0002]

2. Description of the Related Art Conventionally, as an ultra-thin display device, for example, a field emission display (FED) using a field emission cathode as an electron emission source.
y) is known.

In a known FED, an electron emission source is provided inside the screen, a large number of microchips made of an electron emission material are formed in each pixel area, and a microchip of the corresponding pixel area is formed according to a predetermined electric signal. The fluorescent surface of the screen is caused to emit light by exciting.

In the above-mentioned electron emission source, a plurality of strip-shaped cathode electrode lines and a plurality of strip-shaped gate electrode lines intersecting the cathode electrode lines above the cathode electrode lines are formed. And each intersection region of the cathode electrode line with the gate electrode line is formed as one pixel region.

According to the conventional electron emission source,
As shown in FIGS. 11 to 13, a plurality of strip-shaped cathode electrode lines 10 are formed on the surface of the lower substrate 101 made of, for example, a glass material.
3 is formed.

An insulating layer 105 is formed on each of the cathode electrode lines 103 except for each connecting portion 103a, and a plurality of gate electrode lines 104 are formed in a strip shape so as to intersect with each cathode electrode line 103. In addition, a matrix structure is formed with each cathode electrode line 103.

Further, the connecting end portion 103a of each cathode electrode line 103 and the connecting end portion 104 of each gate electrode line 104.
a is connected to the control means 107 and is electrically connected.

Here, in each intersection region 122 of each cathode electrode line 103 with each gate electrode line 104, the insulating layer 105 has a large number of circular fine holes with a hole diameter w communicating from the cathode electrode line 103 to the gate electrode line 104. (Small) hole 12
0 is formed as a cathode hole, and the microchip 106 as a field emission type cathode is provided in each of these holes by several μ.
It is provided in a minute size of m or less.

Each of these microtips 106 is made of an electron emitting material, for example, molybdenum, is formed in a substantially conical shape, and is arranged on each cathode electrode line 103. The tip of the conical body of each microchip 106 is located substantially at the electron passing gate portion 104b formed in the gate electrode line 104.

As described above, a plurality of microchips 106 are provided in each intersection region 122 of each cathode electrode line 103 and each gate electrode line 104 to form a pixel region, and each pixel region is a pixel. It corresponds to (pixel).

In the electron emission source (field emission type cathode) configured as described above, the control means 107 selects a predetermined cathode electrode line 103 and a gate electrode line 104 and applies a predetermined voltage between them. Thus, when this applied voltage is applied to each microchip 106 in the corresponding pixel region, electrons are emitted from the tip of each microchip 106 by the tunnel effect. Note that this predetermined applied voltage value is such that, when each microchip 106 is made of molybdenum, the electric field strength near the tip of the conical body of each microchip 106 is 10 ⁸ to 10 ¹⁰ V / m. belongs to.

At this time, in the display (FED) in which the electron emission source is built in, the electrons emitted from each microchip 106 by exciting a predetermined pixel area are controlled by the control means 107 to the cathode electrode line 103.
The gate electrode line 104 is further accelerated by a voltage applied between the anode and the anode (transparent electrode of the fluorescent panel).
Through the vacuum formed between the anode and the anode to reach the fluorescent surface. Visible light is emitted from the fluorescent surface by this electron beam.

The structure of this display device will now be described with reference to FIG. 11, for example, R (red), G (green), and B.
Each blue (blue) primary color phosphor element is an ITO (Indium Tin O
xide: a transparent electrode composed of a mixed oxide of In and Sn)
A light-transmissive fluorescent panel 114 having a color fluorescent surface 123 arranged in a stripe pattern through 100R, 100G, and 100B, and an electrode assembly 115 having a field emission cathode.
The rear panel 101 on which the (electron emission source) is formed is hermetically sealed with a sealing material or the like, and is maintained at a predetermined vacuum degree.

The fluorescent surface panel 114 and the rear panel 101 are
In order to keep the interval constant, the column (so-called pillar) 110 having a predetermined height is used for sealing.

As a method of performing color display by the FED, a method of associating each cathode of the selected intersection 122 with a phosphor of one color and a method of associating each cathode with a phosphor of a plurality of colors. There is a so-called color selection method. The color selection operation in this case will be described with reference to FIGS. 14 and 15.

In FIG. 14, R, G, and B phosphors corresponding to respective colors are sequentially arranged and formed on a plurality of stripe-shaped transparent electrodes 100 on the inner surface of the fluorescent surface panel 114, and electrodes of respective colors are formed. Are 3R for red, 3G for green, and 3B for blue.
It is derived by being integrated into the terminal of.

[0017] On the opposite back panel 101 is provided in stripes cathode electrode 103 and the gate electrode 104 as described above are orthogonal, 10 ⁸ to the microchip tip
When a voltage is applied between the cathode electrode 103 and the gate electrode 104 so that an electric field of 10 ¹⁰ V / m is applied, the intersection 12 of each electrode 12
Microchip formed on 2 (field emission cathode)
Electrons are emitted from 106.

On the other hand, the transparent electrode 100 (that is, the anode electrode)
A voltage of 100 to 1000 V is applied between the cathode and the cathode electrode 103 to accelerate electrons and cause the phosphor to emit light. In the example of FIG. 14, a voltage is applied only to the red fluorescent substance R to accelerate electrons as indicated by arrow e.

As described above, the colors R, G, and
Color display can be performed by selecting B in time series. NTS of one point cathode, gate and anode (fluorescent stripe) on each cathode electrode row
FIG. 15 shows a color selection timing chart in the C method.

When each cathode electrode 103 is line-sequentially driven at a cycle of 1H, H / 3 signals of + HV are supplied to each of the color phosphors R, G, and B in the cycle H, while
The gate signal and the cathode signal are given as + αV as the gate signal and −αV to −βV as the cathode signal in synchronization with each other in the H / 3 cycle, and the gate-cathode voltage V _PP = + 2
At the time of αV, electrons can be emitted and each of the R, G, and B phosphors selected for each H / 3 can be made to emit light to perform color selection, whereby full-color display can be performed.

However, as a result of the present inventor's examination of the above-mentioned electron emission source, it was found that the following drawbacks existed.

First, as shown in FIG. 16, the cathode electrode 10
When the voltage is applied between the gate electrode 104 and the cathode electrode 103, the microchip 106 arranged in the micropores 120 above 3 is formed in a substantially conical shape over the thickness of the insulating layer 105. The potential surface E _C is formed in the micropore 120 along the conical surface of the microchip 106.

However, since the electrons e emitted from the microchip 106 travel perpendicularly to the equipotential surface E _C , the holes e
The path of the electron e emitted from 120 largely fluctuates, and the deflection angle θ becomes ± 30 degrees. As a result, on the fluorescent surface, the electron beam e is a predetermined fluorescent body (for example, a red fluorescent body).
To reach an undesired fluorescent body (for example, an adjacent green fluorescent body), and mislanding is likely to occur.
In this case, the desired color of light emission cannot be obtained, the performance of the display is impaired, and there is a problem in achieving high definition.

Moreover, in the above electron emission source,
The amount of electrons emitted from each microchip 106 (ie,
The amount of current) varies and tends to be inhomogeneous. Therefore, in such a display device, the bright spots generated on the screen become inhomogeneous, which is very annoying.

In the electron emission source described above, the microchip 106 and the gate electrode line 104 are connected by the metal particles or the like, the cathode electrode line 103 and the gate electrode line 104 are short-circuited, and the microchip 106 is destroyed. It turned out that there are cases where In addition, the ions existing in the high vacuum region 130 between the gate electrode line 104 and the fluorescent surface 114 may sputter the microchip 106 and shorten the life of the display.

Destruction of the microchip 106 due to the above short circuit will be described with reference to the manufacturing process shown in FIGS.
First, as shown in FIG. 17, the lower substrate 101 made of glass or the like is used.
A conductor film having a thickness of about 2000 Å is formed on the upper surface of the material using niobium or the like, and then the conductor film is patterned into a line shape by photolithography and reactive ion etching to form the cathode electrode 103.

Insulating layer 105 (eg, silicon dioxide)
Is deposited on the conductor film by sputtering or chemical vapor deposition, and a gate electrode material (for example,
Niobium) is formed, and then the conductor film is processed into a gate electrode line 104 that intersects with the cathode electrode line 103 by photolithography and reactive ion etching. Then, the gate electrode line 104 and the insulating layer 105 are formed.
A circular fine hole 120 penetrating through is formed by photolithography and reactive ion etching.

After that, as shown in FIG. 18, a peeling layer 124 (for example, aluminum) is formed by vacuum evaporation from an oblique direction with respect to the main surface portion of the electron emission source.

Then, as shown in FIG. 19, molybdenum is deposited in a conical shape on the cathode electrode 103 in the fine holes 120 by a vapor deposition method to form a microchip 106. At this time, molybdenum 106 is deposited on the peeling layer 124, and with the progress of this deposition, the upper part of the hole 120 is gradually closed by the deposited molybdenum, and at the same time, the microchip 106 is deposited in a conical shape.

Next, as shown in FIG. 20, the peeling layer 124 is melted to peel off the molybdenum 106 on the peeling layer 124 and remove (lift off) it to form a structure as shown in FIG.

However, the metal pieces 125 and the like generated at the time of the lift-off and the like are the microchip 106 and the gate electrode line 104.
Between them and short them together. Therefore, when a voltage is applied between the cathode 103 and the gate 104 during operation and the voltage is increased, the temperature of the microchip 106 becomes extremely high and finally reaches an unbearable temperature.

As a result, as shown in FIG. 21, the microchip 106 itself and the gate 104 and the cathode 103 in the region around a radius of several tens of μm around the microchip 106 are also fused as shown by the arrow 126, causing destruction. . This would result in a significant area of inactivity and a reduction in the effective area.

[0033]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned drawbacks of the prior art, improve the emission capability of electrons and the like, and improve the directionality thereof, and enable low voltage driving to emit electrons. Provided are a particle emission device, a field emission device, and a manufacturing method thereof, which are capable of homogenizing the amount of current flowing through the device, have high reliability and long life, and are sufficiently compatible with high-definition, large ultra-thin display devices. To do.

[0034]

That is, according to the present invention, a first electrode (for example, a cathode electrode 13 described later) and a second electrode (for example, a gate electrode 14 described later) have insulating layers (for example,
Are provided so as to face each other via a SiO ₂ layer 15) described later,
A minute hole (for example, a substantially circular or slit-like minute hole or a cathode hole 20 described later) penetrating each of the second electrode and the insulating layer is formed to connect the first electrode and the second electrode. In a particle emission device (for example, a field emission cathode) configured to emit predetermined particles (especially electrons) from the first electrode side through the micropores by applying a voltage between them. A particle emitting device characterized in that a thin film (for example, a diamond thin film 16 described later) made of a particle emitting substance having a work function smaller than that of the constituent material of the first electrode is provided in the minute hole. is there.

In the particle emitting device according to the present invention, the particle emitting substance having a small work function is provided in the thin film in contact with the first electrode in the micropore for emitting energetic particles such as electrons. When a voltage is applied between the electrode and the second electrode, the equipotential surface is formed flat along the thin film. Therefore, the particles traveling orthogonally to the flat equipotential surface travel to the object (for example, the fluorescent body surface) from the micropores with a fairly uniform direction, and thus always reach the target object. You can
Mislanding can be greatly reduced and high definition can be achieved.

Further, since the work function of the particle emitting substance forming the thin film is smaller than that of the constituent material of the first electrode, it is applied between the first electrode and the second electrode for emitting the particles. The voltage can be reduced, and the required emission amount can be stably obtained by driving at a low voltage.

Further, since the portion for emitting particles is the above-mentioned thin film, when the thin film is formed, even if a metal piece is generated due to the lift-off after the above-mentioned vapor deposition, for example, a gap between the thin film and the second electrode is generated. Since they are sufficiently separated from each other, a metal piece does not adhere between them to cause a short circuit. As a result, the electrodes are not blown when the applied voltage is increased, and reliable operation can be performed.

Furthermore, since the portion that emits particles is the thin film, ions do not concentrate at one point unlike the tip of the microchip, and the ions existing in the high vacuum region reach the thin film and sputter it. Since the rate of decrease is drastically reduced, the life of the device can be extended.

Specifically, in the particle emitting device according to the present invention, the cathode electrode line and the gate electrode line which intersect each other (the intersection region becomes the pixel region) are laminated on the substrate through the insulating layer, and the gate is formed. Micro holes are formed to penetrate the electrode lines and the insulating layer, respectively,
It is desirable that a thin film micro cold cathode made of an electron emitting substance having a work function smaller than that of the constituent material of the cathode electrode line is provided in the micro hole to be configured as an electron emitting source.

Further, it is preferable that the thin film made of the above-mentioned particle-releasing substance is provided to have a thickness of ½ or less of that of the insulating layer. For example, if the insulating layer is 1 μm thick, the thin film is 5000
Å It has the following thickness. The thickness of this thin film is preferably set so that the effects of the present invention described above can be effectively exhibited, and can be controlled by the amount of vapor deposition or the like.

The work function of the above-mentioned particle emitting material is the first
It is essential that the work function is smaller than the work function of the electrode constituent material, and it is desirable that the work function is 3.0 eV or less.
More preferably, it is eV or less. This is because the applied voltage between both electrodes (the first electrode and the second electrode) is lowered, and the required amount of current can be obtained even at several tens of V, and the device can be sufficiently operated for a display, for example. Note that examples of the constituent material of the first electrode include Nb (work function 4.02 to 4.87 eV), Mo (work function 4.53 to 4.95 eV), Cr (work function 4.5 eV), and the like.

As such a particle emission material, diamond (particularly amorphous diamond: work function 1.0e
V or less) is preferable. When the thin film is an amorphous diamond thin film, the amount of current required for a display can be obtained with an electric field strength of 5 × 10 ⁷ V / m or less, so that further low voltage driving is possible.

Further, since such an amorphous diamond thin film is an electrical resistor, it is possible to homogenize the amount of current emitted from the thin film in each micropore. Since the amorphous diamond thin film is chemically inert and is difficult to be sputtered by ions, stable emission can be maintained for a long time.

As the particle-releasing substances which can be used other than diamond, LaB ₆ (work function 2.66 to 2.76 eV), B
aO (work function 1.6-2.7 eV), SrO (work function 1.
25 to 1.6 eV), Y ₂ O ₃ (work function 2.0 eV), Ca
O (work function 1.6 to 1.86 eV), BaS (work function 2.05
eV), TiN (work function 2.92 eV), ZrN (work function 2.92 eV) and the like.

Such a particle emission material is molybdenum (work function) which is a constituent material of the microchip 106 described above.
It is characteristic that the work function is considerably smaller than that of 4.6 eV). This work function is preferably 3.0 eV or less, but this can be determined by the correlation with the applied voltage between both electrodes. If the work function is small, the applied voltage can be lowered (for example, If the work function is 2.0 eV or less, the applied voltage can be 100 V or less), or if the work function is large, the applied voltage can be increased.

The present invention also provides a field emission device comprising a particle emission device such as an electron emission source such as a field emission cathode as described above, for example such a particle emission device and particles such as the fluorescent surface panel described above. It also provides a field emission device configured in combination with an incident light emitting device or the like. Also, the emitted particles are usually electrons,
It is not necessarily limited to electrons, but other elementary particles may be targeted.

As such a field emission device, there is provided a first panel comprising a cathode electrode line, a gate electrode line, an insulating layer with micropores and a thin film microcold cathode in the micropores, and a luminous body of a plurality of colors. And a field emission type light emitting device constituted by a second panel including electrodes to which these light emitting bodies are respectively applied. In this case, the field emission display device (FE) in which the light emitter is a phosphor is used.
D).

The particle emission device and the field emission device according to the present invention have a first (first) substrate (for example, a glass substrate 11 described later) on a substrate.
And a step of forming an electrode (for example, a cathode electrode 13 described later) on the region including the first electrode.
A step of forming a SiO ₂ layer 15) described below, a step of forming a second electrode (for example, a gate electrode 14 described below) on the insulating layer, and penetrating the second electrode and the insulating layer, respectively. A step of forming micropores (for example, a substantially circular or slit-shaped microhole or a cathode hole 20 described later), and a step of forming a peeling layer (for example, an aluminum layer 24 described later) on the second electrode, Thereafter, a particle emitting substance (for example, diamond) is deposited in the micropores to form a thin film of the particle emitting substance (for example, a diamond thin film described later).
It is desirable to manufacture it by a method including a step of forming 16) and a step of removing the particle-releasing substance on the release layer together with the release layer (lift-off).

According to this manufacturing method, when the thin film of the particle-releasing substance is formed, the thickness of the thin film (preferably,
Since it is sufficient to deposit only half or less of the thickness of the insulating layer), it is not necessary to form the height and shape with high precision as in the microchip described above. The deposited particle emission material is easily lifted off together with the peeling layer, and even if a metal piece is generated at the time of this liftoff, the metal piece does not come into contact with the cathode-gate and short-circuit because the thin film is thin.

[0050]

Embodiments of the present invention will be described below.

1 to 9 show a first embodiment in which the present invention is applied to an electron emission source (electrode structure including a field emission cathode) and a very thin display device (FED).

The display device according to this embodiment is shown in FIG.
Similar to the one shown in FIG. 1, by combining the electron emission source (the electrode structure 25 including the field emission type cathode) shown in FIG. 1 and the fluorescent panel serving as the anode facing the electron emission source through the vacuum portion. It is configured and performs a display operation as described above.

In the electron emission source, as shown in FIG. 1 (further, FIG. 2 showing the pixel region in plan view) showing a main part in a vertical section, it is formed on the surface of a lower substrate 11 made of, for example, a glass material. A plurality of strip-shaped cathode electrode lines 13 are formed.

An insulating layer 15 is formed on these cathode electrode lines 13 except for each connection end 13a, and a plurality of strip-shaped gates intersecting each cathode electrode line 13 in the region 22 are formed thereon. Electrode lines 14 are formed, and each cathode electrode line 13 constitutes a matrix structure.

Further, the connection end 13a of each cathode electrode line 13 and the connection end 14a of each gate electrode line 14 are connected to a control means (similar to 107 in FIG. 13),
It is electrically conducting.

Here, the insulating layer 15 has a cathode electrode line.
A large number of circular fine (small) holes 20 having a hole diameter w leading from 13 to the gate electrode line 14 are formed as cathode holes, and a thin film 16 as a field emission type cathode is formed in each of these holes.
It has a thickness of 00Å or less (for example, 2000Å).

Each of these thin films 16 is made of an electron emitting material having a work function smaller than that of the cathode electrode line 13, for example, an amorphous diamond thin film, and can be easily formed in the fine holes 16 by a method described later.

The substrate on the side of the fluorescent panel is provided so as to face the main surface of the electron emission source through the vacuum portion at the lower surface which is one main surface. A fluorescent surface is applied to the lower surface of the upper substrate to form strip-shaped fluorescent surfaces parallel to the respective cathode electrode lines 13.

In the electron emission source, a predetermined cathode electrode line 13 and a gate electrode line 14 are selected by the control means, and a predetermined voltage is applied between them, so that each fine pixel in the corresponding pixel region is selected. Thin film 16 in hole 20
When a predetermined electric field is applied to the thin film 16, electrons are emitted from the thin film 16 in each micropore 20 by the tunnel effect.

At this time, in the display device in which the electron emission source is built in, the electrons emitted from the thin film 16 in each fine hole 20 by exciting a predetermined pixel region are connected to the cathode electrode line 13 by the control means. It is further accelerated by the voltage applied between the anode and the upper substrate, and reaches the fluorescent surface through the vacuum portion 30 formed between the gate electrode line 14 and the upper substrate. Visible light is emitted from the fluorescent surface by this electron beam.

Here, as shown in FIG. 3, since the thin film 16 disposed in the fine holes 20 on the cathode electrode line 13 is formed to have a very thin thickness and the upper surface 16A is flat, the gate When a voltage is applied between the electrode 14 and the cathode electrode 13, the equipotential surface _Em is formed in the fine hole 20 along the surface of the thin film 16 in a substantially flat manner.

Therefore, the electrons e emitted from the thin film 16 travel orthogonally to the equipotential surface E _m , so that the paths of the electrons e emitted from the holes 20 do not fluctuate so much and the vacuum portion (high vacuum region) is formed. Predetermined phosphor through 30 (eg red phosphor)
And will not misland. As a result, the desired color of light emission is always obtained, the performance of the display is improved, and high definition can be achieved.

Moreover, in the above electron emission source,
A thin cold cathode of the thin film 16 is formed in a large number of circular fine holes 20 penetrating the gate electrode line 14 and the insulating layer 15, and the thin cold cathode 16 is electrically connected to the cathode electrode line 13. Is made of a material having a work function smaller than that of the cathode electrode 13 such as amorphous diamond, so that even if the voltage applied between the cathode electrode 13 and the gate electrode 14 is lowered (even several tens of V or less) The amount (that is, the amount of current) can be stably obtained.

In this case, when the thin film 16 is particularly amorphous diamond, since the micro cold cathode itself is a resistor, the amount of current emitted from the thin film 16 in each micro hole 20 is homogenized. As a result, the bright spots generated on the screen of the display device become uniform, and the appearance becomes very good.

Further, the amorphous diamond thin film is chemically inactive, and like the tip of the microchip,
Ions do not concentrate at the points and it is difficult for the ions to be generated in the vacuum section 30 to be sputtered, so that stable emission can be maintained for a long time. Regarding such sputtering, since the thin film 16 itself is thin and exists on the bottom surface of the fine holes 20, the thin film 16 has a structure that is difficult to be sputtered.

Further, the portion that emits electrons is the thin film 16 described above.
Therefore, when forming this thin film, even if a metal piece is generated due to lift-off after vapor deposition described later, the thin film 16
Since the gate electrode 14 and the gate electrode 14 are sufficiently separated from each other, a metal piece does not adhere between them and a short circuit does not occur. As a result, the electrodes are not blown when the applied voltage is increased, and reliable operation can be performed.

Next, an example of a method of manufacturing the electron emission source (the electrode structure 25 including the field emission type cathode) which constitutes the display device according to the present embodiment will be described with reference to FIGS.

First, as shown in FIG. 4, a conductive material such as niobium, molybdenum or chromium is formed into a film having a thickness of about 2000 Å on the lower substrate 11 made of glass or the like, and thereafter, the photoengraving method and the reactive ion are used. Etching methods (eg Cl ₂ and O ₂
This mixed film is used to process the conductor film into a line shape, and the cathode electrode line 13 is formed.

Next, as shown in FIG. 5, an insulating layer 15, for example, silicon dioxide (SiO ₂ ) is formed by sputtering or chemical vapor deposition (CVD) on the surface including the cathode electrode line 13 to a thickness of about 1 μm. Further, a gate electrode material 14, such as niobium or molybdenum, having a thickness of 2000 is formed on the insulating layer 15.
Å The film is formed.

Then, as shown in FIG. 6, the gate electrode material film is processed into a line-shaped gate electrode line 14 which intersects with the cathode electrode line 13 by photolithography and reactive ion etching. Then, a circular fine hole 20 penetrating the gate electrode line 14 and the insulating layer 15 is formed by a photolithography method and a reactive ion etching method (for example, CHF).
₃ and CH ₂ F ₂ mixed gas).

Then, as shown in FIG.
The insulating layer 15 facing the micropores 20 is over-etched by wet etching (isotropic etching: for example, using hydrofluoric acid with ammonium fluoride added as a buffer) by using the mask as a mask, thereby expanding the micropores 20. Along with
An overhang portion 14A is formed on the gate electrode 14.

Then, as shown in FIG. 8, a peeling layer 24, for example, aluminum or nickel is formed by vacuum evaporation from an oblique direction with respect to the main surface portion of the electron emission source.

Then, as shown in FIG. 9, a thin cold cathode of a thin film 16, for example, an amorphous diamond thin film 16 is formed on the conductor portion (cathode electrode 13) in the fine hole 20 to a thickness of 2000 Å by chemical vapor deposition (CVD), for example. The film is formed to a degree. This C
The reaction gas used in VD is a mixed gas of CH ₄ and H ₂ ,
Alternatively, it is a mixed gas of CO and H _2, and the diamond thin film 16 is deposited by thermal decomposition of this reaction gas.

Then, by dissolving the release layer 24,
The minute cold cathode material 16 deposited on the peeling layer 24 is peeled and removed (lifted off). As a result, as shown in FIG. 1, the electrode structure 25 (electron emission source) in which the fine cold cathodes 16 are selectively formed in the fine holes 20 is completed.

As described above, according to the above-mentioned manufacturing method,
When forming the thin film 16 of the electron-emitting substance, the thickness of the thin film 16 is much smaller than that of the insulating layer 15, and the thickness can be easily deposited. Is not required to be formed with high precision, and the electron-emitting substance other than the deposited film in the fine holes 20 is easily lifted off together with the peeling layer 24.

Moreover, even if a metal piece is generated at the time of lift-off, the thin film 16 is thin, so that the cathode 13 and the gate 14 are sufficiently separated from each other, and the metal piece does not come into contact between them to cause a short circuit. (However, any of the substances having a small work function such as diamond illustrated above is an insulator and does not cause a short circuit). As a result, when the voltage applied between the cathode 13 and the gate 14 is increased, the electrodes are not blown, and reliable operation can be performed.

When depositing the thin film 16 shown in FIG.
Due to the presence of the overhang portion 14A of the gate electrode 14,
It is possible to prevent the deposited film 16 from adhering to the inner wall surface of the insulating layer 15 in the fine pores 20 (hence, contact between the gate electrode 14 and the thin film 16) and improve the electron emission performance of the thin film 16. Further, the mechanical strength of the gate electrode 14 can be maintained by not projecting the overhang portion 14A so much.

FIG. 10 shows an electron emission source (electrode assembly 25) according to the second embodiment of the present invention.

The electron emission source according to the second embodiment has substantially the same structure as the electron emission source according to the first embodiment described above, except that the fine holes 20 are slit-shaped. .

That is, in the electron emission source according to the present embodiment, a large number of slit-shaped fine holes 20 are formed through the gate electrode line 14 and the insulating layer 15, and the fine holes of the thin film 16 are formed in these fine holes 20. Cold cathode is formed and cathode electrode line
It is electrically connected to 13.

When the thin film 16 is made of amorphous diamond, it can be driven at a low voltage as described above, and since the micro cold cathode itself is a resistor, the amount of current emitted from the thin film 16 in each micropore 20 is small. Is homogenized. Further, since the amorphous diamond thin film 16 is chemically inert and is difficult to be sputtered, stable emission can be maintained for a long time.

In the present embodiment, the micropores 20 are slit-shaped, but the electric field strength on the surface of the thin film 16 of the micro cold cathode is almost equal to that of the circular micropores according to the first embodiment described above. It can be driven with almost the same voltage. Since the slit-shaped fine holes 20 have a larger emission region (electron emission area) than the circular fine holes, a larger current density can be obtained even if they are driven at the same voltage.

Although the embodiments of the present invention have been described above, the above embodiments can be further modified based on the technical idea of the present invention.

For example, the thin film 16 and the cathode electrode 13 described above
The material, thickness, film forming method, and the like may be variously changed. The film forming method is not limited to the above-described CVD, but is also a laser ablation method (a deposition method utilizing an etching phenomenon by laser light irradiation: graphite can be used as a target in the case of a diamond thin film), a sputtering method (for example, A
Sputtering using r gas: In the case of a diamond thin film, graphite can be used as the target).

The electron emission source described above is suitable for the FED, but the structure of the facing fluorescent panel, the pattern and material of each part, etc. are not limited to those described above, and various manufacturing methods are adopted. it can.

The above-mentioned use of the electron emission source is FE.
The present invention is not limited to D or other display devices, and is used for a vacuum tube (that is, an electron tube in which an electron flow emitted from the cathode is controlled by a gate electrode (grid) and amplified or rectified), or a cathode. A circuit element for taking out electrons emitted from the device as a signal current (this is a photoelectric conversion element attached to the fluorescent surface panel of the FED described above, and the light emission pattern of the fluorescent surface panel is converted into an electric signal by the photoelectric conversion element. Also includes elements for optical communication.)
It is also applicable to

[0087]

According to the present invention, as described above, the first electrode and the second electrode are provided so as to face each other with the insulating layer interposed therebetween, and penetrate the second electrode and the insulating layer, respectively. Micropores are formed, and predetermined particles are emitted from the first electrode side through the micropores by applying a voltage between the first electrode and the second electrode. In the particle emitting device according to the present invention, since the thin film made of the particle emitting substance having a work function smaller than that of the constituent material of the first electrode is provided in the micropores, the first electrode and the second electrode are provided. When a voltage is applied between and, the equipotential surface is formed flat along the thin film. Therefore, the particles traveling orthogonally to the flat equipotential surface travel with a fairly uniform directionality from the micropores to the target object (for example, the fluorescent surface), and thus always reach the target object. Therefore, mislanding can be greatly reduced, and high definition can be achieved.

Further, since the work function of the particle emitting material forming the thin film is smaller than that of the constituent material of the first electrode, the particle emitting material is placed between the first electrode and the second electrode to release particles. The voltage applied to the device can be reduced, and the required amount of emission can be stably obtained by driving at a low voltage. In this case, if the thin film of the micropores is a resistor, the amount of particles emitted from the thin film in the micropores can be homogenized.

Further, since the portion from which particles are emitted is the thin film, when the thin film is formed, even if a metal piece is generated due to lift-off after vapor deposition, for example, a gap between the thin film and the second electrode is generated. The sufficient separation prevents metal pieces from adhering between them and causing a short circuit. As a result, the electrodes are not blown when the applied voltage is increased, and reliable operation can be performed.

Furthermore, since the portion that emits particles is the thin film, the ions do not concentrate at one point unlike the tip of the microchip, and the ions existing in the high vacuum region reach the thin film and sputter it. Since the rate of decrease is drastically reduced, the life of the device can be extended. In this case, if the thin film of micropores is made of a material that is chemically inactive and difficult to be sputtered, more stable emission can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an electron emission source according to a first embodiment of the present invention.

FIG. 2 is an enlarged plan view of a part of the electron emission source.

FIG. 3 is a schematic cross-sectional perspective view for explaining the electron emission performance of the electron emission source.

FIG. 4 is a schematic cross-sectional view showing a step in the manufacturing process of the electron emission source.

FIG. 5 is a schematic cross-sectional view showing another step in the manufacturing process of the electron emission source.

FIG. 6 is a schematic cross-sectional view showing another step in the manufacturing process of the electron emission source.

FIG. 7 is a schematic cross-sectional view showing another step in the manufacturing process of the electron emission source.

FIG. 8 is a schematic cross-sectional view showing another step in the manufacturing process of the electron emission source.

FIG. 9 is a schematic cross-sectional view showing still another step in the manufacturing process of the electron emission source.

FIG. 10 is a schematic view of a partial cross section of an electron emission source according to a second embodiment of the present invention.

FIG. 11 is an exploded cross-sectional perspective view of a part of a display device to which a conventional electron emission source is applied.

FIG. 12 is an enlarged cross-sectional perspective view of a part of the electron emission source.

FIG. 13 is a schematic cross-sectional view of the electron emission source.

FIG. 14 is a partial schematic cross-sectional view for explaining color selection by switching R, G, and B three terminals in the display device.

FIG. 15 is a timing chart when selecting the same color.

FIG. 16 is a schematic cross-sectional perspective view for explaining the electron emission performance of the electron emission source.

FIG. 17 is a schematic cross-sectional view showing a step in the manufacturing process of the electron emission source.

FIG. 18 is a schematic cross-sectional view showing another step in the manufacturing process of the electron emission source.

FIG. 19 is a schematic cross-sectional view showing another step in the manufacturing process of the electron emission source.

FIG. 20 is a schematic cross-sectional view showing still another step in the manufacturing process of the electron emission source.

FIG. 21 is a schematic cross-sectional view showing a situation in which fusing occurs in the manufacturing process of the electron emission source.

[Explanation of symbols]

11 ... Lower substrate 13 ... Cathode electrode line 14 ... Gate electrode line 15 ... Insulating layer 16 ... Thin film 20 ... Micro hole (cathode hole) 22 ... Crossing area 24 ... -Peeling layer 25 ... Electron emission source (electrode structure) 30 ... Vacuum part e ... Electron _Em ... Equipotential surface R, G, B ... Fluorescent substance of each color

Claims (11)

[Claims] 1. A first electrode and a second electrode are provided so as to face each other with an insulating layer interposed therebetween, and minute holes are formed to penetrate the second electrode and the insulating layer, respectively, and the first electrode is provided. In a particle emission device configured so that predetermined particles are emitted through the micropores by applying a voltage between an electrode and the second electrode, the particle emission device has a higher work than that of the constituent material of the first electrode. A particle emitting device, wherein a thin film made of a particle emitting substance having a small function is provided in the minute hole. 2. A cathode electrode line and a gate electrode line, which intersect each other, are laminated on a substrate via an insulating layer,
Micro holes are formed to penetrate the gate electrode line and the insulating layer, respectively, and a thin film micro cold cathode made of an electron emitting substance having a work function smaller than that of the constituent material of the cathode electrode line is formed in the micro hole. Is provided in
The particle emitting device according to claim 1, configured as an electron emitting source. 3. The thin film made of a particle-releasing substance is provided in a thickness not more than ½ of that of the insulating layer.
The particle emission device described in 1. 4. The particle emitting device according to claim 1, wherein the particle emitting substance has a work function of 3.0 eV or less. 5. The particle emitting device according to claim 4, wherein the particle emitting substance is diamond. 6. The micropores are substantially circular, and the micropores are substantially circular.
The particle emission device according to any one of 1. 7. The micropores are slit-like, and the micropores are slit-shaped.
5. The particle emitting device according to any one of 5 above. 8. A field emission device comprising the particle emission device according to claim 1. Description: 9. A first panel comprising a cathode electrode line, a gate electrode line, an insulating layer with micropores, and a thin-film microcold cathode in the micropores, a plurality of color light emitters, and these light emitters. Second, each consisting of deposited electrodes
9. The field emission device according to claim 8, which is configured as a field emission light emitting device with the panel of. 10. The field emission device according to claim 9, which is configured as a field emission display device in which the light emitter is a phosphor. 11. A step of forming a first electrode on a substrate,
Forming an insulating layer on the region including the first electrode, forming a second electrode on the insulating layer, and forming micropores penetrating the second electrode and the insulating layer, respectively. And a step of forming a peeling layer on the second electrode, and thereafter depositing a particle-releasing substance in the micropores to form a thin film of the particle-releasing substance, together with the peeling layer. The method of manufacturing an apparatus according to claim 1, further comprising: removing the particle-releasing substance on the release layer.