JP3258108B2 - Electron emission device and flat display device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, relates to the electron-emitting device using a vacuum microelectronics technology and the planar display equipment using the same.

[0002]

2. Description of the Related Art Recently, it has become possible to manufacture a fine vacuum triode, and its application and development have been actively carried out.
In particular, there are active attempts to use this vacuum triode as an electron source for vacuum ICs and flat display devices. In a flat display, a large number of ultra-fine vacuum triodes (emitters, bases, anodes) are arranged, and electrons are applied to a phosphor applied on the anode side to generate light. A display device based on this principle is excellent in high speed and environmental resistance because it uses electrons.

[0003]

By the way, there are a Spindt type and a planar type in the emitter shape of the above-mentioned ultrafine vacuum triode. In the Spindt type, since the single emitter shape is a cone, when the emitters are integrated, the interval between the emitters is limited by the diameter of the base of the cone. It is generally said that the limit of the pitch of the emitter is 5 μm. Further, since the process of forming the cone is complicated, it is difficult to make the shapes of all the emitters uniform with high precision. And, the mismatch of the emitter shape causes the emitter breakdown.

That is, in the Spindt type, since the interval between the emitters is limited by the diameter of the base of the cone, the number of emitters per unit area is limited. Since the magnitude of the emission current is affected by the number of emitters, it has conventionally been difficult to increase the emission current.

On the other hand, the planar type has the advantages that the number of process steps is small and that the pitch of the emitter can be reduced to the resolution of the patterning device. However, if the number of emitters increases, the number of wirings also increases, so it is necessary to increase the wiring area. That is, since the emitter region is limited, the number of emitters cannot be simply increased. Therefore, it is difficult to increase the emission current even in the planar type. That is, it is an object of the invention of claim 1 is that the value of the emission current can be formed a number of electrodes to provide a high electron emission device. Further, it is an object of the invention of claim 2 is to provide the value of the emission current is higher flat display device per pixel.

[0006]

In order to achieve the above object, according to the present invention, there is provided a substrate, a first conductive film formed on the substrate, and a first conductive film. An insulating film formed on the film and a second conductive film formed on the insulating film are provided, and the second conductive film is surrounded by the groove by forming a groove. Divided into an inner part and an outer part of this groove,
A contact hole for connecting the first conductive film and the second conductive film is formed in the inner portion,
Further, a plurality of planar projection electrodes are alternately formed on the inner portion and the outer portion so as to alternately sandwich the groove , and the projection electrode sandwiches the groove.
So that the distance between the protruding electrodes facing each other is shortened,
An electron-emitting device which is connected to the adjacent protruding electrodes by a curve .

[0007] according to claim 2 invention, a light transparent conductive thin film and the phosphor thin film is laminated on the light transmitting insulating substrate, it is spaced the phosphor thin film to the electron-emitting device of claim 1 Symbol placement The flat display device is characterized in that electrons emitted from the electron-emitting devices are applied to the phosphor thin film to emit light.

[0008]

BRIEF DESCRIPTION based on the embodiments of the present invention in FIGS. 1 to 10. 1 to 5 show one embodiment of the electron-emitting device of the present invention.

FIGS. 1A to 1C sequentially show a manufacturing process of an electron-emitting device of this embodiment. First, FIG.
As shown in (a), a Si wafer 1 as an insulating substrate
A first conductive thin film (hereinafter, referred to as a first layer) 2 is formed thereon. These first layers 2 are formed in a linear pattern at substantially equal intervals. Further, as shown in (b) and (c), an insulating thin film (hereinafter, referred to as a second layer) 3 and a second conductive thin film (hereinafter, referred to as a third layer) 4 are sequentially stacked. A plurality of line grooves 5 remain on the surface of the third layer 4.

[0010] In FIG.
A large diagram is shown in FIG. As shown in FIG. 2, a plurality of division grooves 6 are formed in the third layer 4. These division grooves 6 are arranged at substantially equal intervals from each other, and are located on the first layer 2. Further, each of the dividing grooves 6 is drawn in a regular square shape continuously, and divides the third layer 4 into an inner part 7 and an outer part 8.

A contact hole 9 is formed in the inner portion 7 , and each contact hole 9 has a rectangular opening at the center of the inner portion 7. This contact
As shown in FIG. 3, the hole 9 penetrates the second layer 3 in the thickness direction. Further, a third layer 4 is formed along the contact hole 9, and the bottom of the contact hole 9 is closed by the third layer 4. And contact
At the bottom of the shell 9, the third layer 4 is connected to the first layer 2.

As shown in FIG. 4, a large number of fine projecting electrodes (hereinafter referred to as electrodes) 10... 11 are patterned on the third layer 4. These electrode groups 10 ..., 11
Are periodically formed along the edge facing the dividing groove 6, and face each other while being separated from each other.

Each of the electrodes 10 and 11 is of a planar type. Also,
Each of the electrodes 10 and 11 has a triangular wedge shape.
The tips of 0 and 11 are pointed. Furthermore, each electrode 10, 1
Both sides of the proximal end of 1 are notched sharply. The inner electrode group 10 and the outer electrode group 11 are displaced from each other, and the tip of the electrode 10 (or 11) approaches the base end of the counterpart electrode 11 (or 10). Further, as shown in FIG. 5, portions of the second layer 3 around the electrodes 10 and 11 have been removed with the production of the electrodes 10 and 11.

That is, each of the electron-emitting devices 12 of this embodiment has the dividing groove 6, and a large number of the electron-emitting devices 12.
Are integrated on the Si substrate 1. Further, in the electron-emitting device 12, the electrodes 10,.
.. Are formed in large numbers. Next, a method of driving the emission current in the above-described electron-emitting device 12 will be described.

In the electron-emitting device 12, FIG.
Are applied to the first layer 2 and the third layer 4. Then, the electrode groups 10 ...
Field emission occurs in the electrode group 11 and electrons are emitted from many electrodes.

That is, since the inner portion 7 of the third layer 4 is connected to the first layer 2 by the contact hole 9,
An AC voltage acts on both the inner part 7 and the outer part 8 of the third layer 4. The electrodes 10... 11 function alternately as bases or emitters.

In a general fine vacuum triode, an AC voltage may be applied to the gate in order to improve the lifetime of the emitter. And usually, FIG.
As shown in FIG. 7, a voltage that periodically changes between 0 and positive is applied. Assuming that the value of the voltage necessary for flowing the emission current is Va, the emission current is generated only when the voltage value is equal to or higher than Va (shown by a thick line in the waveform in the figure).

On the other hand, the electron-emitting device 1 of this embodiment
In FIG. 2, since an AC voltage as shown in FIG. 6A is applied, as compared with a case where a voltage that changes only positively is used as shown in FIG. An emission current can be generated.

That is, the electron-emitting device 12 as described above
, A single conductive thin film (third layer 4) is divided into an inner portion 7 and an outer portion 8, and each of the inner portion 7 and the outer portion 8 has a plurality of planar electrodes. , 11 ... are formed. Further, since the inner portion 7 is connected to the first layer 2 by the contact hole 9, if a voltage is applied to the first layer 2 and the third layer 4,
Both the inner electrode group 10 and the outer electrode group 11 are energized. Therefore, wiring for the third layer 4 is unnecessary, and the number of electrodes 9 and 10 is not limited by the wiring area.

Therefore, it becomes possible to manufacture several times the number of electrodes as compared with the conventional case. Since one field emission device 12 has a large number of electrodes 10,..., 11, the number of electron sources increases, and the current density increases. Then, the emission current of the field emission device 12 can be increased. Further, since the electrodes 10..., 11.
The production of 0... 11 is easy.

Since the electrode groups 10 and 11 function as both the emitter and the base, there is no need to distinguish between the emitter and the base. Therefore, the AC power can be directly used without rectification. Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

Reference numeral 21 in FIG . 8 indicates a flat display device using the electron-emitting devices 12 of the first embodiment. A large number of electron-emitting devices 12 are integrated on the Si substrate 1. Further, a glass substrate 22 as a light-transmitting insulating substrate is combined with the Si substrate 1, and both substrates 1,
22 are facing in parallel. Then, the electron-emitting device 12
Are directed to the glass substrate 22.

A plurality of transparent conductive films 23 such as ITO are formed on one surface of the glass substrate 22. Transparent conductive film 23 ...
(Only one is shown) is formed in a linear pattern at substantially equal intervals. Further, the lines of the transparent conductive films 23 .
9 , only one of them is orthogonal to the first layer 2 of the Si substrate 1. The width of the transparent conductive films 23 is set equal to that of the first layer 2 of the Si substrate 1.

A phosphor thin film 24 is laminated on the transparent conductive films 23. The phosphor thin film 24 covers the surface of the glass substrate 22. The phosphor thin film 24 is made of S
An interval is provided between the i-substrate 1 and the third layer 4.

That is, in the flat display device 21, one electron-emitting device 12 constitutes one pixel. Further, a simple matrix system is adopted as a driving system. When the electron-emitting device 12 is driven while the transparent conductive films 23 are energized, the electrons emitted from the electron-emitting device 12 hit the phosphor thin film 24, and the pixel emits light.

That is, the flat display device 21
, The electron-emitting device 12 having a large number of electrodes 10, 11... Constitutes each pixel, so that the emission current per pixel is high. Therefore, the light emission amount is large and the luminance is high.

The number of electrodes per pixel is determined by the thickness of the first layer 2 of the Si substrate 1 and the transparent conductive film 23 of the glass substrate 22 (the area where the first layer 2 and the transparent conductive film 23 intersect). Depends on

In the above-described first embodiment, the shapes of the electrodes 10,..., 11 are set in a triangular saw blade shape. However, the present invention is not limited to this. Can be set, for example, as shown in FIG. 10 (a) or (b).

That is, in FIG.
The edges of 1,..., 32 are curved, and adjacent electrodes are connected by an arc. And each electrode 31,
Thirty-two electrodes alternately face each other.

In FIG. 10B, the electrode 33
, 34 ... are set in a rectangular comb shape, and the respective electrodes 33, 34 mesh with each other via the dividing groove 35. (And 34...)
Electrons are emitted from a, 33b (and 34a, 34b). The present invention can be variously modified without departing from the gist.

According to the first and second aspects of the present invention, it is possible to form many electrodes without being limited to the wiring region, and it is possible to increase the value of the emission current.

According to the invention of claim 3, there is an effect that the value of the emission current per pixel of the flat display device can be increased.

[Brief description of the drawings]

FIGS. 1A to 1C are explanatory views sequentially showing a manufacturing process of an electron-emitting device according to a first embodiment of the present invention.

FIG. 2 is an enlarged plan view of a portion surrounded by a circle A in FIG. 1 (c).

FIG. 3 is an enlarged view showing a cross section taken along line BB in FIG. 2;

FIG. 4 is an enlarged view of a portion surrounded by a circle C in FIG. 2;

FIG. 5 is a sectional view taken along line DD in FIG. 4;

FIG. 6 is an explanatory diagram showing a driving method of the electron-emitting device of the first embodiment.

7A is a graph showing a voltage applied to the electron-emitting device of the first embodiment, and FIG. 7B is a graph showing a voltage applied to a general vacuum triode.

FIG. 8 is a diagram showing a flat display device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing one pixel of the flat display device of FIG. 8;

10A is a diagram showing a modified example of the protruding electrode, and FIG.
FIG. 9 is a view showing another modified example of the bump electrode.

[Explanation of symbols]

1 ... Si substrate (insulating substrate), 2 ... first conductive thin film,
3 ... insulating thin film, 4 ... second conductive thin film, 6 ... dividing groove,
7 ... inner part, 8 ... outer part, 9 ... contact hole
, 10, 11 ... projecting electrode, 12 ... electron-emitting device, 21
... a flat display device, 22 ... a glass substrate (light-transmitting insulating substrate), 23 ... a conductive thin film, 24 ... a phosphor thin film.

Claims (2)

(57) [Claims] 1. A substrate, a first conductive film formed on the substrate, an insulating film formed on the first conductive film, and a first conductive film formed on the insulating film. And the second conductive film is formed by forming a groove.
And a contact hole for connecting the first conductive film and the second conductive film is formed in the inner portion. is formed, further wherein the inner portion and the outer portion, a plurality of planar projections electrodes, are alternately protrude across a periodically the groove and the projecting electrode
The distance between the pole and the protruding electrode that faces each other across the groove is
Connected to the adjacent protruding electrodes so as to be shorter
An electron emission element characterized by being. 2. A light-transmissive conductive thin film and a phosphor thin film are laminated on a light-transmissive insulating substrate, and said phosphor thin film is opposed to said electron-emitting device while being spaced apart from said electron-emitting device. A flat display device, wherein electrons emitted from an emitting element are applied to the phosphor thin film to emit light.