JPH1031956A - Manufacture of field emission cathode with convergence electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten manufacturing time and suppress manufacturing cost. SOLUTION: A cathode electrode 101, resistance layer 102, a first insulative layer 103, and a gate electrode 104 are provided on a base plate 100 one over another by the film formation process, and holes are made in the gate electrode 104 and the first insulative layer 103, followed by film formation of the second insulative layer 105 by the CVD method on the gate electrode 104 of a field emission cathode where emitters 115 are formed, and a film as a convergence electrode 106 is formed on the second insulative layer 105 by means of the sputter method. Then the convergence electrode 106 and the second insulative layer 105 are provided with holes for each row of emitters 115 corresponding to the picture element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission cathode known as a cold cathode, and more particularly to a method for manufacturing a field emission cathode having a focusing electrode.

[0002]

2. Description of the Related Art A voltage applied to a metal or semiconductor surface is 10
^At about ⁹ [V / m], electrons pass through the barrier due to the tunnel effect, and electrons are emitted in a vacuum even at room temperature. This is called field emission (Field Emission), and a cathode that emits electrons based on such a principle is called a field emission cathode (Field Emission Cathode) or a field emission element.

In recent years, it has become possible to manufacture a surface emission type field emission cathode composed of a micron-sized field emission cathode by making full use of semiconductor fine processing technology. A large number of field emission cathodes are formed on a substrate. This is expected as an electron supply means for constituting a flat display device or various electronic devices by irradiating electrons emitted from the respective emitters to the phosphor screen.

[0004] As an example of such a field emission cathode, FIG. 4 shows a perspective view of a field emission cathode called Spindt type (hereinafter referred to as "FEC"). In this figure, a cathode electrode layer 101 is formed on a substrate 100, and a resistance layer 102, an insulating layer 103, and a gate electrode layer 104 are sequentially formed on the cathode electrode layer 101. Then, an emitter cone 115 is formed in a hole formed in the insulating layer 103, and a tip portion of the emitter cone 115 faces from an opening of the gate electrode layer 104.

In the FEC, the emitter cone 115 and the gate electrode layer 1 are formed by using a fine processing technique.
Since the distance to 04 can be submicron,
By applying a voltage of only several tens of volts between the emitter cone 115 and the gate electrode layer 104, electrons can be emitted from the emitter cone 115. Therefore, as shown in FIG. 4, when the anode substrate 116 on which the fluorescent material is applied is disposed above the substrate 100 on which a large number of the FECs are formed in an array and the voltages VGE and VA are applied, the emission is performed. A display device capable of causing the phosphor to emit light by the emitted electrons can be obtained.

In a display device constituted by an FEC as shown in FIG. 4, since electrons emitted from the emitter cone 115 are emitted with a spread of about 30 degrees, they are arranged adjacently on the anode substrate 116. However, there is a problem that phosphors of different colors also emit light.

In order to prevent the spread of electrons emitted from the FEC, an FEC having a focusing electrode has been proposed. FIG. 5 shows a schematic view of one configuration example of the FEC.
The same components as those of the FEC shown in FIG. 4 are denoted by the same reference numerals, and the description will not be repeated.

In the FEC having the focusing electrode shown in FIG. 1, an insulating layer 105 is formed on the gate electrode 104 of the FEC shown in FIG. 4, and a focusing electrode 106 is formed on the insulating layer 105. Further, the insulating layer 105 and the focusing electrode 106 are also provided with openings corresponding to the positions where the emitter cones 115 are formed. When the focusing electrode 106 is formed above the gate electrode 104 and a negative potential is applied to the focusing electrode 106 with respect to the gate electrode 104, the trajectory of the electrons emitted from the emitter cone 115 is changed by the focusing electrode 106. It is focused and reaches a predetermined region of the anode substrate disposed above without diffusion.

However, in the FEC having such a focusing electrode, since the electric field of the focusing electrode 106 greatly affects the gate electrode 104, the emitter cone 115
Attempts to increase the convergence of the electrons emitted from the FE
There is a problem that the amount of emission current emitted from C is greatly reduced.

Therefore, in order to solve such a problem,
An FEC in which a focusing electrode is formed for each array of a plurality of emitters (emitter array) corresponding to each pixel has been proposed (Japanese Patent Application Laid-Open No. 7-104679). FIG. Show. In the FEC shown in this figure, a focusing electrode 106 is formed for each emitter array 117, and in this case, electrons emitted from the emitter array 117 are focused by the focusing electrode 106 and are arranged without being diffused. It is possible to prevent a decrease in the amount of emission current emitted while reaching a predetermined region of the anode substrate.

Next, a manufacturing process of the FEC having the focusing electrode as shown in FIG. 6 will be described with reference to FIG. First, a cathode electrode 101, a resistance layer 102, an insulating layer 103, and a gate electrode 104 are sequentially formed on a substrate 100 made of glass or the like, and an opening is formed in the gate electrode 104.
03, a hole 114 is formed. Then, Mo (molybdenum) or the like, which is an emitter material, is deposited from the hole 114 side by vapor deposition to form an emitter cone 115 on the resistance layer 102 in the hole.

Next, as shown in FIG. 7A, a photoresist layer 1 is formed on the surface of the gate electrode 104 where the opening is formed.
After applying 20, the photoresist layer 120 is patterned by a photolithography method using a mask 121 for each emitter array as shown in FIG.
Then, electron beam evaporation (E
(B vapor deposition) or by sputtering
As shown in FIG.
An insulating layer 105 is formed on the insulating layer 20.
The focusing electrode 106 is formed on the substrate 05 by EB evaporation or sputtering.

As a result, between the insulating layer 105 and the focusing electrode 106 formed on the gate electrode 104 and the insulating layer 105 and the focusing electrode 106 formed on the photoresist layer 120, A step corresponding to the film thickness of the resist layer 120 is generated, and by removing the photoresist layer 120, an FEC in which the focusing electrode 106 is formed for each emitter array as shown in FIG. Can be.

[0014]

By the way, in the above-mentioned method of manufacturing the FEC, the photoresist layer 1
When the material of the focusing electrode 106 adheres to the wall of the photoresist layer 20, the photoresist layer 120 is not exposed, and the photoresist layer 120 cannot be peeled off. For this reason, the step of forming the insulating layer 105 is limited to EB evaporation or sputtering, which is excellent in linearity and can form a film with a uniform thickness.

However, when the insulating layer 105 is formed by EB evaporation or sputtering as described above, there is a problem that the manufacturing time and the manufacturing cost are significantly increased because the film forming speed is low.

The present invention has been made in order to solve such problems, and provides a method of manufacturing a field emission cathode having a focusing electrode which is more industrially advantageous, reduces manufacturing time and manufacturing cost. The purpose is to:

[0017]

In order to achieve the above object, a method for manufacturing a field emission cathode having a focusing electrode according to the present invention comprises a cathode electrode, a resistive layer, a first insulating layer,
A first step of sequentially forming a gate electrode, providing a first hole in the gate electrode and the first insulating layer, forming an emitter in the first hole, and forming the gate in the first hole. A second step of forming a second insulating layer on the electrode by a CVD method, a third step of forming a focusing electrode on the second insulating layer by a sputtering method, a focusing electrode and a second insulating layer. Forming a second hole in the layer for each arrangement of the plurality of emitters corresponding to each pixel, and exposing the emitter.

A cathode electrode, a resistance layer, a first insulating layer, and a gate electrode are sequentially formed on a substrate, and a first hole is provided in the gate electrode and the first insulating layer. A second step of forming a second insulating layer by a CVD method on the gate electrode in which the first hole is formed, and a step of forming a second insulating layer on each of the pixels on the second insulating layer. Forming a second hole for each corresponding arrangement of the plurality of emitters, exposing the emitter, and forming a focusing electrode on a surface of the second insulating layer where the second hole is formed. And a fourth step of performing the above.

According to the present invention, the second insulating layer is formed without applying a photoresist layer on the gate electrode in which the first hole is formed. A film can be formed by a thick film forming means such as a CVD method or printing, so that manufacturing time and manufacturing cost can be significantly reduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a field emission cathode having a focusing electrode according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. First, FIG.
As shown in FIG. 2, Nb (niobium), which is a material of a cathode electrode, is formed on a substrate 100 such as glass by sputtering.
A cathode electrode 101 is formed by forming a film having a thickness of 2 μm, and α-Si (amorphous silicon) doped with impurities is deposited on the cathode electrode 101 by CVD (Chemical Vapor Deposi).
) to form a resistance layer 102, and further, SiO ₂ (silicon dioxide) is
The first insulating layer 103 is formed by VD.
Then, Nb to be the gate electrode 104 is formed over the first insulating layer 103 by sputtering.

Further, after a photoresist layer 111 is applied on the gate electrode 104, the photoresist layer 111 is patterned by a photolithography method using a mask 112 to form an opening pattern in the photoresist layer 111. Thereafter, anisotropic etching is performed by reactive ion etching (RIE) from the direction in which the photoresist layer 111 is applied using a gas such as SF ₆ .
As shown in FIG. 3B, an opening 113 similar to the pattern of the photoresist layer 111 is formed in the gate electrode 104.

Further, the first etching is performed by dry etching.
The hole 114 is formed in the first insulating layer 103 as shown in FIG. When the laminated substrate is rotated in the same plane and Al (aluminum) serving as the release layer 110 is obliquely deposited, the Al is not deposited in the hole 114 but the gate electrode 104 as shown in FIG. The separation layer 110 is formed on the surface of the gate electrode 104 by selectively adhering only to the surface of the gate electrode 104.

Next, the hole 114 of such a laminated substrate will be described.
By depositing and depositing Mo (molybdenum) as the emitter material on the side, the Mo as the emitter material becomes the bottom of the hole 114, that is, the resistance layer 1 as shown in FIG.
At the same time as the deposition and deposition on the release layer 02, the emitter material 106 is deposited on the release layer 110. And this release layer 110
When the opening is closed by the emitter material 106 deposited thereon, a cone-shaped emitter (hereinafter, referred to as “emitter cone”) 115 is formed on the anti-layer 102.

Thereafter, the substrate is immersed in phosphoric acid which is a solution of the release layer 110, whereby the release layer 110 and the emitter material 106 on the gate electrode 104 are removed, and the shape as shown in FIG. Is formed.

Next, as shown in FIG. 2A, a gate electrode 104 having an opening for each emitter cone 115 is formed.
SiO ₂ (silicon dioxide) is formed thereon by CVD to form a second insulating layer 105.
05 on the second gate electrode (converging electrode) 106
b is formed by sputtering. Then, after applying a photoresist layer 120 on the focusing electrode 106 as the outermost surface, the photoresist layer 120 is patterned by a photolithography method using a mask 121, and the photoresist layer 120 is patterned as shown in FIG. At 120, an aperture pattern is formed for each emitter array corresponding to each pixel.

Next, anisotropic etching is performed by reactive ion etching (RIE) from the direction in which the photoresist layer 120 is applied using a gas such as SF ₆ to apply the photoresist layer 120 to the focusing electrode 106. By forming an opening similar to the above pattern, and further successively etching the second insulating layer 105 by dry etching or wet etching, holes are formed in the second insulating layer 105 for each emitter array, An FEC having the focusing electrode 106 as shown in FIG.

FEC having such a focusing electrode 106
According to the manufacturing method described above, the second insulating layer 105 can be formed by the CVD method without having to be formed by conventional EB evaporation or sputtering having straightness, and thus can be formed by conventional EB evaporation or sputtering. The manufacturing time and manufacturing cost of the FEC can be greatly reduced as compared with the case where the film is formed.

By the way, the method of manufacturing an FEC having a focusing electrode as described above can manufacture an FEC having a thin film structure in which the thickness of the second insulating layer 105 is several microns, at most about 5 microns. . Next, the second insulating layer 1
FE with a thick film structure whose film thickness is about 50 microns
The method of manufacturing C will be described.

Hereinafter, a method of manufacturing a field emission cathode having a focusing electrode having a thick film structure will be described with reference to the schematic diagram of FIG. In this case, the FEC having the shape as shown in FIG. 1E is first formed in the manufacturing process shown in FIG.

In this case, as shown in FIG. 3A, the gate electrode 1 provided with an opening for each emitter cone 115 is provided.
A second insulating layer 105 is formed on the substrate 04 by forming a film of SiO ₂ to a thickness of at least about several tens μm by a thick film forming means such as printing, spin coating, spraying or the like. Further, a photoresist layer 1 is formed on the second insulating layer 105.
After applying 20, the photoresist layer 120 is patterned by a photolithography method using a mask 121 to form an opening pattern for each emitter array as shown in FIG.

Next, the second insulating layer 105 is etched by dry etching or wet etching.
Holes 122 corresponding to each emitter array are formed in the second insulating layer 105. In this case, the second insulating layer 1
It is desirable to form the hole 122 so that the wall surface of the hole 05 is etched largely.

Then, while rotating the laminated substrate in the same plane, Nb to be the focusing electrode 106 is obliquely vapor-deposited until the film thickness becomes about 10 μm. In this case, the second insulating layer 105
Has a thickness of about several tens of μm, so that Nb is not deposited in the holes 122 but selectively adheres only to the surface of the second insulating layer 105 and is focused on the surface of the second insulating layer 105. The electrode 106 will be formed. Thus, an FEC having a focusing electrode having a thick film structure as shown in FIG. Note that the focusing electrode 106 formed on the surface of the second insulating layer can be formed by printing.

In the method of manufacturing an FEC having a focusing electrode having such a thick film structure, the second insulating layer 105
It is not necessary to form a film by conventional EB evaporation or sputtering having straightness, and printing, spin coating,
Since the film can be formed by a thick film forming means such as spraying, the manufacturing time and manufacturing cost of the FEC can be significantly reduced as compared with the case where the film is formed by conventional EB evaporation or sputtering.

[0034]

As described above, according to the method for manufacturing a field emission cathode having a focusing electrode of the present invention, the second insulating layer formed on the gate electrode is formed by the CVD method or the thick film forming means. Therefore, manufacturing time and manufacturing cost can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a part of a manufacturing process of a field emission cathode having a focusing electrode according to an embodiment of the present invention.

FIG. 2 is a view showing a part of a process of manufacturing a field emission cathode having a focusing electrode according to the first embodiment of the present invention.

FIG. 3 is a view showing a part of a process of manufacturing a field emission cathode having a focusing electrode according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a display device using a conventional field emission cathode.

FIG. 5 is a diagram showing an example of a field emission cathode having a focusing electrode.

FIG. 6 is a diagram showing an example of a field emission cathode in which a focusing electrode is formed for each emitter array.

FIG. 7 is a view illustrating a process of manufacturing a conventional field emission cathode having a focusing electrode.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 substrate 101 cathode electrode 102 resistive layer 103 first insulating layer 104 gate electrode 105 second insulating layer 106 focusing electrode 112, 121 mask 113 opening 114, 122 hole 115 emitter cone 115 anode substrate 117 emitter array 120 photoresist layer

Claims (7)

[Claims] A first electrode formed on the substrate, a resistance layer, a first insulating layer, and a gate electrode sequentially formed on the substrate; a first hole provided in the gate electrode and the first insulating layer; A first step of forming an emitter in the hole, and a CV on the gate electrode where the first hole is formed.
A second step of forming a second insulating layer by a method D, a third step of forming a focusing electrode on the second insulating layer by a sputtering method, the focusing electrode and the second insulation Forming a second hole for each array of the plurality of emitters corresponding to each pixel in the layer, and exposing the emitters. Manufacturing method of cathode. 2. A method according to claim 1, wherein a cathode electrode, a resistance layer, a first insulating layer, and a gate electrode are sequentially formed on a substrate, and a first hole is provided in the gate electrode and the first insulating layer. A first step of forming an emitter in the hole, a second step of forming a second insulating layer on the gate electrode in which the first hole is formed by a thick film forming means, Forming a second hole for each array of the plurality of emitters corresponding to each pixel in the insulating layer, and exposing the emitter; and forming the second hole in which the second hole is formed. A fourth step of forming a focusing electrode on the surface of the insulating layer; and a method of manufacturing a field emission cathode having a focusing electrode. 3. The method according to claim 2, wherein the focusing electrode is formed by a thick film forming unit. 4. The method of claim 2, wherein the focusing electrode is formed by oblique deposition. 5. The method for manufacturing a field emission cathode having a focusing electrode according to claim 2, wherein the second insulating layer and the focusing electrode are formed by printing. 6. The method according to claim 2, wherein the second insulating layer is formed by a spin coating method.
5. A method for producing a field emission cathode having a focusing electrode according to item 1. 7. The method for manufacturing a field emission cathode having a focusing electrode according to claim 2, wherein the second insulating layer is formed by spray coating.