JP3304925B2 - MIM type cold cathode device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electron-emitting device, and more particularly, to a cold-cathode device having a flat electron-emitting surface, the electron-emitting surface having an improved electron-emitting property from the surface. Metal / insulator / metal mold (or M
(IM type) cold cathode device and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, demands for a larger image display surface of a display (image display device), higher definition, higher definition, a wider viewing angle, higher image quality, and the like have been further increased, and these are realized. There is a high possibility that a flat panel display (flat image) replacing a conventional CRT display will be used.

In recent years, as such flat panel displays, plasma displays, liquid crystal panel displays, and front-conduction type electron-emitting device displays (S
CE-type display).

In view of the above, hot cathode devices, cold cathode devices, and the like are conventionally known as electron-emitting devices used in such displays. Among them, examples of the cold cathode device include a surface conduction type emission device and a field emission type device (F
E type), metal / insulator / metal type emission element (MIM type), and the like.

Further, these cold cathode devices emit electrons at a lower temperature than the hot cathode device, do not require a heater for that purpose, have a simple structure, and enable formation of fine devices. It is. Further, the density can be increased on the substrate.
Also, since the hot cathode element operates by heating the heater, unlike the response speed is slow, this cold cathode element is
It also has the advantage of fast response speed.

Accordingly, as such a conventional MIM type cold cathode device, for example, the following are known.
As shown in FIG. 1, an insulator layer 3 is provided on a metal or semiconductor layer 2 on a substrate 1, and a surface metal layer 4 is further formed thereon. This is a general MIM type cold cathode device. is there. Here, electrons are emitted by applying a voltage E between the metal or semiconductor layer 2 and the upper metal layer 4.

[0007]

However, in the MIM type cold cathode device which is a conventional planar electron emission source as described above, the thickness of the surface layer on the emission surface is reduced in order to reduce scattering. Then, the sheet resistance increases, and it tends to be difficult to apply a voltage effectively and uniformly.

As a result, in the conventional planar electron emission source, in recent years, the image display surface has been increased in size, definition, and definition.
It is not possible to sufficiently cope with a wide viewing angle, a high image quality, a flat surface, and the like, and in reality, a satisfactory electron-emitting device for a display has not yet been obtained.

Accordingly, an object of the present invention is to provide a MIM-type cold cathode device having an electron emission surface, to reduce the resistance of the device, and to improve the electron emission efficiency and the uniformity of emission from the surface. An MIM type cold cathode device is provided.

[0010]

Means for Solving the Problems Accordingly, the present inventors have:
In view of the above-mentioned problems, as a result of intensive studies, a cold cathode device having an MIM-type electron emission surface in which a first electrode layer, an insulating layer, and a second electrode layer are sequentially formed on a substrate in a multilayered manner, By focusing on the electrical characteristics of the second electrode layer provided on the insulating layer, the inventors have found a method capable of efficiently emitting electrons from the electron emission surface, and have completed the present invention.

Accordingly, the present invention provides an MIM in which a first electrode layer, an insulating layer, and a second electrode layer are sequentially formed on a substrate in multiple layers.
Provided is a cold-cathode device having an electron emission surface which is of a type, a plane type, has a high emission efficiency and a uniform surface emission.

That is, the present invention focuses on the second electrode provided on the insulating layer on the first electrode layer, wherein the first electrode layer is made of a metal or a semiconductor layer, and the electric characteristics of the second electrode are changed. In order to make the structure easily controllable, on a sheet-like metal surface that is an electron emission surface provided on the insulating layer,
A MIM-type cold cathode device characterized in that a metal having an electrical characteristic different from that of the electron emission surface is provided as a pattern electrode at predetermined intervals.

Further, the present invention is another embodiment different from the above-described cold cathode device, that is, the MIM type cold cathode device as described above, wherein the flattening of the electron emission surface can be more easily performed. A first electrode layer, an insulating layer, and a second electrode layer, which is a similar pattern electrode as described above, are sequentially formed on the substrate in multiple layers, and after a planarization process,
The MIM type cold cathode device further includes a sheet-shaped metal layer serving as an electron emission surface.

By providing a pattern electrode having a lower resistance than the metal of the electron emission surface, for example, as the second electrode layer on the electron emission surface, the electron emission surface is easily flattened structurally, and Even if the electron-emitting metal is thinned, the sheet resistance of the device does not increase, and the electron emission efficiency and the surface uniformity of electron emission can be improved.

The present invention also provides a MIM type cold electrode having an excellent electron-emitting surface as described above, in which a first electrode layer, an insulating layer and a second electrode layer are sequentially formed on a substrate in multiple layers. Provided is a method for manufacturing a cathode device.

That is, in the first manufacturing method, a sacrificial layer is further formed on a flat metal layer which is sequentially laminated on a substrate in the form of a first electrode layer, an insulating layer and an electron emission surface. After the formation, a photoresist is formed in a predetermined pattern. After the sacrificial layer is selectively removed through a pattern mask of the photoresist, a low electric resistance material for forming the second electrode layer is selectively formed. To be deposited.

Next, using the photoresist as a pattern mask, the remaining resist is removed by etching, and the exposed sacrificial layer is removed by anisotropic etching.

Further, the second manufacturing method according to the present invention for further improving the flattening of the electron emission surface and improving the emission efficiency and the uniformity of the surface emission thereof is different from the first manufacturing method described above. A major difference is that a second electrode is first provided as a pattern electrode on an insulating layer, and a sheet-shaped metal layer serving as an electron emission surface is provided on the surface after the planarization process.

That is, after forming a first electrode layer on the substrate by lamination, a first groove pattern is formed on the first electrode layer via a predetermined pattern mask.

Next, an insulating layer is laminated and formed on the first electrode layer.
After that, a second groove pattern is formed on the insulating layer via a pattern mask similar to the first groove pattern .

Next, a low electric resistance material for forming a second electrode layer is selectively deposited on the second groove pattern.

Next, after flattening the second electrode layer to the surface of the insulating layer, a sheet-like metal layer is formed on the entire surface. Then, if necessary, the metal layer can be easily made a flattened electron emission surface by a conventionally known method.

As described above, the contamination of the electron emission surface during the manufacturing process can be significantly reduced, and the MIM type electron emission surface can be more effectively and easily flattened. A method for manufacturing a cold cathode device can be provided.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of a MIM-type cold cathode device having an electron emission surface and a method of manufacturing the same in which a first electrode layer, an insulating layer, and a second electrode layer are sequentially formed on a substrate according to the present invention in multiple layers is described. Will be further described.

Therefore, in the present invention, the second electrode layer comprises:
As already described above, the second electrode layer connected to the electron emission surface 4 as shown in FIG. 1 may be formed in a face-up type, and as already described above, the electron emission layer may be formed as shown in FIG. A face-down type may be formed on the surface 4.

In the present invention, the second electrode layer thus formed preferably has an electric resistance lower than the electric resistance of the electron emission surface 4.

In any of these cases, it can be easily formed in a predetermined pattern, and the width of the pattern electrode and the film thickness can be appropriately formed to a desired thickness. is there.

Therefore, the electric characteristics of the second electrode layer, in particular, in the present invention, the electric resistance of the second electrode layer can be easily controlled in terms of material, volume and area to form a structure which can be formed. is there.

The second electrode layer material is preferably an electrode made of a metal material which is a good conductor.

The electron emission surface is preferably flatter in order to improve the surface characteristics of electron emission. Therefore, in the present invention, a conventionally known flattening treatment can be appropriately used as needed, depending on the metal material, its forming method and its film thickness.

The embodiment shown in FIG. 1 is a so-called face-up type according to the present invention, which has already been described above. In FIG. 1, the metal layer 4 which is the electron emission surface has a thickness of:
Usually, it is preferably about 10 nm. In addition, if a uniform film can be formed, it is more preferable that the thickness be smaller than 10 nm.

As described above, the face-up or face-down type second electrode layer 5 formed on the electron emission surface reduces the sheet resistance when a bias voltage is applied in the present invention. It is provided for the purpose. Therefore, it is important that the second electrode layer is electrically connected (conductive) in both types (types).

The second provided for the purpose of reducing the resistance as described above
The thickness of the electrode layer 5 is preferably more than 10 nm in order to ensure uniformity.

Here, the bias voltage is applied to the electron emission surface 4 by applying a bias voltage between the first electrode layer 2 made of metal or semiconductor on the substrate 1 and the second electrode layer 5 described above. Can release electrons into the vacuum. The electrons are emitted from the surface of the electron emission surface 4 of the electrode-receiving layer 5.

As described above, in order to sufficiently reduce the sheet resistance of the first electrode layer 5, it is preferable to increase the cross-sectional area thereof.
For the reason described above, such adjustment of the resistance can be easily and appropriately formed structurally when the electrode layer 5 is formed.

The metal layer for reducing the sheet resistance does not need to be a metal, but may be a conductive semiconductor film such as doped polysilicon.

The embodiment shown in FIG. 2A is a so-called face-down type according to the present invention, which has already been described above.

In order to form such a face-down type, as shown in FIG. 2 (b), a second electrode layer 5 is previously formed in a pattern on a first electrode layer 2 which is laminated and formed on a substrate 1. The formation of the first groove pattern 8a, 8b, 8c and the formation of a groove for the second electrode layer is a feature different from the face-up type (see FIG. 1) already described above. .

Next, an insulating layer 3 having a shape similar to the groove pattern is formed. That is, the second electrode layer 5
9a, 9b, 9 of the second groove pattern corresponding to the pattern
The feature is that c is formed so as to have a male-female relationship.

Therefore, on such a base structure, FIG.
As shown in FIG. 3A, the second electrode layer 5 and the electron emission surface 4 are formed face-down.

As described above, by adopting the face-down type as described above, as is apparent from FIG. 2A, a flat shape without any obstruction is obtained. It can be clearly seen that the flattening method makes it easy to flatten the electron emission surface 4 of the finally obtained cold cathode device.

With reference to FIG. 3, an embodiment of the manufacturing method of the above-described face-up type cold cathode device having the MIM type electron emission surface according to the present invention will be further described below as an example.

As shown in FIG. 3A, a first electrode layer 2, an insulating layer 3, and a metal layer 4 which is a metal and is an electron emission surface are sequentially formed on the substrate 1 in a multilayer manner. A multilayer film is formed.

Next, after the sacrificial layer 7 is formed, a photoresist is formed thereon in a predetermined pattern, and the photoresist is formed through the photoresist pattern mask 6 in FIG.
As shown in FIG. 7, the sacrificial layer 7 is selectively removed by anisotropic etching.

Here, the material used for the sacrificial layer 7 is such that the metal layer 4 has resistance or selectivity to etching.
For example, metal oxides such as aluminum oxide and SiO ₂ are preferable. Here, in the case of aluminum oxide, for example, when the metal layer 4 uses aluminum, it can be easily formed by, for example, an anodic oxidation method.

Next, as shown in FIG.
A low electric resistance material for forming the second electrode layer 5 is selectively deposited by sputtering or the like. In this case, preferably,
As a measure of the deposition thickness, it is preferable that the film thickness deposited in the pattern groove is slightly higher than the sacrificial layer 7, as is apparent from FIG.

The reason is as shown in FIG.
The photoresist 6 remaining in the previous step and the second on the layer
This is because the surface of the second electrode layer 5 to be formed can be easily cleaned after removal and removal by lift-off, including the electrode layer material.

Next, after being removed by this etching, the exposed sacrificial layer 7 (see FIG. 3D) is removed by anisotropic etching to obtain an electron-emitting metal layer as shown in FIG. As a method of closely connecting the second electrode layer 5 to the fourth electrode 4, a so-called face-up type MIM type cold cathode device can be obtained.

As described above, by using the sacrificial layer 7 as an intermediate step, the electron emission surface 4 can be completely covered and completely prevented from being contaminated until the final step of the production. It is.

[0050]

As described above, according to the present invention, in a MIM type cold cathode device having an electron emitting surface, a so-called face-up type or face-down type By connecting and forming a pattern electrode layer (second electrode layer) having a lower electric resistance than the emission metal surface, the electron emission surface is easily flattened structurally, and
Even if the surface layer is thinned, the influence of the sheet resistance of the cold cathode device can be reduced, the controllability of the applied voltage at the time of electron emission is improved, and the emission efficiency and the surface uniformity of electron emission can be improved.

Further, according to the present invention, it is possible to remarkably reduce the contamination of the electron emission surface, and to manufacture a MIM type cold cathode device capable of further flattening the electron emission surface. We can provide a method.

[Brief description of the drawings]

FIG. 1 is a schematic sectional perspective view of an embodiment of a MIM type cold cathode device according to the present invention.

FIG. 2 is a conceptual sectional perspective view of another embodiment of the MIM type cold cathode device according to the present invention.

FIG. 3 is a process diagram illustrating a method of manufacturing a MIM-type cold cathode device according to the present invention.

FIG. 4 is a schematic sectional view of a conventional MIM type cold cathode device.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 first electrode layer (metal layer or semiconductor layer) 3 insulating layer 4 electron emission surface (or electron emission metal layer) 5 second electrode layer 6 photoresist 7 sacrificial layer 8a, 8b, 8c first groove pattern 9a, 9b, 9c Second groove pattern

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 1/312 H01J 9/02

Claims (9)

(57) [Claims] An MI having an electron emission surface formed by sequentially forming a multilayer of a first electrode layer, an insulating layer and a second electrode layer on a substrate.
In the M-type cold cathode device, the first electrode layer is made of a metal or a semiconductor layer, a sheet-shaped metal layer is provided on the entire surface of the insulating layer, and a predetermined interval is provided on the sheet-shaped metal layer. An MIM-type cold cathode device, comprising: the second electrode layer patterned by the method described above; and using a metal layer to be electroded between the second electrode layers as the electron emission surface. 2. The MIM type cold cathode device according to claim 1, wherein the second electrode layer has a lower electric resistance than an electric resistance of the metal layer on the electron emission surface. 3. The MIM type cold cathode device according to claim 1, wherein the metal layer on the electron emission surface is flattened. 4. An MI having an electron emission surface formed by sequentially forming a multilayer of a first electrode layer, an insulating layer and a second electrode layer on a substrate.
In the M-type cold cathode device, the first electrode layer is made of a metal or a semiconductor layer, and the first electrode layer is a predetermined first electrode layer.
A groove pattern, wherein the insulating layer has a second groove pattern similar to the first groove pattern, and the second electrode layer is provided so as to fill the second groove pattern;
In addition, a metal layer formed on a flat surface which is flattened in accordance with the insulating layer surface is used as the electron emission surface. 5. The MIM-type cold cathode device according to claim 4, wherein the second electrode layer has an electric resistance lower than an electric resistance of the metal layer on the electron emission surface. 6. The MIM type cold cathode device according to claim 4, wherein said second electrode layer is a metal electrode. 7. The M according to claim 4, wherein the metal layer on the electron emission surface is flattened.
IM type cold cathode device. 8. An MI having an electron emission surface in which a first electrode layer, an insulating layer, and a second electrode layer are sequentially formed on a substrate in multiple layers.
In the method for manufacturing an M-type cold cathode device, a step of sequentially laminating and forming the first electrode layer, the insulating layer, and a sheet-like metal layer on the substrate; and further, after forming a sacrificial layer, Forming a resist in a predetermined pattern, and selectively removing the sacrificial layer via the pattern mask of the photoresist; and then selectively removing a low electrical resistance material for forming the second electrode layer. Depositing, and then removing the remaining photoresist by etching using the photoresist pattern mask, and removing the exposed sacrificial layer by anisotropic etching. A method for manufacturing a MIM type cold cathode device, which is characterized by the following. 9. An MI having an electron emission surface in which a first electrode layer, an insulating layer, and a second electrode layer are sequentially formed on a substrate in multiple layers.
In the method for manufacturing an M-type cold cathode device, a step of forming a first groove pattern on the first electrode layer via a predetermined pattern mask after forming the first electrode layer on the substrate by lamination. Next, the insulating layer is laminated and formed on the first electrode layer.
And then, through a pattern mask similar to the first groove pattern, and forming a second groove pattern on the insulating layer, then, low electricity to form the second electrode layer on said second groove pattern A step of selectively depositing a resistive material, and then, after flattening according to the surface of the insulating layer, forming a sheet-shaped metal layer on the entire surface, performing at least a flattening process, Forming an emission surface; and a method for manufacturing a MIM-type cold cathode device.