JPH06231673A - Electron emitting element and its manufacture - Google Patents

Abstract

PURPOSE:To obtain electron sources and image indicating elements in a simple structure with no complex process entailed by forming emitter wiring on an emitter substrate, and concurrently forming a separation layer on the surface of a gate electrode in advance. CONSTITUTION:After a gate electrode 1 including a plurality of through holes has been made, a separation layer is formed over the surface of the electrode 1. Emitter wiring 21 is then formed, and an insulating spacer 2 is formed in an emitter substrate 20 on which an emitter electrode 21 is formed, and the electrode 1 is stuck together with the substrate 20 thereafter on which the electrode 21 and the spacer 2 are formed. Subsequently, each emitter electrode 22 in a minute projection shape is self-adjustably formed using emitter material by means of deposition. After that, the emitter material 12 adhered onto the electrode 1 by means of deposition, is peeled off via the separation layer. Thus as mentioned above, since the electrode 1 provided with the separation layer and the substrate 20 are separately manufactured, and they are stuck together so as to allow each electrode 22 in a minute projection shape to be formed thereafter, there is no need for complex processes such as one for the oblique deposition of the separation layer, so that electron emitting elements can thereby be manufactured in a comparatively simple way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source utilizing the field emission phenomenon, and more particularly to an electron emitting element applied to an image display device, an optical printer, an illuminating lamp and the like and a manufacturing method thereof.

[0002]

2. Description of the Related Art In order to extract electrons from the surface of an object in a normal state, it is necessary to apply energy corresponding to the work function of the object. This is because there is an energy barrier for the work function. Therefore, when a strong electric field is applied to the surface of the object in order to break the energy barrier, the width of the barrier becomes narrow and electrons are emitted by the tunnel phenomenon. This is the field emission phenomenon.

Since the electric field is governed by Poisson's equation, if there is a protrusion, electrons concentrate at the tip. That is, if the projection shape is used, it is possible to cause field emission of electrons at a relatively low voltage, and it can be used as an electron source.

Conventionally, as an example of an electron-emitting device utilizing the field emission phenomenon, Journal of Applied Physics, Vol. 47, No. 12 (December 1976), pages 5248 to 5263 (Journal of Applied Physics, Vol. 47, Number12 (D
ecember1976) 5248-5263.

In this method, as shown in FIGS. 4 (a) to 4 (c), a small hole 1b is formed in the insulating film 2'and the gate electrode 1 formed on the substrate 20, and then the small hole 1b is formed in FIG. 4 (d). As shown in Fig. 4 (e), the peeling layer 11 is provided by the oblique vapor deposition method.
The emitter material 1 toward the inside of the small hole 1b.
For example, Mo (molybdenum) is vapor-deposited as 2 and the small hole 1b is formed.
A conical emitter electrode 22 is formed inside. Release layer 11
Emitter material 12 (M
o) is peeled from the gate electrode 1 through the peeling layer 11,
An electron emitting element as shown in FIG. 4 (f) is obtained. 4 (g) is a perspective view showing the conical emitter electrode 22 formed on the substrate 20 inside the small hole 1b of the electron emitting element.

As another example, Japanese Patent Laid-Open No. 4-9401
2 are disclosed. In this method, as shown in FIG.
As shown in FIG. 5C, the silicon substrate 20 is etched with the mask 4 attached, etching recesses 1c are provided around the mask 4, and thermal oxidation is performed.
As shown in (e), the insulator 2'and the metal 1 (gate electrode) are vapor-deposited in the etching recess 1c, and then the mask 4 is removed, and the insulator 2'is removed by etching leaving the metal 1 (gate electrode). By doing so, as shown in FIG.
By the mask 4, the electron-emitting device having the protruding portion remaining as the emitter electrode is obtained.

Regarding the electron-emitting device manufactured by the former method (FIGS. 4 (a) to 4 (f)), an image display device in which this and an anode electrode (anode) coated with a phosphor are opposed to each other has been developed. Has been done. (Japan Display '86 512 ~ 515
page)

[0008]

However, in the former method, when the peeling layer 11 is formed on the gate electrode 1 by vapor deposition, in order to prevent the peeling layer 11 from being directly vapor deposited on the substrate 20, Vapor deposition on the latter (Fig. 5
In (a) to (f), it is necessary to stop the etching while leaving the mask 4 on the silicon etched in an acute angle, and all of them have the drawback that the process is complicated and difficult.

The present invention is to obtain an electron source and an image display device having a simple structure, which does not require such complicated steps.

[0010]

According to the present invention, a gate electrode having a through hole and an emitter substrate having an electron-emitting microprojection-shaped emitter electrode in a conductive region facing the through hole are provided via an insulating spacer. In the electron-emitting device bonded by means of the above-mentioned method, the conductive region having the emitter electrodes in the form of minute protrusions is formed in an appropriate pattern on the emitter substrate surface.

Further, according to the present invention, a gate electrode having a through hole for allowing electrons to pass therethrough and having a release layer on the surface thereof and an emitter substrate having a conductive region are bonded together via an insulating spacer. A method of manufacturing an electron-emitting device characterized in that an emitter material is vapor-deposited from the release layer side through a through hole, and a microprojection-shaped emitter electrode for emitting electrons is formed on an emitter substrate side facing the through hole. is there.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, an electron-emitting device according to the present invention has an emitter substrate 2 which is bonded to an electrode 1 having a plurality of through holes 1a through an appropriate number of insulating spacers 2.
An appropriate patterned emitter wiring 21 formed on
And the through hole 1a formed on the emitter wiring 21.
The emitter electrode portion 3 has the same number of micro-projection-shaped emitter electrodes 22 as the above.

The fabrication is performed by the steps shown in FIGS. 2 (a) to 2 (k). First, FIGS. 2A to 2C
As shown in FIG. 2, a gate electrode 1 having a plurality of through holes 1a is produced from the gate electrode 1, and subsequently, a peeling layer 11 is applied to the surface of the gate electrode 1 in FIG. The emitter wiring 21 is applied, and the insulating substrate 2 is applied to the emitter substrate 20 on which the emitter electrode 21 is formed as shown in FIG.
As shown in FIG. 2I, after the emitter substrate 20 provided with the emitter electrode 21 and the insulating spacer 2 and the gate electrode 1 are bonded together, FIG. The emitter electrode 22 is formed by vapor deposition using an emitter material (vacuum vapor deposition is suitable, but sputtering is also possible), and then, as shown in FIG. 2 (k), the gate electrode 1 is vapor deposited through the peeling layer 11. The emitter material 12 deposited on the top is peeled off to form an electron-emitting device.

In the electron-emitting device of the present invention, since the peeling layer 11 is formed in advance on the gate electrode 1 having the plurality of through holes 1a, the emitter wiring in the emitter substrate 20 can be obtained without using the oblique vapor deposition method. In the area of 21,
Since the peeling layer 11 does not adhere, the step of oblique vapor deposition becomes unnecessary. That is, the element can be easily manufactured by removing the peeling layer 11 after forming the emitter electrode 22 in the form of minute protrusions.

In the element thus manufactured, when a negative voltage is applied to the emitter with the gate as a reference, electrons are emitted from the tip of the emitter. Some of them directly reach the gate, but most of the electrons pass through the through hole 1 a of the gate electrode 1.

[0016]

In the electron emitting device of the present invention, the emitter substrate 20 is formed with the emitter wiring 21 in the form of a wiring pattern.
Even if the oblique vapor deposition method is not adopted, the minute projection-shaped emitter electrode 22 can be formed relatively easily by vapor deposition.

The method for manufacturing an electron-emitting device according to the present invention is
Since the peeling layer 11 is formed in advance on the surface of the gate electrode 1 for manufacturing, there is no need for a step of oblique vapor deposition as in the conventional case, and there is an effect that an element can be easily formed.

Specific examples of the electron-emitting device and the method for manufacturing the same according to the present invention will be described below. <Example>

First, FIGS. 2A to 2D show a manufacturing process of the gate electrode 1. As the material, 426 alloy was used. 2A, a part of the substrate for forming the gate electrode 1 having a thickness of 0.2 mm is processed in multiple steps by photolithography and wet etching to obtain a film having a thickness of about 10 μm as shown in FIG. 2B. A thin portion was formed, and a plurality of small through-holes 1a each having a diameter of about 8 μm were formed therein as shown in FIG. 2 (c). As shown in FIG. 2D, a photoresist (a positive photoresist in this example) is coated on the upper surface of the gate electrode 1 thus formed, and the amount of the photoresist clogged in the inside of the through hole 1a or wrapping around the lower surface. Was removed by light irradiation from below and development.

On the other hand, FIGS. 2 (e) to 2 (h) are manufacturing steps on the side of the emitter substrate 20. First, using the emitter substrate 20 shown in FIG. 2 (e), the emitter of FIG. The wiring 21 is patterned into an appropriate pattern as shown in FIG. 2G to form an emitter wiring, and the emitter wiring 21 is provided.
As shown in FIG. 2H, the insulating spacer 2 having an appropriate thickness is installed.

First, as shown in FIGS. 2 (f) and 2 (g), the emitter wiring 21 is formed on the glass-made emitter substrate 20 shown in FIG. 2 (e) by vapor deposition, photolithography and etching.
Was formed. The emitter wiring 21 is made of tungsten and has a thickness of 0.2 μm.

Next, the insulating spacer 2 shown in FIG. 2 (h) was provided. The insulating spacer 2 is made of polyimide resin and has a height of about 20 μm. Specifically, first, a photosensitive polyamic acid solution (a positive photosensitive resin solution for forming the insulating spacer 2 made of a polyimide resin by heat treatment) was spin-coated, and prebaking was performed at 90 ° C. for 20 minutes. Then, it was exposed to ultraviolet rays through a photomask, developed, and post-baked at 120 ° C. for 10 minutes, and further cured at 380 ° C. for 1 hour in a high vacuum.
Thus, by using lithographic techniques,
The fine spacer 2 can be formed.

Then, as shown in FIG. 2 (i), the gate electrode 1 and the substrate 20 thus produced are opposed to each other and overlapped, and a part of the periphery is fixed with an epoxy adhesive (or a polyimide resin adhesive or the like). By doing so, the bonding was performed.

After the completion of the bonding, the emitter material 12 shown in FIG. 2 (j) was vacuum-deposited. In this embodiment, tungsten is used as the emitter material 12. Figure 2 (j)
As shown in FIG. 5, the through hole 1a of the gate electrode 1 becomes narrower due to the deposition of the emitter material 12, that is, tungsten as the vapor deposition progresses, and is eventually completely blocked. In this way, the conical cone-shaped emitter electrode 22 having a height of about 15 μm is formed under the through hole 1a.

In this state, the resist as the peeling layer 11 was removed with an organic solvent to remove the tungsten on the gate electrode 1 to complete the electron-emitting device.

The substrate 20 is not limited to glass, but Si, G
An aAs substrate or the like may be used. In that case, the emitter wiring 21 may be provided on the substrate, or a conductive region may be formed in the substrate by ion implantation or the like. Also, other metals can be used for the gate electrode 1. However, the substrate 20
It is important that the difference in thermal expansion coefficient between the gate electrode 1 and the gate electrode 1 is small. The insulating spacer 2 includes an insulator other than polyimide,
For example, SiO ₂ or the like can be used.

The emitter material is a metal such as W (tungsten), Mo (molybdenum) or Ta (tantalum), a boride such as LaB ₆ or the like, a carbide such as TiC or TiN.
It is also possible to use a nitride such as. A material other than a resist can be used for the peeling layer 11, but it is necessary to select an etchant that can remove the insulating spacer without damaging it.

Further, the present invention is a structure of an electron-emitting device described in the claims and a method of manufacturing the electron-emitting device, and is limited to the above materials as long as it does not deviate from the invention described in these claims. Not a thing.

Further, it goes without saying that a light emitting device or an image display device can be manufactured by combining the device thus manufactured with a transparent counter substrate provided with a transparent electrode (anode electrode) and an electron beam excited phosphor.

One method for displaying an image using the electron-emitting device of the present invention is to drive at least two of an emitter, a gate and an anode by XY matrix driving.

FIG. 3 shows the gate electrode 1 and the emitter wiring 21.
FIG. 2 is a schematic view showing an example of an electron-emitting element used in an image display panel in which and are formed in a stripe pattern, and are arranged in a direction orthogonal to each other and bonded to each other, and 2 is an insulating spacer. In FIG. 3, reference numeral 31 denotes a color-emitting phosphor (each color-emitting pattern R, G, B) formed in a stripe pattern for color display, which is superposed on the emitter substrate 20 to which the gate electrode 1 is attached. The counter electrode substrate 30 provided is shown.

In the present invention, the through hole 1a formed in the gate electrode 1 is formed even when the emitter wiring 21 has a stripe pattern or other patterns.
It is not always necessary to limit the formation region of the gate electrode 1 region right above the emitter wiring 21 region, for example, to be wider than the emitter pattern 21 region of the wiring pattern or over the entire surface of the gate electrode 1. You may. Since the emitter protrusion 22 not on the emitter wiring 21 is only invalidated, the positioning becomes easy.

When the gate electrode 1 has a stripe structure, the gate electrode 1 is formed in a state where the stripes are connected to each other by providing connecting portions at both ends of the stripes so that the stripes can be kept parallel to each other. Then, after bonding to the emitter substrate 20 side, the connecting portion may be removed by cutting or the like. However, it is necessary to prevent the extra intrusion of the emitter material 12 when the emitter electrode 22 is vapor-deposited with the emitter material 12 after the attachment by attaching a peeling layer also between the stripes.

[0034]

According to the electron-emitting device of the present invention, the gate electrode having the peeling layer and the emitter substrate are separately manufactured, and the microprojection-shaped emitter electrodes are formed after bonding them together. Without the complicated process of
There is an effect that the electron-emitting device can be manufactured relatively easily.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an example showing the structure of an electron-emitting device of the present invention.

FIG. 2 is an explanatory view showing a manufacturing process of the electron-emitting device of the present invention.

FIG. 3 is a schematic perspective view of a color image display panel using the electron emitting element of the present invention.

FIG. 4 is an explanatory diagram showing an example of a manufacturing process of a conventional electron-emitting device.

FIG. 5 is an explanatory diagram showing another example of a conventional manufacturing process of an electron-emitting device.

[Explanation of sign]

1 ... Gate electrode 1a ... Through hole 1b ... Small hole 1c ...
Etching concave portion 2 ... Insulating spacer 2 '... Insulating layer 3 ... Emitter electrode portion 4 ... Mask layer 11 ... Stripping layer 12 ... Emitter material 20 ... Emitter substrate 21 ... Emitter wiring 22
... Emitter electrode 30 ... Counter electrode substrate 31 ... Phosphor

Claims (2)

[Claims] 1. An electron-emitting device in which a gate electrode having a through hole and an emitter substrate having an electron-emitting microprojection-shaped emitter electrode in a conductive region facing the through hole are bonded together via an insulating spacer, An electron-emitting device characterized in that the conductive region having minute projection-shaped emitter electrodes is formed in an appropriate pattern on the emitter substrate surface. 2. A peeling layer is provided after a gate electrode having a through hole for allowing electrons to pass therethrough and having a peeling layer provided on the surface thereof and an emitter substrate having a conductive region are bonded together via an insulating spacer. A method of manufacturing an electron-emitting device, characterized in that an emitter material is vapor-deposited from the side through a through hole, and a minute projection-shaped emitter electrode for emitting electrons is formed on the side of the emitter substrate facing the through hole.