KR20070046665A - Electron emission device, manufacturing method of the device, and electron emission display device with the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission device capable of easily forming minute openings in a gate electrode and an insulating layer, a method for manufacturing the same, and an electron emission display device using the same. Forming cathodes, the insulating layer and the gate electrodes in sequence, and forming an opening consisting of effective openings spaced apart from each other in the gate electrode and a communicating portion located between at least two effective openings to communicate the effective openings, Etching the portion of the insulating layer exposed by the gate electrode opening to form an opening having the same shape as the gate electrode opening, and forming an electron emission portion on the cathode inside the effective opening.

Gate electrode, insulating layer, cathode electrode, effective opening, communicating part, electron emitting part

Description

ELECTRON EMISSION DEVICE, MANUFACTURING METHOD OF THE DEVICE, AND ELECTRON EMISSION DISPLAY DEVICE WITH THE SAME

1A to 1F are schematic diagrams at each step shown to illustrate a method of manufacturing an electron emitting device according to an embodiment of the present invention.

2 is a partially exploded perspective view of an electron emission display device according to an exemplary embodiment.

3 is a partial plan view of an electron emitting device according to another embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emitting device, and more particularly, to an electron emitting device capable of easily forming minute openings in a gate electrode and an insulating layer, a method of manufacturing the same, and an electron emitting display device using the same.

In general, an electron emission element may be classified into a method using a hot cathode and a method using a cold cathode according to the type of electron source.

Here, the electron-emitting device using the cold cathode is a field emitter array (FEA) type, a surface conduction emission type (SCE) type, a metal-insulation layer-metal Metal (MIM) type and Metal-Insulator-Semiconductor (MIS) type are known.

Among them, the FEA type electron emission device includes an electron emission portion and a driving electrode for controlling electron emission of the electron emission portion, and includes one cathode electrode and one gate electrode, and a work function is formed as a constituent material of the electron emission portion. The use of low or high aspect ratio materials, such as carbon nanotubes and carbon-based materials such as graphite and diamond-like carbon, utilizes the principle that electrons are easily released by an electric field in vacuum.

The electron emission devices are arranged in an array on one substrate to form an electron emission device, and the electron emission device is combined with another substrate having a light emitting unit including a fluorescent layer and an anode electrode to display an electron emission display. A device (electron emission display device) is configured.

Known FEA type electron emission devices have cathode electrodes, insulating layers, and gate electrodes sequentially formed on a substrate, and openings are formed in the gate electrodes and insulating layers to expose a portion of the surface of the cathode electrode, and the cathode electrodes inside the openings. The electron emission portion is disposed on the field.

In the above, the intersection area between the cathode electrode and the gate electrode forms a unit pixel, and as more electron emitters are disposed in one unit pixel, the amount of emission current and emission uniformity can be increased. The amount of emission current is proportional to the brightness of the screen, and the emission uniformity is proportional to the uniformity of emission of the fluorescent layer.

However, in order to arrange a larger number of electron emitters in the limited unit pixel in the above-described structure, a smaller opening must be formed in the gate electrode and the insulating layer, and the smaller the opening of the gate electrode is exposed by the opening of the gate electrode. When the insulating layer portion is etched to form the opening, the etchant is difficult to penetrate into the insulating layer.

As a result, there is a problem that the etching unevenness of the insulating layer is intensified such that a portion of the insulating layer is partially etched or is not etched, thereby making it difficult to form an opening having excellent pattern precision in the insulating layer.

Accordingly, an object of the present invention is to provide an electron emission device, a method for manufacturing the same, and an electron emission display device using the same, which can easily form fine openings in a gate electrode and an insulating layer. have.

In order to achieve the above object, the present invention,

Cathode electrodes, insulating layers, and gate electrodes are sequentially formed on the substrate, and effective openings spaced apart from each other on the gate electrode are formed, and an opening is formed between at least two effective openings and a communicating portion communicating the effective openings. And etching the portion of the insulating layer exposed by the gate electrode opening to form an opening having the same shape as the gate electrode opening, and forming an electron emitting portion over the cathode electrode inside the effective opening. to provide.

The effective opening may be formed to have a planar shape corresponding to the electron emitting portion and the same shape center point as the electron emitting portion, and the communicating portion may be formed to have a width smaller than the width of the effective opening and larger than or equal to 3 μm.

In addition, the effective openings may be formed in a line along the length direction of any one of the cathode electrode and the gate electrode, and a communication portion may be formed between at least two adjacent effective openings along this length direction.

In addition, the present invention, in order to achieve the above object,

A substrate, cathode electrodes formed on the substrate, electron emission portions electrically connected to the cathode electrode, and gate electrodes positioned on the cathode electrodes with an insulating layer interposed therebetween, the gate electrode and the insulating layer being each other It provides an electron emitting device in which an opening is formed of spaced apart effective openings and a communicating portion located between at least two effective openings to communicate the effective openings, the electron emitting section being located inside the effective opening.

In addition, the present invention, in order to achieve the above object,

A gate electrode positioned on the cathode electrodes with the first substrate and the second substrate disposed to face each other, the cathode electrodes formed on the first substrate, the electron emission parts electrically connected to the cathode electrode, and the insulating layer interposed therebetween And an anode electrode formed on any one surface of the fluorescent layers and the fluorescent layers formed on one surface of the second substrate, wherein the effective openings and at least two effective openings in which the gate electrode and the insulating layer are spaced apart from each other, respectively; The present invention provides an electron emission display device in which an opening made up of a communicating portion positioned between the communication portions to communicate effective openings is provided, and the electron emission portion is located inside the effective opening.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A to 1F are schematic diagrams at each step shown to illustrate a method of manufacturing an electron emitting device according to an embodiment of the present invention.

Referring first to FIG. 1A, a conductive film is formed on a substrate 2 and patterned to form stripe cathode electrodes 4, and an insulating material is deposited on the entire substrate 2 over the cathode electrodes 4. Screen printing is performed to form the first insulating layer 6. A conductive film is formed on the first insulating layer 6 and patterned to form gate electrodes 8 having a stripe shape orthogonal to the cathode electrode 4. At this time, the intersection area between the cathode electrode 4 and the gate electrode 8 forms a unit pixel.

Subsequently, an insulating material is deposited or screen printed on the entire substrate 2 over the gate electrodes 8 to form a second insulating layer 10, and a conductive material is coated on the second insulating layer 10 to form the focusing electrode 12. ). The surface of the gate electrode 8 is exposed by partially etching the focusing electrode 12 and the second insulating layer 10 to form respective openings 101 and 121. The openings 121 and 101 of the focusing electrode 12 and the second insulating layer 10 may be formed for each unit pixel.

In this case, since the second insulating layer 10 and the focusing electrode 12 are optional additions, only the cathode electrode 4, the first insulating layer 6, and the gate electrode 8 may be formed on the substrate 2. Do.

Next, as shown in FIGS. 1B and 1C, a mask layer 14 is formed on the structure provided on the substrate 2 and patterned to form an opening 141 exposing a part of the surface of the gate electrode 8. . The mask layer 14 may be formed of a photoresist layer, and is patterned through exposure and development to form the opening 141 described above.

The mask layer openings 141 are formed to have a smaller width than the effective openings 141a between the plurality of effective openings 141a and spaced apart from each other, and the effective openings 141a are adjacent to each other. It consists of a communication part 141b which communicates.

1D and 1E, portions of the gate electrode 8 exposed by the mask layer openings 141 are removed by etching to form the openings 81. The gate electrode opening 81 includes an effective opening 81a and a communicating portion 81b along the shape of the mask layer opening 141.

The effective opening 81a is an opening defined to surround the electron emitting portion by placing the electron emitting portion therein in a subsequent process. The communication portion 81b is an opening located between the adjacent effective openings 81a to communicate the effective openings 81a. The communicating portion 81b provides a movement path of the etching solution of the first insulating layer 6 in a subsequent process. This effective opening 81a has a planar shape corresponding to the planar shape of the desired electron emitting portion, and is formed to have the same shape center point as the electron emitting portion.

Next, a portion of the first insulating layer 6 exposed through the gate electrode opening 81 is etched to form an opening 61 exposing a part of the surface of the cathode electrode 4 to the first insulating layer 6. do.

In this process, as the communicating portion 81b of the gate electrode opening 81 provides a movement path of the first insulating layer 6 etchant, even when the effective opening 81a of the gate electrode 81 has a fine width, Etching of the first insulating layer 6 can be facilitated to form an opening 61 having excellent pattern accuracy in the first insulating layer 6. That is, even when a portion of the etchant infiltrate is weak when the first insulation layer 6 is etched, since the infiltration of the etchant occurs uniformly through the communicating portion 81b, the etching inhomogeneity of the first insulation layer 6 may be eliminated. .

At this time, the communicating portion 81b has a width smaller than the effective opening 81a and is formed to have a width of at least 3 μm so that the etchant of the first insulating layer 6 can be easily transferred to the adjacent effective opening 81a. .

The first insulating layer 6 has an opening 61 formed of an effective opening 61a and a communicating portion 61b corresponding to the shape of the gate electrode opening 81, and is patterned by the gate electrode communicating portion 81b. The opening 61 which is excellent in precision can be formed.

Finally, as shown in FIG. 1F, the electron emission unit 16 is formed on the exposed cathode electrode 4.

The electron emission unit 16 may be formed of materials emitting electrons when applied to an electric field in a vacuum, for example, carbon-based materials or nanometer-sized materials. The electron emission unit 16 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond phase carbons, C ₆₀ , silicon nanowires, and combinations thereof. Chemical vapor deposition or sputtering may be applied.

Thus, according to the manufacturing method of this embodiment, the opening 81 which consists of the effective opening 81a and the communication part 81b is formed in the gate electrode 8, and the 1st insulating layer exposed by this opening 81 is shown. (6) Etching a portion to form the opening 61 facilitates penetration of the etchant into the first insulating layer 6, thereby easily forming a fine opening 61 having excellent shape accuracy in the first insulating layer 6. can do. As a result, a larger number of electron emitters 16 can be arranged in the unit pixel, so that the amount of emission current and emission uniformity can be increased.

Hereinafter, a configuration of an electron emission display device using the electron emission device manufactured through the above-described method will be described with reference to FIG. 2.

Referring to FIG. 2, the electron emission display device includes a first substrate 2 and a second substrate 18 that are disposed to be parallel to each other at predetermined intervals. Sealing members (not shown) are disposed at the edges of the first substrate 2 and the second substrate 18 to bond the two substrates, and the internal space is evacuated with a vacuum of approximately 10 ⁻⁶ torr to form the first substrate 2. ), The second substrate 18 and the sealing member constitute a vacuum container.

On the opposite surface of the first substrate 2 to the second substrate 18, electron emission elements are arranged in an array to constitute the electron emission device 100, and the electron emission device 100 is connected to the second substrate 4. And the light emitting unit 110 provided on the second substrate 18 to form an electron emission display device.

First, cathode electrodes 4, which are first electrodes, are formed on the first substrate 2 in a stripe pattern along one direction (y-axis direction in the drawing) of the first substrate 2, and the cathode electrodes 4 are formed. The first insulating layer 6 is formed on the entire first substrate 2 while covering it. Gate electrodes 8 serving as second electrodes are formed on the first insulating layer 6 in a stripe pattern along a direction orthogonal to the cathode electrode 4 (x-axis direction in the drawing).

An intersection area between the cathode electrode 4 and the gate electrode 8 forms a unit pixel, and a plurality of electron emission units 16 are formed on each unit pixel above the cathode electrode 4. Openings 61 and 81 corresponding to the electron emission portions 16 are formed in the first insulating layer 6 and the gate electrode 8 to expose the electron emission portions 16 on the first substrate 2. Be sure to

The openings 81 of the gate electrode 8 are located between the effective openings 81a corresponding to the electron emission portions 16 and surrounding the at least two effective openings 81a. It consists of a communication part 81b which communicates 81a). The first insulating layer 6 also includes an opening 61 corresponding to the gate electrode opening 81.

In FIG. 2, a configuration in which all of the effective openings 81a positioned in one unit pixel are connected through the communicating portion 81b is illustrated. In FIG. 3, one communicating portion is provided between the pair of effective openings 81a. 81b is formed so that the effective openings 81a form a pair and are connected through the communicating portion 81b. In the embodiment shown in Fig. 3, since the electron emission section 16 is surrounded by the gate electrode 8 over a larger area, the emission efficiency is increased.

The electron emission unit 16 may be formed of materials emitting electrons when a electric field is applied in a vacuum, such as a carbon-based material or a nanometer-sized material. The electron emission unit 16 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, C _60, silicon nanowires _, and combinations thereof.

In the drawing, the electron emission parts 16 are formed in a circular shape and arranged in a line along the length direction of the cathode electrode 4 in each pixel area. However, the planar shape of the electron emission unit 16, the number and arrangement form per pixel area, etc. are not limited to the illustrated example and may be variously modified.

The focusing electrode 12, which is a third electrode, may be formed on the gate electrode 8 and the first insulating layer 6. A second insulating layer 10 is disposed below the focusing electrode 12 to insulate the gate electrode 8 and the focusing electrode 12, and to pass the electron beam through the second insulating layer 10 and the focusing electrode 12. Openings 101 and 121 are provided. In FIG. 2, one opening 121 is provided in each pixel area, and the focusing electrode 12 comprehensively focuses electrons emitted from one pixel area.

Next, on one surface of the second substrate 18 opposite to the first substrate 2, the fluorescent layer 20, for example, the red, green, and blue fluorescent layers 20R, 20G, and 20B may be disposed at random intervals. The black layer 22 is formed between the fluorescent layers 20 to improve contrast of the screen. The fluorescent layer 20 is formed so that the fluorescent layers 20R, 20G, and 20B of one color correspond to the pixel areas set on the first substrate 2.

An anode electrode 24 made of a metal film such as aluminum is formed on the fluorescent layer 20 and the black layer 22. The anode electrode 24 receives a high voltage necessary for accelerating the electron beam from the outside, and reflects the visible light emitted toward the first substrate 2 of the visible light emitted from the fluorescent layer 20 toward the second substrate 18 to improve luminance. Height plays a role.

On the other hand, the anode electrode may be made of a transparent conductive film such as indium tin oxide (ITO) rather than a metal film. In this case, the anode electrode is positioned on one surface of the fluorescent layer 20 and the black layer 22 facing the second substrate 18, and may be formed in plural in a predetermined pattern. In addition, a structure in which the above-described transparent conductive film and the metal film are formed simultaneously on both surfaces of the fluorescent layer 20 and the black layer 22 as an anode electrode is also possible.

Spacers 26 are disposed between the first substrate 2 and the second substrate 18 to support the compressive force applied to the vacuum container, and to maintain a constant gap between the two substrates. The spacers 26 are positioned corresponding to the black layer 22 so as not to invade the fluorescent layer 20.

The electron emission display device having the above configuration is driven by supplying a predetermined voltage to the cathode electrodes 4, the gate electrodes 8, the focusing electrode 12, and the anode electrode 24 from the outside.

For example, any one of the cathode electrodes 4 and the gate electrodes 8 receives a scan driving voltage to serve as scan electrodes, and the other electrodes receive a data driving voltage to serve as data electrodes. The focusing electrode 12 receives a voltage required for electron beam focusing, for example, 0 V or a negative DC voltage of several to several tens of volts, and the anode electrode 24 has a voltage necessary for accelerating the electron beam, for example several hundreds to thousands of volts. A positive DC voltage is applied.

Then an electric field is formed around the electron emission section 16 in the pixels where the voltage difference between the cathode electrode 4 and the gate electrode 8 is greater than or equal to the threshold, and electrons are emitted therefrom. The emitted electrons are focused to the center of the electron beam bundle while passing through the opening 121 of the focusing electrode 12, and attracted by the high voltage applied to the anode electrode 24 to collide with the corresponding fluorescent layer 20 to emit light.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

As described above, according to the method for manufacturing the electron emitting device according to the present invention, adjacent effective openings are communicated with the communicating portions to facilitate the formation of the openings in the first insulating layer. As a result, even if the effective opening is made smaller, the opening having excellent shape accuracy can be formed in the first insulating layer, so that a larger number of electron emitting portions can be arranged in the unit pixel. Therefore, the electron emission device according to the present invention has the effect of improving the display quality by increasing the amount of emission current and emission uniformity.

Claims (11)

Forming cathode and insulating layers and gate electrodes sequentially on the substrate; Forming openings in the gate electrode, the openings being spaced apart from each other and a communicating portion positioned between at least two effective openings to communicate the effective openings; Etching the portion of the insulating layer exposed by the gate electrode opening to form an opening having the same shape as the gate electrode opening; Forming an electron emission portion over the cathode electrode inside the effective opening. The method of claim 1, And a planar shape corresponding to the electron emitting portion and a shape center point identical to the electron emitting portion when the effective opening is formed. The method of claim 1, And forming a width smaller than the width of the effective opening and greater than or equal to 3 μm when forming the communicating portion. The method of claim 1, And the effective openings are formed in a line along the longitudinal direction of one of the cathode electrode and the gate electrode, and the communication portion is formed between at least two adjacent effective openings along the longitudinal direction. The method of claim 1, Forming an additional insulating layer and a focusing electrode over the gate electrodes; And partially etching the focusing electrode and the additional insulating layer to form an opening. The method of claim 1, And forming at least one material selected from the group consisting of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, C ₆₀ and silicon nanowires when forming the electron emitters. A substrate; Cathode electrodes formed on the substrate; Electron emission parts electrically connected to the cathode electrode; And Gate electrodes disposed on the cathode electrodes with an insulating layer interposed therebetween, An opening including a plurality of effective openings in which the gate electrode and the insulating layer are spaced apart from each other, and a communicating portion located between at least two effective openings to communicate the effective openings, And the electron emitting portion is located inside the effective opening. The method of claim 7, wherein And the communication portion is formed with a width smaller than the width of the effective opening and greater than or equal to 3 μm. The method of claim 7, wherein And the effective openings are arranged in a line along the longitudinal direction of one of the cathode electrode and the gate electrode, and the communication portion is located between at least two adjacent effective openings along the longitudinal direction. The method of claim 9, Further comprising a focusing electrode positioned to be insulated from the gate electrode on the gate electrodes, And the focusing electrode forms one opening that simultaneously covers the effective openings. An electron emitting device according to any one of claims 7 to 10; Another substrate disposed to face the substrate; Fluorescent layers formed on one surface of the other substrate; And And an anode electrode formed on one surface of the fluorescent layers.

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