KR20070012133A - Electron emission device and electron emission display device having the same and method for manufacturing thereof - Google Patents

Abstract

An electron emission device, an electron emission display device having the same, and a method for manufacturing thereof are provided to improve a withstand voltage by forming double diffusion barriers between the auxiliary electrode and the insulating layer. A cathode electrode(21) having a predetermined shape is formed on a substrate(20). An auxiliary electrode(22) is formed on one side of the cathode electrode by using a metal having resistance lower than resistance of the cathode electrode. A first diffusion barrier(23) is formed to surround the auxiliary electrode. A second diffusion barrier(24) is formed on the first diffusion barrier. An oxide layer is formed on the second diffusion barrier. A gate insulating layer(26) is formed by using an insulating material on the oxide layer. A gate electrode(27) is formed by using a metal material on the gate insulating layer.

Description

ELECTRON EMISSION DEVICE AND ELECTRON EMISSION DISPLAY DEVICE HAVING THE SAME AND METHOD FOR MANUFACTURING THEREOF

1A to 1C are diagrams showing an example of a manufacturing process of a conventional electron emitting device.

2A to 2D show a first embodiment according to the present invention.

3A to 3C show a second embodiment according to the present invention.

4 is a diagram illustrating an example of an electron emission display device constructed according to an exemplary embodiment of the present invention.

*** Description of the main symbols in the drawings ***

22, 32, 42: auxiliary electrode 25, 35, 45: third diffusion barrier layer

23, 33, 43: first diffusion barrier layer 26, 36, 46: gate insulating layer

24, 34, 44: second diffusion barrier layer 27, 37, 47: gate electrode

The present invention relates to an electron emission device, an electron emission display device including the same, and a method of manufacturing the same. More particularly, the present invention provides an electron emission device in which a diffusion barrier layer is formed to prevent diffusion of an auxiliary electrode due to heat treatment of a gate insulating layer. And an electron emission display device including the same and a method of manufacturing the same.

Recently, a flat panel display such as a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescent display (ELD), an electron emission display (EED), or the like Is actively being researched and developed. Among these, the electron emission display device includes an electron emission area that includes an electron emission device and emits an electron, and an image expression area that emits emitted electrons by colliding with a fluorescent layer to emit light. In particular, an electron emission display device using carbon nanotubes has advantages of a cathode ray tube (CRT) having excellent image characteristics such as high definition, high resolution, and a wide viewing angle, and a flat panel display characterized by light weight, thinness, and low power consumption. It is an ideal display device that combines bays. In general, an electron emission device has a method using a hot cathode and a cold cathode as an electron source. The electron-emitting devices using the cold cathode are Field Emitter Array (FEA), Surface Conduction Emitter (SCE), Metal-Insulator-Metal (MIM), Metal-Insulator-Semiconductor (MIS), and BSE (Ballistic). electron surface emitting) and the like are known.

The FEA type electron emitting device uses a low work function or high β function as an electron emission source and uses the principle that electrons are emitted by an electric field difference in vacuum. In addition, devices using electron emission sources for nanomaterials have been developed.

The SCE type electron emission device is a device in which an electron emission part is formed by providing a conductive thin film between two electrodes disposed to face each other on a substrate and providing a micro crack in the conductive thin film. The device utilizes a principle that electrons are emitted from the electron emission portion, which is the fine gap, by applying a voltage to an electrode to flow a current to the surface of the conductive thin film.

The MIM and MIS type electron emission devices each form an electron emission portion composed of a metal-dielectric layer-metal (MIM) and a metal-dielectric layer-semiconductor (MIS) structure, and are disposed between two metals or metals and semiconductors having a dielectric layer interposed therebetween. When a voltage is applied to the device, a device using the principle of emitting electrons while moving and accelerating from a metal having a high electron potential or a metal having a low electron potential toward the metal.

The BSE type electron emitting device forms an electron supply layer made of a metal or a semiconductor on an ohmic electrode by using the principle that electrons travel without scattering when the size of the semiconductor is reduced to a dimension area smaller than the average free stroke of electrons in the semiconductor. And an insulating layer and a metal thin film formed on the electron supply layer to emit electrons by applying power to the ohmic electrode and the metal thin film.

Like the CRT (Cathode-Ray Tube), the electron-emitting device operates by cathode polarization (self-light source, high efficiency, high luminance and wide luminance region, natural color and high color purity, wide viewing angle), and operating speed. Due to the advantages of lighting, the operating temperature range is wide, it can be used in various fields, and active research has been made until recently.

1A to 1C are diagrams illustrating a manufacturing process of a conventional electron emitting device.

Referring to FIGS. 1A to 1C, a conventional electron emission device first deposits a transparent electrode (ITO) on a substrate 10 using a sputtering method, and then forms a cathode electrode patterned through an etching process. 11) form. The cathode electrode 11 may be formed in a screen printing manner by an ITO paste having a viscosity and a solid component suitable for printing.

Then, the auxiliary electrode 12 is formed on at least one surface of the cathode electrode 11. The auxiliary electrode 12 is formed to improve the resistance of the cathode electrode 11, and may use silver (Ag). (Figure 1a)

Next, the gate insulating layer 13 is formed by screen printing and printing the insulating material on the auxiliary electrode 12, followed by heat treatment and drying.

The gate insulating layer 13 is formed using an insulating material composed mainly of ceramic materials such as SiOx and PbO, and insulates the auxiliary electrode 12 and the cathode electrode 10 from the gate electrode 14. Thereafter, the gate electrode 14 is formed on the gate insulating layer 13.

The gate electrode 14 uses a metal having excellent conductivity, and may be formed by forming and then etching a metal layer by a sputtering method. (Fig. 1b)

After the structures are formed in the above-described order, the holes 15 are patterned in a predetermined shape, and the electron emission sources 16 are formed on the cathode electrode 11 exposed by the holes 15. As the material used as the electron emission source 16, a carbon-based material such as graphite, diamond, diamond-like carbon or C60, a nano-material such as carbon nanotubes (CNT) or silicon nanowires, and the like may be used. It may be a species or a mixture of two or more kinds. (Figure 1c)

In the conventional electron emission device as described above, the material of the auxiliary electrode 12 formed to improve the resistance of the cathode electrode 11 is diffused into the gate insulating layer 13 due to the heat treatment process performed after the insulating layer 13 is formed. do. Therefore, the problem which reduces the withstand voltage grade of an electron emitting element arises.

Accordingly, the present invention is to solve the above problems of the conventional electron emitting device, an object of the present invention is to apply a diffusion barrier between the auxiliary electrode and the insulating layer in order to prevent the phenomenon that the auxiliary electrode is diffused into the insulating layer, preferably It is an object of the present invention to provide an electron emitting device for forming a double barrier layer.

As a technical means for achieving the above object, the first aspect of the present invention is a substrate, a cathode electrode formed in a predetermined shape on the substrate, at least one surface of the cathode electrode using a metal having a lower resistance value than the cathode electrode An auxiliary electrode formed on the first diffusion barrier layer formed around the auxiliary electrode, a second diffusion barrier layer formed on the first diffusion barrier layer, and a gate insulation layer formed using an insulating material on the second diffusion barrier layer, A gate electrode formed in a predetermined shape using a metal material on the gate insulating layer, and a metal oxide layer formed in the form of a thin film on the second diffusion barrier layer by oxidizing the second diffusion barrier layer after a predetermined thermal process. It is to provide an electron emitting device.

The second aspect of the present invention is a first substrate in which an electron emitting device is formed on one side, the inner side of the first substrate spaced apart at a predetermined interval and facing the surface of the first substrate is emitted from the electron emitting device And a spacer spaced apart from each other at predetermined intervals by a second substrate on which an image display area for emitting light is formed as the electrons collide with each other. The present invention provides an electron emission display device which is an electron emission device according to claim 5.

According to a third aspect of the present invention, (a) forming a cathode electrode and an auxiliary electrode on a substrate, (b) sequentially forming a titanium nitride film and a titanium film in a form surrounding the auxiliary electrode, and (c) the titanium Forming a gate insulating layer on the film and performing a heat treatment to form a titanium oxide film on the titanium film; and (d) forming a gate electrode on the titanium oxide film. It is.

Hereinafter, described in detail with reference to the drawings showing a preferred embodiment of the present invention.

2A to 2D show a first embodiment of an electron emitting device according to the present invention.

Referring to FIGS. 2A to 2D, the electron emission device according to the first embodiment of the present invention, first, the cathode electrode 21 on the substrate 20 in a predetermined shape according to the size and number of each device. Pattern. On the other hand, the cathode electrode 21 can be formed by screen printing by ITO paste having a viscosity and a solid component suitable for printing.

Next, the auxiliary electrode 22 is formed on at least one surface on the cathode electrode 21. The auxiliary electrode 22 lowers the resistance of the cathode electrode 21, thereby reducing the voltage drop. In this case, the auxiliary electrode 22 may be formed using silver (Ag). (FIG. 2A)

In a subsequent process, the first diffusion barrier layer 23 is formed in the form of enclosing the auxiliary electrode 22, and the first diffusion barrier layer 23 is assisted by a thermal process performed when the gate insulation layer 26 is formed. Silver (Ag) used as the electrode 22 serves to prevent the diffusion into the gate insulating layer 26. If the gate insulating layer 26 is formed immediately without forming the first diffusion barrier layer 23 on the auxiliary electrode 22, the heat treatment process of about 570 ° is performed after the gate insulating layer 26 is formed. Since silver (Ag) diffuses into the gate insulating layer 26, material properties of the gate insulating layer 26 may be changed. A titanium nitride (TiN) film is used as the first diffusion barrier layer 23 and is formed on the auxiliary electrode 22 by a sputtering method.

The second diffusion barrier layer 24 is formed on the first diffusion barrier layer 23 for the same reason as the first diffusion barrier layer 23 described above, and the second diffusion barrier layer 24 is a first diffusion barrier layer using a titanium (Ti) film. It is formed on the 23 by the sputtering method.

Meanwhile, the titanium (Ti) film used as the second diffusion barrier layer 24 is oxidized when the heat treatment process is performed to form the titanium oxide based (TiOx) film 25. As a result, the diffusion barrier layers 23, 24, and 25 may be formed in a triple structure to more stably prevent the diffusion of silver (Ag). (FIG. 2B)

The gate insulating layer 26 is formed on the second diffusion barrier layer 24, and the gate insulating layer 26 is formed by screen printing, printing, heat treatment, and drying the insulating material. In this case, the insulating material may be a ceramic material such as SiOx, PbO, etc., and insulates the auxiliary electrode 22, the cathode electrode 20, and the gate electrode 27.

A gate electrode 27 is formed on the gate insulating layer 26. In this case, the gate electrode 27 may be formed by forming and then etching a metal layer (not shown) by a sputtering method. As the metal layer, a metal having excellent conductivity is used. (FIG. 2C)

After forming the above-described structures, a hole 27 is formed in a predetermined pattern, and an electron emission source 28 is formed on the cathode electrode 20 inside the formed hole 27. As the material used as the electron emission source 28, a carbon-based material such as graphite, diamond, diamond-like carbon or C60, a nano-material such as carbon nanotubes (CNT) or silicon nanowires may be used. It may be a single species or a mixture of two or more species. (FIG. 2D)

The electron emitting device according to the first embodiment described above is an electron emitting device using a principle that electrons are emitted by an electric field difference in vacuum by using a material having a low work function or a high β function as an electron emission source. .

3A to 3C show a second embodiment of the electron emitting device according to the present invention.

Referring to FIGS. 3A to 3C, the electron emission device according to the second exemplary embodiment of the present invention first forms the cathode electrode 31 on a substrate 30 in a predetermined shape. In this case, the cathode electrode 31 may be formed by depositing aluminum on the substrate 30 and selectively wet etching aluminum to pattern the aluminum.

Next, the auxiliary electrode 32 is formed on one surface of the cathode electrode 31 by using a metal having excellent conductivity for improving the resistance value of the cathode electrode 31. That is, by forming the auxiliary electrode 32 on the cathode electrode 31, the resistance of the cathode electrode 31 is lowered, thereby reducing the voltage drop. In this case, the auxiliary electrode 32 may be formed using silver (Ag). (FIG. 3A)

In a subsequent process, the first diffusion barrier layer 33 is formed on the auxiliary electrode 32 in the form of surrounding the auxiliary electrode 32. The first diffusion barrier layer 33 serves to prevent the silver (Ag), which is the auxiliary electrode 32, from being diffused into the gate insulation layer 36 due to a thermal process performed when the gate insulation layer 36 is formed. . A titanium nitride (TiN) film is used as the first diffusion barrier layer 33, and may be formed on the auxiliary electrode 32 by sputtering.

The second diffusion barrier layer 34 is formed on the first diffusion barrier layer 33 for the same reason as the first diffusion barrier layer 33 described above, and the second diffusion barrier layer 34 is a first diffusion barrier layer using a titanium (Ti) film. It is formed on the 33 by a sputtering method. In addition, the titanium (Ti) film used as the second diffusion barrier layer 34 is oxidized when the heat treatment process is performed to form a titanium oxide (TiOx) film 35. As a result, the diffusion barrier layer may eventually be formed in a triple structure to more stably prevent the diffusion of silver (Ag). (FIG. 3B)

Subsequently, the gate insulating layer 36 is formed on the titanium oxide (TiOx) by screen printing an insulating material and printing the same, followed by heat treatment and drying. As an insulating material, a ceramic material such as SiOx or PbO may be used, and the gate insulating layer 26 insulates the auxiliary electrode 32, the cathode electrode 30, and the gate electrode 37. In addition, the gate insulating layer 36 is formed of a thin film so that electrons from the cathode electrode 30 can tunnel.

A gate electrode 37 is formed on the gate insulating layer 36, and the gate electrode 37 may be formed by using a metal having excellent conductivity, and then etching and forming a metal layer by a sputtering method. (FIG. 3C)

The electron emitting device according to the second embodiment described above has a structure in which a thin insulating layer exists between two electrodes, and when a voltage is applied to the gate electrode 37, the gate electrode 37 is formed of electrons tunneling the thin insulator. It is based on the principle that electrons having energy higher than the work function of (1% or less) are emitted toward the anode (not shown).

4 is a diagram illustrating an example of an electron emission display device configured according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the electron emission display device according to the present invention includes a lower substrate 40 and an upper substrate 50 and emits electrons from the lower substrate 40 to the upper substrate 50. The image is displayed by transmitting.

The cathode electrode 41 is formed on the lower substrate 40, and the auxiliary electrode 42 for controlling the resistance of the cathode electrode 41 is formed on the cathode electrode 41. Next, the first diffusion insulating layer 43 is formed to surround the auxiliary electrode 42, and the second diffusion insulating layer 44 is formed on the first diffusion insulating layer 43. A gate insulating layer 46 is formed on the second diffusion insulating layer 44 to insulate the gate electrode 47 and the cathode electrode 41, and a plurality of gate electrodes (above the gate insulating layer 46). 47) is formed. The gate electrode 47 is formed in a line shape perpendicular to the cathode electrode 41 with the gate insulating layer 46 interposed therebetween.

After the formation of the structures, a plurality of grooves 48 penetrating through the gate electrode 47 and the insulating layer 46 are formed, and an electron emission source is formed on the cathode electrode 41 inside the grooves 48. 49) is formed. As the material used as the electron emission source 49, a carbon-based material such as graphite, diamond, diamond-like carbon or C60, a nano-material such as carbon nanotubes (CNT) or silicon nanowires may be used. It may be a species or a mixture of two or more kinds.

The upper substrate 50 faces the lower substrate 40 to form the anode electrode 51, and is discharged from the electron emission source 49 on the surface of the anode electrode 51 at the position opposite to the electron emission source 49. There is provided a fluorescent film 52 which emits light when the electrons collide.

In addition, a spacer 60 is positioned on the surface of the anode electrode 51 between the fluorescent film 52 so as to maintain a constant distance between the lower substrate 40 and the upper substrate 50.

Although the technical idea of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and applicable to all other cold electron emitting devices other than the above-described embodiment. In addition, it will be understood by those skilled in the art that various modifications are possible within the scope of the technical idea of the present invention.

According to the electron emission device according to the present invention, the electron emission display device including the same, and a method of manufacturing the same, a double diffusion preventing layer is formed between the auxiliary electrode and the insulating layer, thereby effectively improving the insulation withstand voltage quality, thereby securing stability of driving the device. can do.

Claims (10)

Board; A cathode electrode formed on the substrate in a predetermined shape; An auxiliary electrode formed on at least one surface of the cathode using a metal having a lower resistance value than the cathode; A first diffusion barrier layer formed to surround the auxiliary electrode; A second diffusion barrier layer formed on the first diffusion barrier layer; An oxide film formed on the second diffusion barrier layer; A gate insulating layer formed using an insulating material on the oxide film; And a gate electrode formed in a predetermined shape using a metal material on the gate insulating layer. The method of claim 1, And the oxide film is formed by oxidizing the second diffusion barrier layer. The method of claim 1, The first diffusion barrier layer is an electron emission device using a titanium nitride (TiNx) film. The method of claim 1, The second diffusion barrier layer is an electron emission device using a titanium (Ti) film. The method of claim 1, The auxiliary electrode is an electron emission device using silver (Ag). A first substrate having an electron emitting device formed on one side thereof; A second substrate spaced apart from the first substrate at a predetermined interval and facing the surface of the first substrate, the second substrate having an image display area for emitting light as electrons emitted from the electron emission device collide with each other; It includes a spacer to space the first substrate and the second substrate at a predetermined interval, The electron emission device is an electron emission device according to claim 1 and 5. The method of claim 6, The electron emitting device A cathode electrode formed in a predetermined shape on the first substrate; An auxiliary electrode formed on at least one surface of the cathode using a metal having a lower resistance value than the cathode; A first diffusion barrier layer formed to surround the auxiliary electrode; A second diffusion barrier layer formed on the first diffusion barrier layer; A gate insulating layer formed of an insulating material on the second diffusion barrier layer and having an insulating hole formed to expose a region of the cathode electrode; A gate electrode formed in a predetermined shape on the gate electrode by using a metal material; An oxide film formed on the second diffusion barrier layer by oxidation of the second diffusion barrier layer after a predetermined thermal process; And And an electron emission source formed of a material having a low work function or a high β function in a predetermined shape in the insulating hole. The method of claim 6, The electron emitting device is A cathode electrode formed in a predetermined shape on the first substrate; An auxiliary electrode formed on at least one surface of the cathode using a metal having a lower resistance value than the cathode; A first diffusion barrier layer formed to surround the auxiliary electrode; A second diffusion barrier layer formed on a predetermined region of the cathode electrode including the first diffusion barrier layer; A gate insulating layer formed of a thin film using an insulating material on a predetermined region of the cathode electrode including the second diffusion barrier layer; A gate electrode formed on the gate insulating layer using a metal material in a predetermined shape; A second diffusion barrier layer is oxidized after a predetermined thermal process and includes an oxide film formed on the second diffusion barrier layer, And emitting electrons having a higher energy than a work function of the gate electrode among electrons tunneling the gate electrode by applying a voltage to the gate electrode. (a) forming a cathode electrode and an auxiliary electrode on the substrate; (b) sequentially forming a first diffusion barrier layer and a second diffusion barrier layer in such a manner as to surround the auxiliary electrode; (c) forming a gate insulating layer on the second diffusion barrier layer and performing heat treatment to form an oxide film on the second diffusion barrier layer; (d) forming a gate electrode on the oxide film. The method of claim 9, The step (b) is a step of depositing by sputtering method using a titanium nitride film as the first diffusion barrier layer, and a titanium film as the second diffusion barrier layer.

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