KR100375224B1 - Method for manufacturing of electrode of field emission display - Google Patents

Abstract

Disclosed is an electrode manufacturing method of a field emission device of the present invention. The electrode manufacturing method of the field emission device of the present invention comprises the steps of applying a first photoresist for protecting the gate electrode and the emitter tip on a substrate having a three-pole structure; Forming a metal seed layer for plating on the first photoresist; Applying a second photoresist for forming a focusing electrode pattern on the metal seed layer; Plating the focusing electrode on the opening in which the focusing electrode pattern is formed; And removing the first and second photoresist and the metal seed layer after the plating process of the focusing electrode.

Therefore, by forming a focusing electrode having a uniform height, it is possible to effectively focus electrons emitted from the emitter to improve color purity and simplify the process.

Description

Electrode manufacturing method of field emission device {METHOD FOR MANUFACTURING OF ELECTRODE OF FIELD EMISSION DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display. Specifically, a plating process is performed on a metal seed layer, and then a focusing electrode is formed to obtain a focusing electrode having a uniform height, and the electrons emitted from the emitter. It relates to an electrode manufacturing method of the field emission device to focus effectively.

In general, a thin film type field emission device is a device that emits cold electrons by tunnel effect by applying a relatively low voltage, for example, a voltage of about several tens of volts by using a phenomenon in which an electric field is concentrated on a sharp part of a tip. The field emission device is attracting attention as a next generation display device because it has both the high definition of a cathode ray tube and the light and thin type of a liquid crystal display.

In particular, the field emission device can be manufactured in a light and thin type, and the critical disadvantage of the liquid crystal display device can solve the problems of process yield, manufacturing cost, and size increase.

That is, in the liquid crystal display, if a single unit pixel is defective, the whole product is treated badly. However, in the field emission device, a plurality of smaller unit pixels are formed in one pixel group, thereby causing a defect in one or two unit pixels. Even if the operation of the pixel group does not occur, the yield of the whole product is improved.

In addition, the field emission device has a simple structure, a low power consumption, low unit cost, and a suitable value for a portable display device compared to a liquid crystal display device.

1 to 3 are cross-sectional views showing a gate electrode forming method of the field emission device according to the prior art.

As illustrated in FIG. 1, a resistive layer 120 is formed on a substrate 100 on which a cathode electrode 110 is formed, and a first insulating layer 130 is formed on the resistive layer 120. A gate electrode 150 is deposited on the first insulating layer 130, and the first insulating layer 130 and the gate electrode 150 are etched to form a predetermined hole, and an emitter is formed in the hole. This completes the tripolar structure. The second insulating layer 160 is formed on the tripolar structure and the focusing electrode 170 is formed on the second insulating layer 160. Therefore, the focusing electrode 170 should be formed high in order to bring sufficient focusing effect. However, the focusing electrode 170 is difficult to be formed high, there is a problem that a complicated manufacturing process must be performed.

The field emission device illustrated in FIG. 2 includes a process of forming a second insulating layer 200 on a tripolar structure in which a cathode electrode 110, a gate electrode 150, and an emitter 140 are formed. In this case, a complicated process in which the insulating layer is formed to have a height of 2 μm should be performed, and the degree of focusing is fixed according to the structure of the device.

3 is a method disclosed in patent 5,528,103 filed by candescent, and has a structure in which a focusing electrode 360 is formed next to a gate electrode 350. In this case, the focusing electrode 350 is formed to be at least 10 times the thickness of the gate electrode 350 to focus electrons emitted from the emitter.

A method of manufacturing a field emission device in which a focusing electrode 360 is formed next to the gate electrode 350 includes forming a resistive layer 320 on a substrate 300 on which a cathode electrode 310 is formed, and the resistive layer 320. ) Forming an insulating layer 330 on the insulating layer 330 and forming a lower metal thin film of the gate electrode 350 and the focusing electrode 360 on the insulating layer 330 in the same line and on the lower metal thin film Applying a photoresist and simultaneously patterning the gate electrode 350 and the lower metal thin film; and forming a condensation electrode 360 on the patterned lower metal thin film.

In this case, when the gate electrode and the metal seed layer are the same material, a material having good electrical conductivity cannot be used, thereby causing a problem in that plating non-uniformity and material selection are restricted.

The present invention, in order to effectively solve the above problems of the prior art, by applying a first photoresist on a substrate having a tripolar structure, then forming a metal seed layer, patterning the pattern of the focusing electrode on the metal seed layer Coating a second photoresist, forming a focusing electrode in the hole of the second photoresist by using a plating process, and removing the second photoresist, the metal seed layer, and the first photoresist; The purpose is to provide an electrode.

1 to 3 are diagrams showing the shape of a focusing electrode of a conventional field emission device.

4A to 4H are views showing a process of manufacturing the focusing electrode of the field emission device of the present invention.

<Description of the symbols for the main parts of the drawings>

400: substrate 410: cathode electrode

420: resistive layer 430: insulating layer

440: gate electrode 450: emitter tip

460: first photoresist 470: metal seed layer

480: second photoresist 490: focusing electrode

The electrode manufacturing method of the field emission device of the present invention for achieving the above technical problem is a process of applying a first photoresist for protecting the gate electrode and the emitter tip on a substrate having a three-pole structure; Forming a metal seed layer for a plating process on the first photoresist; Applying a second photoresist for forming a focusing electrode pattern on the metal seed layer; Plating a focusing electrode on an opening in which the focusing electrode pattern is formed; And removing the first and second photoresist and the metal seed layer after the plating process of the focusing electrode.

Hereinafter, a method of manufacturing an electrode of a field emission device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 4 and 5.

As shown in FIG. 4A, the resistive layer 420 is formed on the substrate 400 on which the cathode electrode 410 is formed. In addition, an insulating layer 430 is formed on the substrate 400 on which the resistance layer 420 and the cathode electrode 410 are formed, and the gate electrode 440 is deposited thereon. after that. The insulating layer 430 and the gate electrode 440 are etched by an isotropic etching process to form a predetermined hole 442 in the insulating layer 430 and the gate electrode 440. In this case, the gate electrode 440 protrudes a predetermined distance toward the hole 442. Accordingly, when the metal such as molybdenum is vertically deposited in the hole 442 by using the electron beam deposition method, a conical emitter 450 is formed.

Thereafter, the gate electrode 440 is formed to have a structure intersecting with the cathode electrode 410 is patterned. In this case, the gate electrodes 440 on both sides of the hole 422 in which the emitter 420 is formed are partially etched, and the above structure is a three-pole structure of a general field emission device.

As shown in FIG. 4B, a first photoresist 460 is coated on the substrate on which the tripolar structure is formed. The first photoresist 460 is applied to the gate electrode 440 and the exposed emitter 450 to protect the exposed gate electrode 440 and the emitter 450 from damage.

At this time, the thickness of the first photoresist 460 is most suitable about 5 ~ 8㎛. This is because when the thickness of the first photoresist 460 is less than or equal to 2 μm, the first photoresist 460 is damaged and it is not easy to remove the first photoresist 460 later. On the other hand, when the thickness of the first photoresist 460 is thick, there is a problem that the desired pattern formation cannot be easily formed when forming the pattern of the focusing electrode.

As illustrated in FIG. 4C, the metal seed layer 470 is deposited on the entire surface of the substrate on which the first photoresist 460 is applied. The metal seed layer 470 is first formed with an adhesion layer such as Ti, Nb having good adhesion to increase the adhesion with the insulating layer 430, and then fully deposited. In this case, the metal seed layer 470 may be formed of the same metal as the gate electrode 440, and a metal having good electrical conductivity, such as Cu, Au, Ag, or the like, is generally used as the metal seed layer 470.

Thereafter, as shown in FIG. 4D, the second photoresist 480 is applied and patterned. In this case, a predetermined opening is formed on the lower end 472 on which the metal seed layer 470 is deposited.

As shown in FIG. 4E, a plating process is performed in the opening 472 to form the focusing electrode 490. At this time, by performing a plating process on the metal seed layer 470, the plating speed is adjusted as the distance from the voltage applying unit is adjusted to uniformly form the height of the focusing electrode.

Meanwhile, when the focusing electrode 490 is formed, the height of the highest portion of the focusing electrode 490 is preferably smaller than the height of the second photoresist 480.

4F and 4G, when the plating process is completed, the second photoresist 480 is removed, and then the exposed metal seed layer 470 is removed by etching.

After the etching process, as shown in FIG. 4H, the first photoresist 460 is removed to complete the field emission device having the focusing electrode.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true technical protection scope of the present invention will be defined by the appended claims technical spirit.

According to the electrode manufacturing method of the field emission device according to the present invention as described above, by forming the gate electrode and the metal seed layer of the same material to form a focused electrode of a uniform height during the plating process. Therefore, by effectively focusing electrons emitted from the emitter to improve the color purity, there is an effect of simplifying the process.

Claims (4)

Applying a first photoresist for protecting the gate electrode and the emitter tip on the substrate on which the tripolar structure is formed; Forming an adhesion layer on the first photoresist; Forming a metal seed layer for a plating process on the adhesion layer; Applying a second photoresist for forming a focusing electrode pattern on the metal seed layer; Plating a focusing electrode on an opening in which the focusing electrode pattern is formed; And And removing the first and second photoresist and the metal seed layer after the plating process of the focusing electrode. The method of claim 1, The first photoresist has a thickness of 5 ~ 8㎛ characterized in that the electrode manufacturing method of the field emission device. The method of claim 1, The adhesion layer is an electrode manufacturing method of the field emission device characterized in that the coating of Ti or Nb. The method of claim 1, The metal seed layer is an electrode manufacturing method of the field emission device, characterized in that using a good electrical conductivity of the metal, namely Cu, Au, Ag.