KR20000002643A - Method of field emission display manufacture - Google Patents

Abstract

PURPOSE: A method of field emission display manufacture is provided to enhance the special quality and the reliability of the device by using the special quality of a diamond by forming a field emission display of the three electrode tube structure. CONSTITUTION: A method of field emission display manufacture comprises the steps of: forming a metal wire(15) for a cathode electrode onto a silicon substrate(11) after forming a first silicon oxidized layer(13) onto the silicon substrate; forming a second silicon oxidized film(17) with a hole after spreading photosensitive film onto the whole surface; and forming carbon cluster(19) onto the whole surface including the metal wire for the cathode electrode.

Description

Field emission display device and manufacturing method

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emission display (FED) device and a method of manufacturing the same, and more particularly, to forming a carbon cluster on the cathode metal and selectively growing diamond on the cathode. A technique for easily forming a diamond tip.

The 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 5 to 10V, by using a phenomenon in which an electric field is concentrated on a sharp part of a tip. FED has attracted attention as a next-generation display device because it has both the high definition of CRT and the light and thin advantages of liquid crystal display (LCD).

In particular, the FED can not only manufacture the thin and thin, but also solve the problems of process yield, manufacturing cost, and enlargement, which are crucial disadvantages of the LCD.

That is, in case of LCD, even if one unit pixel is defective, the whole product is treated badly. However, FED has a smaller number of unit pixels in one pixel group, so even if one or two unit pixels are defective, There is no problem in operation, and the yield of the whole product is improved.

In addition, FED has advantages such as simple structure, low power consumption, low unit cost, and suitable for portable display device.

Initially, the FED is exposed to the outside by a cavity, and has a conical emitter having sharp parts, a gate arranged on both sides of the emitter, and an electrode to which a fluorescent plate is attached at a predetermined distance from the gate. Each of which corresponds to a cathode, a grid and an anode of the CRT.

In the FED, a predetermined voltage, for example, a voltage of about 500 to 10 mA is applied and electrons are emitted by an electric field concentrated at the top of the emitter, and the emitted electrons are delivered by an anode to which a positive voltage is applied. To emit the fluorescent material applied to the anode, and the gate controls the direction and amount of electrons.

However, in the early FED having the conical cathode as described above, some of the emitted electrons are induced to the gate, so that the gate current flows to control the electrons, and cations formed by colliding with the electrons between the cathode and the anode, Since the device is destroyed by collision, in order to prevent this, the inside of the device must be maintained in a high vacuum state, and there is a problem that it is difficult to uniformly manufacture a sharp conical cathode.

In addition, since a high voltage is required at the anode and the gate electrode, application to a portable display device is difficult.

In order to solve these problems, a thin film type field emission device has been proposed, in which three conductive thin films insulated from each other are sequentially installed on a substrate conductor, and a part of the three conductive thin films is formed to protrude through the cavity. Proposed structure of the anode by installing an external electrode on the upper side.

The thin film type field emission device having such a structure applies a negative voltage to a cathode, which is a conductive thin film located at the center, and emits electrons by applying an alternating voltage to gate conductive thin films located on both sides of the cathode, and is strong to the substrate conductor. A negative voltage is applied to cause electrons emitted from the cathode to strike the anode, which is an external electrode.

As the thin film type field emission display device according to the related art, a device using silicon as a substrate and an electrode is attracting attention due to its easy manufacturing method and material selection. Such a silicon device has a cathode tip made of polycrystalline silicon on a silicon substrate. Forming a gate insulated from the cathode by forming a wet etching method using a nitride film pattern as an etching mask, applying an oxide film and a metal film to the entire surface, and removing the nitride film pattern by a lift off method. Used.

In the method of manufacturing the field emission display device by the lift-off process using the silicon material according to the prior art as described above, the short circuit between the tip and the gate is likely to occur, the tip is damaged, and the process yield and the uniformity are poor. There is a problem such as lowering the reliability of device operation.

In order to solve the above problem, the diamond or pseudo diamond (hereinafter referred to as DLC) material has the characteristics of chemical stability, low electron affinity, high resistance to ions, etc. It has been used to apply and coat the top of the tip.

1A to 1C are cross-sectional views illustrating a method of manufacturing a field emission display device according to the related art, and are formed using diamond.

First, the upper surface of the silicon substrate 31 is scratched with diamond powder.

Then, the diamond 33 is deposited on the scratched substrate 31. At this time, the diamond 33 is formed in an uneven shape at the top. (FIG. 1A, FIG. 1B)

Next, an insulating film 35 and a gate metal 37 are formed over the entire surface and patterned to expose the diamond 33, thereby forming a field emission display device having a tripolar structure. (FIG. 1C)

In addition, another conventional embodiment uses a DLC, in which a DLC is formed on a substrate on which a cathode metal is formed, a photoresist pattern is formed on the substrate, and then the DLC is patterned using oxygen plasma, and an insulating film and a gate metal are formed on the entire surface. Forming and patterning it to form a field emission display device having a group of triode type that exposes the DLC.

However, the prior art as described above has the following problems.

First, in the case of polycrystalline diamond formed in a high temperature process, the process cost, high and difficult process progression, and also when forming a large area to increase the area.

Secondly, as DLC, in this case, the process can be carried out at a low temperature, but in the subsequent process, when the temperature rises to a certain temperature, for example, 300 ° C. or more, the characteristics of the thin film are changed to deteriorate the characteristics of the field emission display device. For example, the thin film characteristic of DLC falls in the growth process of the insulating film for forming a triode structure.

In other words, diamond has a high manufacturing temperature, DLC is a material having a low temperature, but lacking resistance to temperature, and polycrystalline diamond, which has better emission characteristics than the DLC, is a silicon substrate due to a high manufacturing temperature, Since a ceramic or the like must be used as a substrate, there is a problem in that it is difficult to manufacture a large area FED.

In order to solve the above problems of the prior art, an object of the present invention is to provide a field emission display device and a method of manufacturing the same, which can improve the characteristics and reliability of the device by selectively forming diamond to form a diamond tip. .

1A to 1C are cross-sectional views showing a field emission display device and a method of manufacturing the same according to the prior art.

2A to 2F are cross-sectional views showing a field emission display device and a method of manufacturing the same according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

11,31 silicon substrate 13: first silicon oxide film

15 metal wiring for cathode metal

17: second silicon oxide film

19: carbon cluster 21,33: diamond

23: second silicon oxide film

25,37: metal wiring for gate electrode

35: insulating film, silicon oxide film

In order to achieve the above object, the manufacturing method of the field emission display device according to the present invention,

Forming a first insulating film on the silicon substrate and forming a metal wiring for the cathode electrode thereon;

Forming a second insulating film having a hole through which the metal wiring for the cathode is exposed;

Forming a carbon cluster on the cathode metal wiring;

Growing diamond on the carbon cluster;

Removing the second insulating film;

Forming a planarized third insulating film over the entire surface;

Forming a metal wiring for a gate electrode on the third insulating layer;

And etching the gate electrode metal wiring and the third insulating layer to form a hole in which the diamond is exposed.

In addition, the field emission display device according to the present invention to achieve the above object,

The metal wiring for the cathode electrode is provided on the silicon substrate with the insulating film,

A gate hole exposing the metal electrode for the cathode electrode is provided in a stacked structure of a gate insulating film and a gate electrode,

Diamond is provided on the upper portion of the metal wiring for the cathode electrode of the bottom of the gate hole.

Hereinafter, a method of manufacturing a field emission display device according to the present invention will be described in detail with reference to the accompanying drawings.

2A to 2F are cross-sectional views illustrating a method of manufacturing a field emission display device according to an exemplary embodiment of the present invention.

First, the first silicon oxide film 13 is formed on the silicon substrate 11 and the metal wiring 15 for the cathode electrode is formed thereon. In this case, the cathode metal wiring 15 is formed by a sputtering method. (FIG. 2A)

The second silicon oxide film 17 having holes formed by an etching process using a tip mask (not shown) is applied to the entire surface of the photoresist film and exposes only the cathode metal wiring 15 of the portion where the emitter is formed. ). (FIG. 2B)

Next, carbon clusters 19 are formed on the entire surface including the metal wirings 15 for the cathode electrodes.

At this time, the carbon cluster 19 grows the diamond by the chemical vapor deposition (CVD) method, but the voltage on the metal wiring 15 for the cathode electrode using the Benes (Bias Enhanced Nucleation) method Hang and grow to form. In addition, the carbon cluster 15 is more formed on the metal wiring 15 for the cathode electrode to which a voltage is applied.

The Ben method is performed by flowing a CH ₄ / H ₂ gas having a flow rate of about 10 to 25% of the total gas at a pressure of 5 to 15 torr and a bias voltage of -100 to -200 volts. (FIG. 2C)

Then, the diamond 21 is grown on the carbon cluster 19 by the CVD method. At this time, the carbon cluster 19 serves as a seed (diamond) is grown.

In this case, the carbon cluster 19 on the second silicon oxide film 17 also forms diamond in the diamond forming step, but the second silicon oxide film is formed by hydrogen gas in the composition of the gas in which the second silicon oxide film 17 grows the diamond. As the 17 is etched, the formation base of the carbon cluster 19 serving as the seed of the diamond is restricted. Therefore, diamond is hard to grow on the second silicon oxide film 17.

Here, the growth process of the diamond 21 is performed by flowing a CH ₄ / H ₂ gas having a flow rate of about 1 to 5% of the total gas at a pressure of 35 to 45 torr and a bias voltage of 0 volts.

Then, the second silicon oxide film 17 is removed. At this time, it is difficult to completely remove only the second silicon oxide film 17, so that the carbon cluster 19 can be removed. (FIG. 2D)

Then, a third silicon oxide film 23 is formed on the entire surface and planarized by chemical mechanical polishing. A gate electrode metal wiring 25 is formed on the third silicon oxide film 23.

Next, a hole for exposing the cathode electrode metal wiring 15 by etching the gate electrode metal wiring 25 and the third silicon oxide layer 23 by an etching process using a tip mask (not shown), ie A field emission display device having a triode and a structure is formed by forming a gate electrode metal wiring 25 pattern that exposes a portion where the diamond 21 is formed, that is, a gate electrode and a third silicon oxide film 23 pattern. (FIG. 2F).

As described above, the field emission display device and the method of manufacturing the same according to the present invention have a low work function by selectively forming diamond only on the upper portion of the cathode metal wiring and easily forming the field emission display device having a triode structure in a subsequent process. Along with the negative charge affinity, the electrons can be easily released to improve the characteristics and reliability of the entire emission display device.

Claims (7)

Forming a first insulating film on the silicon substrate and forming a metal wiring for the cathode electrode thereon; Forming a second insulating film having a hole through which the metal wiring for the cathode is exposed; Forming a carbon cluster on the cathode metal wiring; Growing diamond on the carbon cluster; Removing the second insulating film; Forming a planarized third insulating film over the entire surface; Forming a metal wiring for a gate electrode on the third insulating layer; And forming a hole in which the diamond is exposed by etching the gate electrode metal wiring and the third insulating layer. The method of claim 1, The first insulating film, the second insulating film and the third insulating film are formed of a silicon oxide film, the method of manufacturing a field emission display device. The method of claim 1, And the carbon clusters are formed by applying a voltage to the metal wirings for the cathode electrode and performing a ben method. The method of claim 3, wherein In the Ben method, the field emission display device is manufactured by flowing a CH ₄ / H ₂ gas having a flow rate of about 10 to 25% of the total gas at a pressure of 5 to 15 torr and a bias voltage of -100 to -200 volts. Way. The method of claim 1, The diamond is a method of manufacturing a field emission display device characterized in that the growth of the flow CH ₄ / H ₂ gas having a flow rate of about 1 to 5% of the total gas at a pressure of 35 to 45 torr, a bias voltage of 0 volts. The metal wiring for the cathode electrode is provided on the silicon substrate with the insulating film, A gate hole exposing the metal electrode for the cathode electrode is provided in a stacked structure of a gate insulating film and a gate electrode, And a diamond is disposed on the metal wiring for the cathode electrode at the bottom of the gate hole. The method of claim 6, And the insulating film and the gate insulating film are formed of a silicon oxide film.