KR100761260B1 - Method for fabricating field emission device - Google Patents

Abstract

The present invention relates to a field emission device manufacturing method that can increase the field emission efficiency by controlling the density of the carbon nanotubes in the field emission device using the carbon nanotubes as an electron emission source, the carbon nanotubes (CNT) is formed Forming an ion exchange resin pattern in a region to be formed; Adsorbing an organometallic complex on the ion exchange resin pattern using an aqueous solution containing an organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; Forming a carbon nanotube on the metal catalyst conductive film, by controlling the CNT density to increase the field emission efficiency, a large-area flat plate having uniform luminance between the pixel uniformity and excellent mass production and low cost process There is an effect that can produce a display panel.

Description

Field emission device manufacturing method {METHOD FOR FABRICATING FIELD EMISSION DEVICE}

1 is a flow chart of an embodiment of a method for manufacturing a field emission device of the present invention.

Figures 2a to 2d is a cross-sectional view showing a manufacturing process for the side gate type field emission device according to the present invention.

Figures 3a to 3e is a cross-sectional view showing the manufacturing process for the normal gate type field emission device according to the present invention.

Figure 4 is a correlation diagram of the density of metal catalyst formation according to the dipping time of the aqueous solution of the organic metal complex according to the present invention.

The present invention relates to a field emission device manufacturing method, and more particularly to a field emission device manufacturing method that can increase the field emission efficiency by controlling the density of the carbon nanotubes in the field emission device using the carbon nanotubes as the electron emission source. will be.

As satellite and digital broadcasting have been promoted in recent years, demand and interest for large screen displays with high resolution have increased, and expectations and roles for flat panel displays have become very important, and high resolution and high definition image information with high resolution Increasing demands, and research and investment in large-screen liquid crystal display (LCD), plasma display panel (PDP), etc. are actively made.

In the case of the most widely used cathode ray tube TV (CRT), there are many difficulties in realizing a large area, and in recent years, there is a high expectation for a field emission display (FED) flattening this, and technology development has been made. ought.

In general, a field emission display is classified into two types, a hot electron emission device in which electrons are emitted from a heated filament, and a cold cathode electron emission device in which electrons near the Fermi level are tunneled due to an electric field. In particular, among the various technical methods for implementing cold cathode electron emission display, the most attention is the method using carbon nanotube (CNT) as the electron emission source and the surface conduction field emission device recently announced by Canon / Toshiba ( surface conduction electron emission device). In addition, development of spindt type, MIM type, and BSD (Ballistic surface emitter display) using a metal tip is in progress, and technical evolution is being repeated.

Among the above technologies, an optical device using CNT as an electron emission source is excellent in size, structure, and stability than conventional electron emission sources, and its value is recognized in various fields from field emission to surface light source.

Since such CNTs have a small diameter (about 1.0 to several tens of nm), they have a significantly better field enhancement factor than conventional microtip (spindt) field emission tips. Since it can be made in a turn-on field, about 1 to 5 [V / ㎛]), there is an advantage of reducing power loss and production cost.

There are several methods for forming CNTs of such CNT field emission devices, which will be described below.

First, there is a method of implementing a cell using a CNT paste, which can be divided into a side gate type and a normal gate type. The side gate type has a merit that the post-treatment process can be performed relatively easily because the manufacturing process is simple and the CNT is exposed to the surface, but crosstalk occurs due to the spreading of the electron beam, thereby forming a separate grid. In addition, since the electron beam is emitted to the side region, it is difficult to control the beam.

On the other hand, in the normal gate type, a hole of a certain size is formed for focusing a beam, and then filled with CNT paste therein to produce a CNT electron emission source, and a focusing electrode or grid is formed thereon to prevent crosstalk between pixels. It is manufactured through a complicated process, but has an advantage over the side gate type in terms of the stable side of the device.

In addition, in order to utilize the image display device, there is a difficulty in securing uniformity of luminance, and thus, technology development is being progressed through various post-processing processes. In other words, the technology using the CNT paste has the advantage of utilizing a low-cost process in manufacturing a large area panel, but it is not easy to artificially control the density and uniformity of the CNT, and since the CNT is embedded in the paste, The treatment process is a very important variable.

Another method of forming CNTs may be formed using chemical vapor deposition (CVD), which selectively grows CNTs directly inside the holes using CVD to serve as an electron emission source. This CVD method selectively grows CNTs by arranging a catalyst region in a desired hole, but there is a problem that CNTs grow densely on a substrate and control length, amount, distance between CNTs, and the like. In particular, when CVD is applied to an electron-emitting device, it is important to concentrate an electric field on a single strand of CNTs separated by about the length of the CNT in order to apply an electric field to the CNT to obtain as many electron emitters as possible. .

In order to solve this problem, there is a method in which CNTs are mixed and applied in a solvent in advance, and it is also difficult to control the distance or density between CNTs, and it is difficult to obtain good electron emission characteristics.

Another method of forming CNTs is to mix catalyst particles such as Fe and Ni in metal powders such as Cu and expose the catalyst only to the surface through compression and sintering. Cu is also a metal. There were problems such as the inherent performance of the catalyst or the high temperature required for sintering of the substrate.

As such, the conventional method using CVD has difficulty in controlling the uniform distribution and period of the metal catalyst, and thus, when grown by CVD, too much CNT bundles are formed, and thus, electron emission efficiency is lowered.

Accordingly, the present invention has been made to solve the conventional problems as described above, and formed by patterning the photosensitive ion exchange resin in the region where CNTs are to be formed, adsorbs the metal complex in the region where the ion exchange resin is formed and adsorbed thereon Heat-treat the formed metal complex to form a metal catalyst conductive film, and form CNT on the metal catalyst conductive film to adjust the CNT density to increase the field emission efficiency, and to achieve uniform uniformity between pixels and excellent mass productivity and low cost process. It is an object of the present invention to provide a method for manufacturing a field emission device capable of manufacturing a large area flat panel display panel having luminance.

The present invention for achieving the above object comprises the steps of forming an ion exchange resin pattern in the region where the carbon nanotubes (CNT) will be formed; Adsorbing an organometallic complex on the ion exchange resin pattern using an aqueous solution containing an organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; Forming a carbon nanotube on the metal catalyst conductive film, characterized in that consisting of.

The present invention for achieving the above object comprises the steps of forming a gate electrode and a cathode electrode on the same plane on the lower substrate; Forming an ion exchange resin in the carbon nanotube forming region on the cathode electrode; Adsorbing the organometallic complex on the ion exchange resin by dipping in an aqueous solution containing the organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; Forming a carbon nanotube on the metal catalyst conductive film, characterized in that consisting of.

The present invention for achieving the above object comprises the steps of sequentially forming a cathode electrode, an ultraviolet blocking film, a dielectric layer and a gate electrode on the lower substrate; Sequentially etching the gate electrode, the dielectric layer, and the UV blocking film to expose a portion of the cathode electrode; Forming an ion exchange resin on the exposed cathode electrode; Adsorbing the organometallic complex on the ion exchange resin by dipping in an aqueous solution containing the organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; Forming a carbon nanotube on the metal catalyst conductive film, characterized in that consisting of.

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

First, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, many specific details, such as specific processing flows, are set forth in the following description to provide a more general understanding of the invention, but are not limited thereto, and it is understood that the invention may be practiced without these specific details. It will be self-evident to those of ordinary knowledge in Esau.

The present invention forms a photosensitive ion exchange resin that can be formed by adjusting the CNT density in the region where the electron emission source is to be formed, adsorbs an organometallic complex on the ion exchange resin, and conducts a metal catalyst through a predetermined heat treatment process. The idea is to form a film and to form a uniform CNT on the formed metal catalyst conductive film to increase the field emission efficiency and to improve the inter-pixel uniformity.

The ion exchange resins are insoluble synthetic resins having ions capable of ion exchange, including cation exchange resins and anion exchange resins, and amphoteric resins, electron exchange resins, and chelate resins.

The organometallic complex adsorbed on the ion exchange resin may include palladium (Pd), and the ion exchange resin is formed by dipping the field emission device in which the ion exchange resin is formed in an aqueous solution in which the Pd organometallic complex is dissolved. Adsorb organometallic complex on top.

The density of the electron emission source CNT can be adjusted through the thickness of the ion exchange resin or the dipping time of the metal complex aqueous solution, and the thickness can be adjusted using the speed of the spin coater as an example of a method of controlling the thickness of the ion exchange resin. have.

The longer the dipping time is, the longer the density of the metal complex adsorbed on the ion exchange resin increases, but it does not increase due to saturation after a predetermined time.

1 is a flow chart of an embodiment showing a process for manufacturing a field emission device according to the present invention, as shown in the drawing, forming an ion exchange resin pattern in a region where a CNT field emission source is to be formed, and an aqueous Pd organometallic complex aqueous solution. Adsorbing the Pd organometallic complex on the ion exchange resin pattern to form a Pd metal catalyst conductive film through a predetermined heat treatment process by dipping to the upper portion of the ion exchange resin pattern; Forming a CNT.

The ion exchange resin is coated by spin coating on the cathode electrode and the gate electrode for applying the FED driving voltage, and is formed in the cathode electrode region using a mask pattern used to form the CNT.

The Pd organic metal complex adsorbed on the ion exchange resin pattern is heat-treated in the air (450-550 [deg.] C. for 20-30 minutes) to form a PdO conductive film, and the formed PdO conductive film is H ₂ : N ₂ = 2: A mixed gas of 98 is injected into a vacuum apparatus, and then heat-treated at a predetermined temperature (about 150 to 200 [° C.]) to form a Pd metal catalyst conductive film (particle). At this time, since the PdO conductive film is converted into the Pd metal catalyst conductive film, additionally about 10% or more shrinkage occurs, thereby reducing the density between particles.

The CNT formed on the Pd metal catalyst conductive film is heat-treated under predetermined conditions (500 [° C.] for 10 to 20 minutes) under a 0.1% ethylene gas stream diluted with nitrogen, and has a diameter of several tens to several tens of nm. CNTs are grown.

FIG. 2 is a cross-sectional view illustrating a process of manufacturing a field emission device according to an exemplary embodiment of the present invention, and a process cross-sectional view of a process of manufacturing a side gate type field emission device as shown in FIG.

Then, the manufacturing process of the side gate type field emission device according to the present invention will be described.

First, as shown in FIG. 2A, the dielectric layer 20 is sequentially formed on the lower substrate 10, and Ti and polysilicon are stacked on the dielectric layer by sputtering. In addition, after the photoresist is applied to form the gate electrode 30 and the cathode electrode 40, a mask pattern is formed by a photolithography process, and a gap between electrodes is 5 by dry etching using carbon fluoride (CF 4) gas. The gate electrode 30 and the cathode electrode 40 are formed so as to be about [μm].

Then, as shown in Figure 2b, using a spin coater on the front of the structure spin-coated a photosensitive ion exchange resin, and dried for 2 to 3 minutes on a 40 ~ 60 [℃] hot plate (cathode electrode 40) Exposed using a photo mast for forming a growth region (Fig. 2a) of the CNT to be formed on the top) and developed in pure water to form an ion exchange resin pattern (50).

Then, as shown in Figure 2c, by dipping the structure on the aqueous solution containing the appropriate concentration of the Pd organometallic complex for a predetermined time (dipping) to adsorb the Pd organometallic complex on top of the structure, the structure is completed Pd organometallic complex is formed only on the ion exchange resin pattern by washing with water for several seconds.

The structure in which the Pd organometallic complex is formed is heat-treated at 450 to 550 [deg.] C for 20 to 30 minutes in the air to form a conductive film (PdO conductive film) having PdO particles having a predetermined number of [nm] particles at a predetermined interval. 40) is formed in the upper CNT formation region.

In order to reduce the PdO conductive film to the Pd metal catalyst conductive film 60, a structure in which the PdO conductive film was formed was disposed in a vacuum processing apparatus, and then a mixed gas having a H ₂ : N ₂ of 2:98 was introduced into the vacuum processing apparatus to a predetermined pressure. Heat treatment at about 150 to 200 [deg.] C. to form a Pd metal catalyst conductive film (particulate) 60 suitable for CNT growth, wherein the Pd metal catalyst conductive film 60 is about 10% as the PdO conductive film is reduced. Since the above shrinkage occurs, the density between Pd particles decreases.

Finally, as shown in FIG. 2D, the Pd metal catalyst conductive film 60 is formed by heat treatment at about 500 [° C.] for 10 to 20 minutes in a nitrogen environment containing 0.1% of ethylene gas. CNTs 70 having a diameter of about several tens [nm] are formed in the CNT growth region on the conductive layer 60. At this time, since the CNT 70 is formed on the Pd metal catalyst conductive layer 60 having a reduced density of Pd particles, the CNT 70 may increase the electron emission efficiency that has been degraded due to the conventionally densely packed CNT bundle.

3 is a procedure sectional view showing an embodiment of a field emission device manufacturing process according to the present invention, a process cross-sectional view of the manufacturing process of the normal gate type field emission device as shown.

Then, the manufacturing process of the normal gate type field emission device according to the present invention will be described.

First, as shown in FIG. 3A, a cathode layer 80, an ultraviolet blocking layer 90, a dielectric layer 100, and a conductive layer 110 for forming a gate electrode are sequentially formed on the lower substrate 10. The photoresist PR is applied to form a hole pattern, and then the region where the hole is to be formed is patterned.

Next, as shown in FIG. 3B, the gate patterned structure is sequentially etched by dry etching to form the hole after the gate electrode 110, the dielectric layer 100, and the UV blocking layer 90 are formed by dry etching. Remove the PR by using a spin coater on the front surface of the structure by spin coating the photosensitive ion exchange resin (50), and dried for 2 to 3 minutes on a hot plate (40 ~ 60 [℃]) and then ultraviolet (UV) White exposure (back exposure) is performed.

Then, as shown in FIG. 3C, the white exposed structure is developed in pure water to form an ion exchange resin 50 only in the hole of the CNT growth region, and the structure having the ion exchange resin 50 formed at an appropriate concentration. Dipping on the aqueous solution containing Pd organometallic complex for a predetermined time to adsorb the Pd organometallic complex on the upper part of the structure and the inside of the hole, and wash the structure having been adsorbed in flowing water for several seconds. The Pd organometallic complex is formed only on the ion exchange resin 50.

Then, as shown in FIG. 3d, the structure in which the Pd organometallic complex is formed in the hole is heat-treated at 450 to 550 [deg.] C for 20 to 30 minutes in the air to form PdO particles having water [nm] particles at regular intervals. A conductive film (PdO conductive film) is formed in the CNT formation region inside the hole.

In order to reduce the PdO conductive film to the Pd metal catalyst conductive film 60, a structure in which the PdO conductive film was formed was disposed in a vacuum processing apparatus, and then a mixed gas having a H ₂ : N ₂ of 2:98 was introduced into the vacuum processing apparatus to a predetermined pressure. Heat treatment is performed at about 150 to 200 [deg.] C to form a Pd metal catalyst conductive film (particulate) 60 suitable for CNT growth.

Finally, as shown in FIG. 3e, the structure in which the Pd metal catalyst conductive film 60 is formed in the hole is heat-treated at about 500 [deg.] C for 10 to 20 minutes in a nitrogen environment containing 0.1% of ethylene gas. CNTs 70 having a diameter of about several tens [nm] are formed in the CNT growth region on the Pd metal catalyst conductive layer 60. Of course, since the CNT 70 is formed on the Pd metal catalyst conductive layer 60 having reduced density of Pd particles, the CNT 70 may increase electron emission efficiency that has been degraded due to the conventionally too crowded CNT bundle.

In addition, the density of intergranular formation of the Pd metal catalyst conductive film for growing the CNTs may be changed by the dipping time and the Pd metal catalyst density of the aqueous solution containing the Pd organic metal complex. The relationship between the density of Pd metal catalyst formation according to the dipping time of the aqueous solution containing the complex is shown.

As shown in FIG. 4, as the dipping time of the Pd organometallic complex aqueous solution having a certain concentration increases, the Pd metal catalyst formation density increases, but the Pd metal catalyst formation density reaches a saturation state after a certain time. That is, by adjusting the dipping time of the Pd organic metal complex aqueous solution, it is possible to control the interparticle formation density of the Pd metal catalyst conductive film formed in the CNT formation region, and thus to control the CNT formation density formed on the particles of the Pd metal catalyst conductive film. have.

In addition, since the present invention forms a Pd metal complex conductive film using a photosensitive ion exchange resin, various patterns can be easily formed where CNTs are desired to be grown, and the thickness of the photosensitive ion exchange resin can be adjusted to adjust the thickness of the Pd organic metal complex. You can also adjust the density. Here, since the thickness of the photosensitive ion exchange resin can be controlled by adjusting the speed of the spin coater, it is possible to control uniform CNT growth in a low cost process. Therefore, the present invention can produce a high-efficiency large-area FED excellent in uniformity between pixels by uniform CNT growth, and can be applied to all FEDs using CNT as an electron emission source.

As described in detail above, the present invention is formed by patterning a photosensitive ion exchange resin in a region where CNTs are to be formed, adsorbing a metal complex to a region where the ion exchange resin is formed, and heat treating the adsorbed metal complex to form a metal catalyst conductive film. And by forming CNT on the metal catalyst conductive film, the CNT density is adjusted to increase the field emission efficiency, and a large area flat panel display panel having uniform luminance between pixels and uniform luminance is obtained by a low cost process. There is an effect that can be produced.

Claims (11)

Forming an ion exchange resin pattern in a region where carbon nanotubes (CNT) are to be formed; Adsorbing an organometallic complex on the ion exchange resin pattern using an aqueous solution containing an organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; And forming a carbon nanotube on the metal catalyst conductive film. The method of claim 1, wherein the organometallic complex is palladium (Pd). The method of claim 1, wherein the organometallic complex adsorbed on the ion exchange resin pattern is heat-treated in the air (450 ~ 550 [deg.] C., 20 to 30 minutes) to form a metal oxide conductive film, the formed metal oxide conductive film H ₂ : N ₂ = 2: 98 A field emission device manufacturing method characterized in that the heat treatment at a temperature of 150 ~ 200 [℃] in a mixed gas environment to form a metal catalyst conductive film. The field emission of claim 1, wherein the carbon nanotubes are formed on the metal catalyst conductive layer by heat treatment (500 [deg.] C. for 10 to 20 minutes) in a nitrogen environment containing 0.1% of ethylene gas. Device manufacturing method. The method of claim 1, wherein the interparticle density of the metal catalyst conductive film is controlled by a thickness of the ion exchange resin. The method of claim 1, wherein the density of intergranular formation of the metal catalyst conductive film is controlled by a dipping time of an aqueous solution containing the organometallic complex. The method of claim 1, wherein the ion exchange resin is a photosensitive ion exchange resin. Forming a gate electrode and a cathode electrode on the same plane above the lower substrate; Forming an ion exchange resin in the carbon nanotube forming region on the cathode electrode; Adsorbing an organometallic binder on the ion exchange resin by dipping in an aqueous solution containing an organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; And forming a carbon nanotube on the metal catalyst conductive film. Sequentially forming a cathode electrode, an ultraviolet blocking film, a dielectric layer, and a gate electrode on the lower substrate; Sequentially etching the gate electrode, the dielectric layer, and the UV blocking film to expose a portion of the cathode electrode; Forming an ion exchange resin on the exposed cathode electrode; Adsorbing the organometallic complex on the ion exchange resin by dipping in an aqueous solution containing the organometallic complex; Forming the adsorbed organometallic complex as a metal catalyst conductive film through a heat treatment process; And forming a carbon nanotube on the metal catalyst conductive film. 10. The method of claim 9, wherein the ion exchange resin formed on the cathode electrode is formed by white exposure. 10. The method of claim 8 or 9, wherein the organometallic complex adsorbed on the ion exchange resin pattern is heat-treated in the air (450 ~ 550 [deg.] C., 20 to 30 minutes) to form a metal oxide conductive film, the formed oxide A method of manufacturing a field emission device comprising forming a metal catalyst conductive film by heat-treating the metal conductive film at a temperature of 150 to 200 [deg.] C. in a mixed gas environment having H ₂ : N ₂ = 2: 98.

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