KR20010029785A - Field Emitter Having Carbon Nanotube Film and Method of fabricating the same, Field Emission Display Device Using the same - Google Patents

Abstract

PURPOSE: Provided is a field emitter equipped with a carbon nanotube film with which a thin film transistor is used in manufacturing a field emission display device having high density of electricity and operating at low voltage. CONSTITUTION: A field emitter includes a substrate (8), a thin film transistor section formed on the substrate (8) and composed of a semiconductor layer (7), especially polycrystalline silicon layer, source electrode (3), drain electrode (4), and gate electrode (2), and a current discharge section composed of carbon nanotube films formed on the drain electrode (4) of the thin film transistor section. The structure of the thin film transistor section is among a plane, stacker, and counter stacker form. And the surface of the drain electrode (4) which the carbon nanotube film connects to includes transition metals like nickel or cobalt for the growth of the carbon nanotube or the drain electrode (4) is made of catalytic metals.

Description

Field Emitter Having Carbon Nanotube Film and Method of fabricating the same, Field Emission Display Device Using the same}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emitter including a carbon nanotube film, a method for manufacturing the same, and a field emission display device using the same. A field emission emitter using a nanotube film as an electron emission unit, a method for manufacturing the same, and a field emission display device using the same.

The field emission display device, which is currently being researched as a next-generation flat panel display device, is based on the emission of electrons in a vacuum, and electrons emitted from a micron-sized tip are accelerated by a strong electric field to collide with a fluorescent material. By emitting light, it has the advantage of being thin and light while being excellent in brightness and resolution.

The electron emission emitter for a field emission display device, which is mainly used in the related art, uses a tip made of metal or silicon, but has a disadvantage in that the structure is very complicated and the current density between pixels is not uniform. In order to solve this drawback, the use of MOSFET (Metal Oxide Semiconductor Field Effect Transistor) as an active circuit for each unit pixel is described in Japanese paper by Kanemaru et al., "Active Matrix of Si Field Emitters Driven by Built-in MOSFETS" (IDW '). 97, pp735-738, 1997), and the use of thin film transistors in Japanese paper by Kamo et al. "Actively-Controllable Field Emitter Arrays with Built-in Thin-Film Transistors on Glass for Active-Matrix FED Applications" (IDW). '98, pp 667-670, 1998). However, the structure disclosed in the above paper has the disadvantage that the structure becomes more complicated by adding other processes to the manufacturing process of the existing field emission display device.

It is a first object of the present invention to provide a field emission emitter having a high current density even under low voltage using a carbon nanotube film.

A second object of the present invention is to provide a method for producing a field emission emitter having a carbon nanotube film by a simple process.

It is a third object of the present invention to provide a field emission display device having a field emission emitter having a high current density even under low voltage using a carbon nanotube film.

1 is a cross-sectional view showing a field emission emitter having a planar thin film transistor and a carbon nanotube pixel according to an embodiment of the present invention.

2 is a cross-sectional view illustrating a field emission emitter having a stackable thin film transistor and a carbon nanotube pixel according to an exemplary embodiment of the present invention.

3 is a cross-sectional view illustrating a field emission emitter having a reverse stack type thin film transistor and a carbon nanotube pixel according to an exemplary embodiment of the present invention.

4 is an equivalent circuit diagram of a field emission display device using a field emission emitter according to an exemplary embodiment of the present invention.

5A is a scanning electron micrograph of a carbon nanotube film grown according to an embodiment of the present invention.

5B is a photograph of a projection electron microscope of a carbon nanotube film deposited on each unit pixel of a field emission display device according to an exemplary embodiment of the present invention.

6 illustrates a cross-sectional structure of a field emission display device according to an exemplary embodiment of the present invention.

※ Explanation of code for main part of drawing

One ; Carbon nanotube membrane 2; Gate electrode

3; Source electrode 4; Drain electrode

5; Gate insulating film 6; Protective insulation film

7; Semiconductor layer 8; Insulation Board

9; Data line 10; Gate line

11; Thin film transistor section 12; Phosphor

13; Upper electrode

The field emission emitter having the carbon nanotube film according to the present invention for achieving the first object of the present invention is formed on an insulating substrate, the insulating substrate, and the semiconductor layer, source electrode, drain electrode and gate electrode And an electron emission unit including a carbon nanotube film formed on the thin film transistor unit and the drain electrode of the thin film transistor unit.

The semiconductor layer of the thin film transistor portion may be a polycrystalline silicon layer or an amorphous silicon layer, and the structure of the thin film transistor portion may be one of a planar type, a stacker type, or an inverse stacker type.

In addition, the surface of the drain electrode in contact with the carbon nanotube film includes a catalyst metal of a transition metal such as nickel or cobalt for carbon nanotube growth, or the drain electrode itself is a catalyst metal for carbon nanotube growth. It may be done.

A method of manufacturing a field emission emitter having a carbon nanotube film according to the present invention for achieving the second object of the present invention, a thin film transistor having a semiconductor layer, a source electrode, a drain electrode and a gate electrode on an insulating substrate Forming a protective insulating film on an entire surface of the insulating substrate on which the thin film transistor is formed; etching a portion of the protective insulating film to expose a portion of the drain electrode; and carbon on the exposed drain electrode surface. Forming a nanotube film.

The forming of the thin film transistor may include forming a semiconductor layer on the insulating substrate when the thin film transistor is planar, forming a source electrode pattern and a drain electrode pattern spaced by a predetermined distance on the semiconductor layer; And forming a gate electrode pattern including a gate insulating layer and a gate electrode between the source electrode pattern and the drain electrode pattern. In addition, when the thin film transistor is a stack type, the forming of the thin film transistor may include forming a source electrode pattern and a drain electrode pattern spaced apart by a predetermined distance on the insulating substrate, between the source electrode pattern and the drain electrode pattern. Forming a semiconductor layer pattern extending laterally by a predetermined length while filling the gap; and forming a gate electrode pattern including a gate insulating layer and a gate electrode on the semiconductor layer pattern between the source electrode pattern and the drain electrode pattern. When the thin film transistor is an inverted staggered type, the forming of the thin film transistor may include forming a gate electrode pattern including a gate electrode and a gate insulating layer on the insulating substrate, and forming a semiconductor layer pattern covering the gate electrode pattern. Forming a semiconductor layer And a step of forming a source electrode pattern and a drain electrode pattern separated by a predetermined distance in teonsang.

Forming the carbon nanotube film on the exposed drain electrode may be coating the carbon nanotube film on the exposed drain electrode surface, or directly growing the carbon nanotube film on the exposed drain electrode surface. In this case, the method may further include forming a catalyst metal layer for carbon nanotube growth on the surface of the drain electrode in contact with the carbon nanotube film, wherein the forming of the catalyst metal layer may include forming the thin film transistor. Or may be performed after the etching of a part of the protective insulating layer.

In the field emission display device according to the present invention for achieving the third object of the present invention, in the field emission display device in which unit pixels divided by a plurality of orthogonal gate lines and data lines are arranged in a matrix form, Each unit pixel is formed on an insulating substrate, and includes a thin film transistor unit including a semiconductor layer, a source electrode, a drain electrode, and a gate electrode, and an electron emission unit formed of a carbon nanotube film formed on the drain electrode of the thin film transistor unit. And an upper electrode formed to face the insulating substrate and a phosphor formed to face the electron emitting portion on an inner surface of the upper electrode.

According to the present invention, since the carbon nanotube film is used as the electron emitting portion of the field emission emitter, the field emission emitter having a high current density even at a low voltage can be realized by a simple manufacturing process, and each pixel is driven by a thin film transistor. A field emission display device having a uniform current density can be implemented.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be embodied in various forms within the scope of the appended claims, the present embodiment merely to make the disclosure of the present invention complete, and at the same time It is intended to facilitate the practice of the invention to those skilled in the art.

The present invention basically relates to the formation of carbon nanotubes as electron emitting portions for emitting electrons in field emission emitters. In general, carbon, the most important component of all living things including the human body, combined with oxygen, hydrogen, nitrogen, etc., forms the four crystalline structures of diamond, graphite, fullerene, and carbon nanotubes. These four crystal structures of carbon each have unique characteristics. Among them, carbon nanotubes have a hexagonal honeycomb structure formed by combining one carbon atom with three other carbons to form a tube shape, and the diameter of the tube is extremely small, ranging from several nanometers to several hundred nanometers. It grows into a single wall structure or a multi-wall structure. These carbon nanotubes may be electrical conductors, such as metals, depending on the shape and diameter of the coil. They may also have properties of poorly conducting semiconductors, and because of their hollow and long lengths, they are excellent in mechanical, electrical, and chemical properties. It is known as a material that can be used for devices, hydrogen storage containers, secondary battery electrodes and the like.

1 is a cross-sectional view showing a field emission emitter having a planar thin film transistor and a carbon nanotube pixel according to an embodiment of the present invention. Referring to FIG. 1, a semiconductor layer 7 is formed on an insulating substrate 8 having rigidity, such as a glass substrate, and a source electrode 3 pattern and a drain electrode 4 pattern on the semiconductor layer 7. It is formed spaced apart by this predetermined distance. The semiconductor layer 7 may be formed of amorphous silicon or polycrystalline silicon doped with or without impurity ions, and the source electrode 3 pattern and the drain electrode 4 pattern may be used in a conventional semiconductor device manufacturing process. It is formed by a photolithography process.

The source electrode 3 and the drain electrode 4 may be formed of a conductive material such as aluminum, tungsten, or refractory metal silicide, and they may be formed in a single layer structure or a multilayer structure. In addition, when the carbon nanotube film is grown directly on the drain electrode, as described below, at least a surface of the drain electrode 4 in contact with the carbon nanotube film 1 is a catalyst metal layer for growing carbon nanotubes (not shown). ), For example nickel or cobalt layers. That is, a catalyst metal layer may be formed only at a portion in contact with the carbon nanotube film 1, or may be formed on the entire surface of the drain electrode 4, and at least part of the process may include the source electrode 3 and the drain. It may be formed on the upper surface of the electrode 4. On the other hand, the drain electrode 4 itself may be formed of a catalyst metal.

On the other hand, on the exposed semiconductor layer 7 between the source electrode 3 pattern and the drain electrode 4 pattern, the gate electrode layer 5 is spaced apart from the source electrode 3 pattern and the drain electrode 4 pattern. Thus, the gate electrode 2 pattern is formed. A protective insulating film 6 is formed between the source electrode 3, the gate electrode 2, and the drain electrode 4 to insulate and protect the source electrode 3, and carbon nanotubes are formed on a portion of the drain electrode 4. The film 1 is formed.

The gate insulating film 5 may be formed of an oxide film, a nitride film, or a composite film thereof. The gate electrode 2 may be formed of aluminum or an impurity doped polysilicon, and the protective insulating film 6 may be an oxide film. It can be formed of an insulating material having excellent planarization capability of the series or nitride film series.

Next, the manufacturing process of the field emission emitter shown in FIG. 1 will be described in detail. The semiconductor layer 7 is formed on the insulating substrate 8 by chemical vapor deposition or physical vapor deposition using sputtering. Subsequently, after the conductive material layer is formed on the entire surface of the semiconductor layer 7, a source electrode 3 pattern and a drain electrode 4 pattern spaced apart from each other by a predetermined distance are formed in a normal photolithography process. In this case, as described above, a catalyst metal layer for growing carbon nanotubes may be used as the conductive material layer, and when the catalyst metal layer is formed in multiple layers on a general conductive material, the catalyst metal layer is formed on the conductive material. Perform the etching process.

Subsequently, after the gate insulating film 5 and the gate electrode 2 material layer are formed on the entire surface of the substrate, the gate insulating film 5 is formed between the source electrode 3 pattern and the drain electrode 4 pattern by a photolithography process. And a gate electrode electrode 2 pattern formed of the gate electrode 2. Subsequently, after the protective insulating film 6 is formed on the entire surface of the substrate on which the thin film transistor is formed, a portion of the protective insulating film 6 is etched to expose a portion of the drain electrode 4. Subsequently, a carbon nanotube film 1 is formed on the exposed surface of the drain electrode 4.

Forming the carbon nanotube film 1 is performed by at least two methods. First, the carbon nanotube film 1 grown externally is coated on the exposed drain electrode 4, and second, the semiconductor layer 7, the source electrode 3, the drain electrode 4, and the gate are coated. A thin film transistor comprising an electrode 2 is formed, and a substrate on which a part of the drain electrode 4 is exposed is loaded into a device for growing carbon nanotubes, and then directly on the exposed drain electrode 4. The tube film 1 is grown.

As a method of growing such carbon nanotubes, the first one produced through arc discharge between two graphite rods was first discovered, and the article "Helical microtubules of graphitic carbon" (NATURE, published by Sumio Iijima, Japan) VOL 354, 7 NOVEMBER 1991, pp 56-58), another method for producing carbon nanotubes, wherein the laser is illuminated on graphite or silicon carbide at about 1200 ° C. or higher for graphite and 1600 for silicon carbide. The production of carbon nanotubes at a high temperature of about 1 ° C. to 1700 ° C. has been described in Japanese paper, Michiko Kusunoki et al., "Epitaxial carbon nanotube film self-organized by sublimation decomposition of silicon carbide" (Appl. Phys. Lett. Vol. 71, 2620, 1977). In addition, a method of producing carbon nanotubes by pyrolyzing a hydrocarbon-based gas through chemical vapor deposition method is described in the paper by Large-Scale Synthesis of Aligned Carbon. Nanotubes "(Science, Vol. 274, 6 December 1996, pp 1701-1703).

As described above, the growth of carbon nanotubes in the present invention may use arc discharge, laser, chemical vapor deposition, or high density plasma.

As an embodiment of the present invention, a high density plasma chemical vapor deposition method was used, and the used plasma chemical vapor deposition apparatus used an inductively coupled plasma (ICP) device capable of generating high density plasma by applying RF (Radio Frequency) power. . As a source gas of plasma for growing the carbon nanotube film 1, hydrocarbon-based gas such as acetylene or benzene containing carbon atoms may be used, but in this embodiment, methane (CH ₄ ) is used, and methane supplied The flow rate of was about 10 SCCM, helium (He) was supplied with an inert gas of about 10 SCCM. The RF power was fixed at 1 Kw, and the carbon nanotube film 1 was grown under a temperature of 600 to 900 ° C. and an internal pressure of 10 to 1000 mTorr. Meanwhile, nitrogen (N ₂ ) gas or hydrogen (H ₂ ) gas may be used together to promote the reaction. The deposition plasma of this example was maintained at a high density of 10 ¹¹ cm ⁻³ or more.

FIG. 2 is a cross-sectional view showing a field emission emitter having a stackable thin film transistor and a carbon nanotube pixel according to another embodiment of the present invention, wherein the same members as shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof Is omitted. Referring to FIG. 2, the source electrode 3 pattern and the drain electrode 4 pattern are formed on the insulating substrate 8 so as to be spaced apart by a predetermined distance, and the source electrode 3 pattern and the drain electrode 4 pattern are formed. A semiconductor layer 7 is formed to fill a spaced portion between them and extend by a predetermined length to the side. A gate electrode 2 pattern including a gate insulating film 5 and a gate electrode 2 is formed on the semiconductor layer 7 over a spaced portion between the source electrode 3 pattern and the drain electrode 4 pattern. The protective insulating film 6 is formed to cover the pattern of the gate electrode 2. A carbon nanotube film 1 is formed on a part of the surface of the drain electrode 4.

As described above, the source electrode 3 and the drain electrode 4 may be formed in a single layer structure or a multilayer structure of a conductive material. In addition, when the carbon nanotube film is directly grown on the drain electrode, at least a surface of the drain electrode 4 in contact with the carbon nanotube film 1 may include a catalyst metal layer (not shown) for carbon nanotube growth. Can be. That is, a catalyst metal layer may be formed only at a portion in contact with the carbon nanotube film 1, or may be formed on the entire surface of the drain electrode 4, and at least part of the process may include the source electrode 3 and the drain. It may be formed on the upper surface of the electrode 4. On the other hand, the drain electrode 4 itself may be formed of a catalyst metal.

Next, the manufacturing process of the field emission emitter illustrated in FIG. 2 will be described in detail. After forming a conductive material layer on the entire surface of the insulating substrate 8, source electrodes spaced apart from each other by a predetermined distance in a normal photolithography process ( 3) A pattern and a drain electrode 4 pattern are formed. In this case, as described above, a catalyst metal layer for growing carbon nanotubes may be used as the conductive material layer, and when the catalyst metal layer is formed in multiple layers on a common conductive material such as aluminum, a catalyst metal layer is formed on the conductive material. After performing the photolithography process. Subsequently, the semiconductor layer 7 is formed on the front surface by chemical vapor deposition or physical vapor deposition using sputtering, and then patterned by photolithography to fill the side between the source electrode 3 and the drain electrode 4. To form a pattern of the semiconductor layer 7 extending by a predetermined length.

Subsequently, after the gate insulating film 5 and the gate electrode 2 material layer are formed on the entire surface of the substrate, the semiconductor layer 7 between the source electrode 3 pattern and the drain electrode 4 pattern is formed by a photolithography process. A pattern of the gate electrode 2 composed of the gate insulating film 5 and the gate electrode 2 is formed. Subsequently, after the protective insulating film 6 is formed on the entire surface of the substrate on which the thin film transistor is formed, a portion of the protective insulating film 6 is etched to expose a portion of the drain electrode 4. Subsequently, a carbon nanotube film 1 is formed on the exposed surface of the drain electrode 4. Forming the carbon nanotube film 1 is the same as the embodiment of FIG.

3 is a cross-sectional view showing a field emission emitter having a reverse stack type thin film transistor and a carbon nanotube pixel according to another embodiment of the present invention, wherein the same member as shown in FIG. Detailed description will be omitted. Referring to FIG. 3, a gate electrode 2 pattern including a gate electrode 2 and a gate insulating film 5 is formed on an insulating substrate 8, and a semiconductor layer (eg, a pattern covering the gate electrode 2 pattern) is formed. 7) A pattern is formed. A source electrode 3 pattern and a drain electrode 4 pattern are formed on the semiconductor layer 7 pattern by a predetermined distance, and are spaced apart between the source electrode 3 pattern and the drain electrode 4 pattern. The protective insulating film 6 is formed in such a manner as to cover the gap. A carbon nanotube film 1 is formed on a part of the surface of the drain electrode 4.

Next, the manufacturing process of the field emission emitter shown in FIG. 3 will be described in detail. After forming the material layers of the gate electrode 2 and the gate insulating film 5 on the entire surface of the insulating substrate 8, the photolithography process is performed. The gate electrode 2 pattern which consists of the gate electrode 2 and the gate insulating film 5 is formed by this. Subsequently, the semiconductor layer 7 is formed on the entire surface of the substrate, and then patterned by a photolithography process to form the semiconductor layer 7 pattern to cover the gate electrode 2 pattern. Subsequently, after the conductive material layer is formed on the entire surface, the source electrode 3 pattern and the drain electrode 4 pattern are spaced apart from each other by a predetermined distance in a conventional photolithography process. Subsequently, after the protective insulating film 6 is formed on the entire surface of the substrate on which the thin film transistor is formed, a portion of the protective insulating film 6 is etched to expose a portion of the drain electrode 4. Subsequently, a carbon nanotube film 1 is formed on the exposed surface of the drain electrode 4. Forming the carbon nanotube film 1 may be the same as the embodiment of FIG.

4 is an equivalent circuit diagram of an active matrix field emission display device using a field emission emitter according to an exemplary embodiment of the present invention. Referring to FIG. 4, the plurality of gate lines 10 and the data lines 9 are arranged to be orthogonal to each other, and unit pixels are determined by the gate lines 10 and the data lines 9, and these unit pixels are Arranged in a matrix. Each unit pixel is formed with a carbon nanotube film 1 as an electron emission unit, and a thin film transistor 11 is provided as a switching element for driving these electron emission units. The gate electrode of each thin film transistor 11 is connected to the gate line 10, the source electrode is connected to the data line 9, and the gate electrode is connected to the carbon nanotube film 1, which is an electron emission unit. The cross-sectional structure of the electron emission emitter having the thin film transistor 11 and the carbon nanotube film 1 may be any one of the planar, stacker, or inverse stacker types of FIGS. 1 to 3.

Figure 5a is a scanning electron micrograph of the carbon nanotube film grown in accordance with an embodiment of the present invention, it can be seen that the bundle of nanotubes are well aligned in one direction. 5B is a photograph of a projection electron microscope of a carbon nanotube film formed on each drain electrode at each unit pixel of the field emission display device according to an exemplary embodiment of the present invention. It can be seen that the carbon nanotube films are selectively grown only on the exposed surface of the drain electrode.

6 is a cross-sectional view of a field emission display device according to an exemplary embodiment of the present invention, and schematically illustrates a cross-sectional structure of a unit pixel in each pixel arranged in the active matrix of FIG. The transistor 11 used the planar thin film transistor shown in FIG.

Referring to FIG. 6, the upper electrode 13 is formed to face the insulating substrate 8 while ensuring a constant space. The semiconductor layer 7 is formed on the insulating substrate 8, and the source electrode 3 pattern and the drain electrode 4 pattern are formed on the semiconductor layer 7 by a predetermined distance. On the exposed semiconductor layer 7 between the source electrode 3 pattern and the drain electrode 4 pattern, the gate is spaced apart from the source electrode 3 pattern and the drain electrode 4 pattern via a gate insulating film 5. The electrode 2 pattern is formed. A protective insulating film 6 is formed between the source electrode 3, the gate electrode 2, and the drain electrode 4 to insulate and protect the source electrode 3, and carbon nanotubes are formed on a portion of the drain electrode 4. The film 1 is formed. On the other hand, inside the upper electrode 13, the phosphors 12 are spaced apart at regular intervals to face the carbon nanotube film 1.

As shown in FIG. 4, the electron emission display device is driven by driving the thin film transistor 11 provided in the pixel selected by the signal transmission by the gate line 10 and the data line 9. Electrons are emitted from 1), and the emitted electrons are accelerated by a strong electric field between the upper electrode 13 and the drain electrode 4 to emit light by collision with the phosphor 12 to perform a display function. Carbon nanotubes are nanometers in size, similar to or smaller than those used in conventional field emission emitters, but exhibit better field emission characteristics than the tips due to the effect of the atomic beam when used as an electron emission device.

As described above, the present invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and those skilled in the art may implement the invention within various modifications and equivalent scope therefrom. Of course it is possible. For example, in the present embodiment, the carbon nanotubes are simply formed using high density plasma, but can be formed using an arc method, a laser method, or a chemical vapor deposition method.

According to the present invention, an active matrix field emission display device using carbon nanotubes and a thin film transistor can be easily manufactured to manufacture a field emission display device having a high current density and driving at a low voltage. In addition, the active field emission display device of the present invention can maintain a uniform and stable emission current by adjusting the current with a thin film transistor, so that it is possible to easily implement a current driven field emission display device that is difficult to implement in a general field emission display device.

Claims (21)

Insulating substrate; A thin film transistor unit formed on the insulating substrate and having a semiconductor layer, a source electrode, a drain electrode, and a gate electrode; And A field emission emitter having a carbon nanotube film including an electron emission section including a carbon nanotube film formed on a drain electrode of the thin film transistor unit. The field emission emitter of claim 1, wherein the semiconductor layer of the thin film transistor portion is a polycrystalline silicon layer. The field emission emitter having a carbon nanotube film according to claim 1, wherein the structure of the thin film transistor portion is one of a planar type, a stacked type, and an inverted stacked type. The field emission emitter having the carbon nanotube film according to claim 1, wherein the surface of the drain electrode in contact with the carbon nanotube film includes a catalyst metal for growing carbon nanotubes. 2. The field emission emitter of claim 1, wherein the drain electrode in contact with the carbon nanotube film is made of a catalyst metal for growing carbon nanotubes. 6. The field emission emitter of claim 4 or 5, wherein the catalyst metal for growing carbon nanotubes is nickel or cobalt. Forming a thin film transistor having a semiconductor layer, a source electrode, a drain electrode, and a gate electrode on an insulating substrate; Forming a protective insulating film on an entire surface of the insulating substrate on which the thin film transistor is formed; Etching a portion of the protective insulating layer to expose a portion of the drain electrode; And A method of manufacturing a field emission emitter having a carbon nanotube film comprising the step of forming a carbon nanotube film on the exposed surface of the drain electrode. The method of claim 7, wherein the forming of the thin film transistor, Forming a semiconductor layer on the insulating substrate; Forming a source electrode pattern and a drain electrode pattern spaced apart by a predetermined distance from the semiconductor layer; And And forming a gate electrode pattern consisting of a gate insulating film and a gate electrode between the source electrode pattern and the drain electrode pattern. The method of claim 7, wherein the forming of the thin film transistor, Forming a source electrode pattern and a drain electrode pattern spaced apart by a predetermined distance from the insulating substrate; Forming a semiconductor layer pattern extending by a predetermined length from the side while filling the source electrode pattern and the drain electrode pattern; And And forming a gate electrode pattern comprising a gate insulating film and a gate electrode on the semiconductor layer pattern between the source electrode pattern and the drain electrode pattern. . The method of claim 7, wherein the forming of the thin film transistor, Forming a gate electrode pattern including a gate electrode and a gate insulating film on the insulating substrate; Forming a semiconductor layer pattern covering the gate electrode pattern; And And forming a source electrode pattern and a drain electrode pattern spaced apart by a predetermined distance from the semiconductor layer pattern. The method of claim 7, wherein the forming of the carbon nanotube film on the exposed drain electrode comprises coating a carbon nanotube film on a surface of the exposed drain electrode. Way. 8. The field emission emitter having a carbon nanotube film according to claim 7, wherein the forming of the carbon nanotube film on the exposed drain electrode comprises directly growing the carbon nanotube film on the exposed drain electrode. Manufacturing method. 13. The field emission emitter with carbon nanotube films according to claim 12, further comprising forming a catalyst metal layer for carbon nanotube growth on the surface of the drain electrode in contact with the carbon nanotube film. Method of manufacturing the foundation. 15. The method of claim 13, wherein the forming of the catalytic metal layer is performed in the forming of the thin film transistor. The method of claim 13, wherein the forming of the catalyst metal layer is performed after etching a portion of the protective insulating layer. The method of claim 12, wherein the drain electrode in contact with the carbon nanotube film is formed of a catalyst metal for growing carbon nanotubes. 13. The method of claim 12, wherein the carbon nanotube film growth conditions, hydrocarbon-based gas is used as the source gas of the plasma, the process temperature is 600 ~ 900 ℃, high density plasma chemistry of 10 ¹¹ cm ^-3 or more A method for producing a field emission emitter with a carbon nanotube membrane, characterized in that the vapor deposition method is used. In a field emission display device in which unit pixels divided by a plurality of orthogonal gate lines and data lines are arranged in a matrix, each unit pixel includes: A thin film transistor unit formed on the insulating substrate and having a semiconductor layer, a source electrode, a drain electrode, and a gate electrode; An electron emission unit including a carbon nanotube film formed on the drain electrode of the thin film transistor unit; An upper electrode formed to face the insulating substrate; And And a phosphor formed on the inner surface of the upper electrode to face the electron emitting portion. 19. The field emission display device of claim 18, wherein the structure of the thin film transistor portion is any one of a planar type, a stacked type, and an inverted stacked type. 19. The field emission display device of claim 18, wherein a surface of the drain electrode in contact with the carbon nanotube film comprises a catalyst metal for growing carbon nanotubes. 19. The field emission display device of claim 18, wherein the drain electrode in contact with the carbon nanotube layer is made of a catalyst metal for growing carbon nanotubes.