KR20060122377A - Carbon nanotube emitter field emission display and mamufacturing method thereof - Google Patents

Abstract

A field emission display having a carbon nano tube emitter and a manufacturing method thereof are provided to improve uniformity of luminance by maximizing electron emission efficiency of a carbon nano tube. A lower substrate(101) is prepared. A cathode electrode(102) is formed on the lower substrate. A carbon nano tube emitter(103) is provided on the cathode electrode. A gate dielectric(104) is formed to surround the carbon nano tube emitter. A gate electrode(105) is formed on the gate dielectric. A whole surface plate(107) is provided to cover the gate electrode from an upper portion thereof at a certain space by the gate electrode and a spacer(106). An anode electrode(108) is formed under the whole surface plate to be faced to the gate electrode. A phosphor layer(109), which emits a light by electrons irradiated from the carbon nano tube, is formed on the anode electrode.

Description

Field emission display with carbon nanotube emitter and manufacturing method thereof {CARBON NANOTUBE EMITTER FIELD EMISSION DISPLAY AND MAMUFACTURING METHOD THEREOF}

1 is a view showing a field emission display having a carbon nanotube emitter according to an embodiment of the present invention,

2 to 5 schematically show a manufacturing process of the field emission display having a carbon nanotube emitter according to an embodiment of the present invention.

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

101: lower substrate 102: cathode electrode

103: tanon nanotube emitter 104: gate insulating layer

105: gate electrode 106: spacer

107: front panel 108: anode electrode

109 phosphor

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emission display (FED) having a carbon nanotube emitter and a method of manufacturing the same, and more particularly, to a direction and shape of a carbon nanotube serving as an emitter of a field emission display. Is controlled using an ion beam, especially a focused ion beam, which maximizes the electron emission efficiency of the carbon nanotube emitters, resulting in high luminance even at low voltages, and also emitting electrons by the carbon nanotube emitters. The present invention relates to a field emission display having a carbon nanotube emitter that can be uniformized to give uniform brightness, and a method of manufacturing the same.

Carbon nanotubes, which have recently been spotlighted as new materials in the nanotechnology field, have excellent electrical, chemical and mechanical properties as well as high aspect ratios. Carbon nanotubes having various excellent physicochemical properties have been sought for application in various fields, and one of them is field emission display technology using carbon nanotubes as emitters.

When using carbon nanotubes as emitters in the field emission display field, the electron emission voltage can be significantly lowered, thereby lowering the driving voltage as well as using carbon such as an emitter such as a spin type tip or a silicon tip. The excellent chemical resistance and mechanical strength of nanotubes makes it possible to manufacture highly reliable devices.

However, in order to maximize electron emission efficiency and to ensure uniformity of electron emission by using carbon nanotubes as emitters of the field emission display, the direction and shape of the carbon nanotubes provided to the cathode electrode of the field emission display are controlled. There is a need to do this. That is, in order to secure such electron emission efficiency and electron emission uniformity, it is necessary to align carbon nanotubes serving as emitters in the electron emission direction.

In general, carbon nanotubes serving as emitters may be provided on the cathode by screen printing using carbon nanotube powder, chemical vapor deposition (CVD), or the like. Among them, the carbon nanotube growth method using chemical vapor deposition method is capable of manufacturing a high resolution display device and growing directly on a substrate. Such chemical vapor deposition methods include plasma enhanced chemical vapor deposition (PECVD) and thermal chemical vapor deposition (thermal CVD).

However, the screen printing method and the chemical vapor deposition method alone have limitations in controlling the direction and shape of the carbon nanotubes, which serve as the emitter. That is, there is a limit in controlling the orientation direction and the shape of the carbon nanotubes by the improvement of such a process.

Japanese Patent Application No. 2003-51542 (JP2003-51542), entitled "FED Cathode with Vertical Alignment of Carbon Nanotube Electrodes and Carbon Nanotubes Arranged Vertically", discloses carbon nanoparticles used as emitters for FEDs. A technique for improving the characteristics of the tube and arranging the carbon nanotubes vertically and at an appropriate density on the FED cathode electrode is disclosed.

Specifically, Japanese Patent Application No. 2003-51542 discloses a low melting point such as indium on a conductive layer serving as an electrode after embedding a soft magnetic material and a low work function material in a carbon nanotube. Forming a metal layer and applying an electric field in the direction to align the carbon nanotubes, standing up perpendicularly to the conductive layer using the magnetic properties of the magnetic material contained in the carbon nanotubes, heating and cooling under a magnetic field to dissolve the low melting point metal layer, A method of fixing carbon nanotubes onto a conductive layer by solidification is disclosed.

However, this method also has a number of problems in terms of effectiveness and efficiency, as described above, merely controlling the orientation of the carbon nanotubes through several processes.

Therefore, in order to obtain better electron emission efficiency and uniformity by adjusting the orientation and shape of the carbon nanotubes acting as emitters in the field emission display, a breakthrough alternative having a different approach from the above-mentioned prior art. The need exists.

An object of the present invention is to maximize the electron emission efficiency of the carbon nanotubes, which act as emitters of the field emission display, to produce high luminance even at low voltage, and to uniformly emit electrons emitted by the carbon nanotube emitter. It is to provide a field emission display having a carbon nanotube emitter capable of producing a and a method of manufacturing the same.

It is an object of the present invention to provide a lower substrate; Forming a cathode electrode on the lower substrate, providing a carbon nanotube to the cathode electrode serving as an emitter of the field emission display, and forming a gate insulating layer to surround the carbon nanotube emitter Forming a gate electrode over the gate insulating layer, providing a front plate covering the gate electrode from the top with a predetermined gap by the gate electrode and a spacer; Forming an anode electrode under the front plate facing each other, and forming a phosphor layer on the anode electrode which is emitted by electrons emitted from the carbon nanotube emitter; As the manufacturing method of the step of providing the carbon nanotubes is the field emission Fabricating a carbon nanotube emitter field emission display comprising irradiating an ion beam to the carbon nanotubes serving as an emitter of a display to align the carbon nanotubes in an electron emission direction of the carbon nanotube emitter Is achieved by the method.

Preferably, the ion beam is a focused ion beam, and the focused ion beam may be any one of a Ga ion beam, Au ion beam, Ar ion beam, Li ion beam, Be ion beam, He ion beam, Au-Si-Bi ion beam. have.

In addition, the accelerated voltage of the focused ion beam is 5kV to 30kV, the current amount is 1pA to 1nA, the carbon nanotube is exposed to the focused ion beam is preferably 1 second to 1 minute, the carbon nanotube is a single Single-walled carbon nanotubes, double-walled carbon nanotubes (double-walled carbon nanotubes) and multi-walled carbon nanotubes (multi-walled carbon nanotubes) may be one.

The present invention also provides a lower substrate, a cathode electrode formed on the lower substrate, a carbon nanotube emitter provided on the cathode electrode, a gate insulating layer formed to surround the carbon nanotube emitter, A gate electrode formed over the gate insulating layer, a front plate covering the gate electrode from the top with a predetermined gap by the gate electrode and the spacer; an anode formed under the front plate to face the gate electrode; A carbon nanotube emitter field emission display comprising a phosphor layer formed on the anode electrode and emitted by electrons emitted from the carbon nanotube emitter, wherein the carbon nanotube emitter is formed by the irradiation of an ion beam. Characterized in that the carbon emitter is aligned in the direction of the electron emission of the tube emitter Tube emitter is achieved by a field emission display.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments will now be described in detail with reference to the accompanying drawings as examples only.

1 illustrates a field emission display (FED) having a carbon nanotube emitter in accordance with an embodiment of the present invention. For convenience, only one pixel structure is shown.

As shown in FIG. 1, a field emission display having a carbon nanotube emitter according to an exemplary embodiment of the present invention may include a lower substrate 101, a cathode electrode 102 formed on the lower substrate 101, and a cascade. Emitter 103 provided over electrode 102, Gate insulating layer 104 formed to surround emitter 103, Gate electrode 105 formed over gate insulating layer 104, Gate electrode 105 Alternatively, the front plate 107, the anode electrode 108 formed below the front plate 107, and the anode electrode formed to cover the gate electrode 105 from the top with a predetermined gap by the emitter 103 and the spacer 106. And a phosphor 109 formed at 108.

Although not shown in FIG. 1, the cathode electrode is divided into a matrix column and a row electrode, and the matrix is addressed to the emitter by the column and row electrodes by the driving circuit so that the electrons are applied during the time when the gate voltage is applied. The phosphor is emitted and accelerated by the anode voltage to hit the phosphor coated on the anode electrode through the vacuum gap to emit the phosphor.

2 is a diagram schematically illustrating a part of a method of manufacturing a field emission display having a carbon nanotube emitter according to an embodiment of the present invention.

In FIG. 2A, first, a lower substrate may be formed of various materials such as glass, and in FIG. 2B, a mask 201 may be mounted on the lower substrate to deposit a cathode electrode in an arrow direction 202. 2 (c) shows that the cathode electrode 102 is formed on the lower substrate after such deposition exaggeration.

After forming the cathode electrode 102, as shown in (d) of FIG. 2, the cathode 102 is provided with a carbon nanotube 103 serving as an emitter of the field emission display. Carbon nanotubes may be provided to the cathode electrode in a variety of ways, such as screen printing or chemical vapor deposition, as mentioned in the prior art. Since the method of providing such carbon nanotubes is well known to those skilled in the art, further description thereof is omitted.

Carbon nanotubes serving as emitters of field emission displays according to an embodiment of the present invention are single-walled carbon nanotubes, double-walled carbon nanotubes or multi-walled carbons. Nano-tubes (multi-walled carbon nanotube) and the like can be used.

However, as mentioned in the prior art, in the step of providing carbon nanotubes as emitters to the cathode by screen printing or image vapor deposition as described above, the direction and shape of the carbon nanotubes are controlled. Because of the limitation, the direction and shape of the carbon nanotubes need an additional process in such a manner that the electron emission efficiency can be maximized and the electron emission uniformity can be achieved.

In general, the electron emission efficiency and uniformity of the field emission emitter are highly influenced by the geometry of the emitter. In the case of the tanno-nanotubes having an excellent aspect ratio, carbon nano-nanophorus is disclosed as described in Japanese Patent Application No. 2003-51542. It is known that the electron emission efficiency and uniformity are the best when the tube is upright in the electron emission direction.

Therefore, in view of the above, the inventors of the present invention, in order to achieve the excellent electron emission efficiency and uniformity of the carbon nanotube emitter, the cathode electrode through the additional process after the step (d) of FIG. Arrange an arbitrary directing direction of the carbon nanotubes 103 provided in the 102 in the electron emission direction, and also correct the warpage or bending of the carbon nanotubes that may occur in the process of FIG. It was recognized that an additional process that could be deployed immediately was needed.

Such further processing led to the inventor of the present invention creating an additional process such as FIG. 3A or 3C. The inventors of the present invention have recognized that when carbon nanotubes are irradiated with ion beams, particularly focused ion beams, the carbon nanotubes are aligned and stretched in the direction of irradiation of the ion beams. Such information is disclosed in Korean Patent Application No. 10-2005-0036631 filed by the applicant of the present invention.

Referring to Figure 3a describes the additional process created by the inventor of the present invention as follows.

Referring to FIG. 3A, an additional process invented by the inventor of the present invention is an ion beam on the carbon nanotube emitter 103 provided to the cathode electrode 102 using the ion column 301 after the process of FIG. 302 is to be investigated. After the ion beam is irradiated on one carbon nanotube emitter, the ion beam is moved toward the arrow 303 shown in FIG. 3A to irradiate the ion beam on the other carbon nanotubes. Although no alternative device is excluded, the ion column is preferably a focused ion beam system (FIB). In addition, the carbon nanotube emitter is inputted in advance, and all carbon nanotube emitters are irradiated with an ion beam through a software-automated scanning method to align the carbon nanotube emitters in the direction of electron emission. You may be able to unfold it.

Various types of ion beams irradiated to the carbon nanotube emitters may be used. For example, Ga ion beams, Au ion beams, Ar ion beams, Li ion beams, Be ion beams, He ion beams, Au-Si-Bi ion beams may be used. have. Further, as a result of the experiment, the acceleration voltage of the ion beam is 5 kV to 30 kV, the current amount is 1 pA to 1 nA, and the time for exposing the carbon nanotubes to the focused ion beam is preferably 1 second to 1 minute.

FIG. 3B shows the carbon nanotube emitters aligned and unfolded in the electron emission direction after completing the additional process of FIG. 3A.

3C is a reference diagram for carrying out such an additional process more efficiently and quickly. As can be seen from FIG. 3C, an ion column 301 'capable of irradiating an ion beam 302' to a large area is used, and scanning is performed more efficiently by scanning in the direction of the arrow 303 'in the same manner as in FIG. 3A. And a rapid process will be possible.

4 is a process explanatory diagram after the process of FIG. 3A or 3C. 4A illustrates that the gate insulation layer 104 is formed, and FIG. 4B illustrates the formation of the gate electrode 105 over the gate insulation layer.

5 is explanatory drawing of the manufacturing process of the upper plate of an electroluminescent display. After forming the transparent anode electrode 108 of FIG. 5 (b) under the transparent front plate shown in (a) of FIG. 5, a phosphor is applied to the anode electrode as shown in (c) of FIG. The manufacture of the plates takes place.

4 to 5 are well known to those skilled in the art, and thus further description thereof will be omitted.

As described above, after the processes of FIGS. 2 to 5 are performed, when the vacuum is maintained using the spacer 106 and the lower and upper panels of the electroluminescent display are combined, the carbon according to the embodiment of the present invention shown in FIG. The process of making a field emission display with nanotube emitters is complete.

So far, a preferred embodiment of the present invention has been described. However, the embodiments described so far should only be taken as examples. That is, those skilled in the art to which the present invention pertains will be able to derive various modifications with reference to the preferred embodiment of the present invention. Accordingly, the technical scope of the present invention should be interpreted only by the appended claims.

The present invention can maximize the electron emission efficiency of the carbon nanotubes, which act as emitters of the field emission display, can produce high luminance even at low voltages, and can uniformly emit electrons emitted by the carbon nanotube emitters. There is an effect of providing a field emission display having a carbon nanotube emitter and a method of manufacturing the same.

Claims (10)

As a method of manufacturing a carbon nanotube emitter field emission display, Providing a lower substrate, Forming a cathode on the lower substrate; Providing carbon nanotubes to the cathode as a emitter of the field emission display; Forming a gate insulating layer to surround the carbon nanotube emitter; Forming a gate electrode over the gate insulating layer; Providing a front plate covering the gate electrode from the top with a predetermined gap by the gate electrode and a spacer; Forming an anode electrode under the front plate to face the gate electrode; In the method of manufacturing a carbon nanotube emitter field emission display comprising the step of forming on the anode electrode a phosphor layer emitted by electrons emitted from the carbon nanotube emitter, In the providing of the carbon nanotubes, the carbon nanotubes serving as emitters of the field emission display are irradiated with ion beams to straighten the carbon nanotubes in the electron emission direction of the carbon nanotube emitters. Characterized in that it comprises a step, Manufacturing method of carbon nanotube emitter field emission display The method of claim 1, The ion beam is characterized in that the focused ion beam (focused ion beam), Method for producing a carbon nanotube emitter field emission display. The method of claim 2, The focused ion beam is any one of a Ga ion beam, Au ion beam, Ar ion beam, Li ion beam, Be ion beam, He ion beam, Au-Si-Bi ion beam, Method for producing a carbon nanotube emitter field emission display. The method of claim 3, wherein The acceleration voltage of the focused ion beam is 5kV to 30kV, the current amount is 1pA to 1nA, characterized in that the carbon nanotubes are exposed to the focused ion beam is 1 second to 1 minute, Method for producing a carbon nanotube emitter field emission display. The method according to any one of claims 1 to 4, The carbon nanotubes are any one of single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes. , Method for producing a tanno nanotube emitter field emission display. A lower substrate, a cathode electrode formed on the lower substrate, a carbon nanotube emitter provided to the cathode electrode, a gate insulating layer formed to surround the carbon nanotube emitter, and a gate insulating layer formed thereon. A gate electrode, a front plate covering the gate electrode from the top with a predetermined gap by the gate electrode and the spacer, an anode formed below the front plate to face the gate electrode, and formed on the anode electrode A carbon nanotube emitter field emission display comprising a phosphor layer emitting by electrons emitted from a carbon nanotube emitter, Wherein the carbon nanotube emitter is characterized in that the straightening (straightening) aligned in the electron emission direction of the carbon nanotube emitter by the irradiation of the ion beam, Carbon nanotube emitter field emission display. The method of claim 6, The ion beam is characterized in that the focused ion beam, Carbon nanotube emitter field emission display. The method of claim 7, wherein The focused ion beam is any one of a Ga ion beam, Au ion beam, Ar ion beam, Li ion beam, Be ion beam, He ion beam, Au-Si-Bi ion beam, Method for producing a carbon nanotube emitter field emission display. The method of claim 8, The acceleration voltage of the focused ion beam is 5kV to 30kV, the current amount is 1pA to 1nA, characterized in that the carbon nanotubes are exposed to the focused ion beam is 1 second to 1 minute, Method for producing a carbon nanotube emitter field emission display. The method according to any one of claims 6 to 9, The carbon nanotubes are any one of single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes. , Tannonanotube emitter field emission display.

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