KR20010058663A - Field emitter array using carbon nanotube and Manufacturing method thereof - Google Patents

Abstract

PURPOSE: A field emission emitter array using a carbon nanotube and a method for manufacturing the same are provided to form a field emission emitter array by depositing a carbon nanotube on a patterned substrate. CONSTITUTION: A cathode(2) of a stripe shape is formed on a substrate(1). An insulating layer(4) is laminated on the cathode(2) in order to form holes for exposing the cathode(2) according a constant interval. A catalytic layer(3) is formed on the cathode(2) exposed by the holes. A carbon nanotube(6) for emitting electrons is formed on the catalytic layer(3). A gate(5) is formed on the insulating layer(4) in order to form an opening portion corresponding to the holes. The gate(5) is formed toward a direction intersected to the cathode(2).

Description

Field emitter array using carbon nanotube and manufacturing method

The present invention relates to a method for manufacturing a field emitter array having a triode structure, and more particularly, to a field emitter array using carbon nanotubes having excellent electron emission characteristics. to an emitter array).

In the conventional field emission dispensing (FED), a spindt type field emitter array (FEA) mainly made of a metal such as Mo or a semiconductor material such as Si, that is, tips arranged at regular intervals The electrons are emitted from the tip by applying a strong electric field from the gate to the tip. The electrons thus emitted are accelerated to an anode plate with a voltage of several hundred to thousands of volts, and emit light by colliding with a phosphor coated on the anode plate. The metal or semiconductor material used in this conventional method has a large work function, so the gate voltage for electron emission is quite high, residual gas particles in vacuum collide with electrons and ionize, and these gas ions bombard the tips. May damage the field emission display device. In addition, the phosphor particles collided with the electrons fall and contaminate the tip, thereby degrading the performance of the field emission display device. This series of problems can also degrade the performance and lifetime of the FEA.

As a technique for depositing carbon nanotubes, arc discharge and laser ablation are the most commonly used techniques. This method uses a large amount of carbon nanotubes at low cost. Although there is an advantage that can be deposited, there is a problem that structure control (structure control) is difficult. Recently, vapor deposition has been developed as a method to overcome these problems, including thermal CVD (Appl. Phys. Lett. 67, 2477 (1995)), dc plasma CVD (Sience 282, 1105). (1999)), MPECVD (Appl. Phys. Lett. 72, 3437 (1998)), ion beam irradiation (Appl. Phys. Lett. 69, 4174 (1996)), and the like.

Although the electron emission field of the diamond film, which has been spotlighted as the material of the field emission emitter, is about 10V / μm, carbon nanotubes have the property of easily emitting electrons even in the electric field of 1V / μm or less. It is attracting much attention as a raw material. The problem is to deposit carbon nanotubes at low cost using a method that can control the carbon nanotubes, and for this purpose, vapor deposition should be used. In the vapor deposition method, similar to the arc discharge or laser ablation method, a transition metal such as Ni, Fe, Co, or silicide such as CoSi ₂ is used as a catalyst. So far, the nanotubes are deposited in a random form on a patterned structure. One patent related to field emitters using such controlled carbon nanotubes is currently registered (US 5,773,834), in which a gate-shaped grid is formed as a gate electrode. I'm using.

The present invention was devised to overcome the above problems, and by depositing carbon nanotubes having low field emission voltage and excellent chemical stability instead of conventional metals or semiconductor materials by vapor deposition on a patterned substrate, It is an object of the present invention to provide a field emission emitter array using carbon nanotubes and a method of fabricating the same.

1a to 1e is a vertical cross-sectional view showing a step-by-step process of manufacturing a triode field emission device using carbon nanotubes (Carbon nanotube) according to the present invention,

2A to 2C are vertical cross-sectional views illustrating another method of manufacturing a triode field emission device using the carbon nanotubes of FIG.

3A to 3D are vertical cross-sectional views illustrating another method of manufacturing a triode field emission device using carbon nanotubes according to the present invention.

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

1. Substrate 2. Cathode line

3. Catalyst layer 4. Insulation layer

5. Gate 6. Carbon nanotube

7. Separation layer

11. Substrate 12. Cathode line

13. Conical microtip 13 '. Flat Head Microtip

14. Insulation layer 15. Gate

16. carbon nanotubes

21. Substrate 22. Cathode line

23. Catalyst layer 24. Insulation layer

25. Gate 26. Carbon nanotube

In order to achieve the above object, a field emission emitter array using carbon nanotubes according to the present invention includes a substrate; Cathodes formed in a stripe shape on the substrate; An insulating layer stacked on the substrate and the cathodes such that the holes exposing the cathodes are provided at regular intervals; Catalyst layers formed on the cathodes exposed by the holes; Carbon nanotubes for electron emission formed on the catalyst layer; And gates formed in a stripe shape in a direction crossing the cathodes on the insulating layer to have openings corresponding to the holes.

In the present invention, the catalyst layer is preferably formed of any one of transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, Cu or an alloy or compound of the transition metals.

In addition, in order to achieve the above object, the manufacturing method of the field emission emitter array using the carbon nanotubes according to the present invention, (A) to form a cathode on the substrate, to promote the growth of carbon nanotubes on the cathode Forming a catalyst layer; (B) depositing an insulating layer and a gate layer over the catalyst layer, and then etching the gate and the insulating layer by patterning holes to expose the catalyst layer; (C) depositing carbon nanotubes on the gate layer so as not to enter the holes, and depositing carbon nanotubes and etching and removing the separation layer to deposit carbon nanotubes only on the catalyst layer; It is characterized by.

In the present invention, in the step (a), the cathodes are formed by ITO or metal by photolithography, and in step (b), the catalyst layer is 300- so as to control the growth of the carbon nanotubes. Heat-treating at 1000 ° C. to form nanometer-sized particles; and may further include transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, and Cu as the catalyst layer. One or more alloys or compounds of the transition metals are used, and in step (c) the carbon nanotubes are thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ionbeam assisted CVD, ion beam One of the following methods: ion beam deposition, high frequency sputtering, dc-sputtering, magnetron sputtering, laser ablation, and filtered cathodic arc methods Two or more of these This method is preferably deposited using a combination of methods with each other.

In addition, in order to achieve the above object, a method of fabricating a field emission emitter array using another carbon nanotube according to the present invention includes: (A) forming cathodes on a substrate and growing carbon nanotubes on the cathodes; Forming a catalyst layer to promote the catalyst; (B) depositing carbon nanotubes on the catalyst layer; (C) forming an insulating layer and a gate metal layer on the substrate, the cathode, the catalyst layer, and the carbon nanotubes; And (d) patterning the gate metal layer and the insulating layer sequentially to form a field emission emitter array.

In the present invention, in the step (a), the cathodes are formed by photolithography of ITO or metal, and heat treatment of the catalyst layer at 300-1000 ° C. to control the growth of the carbon nanotubes. The method may further include the step of forming particles of a nanometer size. The catalyst layer may further include any one of transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or the transition metals. An alloy or a compound is used, and in the step (b), the carbon nanotubes may be thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, ion beam deposition. ), High frequency sputtering, rf-sputtering, dc-sputtering, magnetron sputtering, laser ablation, filter cathodic arc methods, or two or more of them. Two of each other Using the method it is preferred to deposit.

In addition, another field emission emitter array using another carbon nanotube according to the present invention for achieving the above object, the substrate; Cathodes formed in a stripe shape on the substrate; An insulating layer stacked on the substrate and the cathodes such that the holes exposing the cathodes are provided at regular intervals; Microtips formed on the cathodes exposed by the holes; Carbon nanotubes for electron emission formed on the microtips; And gates formed in a stripe shape in a direction crossing the cathodes on the insulating layer to have openings corresponding to the holes.

In the present invention, the microtips are flat surfaces, and the carbon nanotubes are preferably formed on the flat surface.

In addition, the method of manufacturing a field emission emitter array using carbon nanotubes according to the present invention in order to achieve the above object, (A) forming a cathode on a substrate; (B) sequentially depositing an insulating layer and a gate layer on the substrate and the cathodes, and then etching the gate and the insulating layer by patterning holes to expose the cathodes; (C) depositing a microtip on the gate layer so as not to enter the holes and depositing a microtip to form a microtip only on the cathodes exposed by the hole; And (d) depositing carbon nanotubes on the microtips and then etching and removing the separation layer.

In the present invention, in the step (a), the cathodes are formed of ITO or metal by photolithography, and in the step (c), the microtips are formed in a flat surface shape, and the step (d) Depositing the carbon nanotubes on the flat surface, wherein the carbon nanotubes are thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, and ion beam deposition. any one or more of deposition, high frequency sputtering, dc-sputtering, magnetron sputtering, laser ablation, filtered cathodic arc methods or two or more thereof It is preferable to deposit using a method in which the methods are combined with each other.

Hereinafter, a field emission emitter array using carbon nanotubes having good electron emission characteristics and a method of fabricating the same will be described in detail.

A first embodiment of a field emission emitter array using carbon nanotubes according to the present invention, as shown in FIG. 1E, includes a substrate 1 and cathodes 2 formed in a stripe shape on the substrate 1. ), An insulating layer 4 laminated on the substrate 1 and the cathodes 2 so as to have the holes exposing the cathodes 2 at regular intervals, and on the cathodes 2 exposed by the holes. Cathodes 2 on the insulating layer 4 to have catalyst layers 3 formed on the substrates, carbon nanotubes 6 for electron emission on the catalyst layers 3, and openings corresponding to the holes; Gates 5 are formed on the stripe in the crossing direction. In the first embodiment of this configuration, the catalyst layer 3 is preferably formed of any one of transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or an alloy or compound of the transition metals.

The method of fabricating the field emission emitter array using the carbon nanotubes of the first embodiment is as follows.

First, as shown in FIG. 1A, a conductive cathode line such as ITO or a metal is formed by photolithography on a substrate, and the growth of carbon nanotubes is promoted thereon. After the deposition of the catalyst layer (catalytic layer), the catalyst layer is patterned by photolithography.

Next, as shown in FIG. 1B, an insulating layer and a gate layer are deposited over the patterned catalyst layer, and then, as shown in FIG. 1C, the holes are patterned to expose the catalyst layer to etch the gate and the insulating layer. Let's do it. In order to control the growth of carbon nanotubes, the structure of the catalyst layer 3 may be heat-treated at 300-1000 ° C. to make particles of nanometer size.

Next, as shown in FIG. 1D, the carbon nanotubes may be obliquely deposited after the deposition of a parting layer 7 into the hole to prevent the carbon nanotubes from being deposited on the gate. When the carbon nanotubes are deposited and the parting layer is etched and removed, a triode-type electron-emitting emitter in which carbon nanotubes are deposited only on the catalyst layer inside the hole as shown in FIG. 1E. The rotor array is manufactured (first manufacturing method).

Another manufacturing method (second manufacturing method) of the tripolar electron emission emitter array using the carbon nanotubes of the first embodiment as described above is as follows.

As shown in FIG. 2A, carbon nanotubes 26 are deposited on the catalyst layer 23 in the structure as shown in FIG. 1A on which the catalyst layer 23 is formed.

Next, as shown in FIG. 2B, an insulating layer 24 and a gate electrode 25 are deposited thereon.

Next, as shown in FIG. 2C, the gate 25 and the insulating layer are patterned and etched by photolithography to complete the field emission emitter array. In the third manufacturing method, the catalyst layer may be vacuum heat treated at 300-1000 ° C. before depositing the carbon nanotubes in order to promote the growth of the carbon nanotubes.

As the catalyst layer for depositing carbon nanotubes in the present invention, transition metals such as Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and alloys and compounds thereof are used. Carbon nanotube deposition also includes thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, ion beam deposition, and high frequency sputtering (rf-). sputtering, dc-sputtering, magnetron sputtering, laser ablation, filtered cathodic arc, and the like and combinations thereof.

On the other hand, the second embodiment of the field emission emitter array using the carbon nanotube according to the present invention, as shown in Fig. 3c or 3d, on the substrate 11 and the stripe on the substrate (11) The cathodes 12 formed, the insulating layer 14 stacked on the substrate 11 and the cathodes 12 such that the holes exposing the cathodes 12 are provided at regular intervals, and the cathode exposed by the holes Insulation to have microtips 13, 13 ′ formed on the holes 12, and openings corresponding to the electron emitting carbon nanotubes 16 and holes formed on the microtips 13, 13 ′. The gates 15 are formed on the layer 14 in the form of stripes in the direction crossing the cathodes 12.

In a second embodiment of this configuration, the microtips have a conical structure 13, as shown in FIG. 3C, or a flat head structure 13 ', as shown in FIG. 3D. More preferably, the carbon nanotubes 16 are formed on the flat microtip.

A method of fabricating a three-pole electron emission emitter array using the carbon nanotubes of the second embodiment having such a structure is as follows.

First, in a typical Spindt type field emission emitter structure, a microtip 13 as shown in FIG. 3A, or a flat-top microtip 13 as shown in FIG. 3B. ') Is formed under the gate line (15).

Next, after depositing a parting layer (not shown) to be deposited only on the gate electrode 15, as shown in FIGS. 3C and 3D, the microtip 13 or the truncated microtip ( The carbon nanotubes 16 are grown on the planar surface of 13 'and then the separating layer (not shown) is removed so that the carbon nanotubes 16 are formed only on the microtips 13.

The method for depositing carbon nanotubes may include thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, ion beam deposition, High frequency sputtering, dc-sputtering, magnetron sputtering, laser ablation, filtered cathodic arc, or a combination thereof is used.

As described above, the field emission emitter array using the carbon nanotubes according to the present invention includes a catalyst layer of transition metal for promoting the growth of the carbon nanotubes on the cathodes, or a conical or flat head micrometer formed on the cathodes. With a structure in which carbon nanotubes are deposited on the tip, the structure is simple and the existing manufacturing apparatus is almost used as it is, except for one or two processes such as a catalyst layer forming process and a vacuum heat treatment process of a transition metal. There is an advantage in that a field emission emitter array having excellent electron emission characteristics can be manufactured.

Claims (18)

Board; Cathodes formed in a stripe shape on the substrate; An insulating layer stacked on the substrate and the cathodes such that the holes exposing the cathodes are provided at regular intervals; Catalyst layers formed on the cathodes exposed by the holes; Carbon nanotubes for electron emission formed on the catalyst layer; And Gates formed on a stripe in a direction crossing the cathodes on the insulating layer to have openings corresponding to the holes; Field emission emitter array using carbon nanotubes, characterized in that provided. The method of claim 1, The catalyst layer is a field emission emitter array using carbon nanotubes, characterized in that formed of any one of transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, Cu or an alloy or compound of the transition metals. (A) forming a cathode on the substrate, and forming a catalyst layer on the cathode to promote the growth of carbon nanotubes; (B) depositing an insulating layer and a gate layer over the catalyst layer, and then etching the gate and the insulating layer by patterning holes to expose the catalyst layer; (C) depositing carbon nanotubes on the gate layer so as not to enter the holes, and depositing carbon nanotubes and etching and removing the separation layer to deposit carbon nanotubes only on the catalyst layer; Method of producing a field emission emitter array using carbon nanotubes, characterized in that it comprises a. The method of claim 3, In the step (a), the cathode is a method of manufacturing a field emission emitter array using carbon nanotubes, characterized in that to form ITO or metal by photolithography method. The method of claim 3, Heat treating the catalyst layer at 300-1000 ° C. so as to control the growth of the carbon nanotubes in the step (b) to make particles of nanometer size; Method of producing a field emission emitter array using carbon nanotubes further comprising. The method of claim 3, In the step (b), any one of transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or an alloy or compound of the transition metals is used as the catalyst layer. Method of making a field emission emitter array. The method of claim 3, In the step (c), the carbon nanotubes are thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, ion beam deposition, high frequency sputtering (rf- using any one of sputtering, dc-sputtering, magnetron sputtering, laser ablation, filtered cathodic arc methods, or a combination of two or more of them Method for producing a field emission emitter array using carbon nanotubes characterized in that the deposition by. (A) forming a cathode on the substrate, and forming a catalyst layer on the cathode to promote the growth of carbon nanotubes; (B) depositing carbon nanotubes on the catalyst layer; (C) forming an insulating layer and a gate metal layer on the substrate, the cathode, the catalyst layer, and the carbon nanotubes; And (D) patterning the gate metal layer and the insulating layer sequentially to form a field emission emitter array; Method of producing a field emission emitter array using carbon nanotubes, characterized in that it comprises a. The method of claim 8, In the step (a), the cathode is a method of manufacturing a field emission emitter array using carbon nanotubes, characterized in that to form ITO or metal by photolithography method. The method of claim 8, Heat-treating the catalyst layer at 300-1000 ° C. so as to control the growth of the carbon nanotubes in the step (a) to make particles of nanometer size; Method of producing a field emission emitter array using carbon nanotubes further comprising. The method of claim 8, In the step (a) using the carbon nanotubes, characterized in that any one of transition metals of Ti, V, Cr, Mn, Fe, Co, Ni, Cu or alloys or compounds of the transition metals are used as the catalyst layer. Method of making a field emission emitter array. The method of claim 8, In the step (b), the carbon nanotubes are thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, ion beam deposition, high frequency sputtering (rf- using any one of sputtering, dc-sputtering, magnetron sputtering, laser ablation, filtered cathodic arc methods, or a combination of two or more of them Method for producing a field emission emitter array using carbon nanotubes characterized in that the deposition by. Board; Cathodes formed in a stripe shape on the substrate; An insulating layer stacked on the substrate and the cathodes such that the holes exposing the cathodes are provided at regular intervals; Microtips formed on the cathodes exposed by the holes; Carbon nanotubes for electron emission formed on the microtips; And Gates formed on a stripe in a direction crossing the cathodes on the insulating layer to have openings corresponding to the holes; Field emission emitter array using carbon nanotubes, characterized in that provided. The method of claim 13, The microtips are flat surfaces, and the carbon nanotubes are formed on the flat surface. (A) forming cathodes over the substrate; (B) sequentially depositing an insulating layer and a gate layer on the substrate and the cathodes, and then etching the gate and the insulating layer by patterning holes to expose the cathodes; (C) depositing a microtip on the gate layer so as not to enter the holes and depositing a microtip to form a microtip only on the cathodes exposed by the hole; And (D) depositing carbon nanotubes on the microtips and then removing the separation layer by etching; Method of producing a field emission emitter array using carbon nanotubes, characterized in that it comprises a. The method of claim 15, In the step (a), the cathode is a method of manufacturing a field emission emitter array using carbon nanotubes, characterized in that to form ITO or metal by photolithography method. The method of claim 15, In the step (c), the microtip is formed in a flat surface shape, and in the step (d), the carbon nanotubes are deposited on the flat surface. How to make. The method of claim 15, In the step (d), the carbon nanotubes are thermal CVD, rf-CVD, dc plasma CVD, MPECVD, ECR-CVD, ion beam assisted CVD, ion beam deposition, and high frequency sputtering (rf- using any one of sputtering, dc-sputtering, magnetron sputtering, laser ablation, filtered cathodic arc methods, or a combination of two or more of them Method for producing a field emission emitter array using carbon nanotubes characterized in that the deposition by.