KR0163483B1 - Manufacturing method for diamond tip field emitter with molding technology - Google Patents

Abstract

A method of manufacturing a diamond tip field emitter by molding technology capable of lowering the driving voltage is disclosed. A portion of the wafer is etched to form a silicon mold in which pyramidal holes are formed. An oxide film, a diamond thin film for field emitters, and a cathode are sequentially formed on the silicon mold, and then bonded to glass. After removing the silicon mold and the oxide layer and forming an insulating layer and a gate electrode on the diamond thin film, the gate electrode and the insulating layer are etched to form a field emitter having a triode structure. By using molding technology, diamond tips can be manufactured easily and effectively, and diamond field emitters can be manufactured in the form of tips and form triode structures, which greatly reduces the driving voltage required for field emission display operation. The power consumption of the display can be reduced.

Description

Manufacturing method of diamond tip field emitter by molding technology

The present invention relates to a method for manufacturing a diamond tip field emitter for a field emission display. More particularly, the present invention relates to a molding technology capable of significantly reducing the driving voltage of a display by manufacturing a diamond thin film tip having excellent field emission characteristics. To a method for producing a diamond tip field emitter.

A typical field emission display using a conventional diamond field emitter is a flat thin film rather than a tip, and a diode structure is often used instead of a triode. Due to the nature of diamond's negative electron affinity, diamond has a threshold voltage of about 50 times lower than the field emitter material such as metal or silicon and has a high current density. This is because a diode structure is possible. The field emission display of the diamond diode structure has a one-to-one correspondence between pixels and a thin film of diamond, which eliminates the need to produce multiple tips, simplifying the manufacturing process, and eliminating the insulator or gate electrode manufacturing process, and the photolithography process. Because of the simplicity, the process yield is improved, thereby lowering the manufacturing cost of the field emission display.

However, although diamond has superior electron emission characteristics than other materials, the emitter structure and the diode structure of the thin film type have a limitation, and thus, a driving voltage (swing voltage) required for display operation is increased. For example, a diamond diode field emission display presented by SIA Diamond Inc. in the United States requires a driving voltage of about 500V at a distance of 25 μm between the anode and the cathode. This value is too high considering field emission display applications and it is appropriate to lower the drive voltage to at least 300V. In addition, since the distance between the anode and the cathode must be reduced more than necessary because the driving voltage must be reduced, there may be a problem of conductance in forming an initial vacuum in the panel.

Accordingly, an object of the present invention is to solve the above-mentioned problems, an object of the present invention is to provide a diamond tip of a triode structure for a field emission type display which can simplify the manufacturing process and lower the driving voltage of the display by using molding technology. It is to provide a method for producing a field emitter.

1A to 1D are flow charts of diamond tip field emitter fabrication by the molding technique of the present invention.

* Explanation of symbols for the main parts of the drawings

1: silicon mold 2: oxide film

3: diamond thin film 4: cathode electrode

5: glass 6: insulating layer

7: gate electrode

In order to achieve the above object of the present invention, the present invention comprises the steps of: etching a predetermined portion of the silicon wafer to form a silicon mold with a pyrimid-type hole formed, forming an oxide film on the silicon mold, Forming a diamond thin film for a field emitter on the top, forming a cathode electrode on the diamond thin film, and then bonding the glass to the glass, removing the silicon mold and the oxide film on the silicon mold, for the field emitter Forming an insulating layer on the diamond thin film, forming a gate electrode on the insulating layer, and etching the gate electrode and the insulating layer to form a field emitter having a triode structure; It is to provide a method for manufacturing a diamond tip field emitter by molding technology.

According to the present invention, a diamond tip can be manufactured easily and effectively using molding technology, and a diamond field emitter can be manufactured in the form of a tip and a triode structure can be formed to greatly reduce the driving voltage required for the field emission display operation. It is possible to reduce the power consumption of the field emission display.

Hereinafter, a method of manufacturing a diamond tip field emitter by molding technology according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1A to 1D are cross-sectional views showing the manufacturing process of the diamond tip field emitter by the molding technique according to the present invention.

Referring to FIG. 1A, first, a pyramidal hole 11 is formed in a silicon wafer by wet etching the silicon wafer with a potassium hydroxide (KOH) solution. Here, the pyramidal array etching of the silicon wafer is a well established process in the field of micromachining. First, a thin oxide film is formed on a silicon wafer by a thermal oxidation method or a chemical vapor deposition method (the thickness of the oxide film is not important at this time), and a pattern is formed on the oxide film to a predetermined size by a photolithography process. Thereafter, the silicon wafer is immersed in an anisotropic etching solution of silicon, at which the etching rate of the surface of Miller single crystals (Miller's indice) of the silicon single crystal constituting the silicon wafer is (100) is about 100 than that of (111) or (110). Since it is about twice as fast, only the (111) plane remains to form the pyramidal silicon single crystal mold 1.

Referring to FIG. 1B, the silicon single crystal mold 1 is oxidized to form an oxide film 2 on the silicon single crystal mold 1. Thus, by oxidizing the silicon single crystal mold 1, the tip of the silicon single crystal mold 1 is sharpened to improve the performance of the diamond field emitter formed later, and the silicon single crystal mold 1 to be described later. Blocking between the diamond tip emitters prevents contamination of the diamond tips during the manufacturing process.

Subsequently, a thin film of field emitter diamond is deposited on the silicon single crystal mold 1 on which the oxide film 2 is formed to fill the mold, and then a metal thin film is sputtered on top of the diamond thin film 3. By deposition to form a cathode electrode (4). In forming the diamond thin film 3, microwave chemical vapor deposition (chemical vapor depos)

ition: CVD, electron cyclotron Resonance chemical vapor deposition (CVD) to form a polycrystalline diamond thin film, or using plasma chemical vapor deposition or sputtering and electron cyclotron resonance chemical vapor deposition (CVD) To form an amorphous diamond-like carbon thin film, or an amorphous diamond thin film and a transition metal-containing diamond-like carbon thin film may be formed using a laser ablation method.

The cathode electrode 4 is formed by sputtering chromium (Cr), titanium (Ti), or tungsten (W).

Subsequently, the glass 5 is bonded to the cathode electrode 4 formed on the silicon single crystal mold 1 using an electrostatic bonding method.

Referring to FIG. 1C, the silicon single crystal mold 1 is removed using a potassium hydroxide (KOH) solution, and then the oxide film 2 formed on the silicon single crystal mold 1 is removed with a hydrofluoric acid (HF) solution. . When the silicon single crystal mold 1 and the oxide film 2 are removed in this manner, a cathode-side substrate on which the pyramidal diamond tip 12 is formed is formed.

Referring to FIG. 1D, after the insulating layer 6 and the gate electrode 7 are sequentially formed on the diamond thin film 3 having the diamond tip 12, the insulating layer 6 and the gate electrode 7 are formed. Wet etching to form a diamond tip field emitter having a triode structure. In this case, the insulating layer 6 is formed of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ) by a plasma chemical vapor deposition method, as in a method of forming a conventional insulating layer in a semiconductor process, the gate electrode ( 7) is formed by sputtering chromium (Cr), titanium (Ti) or tungsten (W) similarly to the cathode electrode (4).

When a predetermined voltage is applied between the cathode electrode 4 and the gate electrode 7, electrons are emitted at the tip of the diamond tip 12 by the field emission mechanism. At this time, since the electric field for the emission of electrons is concentrated at the tip of the diamond tip 12, it can emit electrons with a smaller voltage than in the case of an emitter having a conventional flat shape. In the present invention, in the case of the diamond tip field emitter of the triode structure, since the distance between the gate electrode and the diamond tip emitter is 1 占 퐉 or less, it is possible to emit electrons even at a small voltage. That is, while a driving voltage of about 500 V is required for a planar emitter having a conventional diode structure, the diamond tip field emitter of the triode structure according to the present invention can emit electrons even with a driving voltage of about 50 V or less. The driving voltage can be lowered more than 10 times. As such, the emitted electrons are accelerated by the voltage formed between the anode (not shown) and the cathode electrode 4 to stimulate the phosphor (not shown) applied on the anode to perform the function of the field emission display. .

According to the present invention, a diamond tip can be manufactured easily and effectively using molding technology, and a diamond field emitter can be manufactured in the form of a tip and a triode structure can be formed to greatly reduce the driving voltage required for the field emission display operation. It is possible to reduce the power consumption of the field emission display.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (7)

Etching a portion of the silicon wafer to form a silicon mold having pyrimid-type holes formed thereon; Forming an oxide film on the silicon mold; Forming a diamond thin film for a field emitter on top of the oxide film; Forming a cathode on the diamond thin film and then bonding the glass to the glass; Removing the silicon mold and the oxide film on the silicon mold; Forming an insulating layer on the diamond thin film for the field emitter; Forming a gate electrode on the insulating layer; And etching the gate electrode and the insulating layer to form a field emitter having a triode structure. The diamond tip of claim 1, wherein the forming of the silicon mold having a pyrimid-type hole by etching a predetermined portion of the silicon wafer is a wet etching step using a potassium hydroxide (KOH) solution. Field emitter manufacturing method. The method of claim 1, wherein the forming of the diamond thin film for the field emitter on the oxide layer comprises forming a polycrystalline diamond thin film by a microwave chemical vapor deposition method or an electron cyclotron resonance chemical vapor deposition method, or by plasma chemical vapor deposition or sputtering and electrons. Forming a amorphous diamond-like carbon thin film by a cyclotron resonance chemical vapor deposition method, or forming a amorphous diamond thin film and a transition metal-containing diamond-like carbon thin film by using laser ablation. Emitter manufacturing method. The method of claim 1, wherein the forming of the cathode electrode on the top of the diamond thin film diamond tip field Emmy by the molding technique, characterized in that performed by sputtering chromium (Cr), titanium (Ti) or tungsten (W) Manufacturing method. The method of claim 1, wherein removing the silicon mold is performed using potassium hydroxide (KOH) solution, and removing the oxide layer is performed using a hydrofluoric acid (HF) solution. How to make a diamond tip field emitter. The diamond tip field emitter of claim 1, wherein the forming of the insulating layer is performed by plasma chemical vapor deposition using silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). Manufacturing method. The method of claim 1, wherein the forming of the gate electrode is performed by sputtering chromium (Cr), titanium (Ti), or tungsten (W).