JPH0521002A - Manufacture of field emission type electrode - Google Patents

Abstract

PURPOSE:To provide manufacture of a field emission type electrode which can properly correct the form of a primarily formed emitter chip and the distance between the emitter chip and gate layers. CONSTITUTION:The surface of a primarily formed chip 1 made up of metal molybdenum and a gate layer 3 are heated at a temperature of approximately 530-630 deg.C to be oxidized so that oxide film 7 of MoO3 is formed on the surfaces. The oxide film 7 thus formed is dissolved in an NH3 solution to be removed, so that the form of the tip of the emitter chip 1 and the distance between gate layers 4 are corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission electrode which emits an electron beam by field emission.

[0002]

2. Description of the Related Art When manufacturing a field emission electrode of this type, there are many types of emitter chips formed by applying a thin film, such as shape and material. In this case, a metal material having a high melting point, a carbide, or a boride is desirable as the material.

On the other hand, it is relatively easy to form a pyramid type emitter chip by anisotropically etching a single crystal of a semiconductor material such as silicon. On the other hand, when using a metal material or a metal carbide having a high melting point, sputtering, vacuum deposition, various CVD methods are used for film formation, but special conditions are required to obtain a single crystal. Therefore, it is difficult to simultaneously form a large number of emitter chips by anisotropic etching.

[0004]

Therefore, when a material such as a single crystal polycrystal or an amorphous material is used when forming an emitter tip using these metal materials or high melting point metal carbide materials, the emitter It was difficult to correct the chip shape after chip formation to an appropriate shape. The present invention has been made in view of the above points, and an object of the present invention is to provide a field emission electrode capable of appropriately correcting the shape of the emitter tip once formed and the distance between the emitter tip and the gate layer. It is to provide a manufacturing method.

[0005]

In order to achieve the above-mentioned object, the present invention has an emitter tip and a radiation hole exposing the tip of the emitter tip, and is arranged in an insulated manner with respect to the emitter tip. The gate layer and the gate layer are disposed in a vacuum, and by applying a voltage to the gate layer so that the Schottky effect is produced by using the emitter tip as a negative electrode, electrons are emitted from the emitter tip through the emission hole. In a field emission electrode that emits a line,
An oxide film is formed on the surface of the emitter chip and the gate layer formed of a metallic material, and the oxide film is removed to correct the shape of the emitter chip and adjust the distance between the emitter chip and the gate layer. ..

[0006]

According to the method of the present invention, an oxide film is formed on the surface of an emitter chip and a gate layer formed of a metallic material, and the oxide film is removed to correct the shape of the emitter chip and adjust the distance between gate layers. Therefore, the shape of the emitter tip formed of a metallic material or a metallic material such as metal carbide, which has been difficult to modify the shape in the past, and the distance between the emitter tip and the gate layer are controlled by the thickness of the oxide film. Therefore, it can be easily corrected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 4 shows a field emission electrode formed temporarily, in which a conductive molybdenum substrate 2 made of fully doped silicon is covered with an insulating layer 3 made of silicon dioxide. An emitter chip 1 made of molybdenum metal is formed in a radiation hole 5 which is formed through the insulating layer 3 and the gate layer 4 and exposes the surface of the substrate 2. There is. The emitter tip 1 emits an electron beam e ⁻ toward the collector 6 through the emission hole 5.

The primary method of manufacturing the field emission electrode is described in SRI International (USA) Dr. It is performed by a known method proposed by Spindt and the like. According to the method of the present invention, when the shape of the emitter chip 1 that has already been formed is changed, the tip shape, the emitter chip 1 and the gate layer are removed by removing the oxide film after oxidizing the surface of the emitter chip 1. This is a method of adjusting the distance between the three, and will be described below with reference to an embodiment.

Example 1 In Example 1, the surfaces of the emitter chip 1 and the gate layer 3 made of molybdenum metal are heated and oxidized at about 530 to 630 ° C., and an oxide film of MoO ₃ is formed on the surface as shown in FIG. Form 7. The thickness of the oxide film 7 was measured by changing the temperature condition for Mo oxidation, and the result was as follows.

Temperature condition 535 ° C., 1 hour oxidation in air flow film thickness measurement 2.5 μm / hr = about 420 Å / min Temperature condition 570 ° C. 1 hour oxidation in air flow film thickness measurement 5 μm / hr = about 840 Å / min In the example, oxidation was performed at 535 ° C. for about 3 minutes to obtain 1000
A thick oxide film 7 was formed.

The oxidation can be expressed by the following chemical formula. Mo + 3 / 2O ₂ → MoO ₃ By removing the oxide film 7 thus formed, the tip shape of the emitter chip 1 is corrected and the distance between the emitter chip 1 and the gate layer 4 is corrected as shown in FIG. ..

[0012] oxide film 7 of MoO ₃ with respect to where NH ₃ water to have a solubility, in the present embodiment, to remove the oxide film 7 with aqueous NH _3. The thickness of the oxide film 7 can be set by the oxidizing conditions (which can be controlled by the temperature and the time) as described above. For example, the thickness of the oxide film 7 of molybdenum metal is the same as that of the metal molybdenum of oxygen in a state of being kept at a constant temperature. It is determined by the diffusion to, which is approximately proportional to the square of time. Since the diffusion coefficient is represented by the exponential function of temperature, setting the temperature high is effective. However, the hexavalent oxide of metallic molybdenum has the property of subliming at a relatively low temperature, and its vapor pressure is 0.30 mm / 700 ° C., 10.1 mm / 80.
0 ° C, 476.2mm / 1100 ° C, 760mm / 11
55 ° C.

When the oxide film 7 is formed in this way,
By controlling the thickness, it is possible to sharpen the emitter tip 1 after removal and to make the distance between the emitter tip 1 and the gate layer 4 appropriate. Example 2 This example is different from Example 1 in the removal method after forming the oxide film 7 under the same conditions as in Example 1 above.

That is, in this embodiment, the sublimation property of the hexavalent oxide of molybdenum metal is utilized to heat the oxide film 7 to remove it by sublimation. In this example, the oxide film 7 was removed by sublimation by heating at 800 ° C. Embodiment 3 In Embodiments 1 and 2 described above, in order to remove the oxide film 7 of metallic molybdenum, solubility in NH ₃ water and sublimability are used. When it becomes a valent oxide film, the sublimation property also disappears and it becomes insoluble in NH ₃ water. Therefore, the oxide film 7 cannot be removed by the methods of Examples 1 and 2.

The tetravalent oxide film has very good conductivity and remains.
If it does not matter, you can leave it as it is
But when raising the work function and raising the threshold of electron beam emission
Need to be removed. The specific resistance of metallic molybdenum is
5.2 x 10^-6Ωcm, MoO ₃Specific resistance of 8.8 × 1
0^-FiveΩcm (500 ° C). Therefore, in this embodiment,
Hydrogen, which is an original gas, is caused to flow on the surface of the oxide film 7 so that metal molybdenum
Remove by reducing to den. Also oxide film on the surface
When 7 was oxidized to be hexavalent, it was removed by the method of Examples 1 and 2.
Leave.

When a tetravalent oxide is formed, it may be sublimated by performing nitric acid treatment to convert it into a hexavalent oxide instead of reducing it as described above.

[0017]

According to the present invention, an oxide film is formed on the surface of an emitter chip and a gate layer made of a metallic material, and the oxide film is removed to correct the shape of the emitter chip and adjust the distance between gate layers. Therefore, the shape of the emitter tip made of a metal material or a metal material such as metal carbide, which was difficult to modify the shape in the past, and the distance between the gate layers can be controlled easily by controlling the thickness of the oxide film. The effect is that it can be corrected to a proper state, and in particular that the emitter tip can be sharpened easily.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a field emission electrode in a state where an oxide film is formed by the method of Example 1 of the present invention.

FIG. 2 is a cross-sectional view of a field emission electrode after removing an oxide film by the method of Example 1 of the present invention.

FIG. 3 is a cross-sectional view of a field emission electrode during primary formation.

[Explanation of symbols]

 1 Emitter Chip 2 Substrate 3 Insulation Layer 4 Gate Layer 5 Radiation Hole 6 Collector 7 Oxide Film

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[Procedure amendment]

[Submission date] September 30, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

[0005]

In order to achieve the above-mentioned object, the present invention has an emitter tip and a radiation hole exposing the tip of the emitter tip, and is arranged in an insulated manner with respect to the emitter tip. The gate layer and the gate layer are disposed in a vacuum, and by applying a voltage that causes the field emission effect with the emitter tip being a negative electrode with respect to the gate layer, electrons are emitted from the emitter tip through the emission hole. In a field emission electrode that emits a line, an oxide film is formed on the surface of the emitter chip and gate layer made of a metallic material, and the oxide film is removed to correct the shape of the emitter chip and the emitter chip and the gate layer. The feature is that the distance is adjusted.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012] oxide film 7 of MoO ₃ with respect to where NH ₃ water to have a solubility, in the present embodiment, to remove the oxide film 7 with aqueous NH _3. The thickness of the oxide film 7 can be set by the oxidizing conditions (which can be controlled by the temperature and the time) as described above. For example, the thickness of the oxide film 7 of molybdenum metal is the same as that of the metal molybdenum of oxygen in a state of being kept at a constant temperature. It is determined by the diffusion to, which is approximately proportional to the square of time. Since the diffusion coefficient is represented by the exponential function of temperature, setting the temperature high is effective. However, the hexavalent oxide of metallic molybdenum has the property of subliming at a relatively low temperature, and its vapor pressure is 0.30 mm / 700 ° C., 10.1 mm / 8.
00 ° C, 476.2 mm / 1100 ° C, 760 mm / 1
155 ° C.

Claims (1)

Claim: What is claimed is: 1. An emitter tip and a gate layer which has a radiation hole for exposing a tip portion of the emitter tip and is arranged insulated from the emitter tip are arranged in a vacuum. In the field emission electrode in which an electron beam is radiated from the emitter tip through the radiation hole by applying a voltage having a Schottky effect with the emitter tip being a negative electrode with respect to the gate layer, the metal An electric field characterized by forming an oxide film on the surface of an emitter chip and a gate layer formed of a conductive material and correcting the shape of the emitter chip and adjusting the distance between the emitter chip and the gate layer by removing this oxide film. A method for manufacturing a radiation electrode.