JP2645708B2 - Electron-emitting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, and more particularly, to an electron-emitting device, in which electrons are emitted from a tip end of an electron-emitting electrode in parallel with an element substrate. The present invention relates to an electron-emitting device that deflects electrons.

[Prior Art] Conventionally, thermionic emission from a hot cathode has been used as an electron generating source. Electron emission using such a hot cathode is large in energy loss due to heating, requires formation of heating means, requires considerable time for preheating, and tends to be unstable due to heat. There was a problem in point.

Therefore, research on electron-emitting devices that do not rely on heating has been promoted, and one of them is a field-effect (FE) electron-emitting device.

FIG. 6 is a schematic configuration diagram of a conventional field-effect type electron-emitting device.

As shown in FIG. 1, a conventional field-effect type electron-emitting device includes a cathode chip 2 provided on a base 1 and having a sharply sharpened tip for obtaining a strong electric field, and an insulating layer 3 on the base 1. And an extraction electrode 4 having a substantially circular opening centered on the pointed tip of the cathode chip 2. The extraction electrode 4 is provided between the cathode chip 2 and the extraction electrode 4. When a high potential is applied, a voltage is applied, and electrons are emitted from the tip of the cathode tip 2 where the electric field intensity increases.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional field-effect type electron-emitting device, it is difficult to sharpen the tip of the cathode chip 2 sharply.
Generally, when manufacturing the cathode chip 2, remolding is performed after performing electric field polishing. This process requires a lot of labor and is complicated, and also has problems such as difficulties in mechanization, variation in manufacturing conditions and unstable quality due to strong empirical factors.

SUMMARY OF THE INVENTION An object of the present invention is to provide a field-effect type electron-emitting device which has a simple structure and can be stably manufactured with good reproducibility in view of the above-mentioned problems of the prior art.

[Means for Solving the Problems] The above problems are caused by the fact that the electron-emitting device deflects the flight direction of emitted electrons on the same substrate almost vertically, an insulating layer covering the same, A structure having an electron emission electrode having a tip at a position substantially corresponding to the deflection electrode on the layer, and a lead electrode having an electric emission port close to and opposed to the tip; The problem can be solved by manufacturing the electrodes with high precision by a fine processing technique.

That is, the present invention provides an electron emission electrode having a protruding end, an extraction electrode having an electron emission port opposed to the prong, and an electron emission electrode and the extraction electrode, which are arranged side by side along the same surface of the substrate. An insulating layer provided below the insulating layer, and a flying direction of electrons, which is provided between the lower surface of the insulating layer and the substrate and is drawn in parallel with the substrate surface from the extraction electrode, is perpendicular to the substrate surface. And a deflection electrode for deflecting upward.

[Operation] In general, the electric field strength required for field emission is 10 ⁷ V / cm or more. When this electric field is applied, electrons in the solid pass through the potential barrier on the surface due to the tunnel effect, and the electrons are emitted. Is done.

Now, assuming that the voltage applied between the opposing electron emitting electrode and the opposing electrode is V, and the radius of curvature of the electron emitting portion of the electron emitting electrode is r, when the radius of curvature r is small, the electric field intensity E of the electron emitting portion is obtained. Is There is a relationship.

When performing electron emission, in order to improve the convergence of the electrons, it is desirable to reduce the energy width of the emitted electrons, and it is desirable to drive at a low voltage. For this reason,
It is desirable that the radius of curvature r be as small as possible.

Furthermore, in order to suppress variations in the electron emission voltage,
It is desired to form the distance between the electron emission electrode and the counter electrode with high accuracy.

In the present invention, by arranging the electron emission electrode and the extraction electrode in the same in-plane direction, an accurate and stable formation of the electron emission portion using the fine processing technique described later is realized. That is, the radius of curvature of the protruding end of the electron emission electrode can be processed to be extremely small, and the extraction electrode can be accurately formed at a position close to the protruding end.

The electrons extracted by the extraction electrode are deflected in a direction substantially perpendicular to the element substrate by applying a negative voltage to the electron emission electrode to a deflection electrode provided at a position via the insulating layer. .

Further, since the deflection electrode can be provided below the electron emission electrode and the extraction electrode via the insulating layer, the element can be reduced in size and the degree of integration can be increased.

EXAMPLES Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

Embodiment 1 FIG. 1 is a structural view showing one embodiment of the electron-emitting device of the present invention, and FIG. 2 is a plan view thereof.

As shown in FIG. 1, the electron-emitting device of the present invention comprises a deflection electrode 9 provided on an insulating substrate 6 made of glass or the like, and an electron-emitting electrode 7 having a protruding end 7a provided thereon via an insulating layer 6a. And a lead-out electrode 8 having an electron emission port which is opposed to and proximate to the protruding end 7a.

The deflection electrode 9 is desirably a non-magnetic metal material, and generally nickel or a non-magnetic stainless material can be used.

In this embodiment, the thickness of nickel is 1000
成膜 A film was formed by a sputtering method so as to have a thickness of at least. Insulating layer
6a was formed by sputtering SiO ₂ to a thickness of 0.2 to 3 μm.

The shape of the protruding end 7a of the electron emission electrode 7 is formed by using a focused ion beam technique or the like so as to minimize the radius of curvature. The shape is a triangular shape, a parabolic shape, or the like, and is desirably formed into a wedge-shaped column, a column having a parabolic side surface, or the like.

The material of the electron-emitting electrode 7 is preferably formed of a material having a small radius of curvature as described above, and is preferably a high-melting-point material because the current density is large and the calorific value is large. It is preferable to use a low work function material to reduce the applied voltage. For example, W, Z
metals such as r, Ti, Au, metal carbides such as TiC, ZrC, HfC, LaB ₆ , S
Metal borides such as mB ₆ and GdB ₆ , metal silicides such as WSi ₂ , TiSi ₂ , ZrSi ₂ and GdSi ₂ , and semiconductor oxides such as SnO ₂ and ITO can be used.

As shown in FIG. 2, the electron extraction electrode 8 is formed of a metal material such as a stainless steel material or a nickel material in a shape having an opening 8a which is an electron emission port facing the tip 7a of the electron emission electrode 7. Formed.

The extraction electrode 8 is desirably formed close to the electron emission electrode 7, and the width w of the opening 8a is desirably provided on the same scale as the protruding end 7a.

In this embodiment, the electron emission electrode 7 and the extraction electrode 8 are Au
The members were formed into the following shapes using a FIB device. The protruding end portion 7a of the electron emission electrode 7 was processed into a substantially isosceles triangle as shown in FIG. 2 to form the radius of curvature r of 500 ° or less. Also, the extraction electrode 8 is separated from the electron emission electrode 7 by
The opening 8a was processed at a position of 0.5 to 2.0 μm (length of 1 in FIG. 2) such that w of the opening 8a was 0.5 to 1.5 μm.

In the above-described field emission type electron-emitting device of the present invention, as shown in FIG. ₁ , a voltage V ₁ is applied to the extraction electrode 8 by the power supply 10 a with respect to the electron emission electrode 7, and a voltage 10 b is applied to the deflection electrode 9 by the power supply 10 b. applying a voltage V _2. Usually, V1 is 20 V or more, but preferably 20 to ₁₀₀ V, and more preferably a low voltage of 20 to 50 V. Fluctuation of the emission current and to drive the voltages V ₁ at least 100V increases, life is shortened.

Voltage V ₂ applied to the deflection electrode 9, it is necessary to change the voltage V _1, typically the electron-emitting electrode 7 0～-
100V is desirable.

In this embodiment, fixing the voltages V ₁ to 30 V, to give the results shown in Table 1 by changing the voltage V _2.

The electron-emitting device according to the present example exhibited characteristics of a current fluctuation of 5% or less and a life of 1000 hours or more, confirming that the characteristics were excellent as a field-type electron-emitting device.

Next, the fine processing technology used in the present invention will be described.

Usually, a lithography technique including a resist process and an etching process is used as the fine processing technique. However, fine processing of 1.0 μm or less is difficult due to a mask shift or the like.

The fine processing technology used in the present invention refers to a technology capable of performing fine processing of 1.0 μm or less. For example, the above-mentioned focused ion beam (FIB) is used.

 FIG. 3 is a configuration diagram showing an example of the FIB device.

The FIB technology scans metal ions focused on a submicron, and performs submicron-order fine processing by utilizing a sputtering phenomenon on a solid surface.

In the figure, an ion source 11 emits liquid metal atoms by an extraction electrode 8, selects a desired ion beam by an EXB mass separator 13 (in the case of using an alloy-based liquid metal), and reduces the ion beam to about 80 keV by an objective lens 14. The accelerated ion beam is focused to about 0.1 μm and the beam deflection electrode 15
Scans the sample 16. The ion beam is positioned by the sample stage 17.

Embodiment 2 FIG. 4 is a configuration diagram showing a second embodiment of the present invention.

In the present embodiment, a step is provided in the insulating layer 6a, the electron emission electrode 7 is formed in the upper stage, and the extraction electrode 8 is formed of one continuous metal in the lower stage in the first embodiment. With such an element configuration, the tip of the electron emission electrode 7
The effect of concentrating the electric field on 7a and preventing charge-up on insulating layer 6a is obtained.

In the present embodiment, it is considered that such an effect is obtained because the electric field in the vicinity of the protruding end 7a is weakened by the electrolysis existing in the insulating substrate. In this case, the same effect can be expected even if a concave portion is provided in the insulating layer 6a between the electron emission electrode 7 and the extraction electrode 8.

Embodiment 3 FIG. 5 is a block diagram showing a third embodiment of the present invention.

This embodiment represents an example in which the electron emission electrode has a plurality of protruding portions, and a lead electrode having an electron emission port is provided in proximity to a portion facing each of the plurality of protruding portions, Using the device configuration of Example 2, 500 electron-emitting devices having a pitch d of 2.5 μm were formed on the same insulating substrate 6.
By creating in this way, not only 500 times the amount of current was obtained, but also the stability was dramatically improved,
10 to 10 almost eliminated ⁶ Hz of shot noise is, the fluctuation of current is within 1.0%.

In any of the embodiments, a shield member can be provided in the electron emission portions of the electron emission electrode 7 and the extraction electrode 8 in order to prevent electric noise due to an external electromagnetic field. If a stainless steel member having a thickness of about 2 mm is provided on the insulating substrate 6 so as to substantially surround the electron emitting portion (not shown), an electromagnetic noise from the outside can be prevented.

Electromagnetic noise not only provides a shield member,
By attaching a shield member to the back of the insulating substrate 6, a stronger effect can be expected.

[Effect of the Invention] As described above, according to the electron-emitting device of the present invention, the electron-emitting electrode and the extraction electrode are formed with high precision by the fine processing technique, and the deflection electrode is provided via the insulating layer. Electrons can be emitted more than the element, and the following effects can be obtained.

1) Low-voltage driving is possible, and variations in the energy of emitted electrons can be reduced.

2) Since the electron emission electrode and the extraction electrode are formed with high precision by the fine processing technology such as FIB, a manufacturing process such as remolding is unnecessary, and the manufacturing process can be simplified.

3) Since the electron emission electrode and the extraction electrode are finely processed in a plane, it is easy to reduce the thickness, size, and weight.

4) Electrons emitted from the element can be deflected by the voltage applied to the deflection electrode.

5) By providing the deflection electrode below the electron emission electrode and the extraction electrode via the insulating layer, the entire device can be made extremely small.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the electron-emitting device of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a block diagram showing an example of an FIB device, and FIGS. FIG. 6 and a schematic diagram showing another embodiment of the invention are schematic structural diagrams of a conventional field-effect type electron-emitting device. DESCRIPTION OF SYMBOLS 1 ... Base 2, Cathode chip 3, 6a ... Insulating layer, 4, 8 ... Extraction electrode 5, 10a, 10b ... Power supply, 6 ... Insulating substrate 7 ... Electron emission electrode, 7a ... Tip Section 8a: Opening, 9: Deflection electrode 11: Ion source, 12: Condenser lens 13: EXB mass separator, 14: Objective lens 15: Beam deflection electrode, 16: Sample 17 ... Sample stage

Claims (1)

(57) [Claims] 1. An electron emission electrode having a protruding end, an extraction electrode having an electron emission port opposed to the protruding end, and an electron emission electrode and an extraction electrode arranged side by side along the same surface of the substrate. An insulating layer provided below, and a flying direction of electrons, which is disposed between the lower surface of the insulating layer and the substrate and is drawn out from the extraction electrode in parallel with the substrate surface, is perpendicular to the substrate surface. An electron-emitting device, comprising: a deflection electrode for deflecting upward.