JPH09306337A - Field emission type electron source element and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a field emission type electron source element which can prevent the degradation of a degree of vacuum, element breakdown and generation of a leak electrode between a cold cathod and a gate electrode and can be driven in low voltage and has the long service life, and a manufacturing method therefor. SOLUTION: This electron source element is formed by working a surface of a silicon substrate 1, and is composed of a silicon projecting part 5 being a cold cathode to emit an electron on the basis of the principle of field emission and a gate electrode layer 6 being an electron extraction electrode arranged on the periphery of the silicon projecting part 5 through an insulating layer 4. In this case, an end part of the gate electrode layer 6 is formed in the shape of projecting so as to surround the tip of the silicon projecting part 5, and surface coat layers 8a, 8b and 8c are arranged on a surface in the vicinity of the tip of the silicon projecting part 5, a surface where the gate electrode layer 6 is opposed to the silicon projecting part 5 and the gate electrode layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission type electron source device having a minute cold cathode that emits electrons based on the principle of field emission and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the field emission type electron source manufacturing technology for emitting electrons in a high electric field has been remarkably advanced by the fine processing technology used in the field of integrated circuits or thin films, and the field emission type cold cathode having an extremely small structure. Can be manufactured. This type of field emission cold cathode is one of the main components that make up a triode micro electron tube or micro electron gun.
It is the most basic electron emission device.

The operation and manufacturing method of the field emission type electron source device composed of such a cold cathode is described in Stanford.
Research Institute (Stanford Research In
Institute of Applied Sciences CASpindt et al. Journal of Applied Physics (Jo
urnal of Applied Physics) Volume 47, Issue 12, 52
It is known by the research report published on pages 48-5263 (December 1976). Also, U.S. Pat. No. 3,789,471 by C.A. Spind et al.
U.S. Pat. No. 4,30 by HFGray et al.
No. 7,507 and No. 4,513,308.

This field emission type electron source element has been proposed for use as, for example, a minute triode or a constituent element of a thin display element, and a device using this element operates as a large number of minute cold cathodes. The function is exhibited by controlling the. The field emission electron source element is a gate that is a cold cathode that emits electrons according to the principle of field emission and a field application electrode that applies a positive voltage to apply an electric field to each cold cathode to emit electrons. And electrodes.

In Japanese Patent Laid-Open No. 5-274998, there is shown in FIG.
As shown in FIG. 3, a silicon oxide film 14, an insulating film 14 ′, and a gate electrode 16 are sequentially formed around a cold cathode 15 formed by processing the surface of the silicon substrate 11, and the substrate is provided at the tip of the cold cathode 15. A metal thin film 18 having a low work function is formed from a direction substantially perpendicular to the surface by a vapor deposition method or the like to increase the amount of emission current, improve the heat resistance of the tip portion of the cold cathode 15, and extend the life of the device. A targeted field emission electron source device is disclosed.

Various other structures as described above have been proposed for the field emission type electron source device. Here, the International Conference on Micro Processes 93 (The 6th International Microp
What was reported by Urayama et al. at the rocess conference will be explained using drawings. Its structure is shown in FIG.
As shown in FIG. 3, a cold cathode 25, which is a conical silicon protrusion, is formed on the silicon substrate 21 that serves as a substrate electrode, and the insulating layer 24 is formed so as to surround and expose only the tip of the cold cathode 25. A silicon oxide layer is arranged, and a gate electrode layer 26 is further arranged on the thermally oxidized silicon layer.

Next, a method of manufacturing the field emission type electron source device having the structure shown in FIG. 5 will be described. First, FIG.
, The surface of the n-type silicon substrate 21 having a specific resistance ρ = 3 to 5 Ω · cm is thermally oxidized to have a thickness of 0.2 to 0.3 μm.
Forming a thermally oxidized silicon layer 22. Then, a pattern such as a circle or a quadrangle is formed on the surface of the thermally oxidized silicon layer 22 by using a resist, and the thermally oxidized silicon layer 22 is etched, so that the circle or the quadrangle as shown in FIG. 6B is formed. Forming a thermal oxide silicon mask 22a.

Using this thermally oxidized silicon mask 22a, the surface of the silicon substrate 21 is isotropically etched by a dry etching method to form a convex portion 25a, which is a basic cold cathode, as shown in FIG. 6C. It is formed on the surface of the substrate 21. Further, the surface of the silicon substrate 21 on which the convex portion 25a is formed is thermally oxidized, and as shown in FIG.
A thermal silicon oxide layer 24a to be an insulating layer is formed with a thickness of about 0.4 μm.

Then, the silicon substrate 21 subjected to these steps is placed in a vacuum vapor deposition apparatus, and the Nb metal to be the gate electrode 26 is obliquely placed on the thermally oxidized silicon layer 24a while rotating the silicon substrate 22. When the gate electrode layer 26 is formed by depositing about 0.4 μm by the vacuum evaporation method, the structure shown in FIG. 6E is obtained.

Finally, the thermal silicon oxide mask 22a and a part of the thermal silicon oxide layer 24a which are unnecessary as an electron emission source are removed by a mixed solution of hydrofluoric acid and ammonium fluoride, as shown in FIG. 6 (F). Thus, the portion of the silicon substrate 21 corresponding to the cold cathode 25 is exposed. Here, cold cathode 2
The end surface of the gate electrode 26 near 5 is formed to have almost the same height as the tip of the cold cathode 25.

As described above, the cold cathode 25 is formed on the surface of the silicon substrate 21, the tip portion of the cold cathode 25 is exposed, and the insulating layer 24 and the gate electrode layer 26 become the cold cathode 2.
It is possible to manufacture a field emission type electron source element arranged so as to surround the periphery of 5.

[0012]

However, in the conventional field emission electron source device described above, the Journal of Applied Physics is used.
hysics), Vol. 47, No. 12, 5248-5263 (December 1976), U.S. Pat. No. 3,789,471, U.S. Pat. No. 4,307,507, and 4,
In the device disclosed in Japanese Patent No. 513,308, the distance between the cold cathode and the electron extraction electrode (gate electrode) is limited by the diameter of the SiO ₂ mask for etching the silicon substrate into a pyramid shape, so that a low operating voltage is required. It was difficult to drive in. In addition, the gas adsorbed on the inner wall surface of the gate electrode, which is an electron extraction electrode, is released during element manufacturing, the degree of vacuum is deteriorated, and the released gas is ionized and the cold cathode surface is destroyed by the sputtering action. There was such a problem.

In the one disclosed in the above-mentioned Japanese Patent Laid-Open No. 5-274998, the metal thin film 18 is the cold cathode 1.
5 was vapor-deposited up to the vicinity of the gate electrode 16 disposed on the substrate around No. 5 via the gate insulating layers 14 and 14 ', and there was a risk that a leak current due to a surface current might occur.

On the other hand, the above-mentioned Micro Process International Conference 9
3 (The 6th International Microprocess Conferenc
In the field emission type electron source device reported in e), the distance between the cold cathode and the electron extraction electrode (gate electrode) is the same because the electron emitting portion of the cold cathode 25 is formed of the same material as the substrate.
There is no selectivity of the material of the electron emitting portion of the cold cathode 25, and the electron emission characteristic is limited by the material. Also,
In many cases, the device form of such a minute electron source is arranged on the same substrate to form an array. In such a case, in order to ensure a sufficient operation as a device,
A highly reliable insulating layer that electrically insulates the electron emitting portion from the gate electrode is desired, and the thermal oxide film 24a of single crystal silicon shown in FIG. 5 is used as the insulating film. In the field emission type electron source device having the structure, the distance between the electron emitting portion and the gate electrode can be shortened.
However, since a predetermined array area is required to perform an effective operation as a practical device, the yield is deteriorated when the thermal oxidation layer 24a is made thin, and the thermal oxidation between the electron emitting portion and the gate electrode layer is performed. The film thickness of the layer 24a is naturally limited, and it is difficult to sufficiently thin the thermal oxide film. Further, it is conceivable to form the metal thin film disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-274998 on the field emission type electron source element of this structure. In this case as well, the cold cathode as described above is similarly formed. There is a problem of generation of leakage current between the gate electrodes.

The present invention has been made in order to solve the above-mentioned problems, and includes deterioration of vacuum degree, element destruction, and
Another object of the present invention is to provide a field emission type electron source device capable of preventing generation of a leak electrode between the cold cathode and the gate electrode, capable of being driven at a low voltage, and having a long life, and a manufacturing method thereof.

[0016]

In order to solve the above-mentioned problems, according to the present invention, a silicon projection portion which is a cold cathode that is formed by processing the surface of a silicon substrate and emits electrons based on the principle of field emission, and the silicon. In a field emission type electron source element composed of a gate electrode layer which is an electron extraction electrode arranged on the periphery of a protrusion with an insulating layer interposed therebetween, the end of the gate electrode layer surrounds the tip of the silicon protrusion. It has a projecting shape, and a surface coating layer is arranged on the surface near the tip of the silicon protrusion, the surface of the gate electrode layer facing the silicon protrusion, and the surface coating layer on the gate electrode layer.

Further, in the present invention, in the above-mentioned field emission type electron source element, the surface coat layer is a thin film made of a metal material having an electric resistance lower than that of single crystal silicon.

Further, in the present invention, in the above-mentioned field emission type electron source element, the surface coat layer is a thin film made of a metal material having a melting point higher than that of single crystal silicon.

Further, in the present invention, in the above-mentioned field emission type electron source element, the surface coat layer is a thin film made of a material having a work function lower than that of single crystal silicon.

Then, in the present invention, a mask is formed on the surface of the silicon substrate, the silicon substrate surface is etched to form convex portions, and the silicon substrate surface including the convex portions is thermally oxidized by thermal oxidation. A thermal silicon oxide forming step of forming a thermal silicon oxide layer to be an insulating layer, and, while rotating the silicon substrate, a thin film is vapor-deposited from an oblique direction by utilizing a masking effect of a mask so that the end portion surrounds the convex portion. Gate electrode layer forming step of forming a gate electrode layer that is an electron extraction electrode having a protruding shape, and removing the mask to expose the silicon protrusion that becomes a cold cathode that emits electrons from the protrusion based on the principle of field emission So as to etch the thermally-oxidized silicon layer, the second etching step, the surface near the tip of the silicon protrusion, and the gate electrode layer Which faces the emission projections, and a method of manufacturing a field emission electron source element including a surface coating layer formation step of forming a surface coating layer and the gate electrode layer above.

Further, according to the present invention, in the above method for manufacturing a field emission electron source element, in the surface coating layer forming step, the silicon substrate is rotated to form an oblique angle larger than the vapor deposition angle in the gate electrode layer forming step. From the direction, the step is to deposit a thin film made of a metal material having an electric resistance lower than that of single crystal silicon.

Further, in the present invention, in the above-mentioned method for manufacturing a field emission type electron source element, the surface coat layer forming step includes
The silicon substrate is rotated, and a thin film made of a metal material having a melting point higher than that of single crystal silicon is vapor-deposited from an oblique direction at an angle larger than the vapor deposition angle in the gate electrode layer formation step.

Further, according to the present invention, in the method for manufacturing the above-mentioned field emission type electron source element, the surface coat layer forming step is performed.
The silicon substrate is rotated, and a thin film made of a material having a work function lower than that of single crystal silicon is deposited from an oblique direction at an angle larger than the deposition angle in the gate electrode layer formation process.

According to the field emission electron source element of the present invention, the cold cathode and the electron extraction electrode are formed by using the silicon oxide layer formed by oxidizing the silicon surface which is the base of the cold cathode as the gate insulating layer. Since the distance to the (gate electrode) can be made shorter and the distance can be controlled by the thickness of the silicon oxide layer, the field emission electron source element can be driven at a lower voltage.

Further, since the surface coat layer is arranged at the tip of the cold cathode, the driving voltage is reduced and the emission current is increased as compared with the conventional field emission type electron source device using silicon.
Heat resistance can be improved. At the same time, the surface coating layer is also placed on the outer surface (non-cold cathode facing surface) and the inner wall surface (cold cathode facing surface) of the gate electrode, preventing the release of gas adsorbed on the surface during device manufacturing. Because you can
It is possible to suppress the deterioration of the degree of vacuum and the destruction of the cold cathode surface due to the sputtering action of the ionized gas.

Further, according to the method of manufacturing the field emission type electron source device of the present invention, by depositing the surface coating layer at an angle larger than the deposition angle at the time of forming the gate electrode,
Since the metal is not deposited near the gate electrode layer on the thermally-oxidized silicon layer which is the gate insulating layer, it is possible to prevent the generation of leak current between the cold cathode and the gate electrode.

[0027]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
FIG. 3 is a cross-sectional view of the main part of the side surface showing the structure of the field emission electron source element that is the embodiment of As shown in FIG. 1, this field emission type electron source device includes a silicon substrate 1 and a silicon substrate 1.
The surface of is processed, and the silicon protrusion 5 is a cold cathode that emits electrons based on the principle of field emission, the insulating layer 4 disposed on the periphery of the silicon protrusion 5, and the insulating layer 4 disposed on the insulating layer 4. Gate electrode layer 6, the surface coating layer 8a disposed on the surface near the tip of the silicon protrusion 5, and the gate electrode layer 6
The surface coating layer 8b is disposed on the surface facing the silicon protrusion 5, and the surface coating layer 8c is disposed on the gate electrode layer 6. Here, the end portion of the gate electrode layer 5 has a projecting shape so as to surround the tip of the silicon protruding portion 1.

Although FIG. 1 shows a side sectional view of only a single field emission type electron source element, normally, as shown in FIG. 2, a silicon protrusion 5 serving as a cold cathode is formed on the silicon substrate 1.
Are two-dimensionally arrayed.

Next, a method of manufacturing the field emission type electron source element of the first embodiment shown in FIG. 1 will be described with reference to FIG. First, as shown in FIG. 3A, the specific resistance ρ =
The surface of the n-type silicon substrate 1 having a thickness of 3 to 5 Ω · cm is thermally oxidized to form a thermally oxidized silicon layer 2 having a thickness of about 0.3 μm. Next, as shown in FIG. 3B, a resist 3 is applied to the surface of the thermal silicon oxide layer 2, and as shown in FIG. 3C, for example, a circular resist pattern 3a having a diameter of 3 μm.
Is used as a mask to anisotropically etch the thermal silicon oxide layer 2 to form a circular thermal silicon oxide mask 2a as shown in FIG. 3 (d). In this embodiment, CH is used as an etching gas for anisotropic etching.
Etching was performed by a reactive ion etching (hereinafter referred to as RIE) method using F ₃ . Here, the shape of the resist pattern 3a may be a quadrangle or the like, and in that case, the thermal oxide silicon mask 2a is also the same quadrangle or the like.

Next, the surface of the silicon substrate 1 is dry-etched by using the thermally-oxidized silicon mask 2a as a mask to form a cone-shaped cold cathode as shown in FIG. 3 (e). The convex portion 1 a is formed on the surface of the silicon substrate 1. In this embodiment, etching is performed by the RIE method using SF ₆ gas as the etching gas. In addition, although the shape of the convex portion 1a is a conical shape in the present embodiment, the shape is not limited to this.

Next, the surface of the silicon substrate 1 on which the convex portion 1a is formed is thermally oxidized to 0.4 as shown in FIG. 3 (f).
Thermally oxidized silicon layer 4a to be the insulating layer 4 having a thickness of about μm
Grow. During this thermal oxidation step, the surface of the convex portion 1a is also thermally oxidized at the same time to form a silicon protrusion 5 which is a cold cathode having a conical sharp tip.

Then, the silicon substrate 1 having the silicon protrusions 5 of this structure is placed in a vacuum vapor deposition apparatus, and as shown in FIG.
As shown in (g), while rotating the silicon substrate 1 about the perpendicular line AB of the silicon protrusion portion 5 as an axis, the silicon substrate 1 is obliquely above the silicon substrate 1 at an angle θ shown by an arrow C in the figure.
N serving as the gate electrode layer 5 which is an electron beam extraction electrode
The gate electrode layer 5 is formed by evaporating b metal to a thickness of 0.4 μm. Although Nb is used as the metal material forming the gate electrode layer 5 in the present embodiment, the material is not limited to this, and Mo, W, Ti, Cr, Al,
Any material that is used for a normal electrode material such as Ta may be used.

Next, as shown in FIG. 3H, a resist pattern 7 is formed on the gate electrode layer 5, and this resist pattern 7 is used as a mask to remove an unnecessary portion of the electron emission source. That is, the thermally oxidized silicon mask 2a,
A part of the thermally oxidized silicon layer 4a functioning as the insulating layer 4 is removed by a mixed aqueous solution of hydrofluoric acid and ammonium fluoride. Then, as shown in FIG. 3I, the tip of the silicon protrusion 5 serving as a cold cathode is exposed, and the thermally-oxidized silicon layer 4a and the gate electrode layer 6 surround the silicon protrusion 5 to surround the silicon protrusion. The tip of the portion 5 is exposed. Here, the height of the upper surface of the portion of the gate electrode layer 6 surrounding the silicon protrusion 5 is set to be approximately the same as the height of the tip of the silicon protrusion 5.

Next, after removing the resist pattern 7,
The silicon substrate 1 provided with the silicon protrusions 5 is placed in a vacuum vapor deposition apparatus and heated to 300 ° C. to 500 ° C. or higher in a high vacuum (in a vacuum of about 1 × 10 ⁻⁷ Torr or less) to obtain a substrate surface. The cleaning process is performed.

Finally, following the cleaning process, as shown in FIG. 3 (j), the silicon substrate 1 is rotated while rotating the silicon substrate 1 about the perpendicular D-E of the silicon protrusion 5 in the vacuum evaporation apparatus. Angle φ indicated by arrow F in FIG.
From diagonally above (φ> θ), the tip of the silicon projection 5, the tip of the inner wall of the gate electrode layer 6 (the surface facing the silicon projection 5), and the outer surface of the gate electrode layer 6 (the surface not facing the silicon projection 5) Then, an Au metal thin film which is the surface coat layer 8 is deposited.

In the present embodiment, Au, which is a metal material having a lower electric resistance than single crystal silicon, is used as the surface coating layer 8. According to this, since the electron emitting portion is made of Au having an electric resistance lower than that of single crystal silicon, generation of Joule heat in the electron emitting portion can be suppressed, and destruction of the electron emitting portion due to heat generation can be prevented. A highly reliable field emission type electron source device can be realized.
In addition, since the vapor deposition angle φ when forming the surface coating layer 8 is larger than the vapor deposition angle θ when forming the gate electrode layer 6, no leak current occurs between the cold cathode (silicon protrusion 5) and the gate electrode layer 6. It was confirmed.

In this embodiment, the surface coating layer 2
Au was used for a and 2b, but it is not limited to this, and W, Ta, Mo, Nb, Al, Cu, Ag, Pt are used.
It is possible to use a metal material having an electric resistance lower than that of single crystal silicon, and a metal material satisfying the condition that the resistivity ρ is ρ ≦ 10 ⁻⁴ Ω · cm is preferable.

Next, a second embodiment will be described. In the first embodiment, the surface coat layer 8 is made of a metal material having a lower electric resistance than that of single crystal silicon.
In the above embodiment, the surface coat layer 8 uses a thin film made of a metal material having a melting point higher than that of single crystal silicon.

The structure of the field emission type electron source element of the second embodiment is exactly the same as that of FIG. 1 used in the description of the first embodiment, except that the surface coating layers 8a, 8b and 8c are provided. Different materials are used. Also, the device fabrication in the second embodiment is almost the same as that described in the first embodiment, but the material of the surface coat layer 8 is different.

That is, in the second embodiment, a thin film made of Nb, which is a metal material having a melting point higher than that of single crystal silicon, is used as the surface coating layer 8, and the surface coating layer 8 is formed by a vacuum vapor deposition apparatus in device fabrication. Formation of Nb
All are the same as those in the first embodiment except that a thin film is deposited.

In the second embodiment, the surface coat layer 8 is made of N, which is a metal material having a melting point higher than that of single crystal silicon.
b was used. According to this, since the electron emitting portion is made of Nb having a melting point higher than that of single crystal silicon, it is possible to prevent the electron emitting portion from being destroyed even if Joule heat is generated, and it is possible to obtain a highly reliable electric field. An emissive electron source element can be realized.

In the present embodiment, Nb is used as the surface coat layer 8, but the present invention is not limited to this.
A metal material having a melting point higher than that of single crystal silicon such as W, Ta, Mo, or Ti can be used. Here, W, Ta, Mo, and Nb that are particularly preferable as the metal material forming the surface coating layer 8 are W, Ta, Mo, and Nb that have lower electric resistance than single-crystal silicon and a melting point sufficiently higher than that of single-crystal silicon.

Next, a third embodiment will be described. The field emission type electron source of the third embodiment is different from the first and second embodiments described above in that a thin film made of a material having a work function lower than that of single crystal silicon is used as the surface coating layer 8 in FIG. That is what happened.

Regarding the fabrication of the element of the third embodiment, the structure is obtained in exactly the same manner as the steps up to FIG. 2I of the first embodiment described with reference to FIG. next,
After removing the resist pattern 7, the silicon substrate 1 provided with the silicon protrusions 5 is placed in the vacuum chamber of the ion beam sputtering apparatus, and in a high vacuum (in a vacuum of about 1 × 10 ⁻⁷ Torr or less). , 300 ° C. to 500 ° C. or higher to clean the substrate surface, and then irradiate the LaB ₆ target with Ar ions generated from the ion source to the gate electrode in the vertical direction of the silicon substrate 1. The deposition angle (φ) is set to be larger than the deposition angle θ when forming the layer 6, and the surface near the tip of the silicon protrusion 5 and the tip of the inner wall of the gate electrode layer 6 (the surface facing the silicon protrusion 5) are obliquely viewed from above. , And the LaB ₆ thin film is vapor-deposited on the outer surface of the gate electrode layer 6 (the surface not facing the silicon protrusion 5) to form the surface coating layer 8 and the fabrication of the field emission electron source element of this embodiment is completed. To do.

In the third embodiment, the surface coat layer 8 is made of L, which is a material having a work function lower than that of single crystal silicon.
aB ₆ was used. According to this, since the electron emitting portion is composed of LaB ₆ having a work function lower than that of single crystal silicon, it can be driven at a low voltage, the emission current from the electron emitting portion can be increased, and a highly efficient field emission type device can be obtained. An electron source element can be realized.

In the present embodiment, LaB ₆ is used for the surface coat layer 8, but the present invention is not limited to this.
CaB ₆ , TiN, ZrN, NbN, TiC, ZrC,
A material having a work function lower than that of single crystal silicon such as NbC can be used.

In the above embodiment, oblique vapor deposition was performed by the vacuum vapor deposition method when forming the gate electrode layer 6, but the present invention is not limited to this, and the ion beam sputtering method or the like should be provided. A film forming method capable of vapor-depositing a thin film can be used. Also, when forming the surface coat layer, a method other than the above can be used as long as it is a film forming method capable of vapor-depositing a thin film with directionality.

[0048]

As described above, according to the present invention, it is possible to prevent the deterioration of the degree of vacuum, the breakdown of the element, the generation of the leak electrode between the cold cathode and the gate electrode, and the low voltage driving and the long-life electric field. It becomes possible to realize an emission type electron source element.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a structure of a field emission type electron source device according to the present invention.

FIG. 2 is a schematic cross-sectional perspective view of an arrayed structure of a field emission electron source device according to the present invention.

FIG. 3 is a cross-sectional view of an essential part of a side surface for explaining a method for manufacturing a field emission electron source element according to the present invention.

FIG. 4 is a cross-sectional view of a main part of a side surface showing a structure of a conventional field emission electron source element.

FIG. 5 is a side sectional view showing a structure of a conventional field emission type electron source device.

FIG. 6 is a cross-sectional view of a main part of a side surface for explaining a method for manufacturing a conventional field emission electron source element.

[Explanation of symbols]

 1 Silicon Substrate 1a Convex 2 Thermally Oxidized Silicon Layer 2a Thermally Oxidized Silicon Mask 3 Resist 3a Resist Pattern 4 Insulating Layer 4a Thermally Oxidized Silicon Layer 5 Silicon Protrusion 6 Gate Electrode Layer 7 Resist Pattern 8, 8a, 8b, 8c Surface Coat Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Yoshishi Takekawa, 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Co., Ltd. Incorporated (72) Inventor Keiichiro Uda 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inori Morino Yano 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within

Claims (8)

[Claims] 1. A silicon projection, which is a cold cathode that is formed by processing the surface of a silicon substrate and emits electrons based on the principle of field emission, and an electron arranged around the silicon projection through an insulating layer. In a field emission type electron source element composed of a gate electrode layer which is an extraction electrode, an end portion of the gate electrode layer has a shape protruding so as to surround the tip of the silicon protrusion, and a portion near the tip of the silicon protrusion is formed. A field emission type electron source device, comprising: a surface, a surface of the gate electrode layer facing the silicon protrusion, and a surface coating layer on the gate electrode layer. 2. The field emission type electron source element according to claim 1, wherein the surface coating layer is a thin film made of a metal material having an electric resistance lower than that of single crystal silicon. 3. The field emission type electron source element according to claim 1, wherein the surface coat layer is a thin film made of a metal material having a melting point higher than that of single crystal silicon. 4. The field emission electron source element according to claim 1, wherein the surface coating layer is a thin film made of a material having a work function lower than that of single crystal silicon. 5. A first method for forming a mask on a surface of a silicon substrate and etching the surface of the silicon substrate to form a convex portion.
Etching step, a thermal silicon oxide forming step of forming a thermal silicon oxide layer serving as an insulating layer on the surface of the silicon substrate including the convex portion by thermal oxidation, and using the masking effect of the mask while rotating the silicon substrate. And a gate electrode layer forming step of forming a gate electrode layer that is an electron extraction electrode having a shape in which the end portion is projected so as to surround the convex portion by vapor-depositing a thin film from an oblique direction, the mask is removed, and A second etching step of etching the thermally oxidized silicon layer so as to expose a silicon protrusion that becomes a cold cathode that emits electrons from the protrusion based on the principle of field emission; and a surface near the tip of the silicon protrusion. A surface coating layer type in which a surface coating layer is formed on the surface of the gate electrode layer facing the silicon protrusion and on the gate electrode layer A method of manufacturing a field emission type electron source device comprising the steps of: 6. The surface coating layer forming step rotates the silicon substrate to obtain a metal material having a lower electric resistance than single-crystal silicon from an oblique direction having an angle larger than a vapor deposition angle in the gate electrode layer forming step. The method for manufacturing a field emission electron source element according to claim 5, which is a step of depositing a thin film made of. 7. The surface coating layer forming step is performed by rotating the silicon substrate, from an oblique direction having an angle larger than a vapor deposition angle in the gate electrode layer forming step, from a metal material having a melting point higher than that of single crystal silicon. The method for manufacturing a field emission electron source element according to claim 5, which is a step of depositing the thin film. 8. The surface coating layer forming step is performed by rotating the silicon substrate, from an oblique direction having an angle larger than a vapor deposition angle in the gate electrode layer forming step, and from a material having a work function lower than that of single crystal silicon. The method for manufacturing a field emission electron source element according to claim 5, which is a step of depositing the thin film.