JP2001155623A - Method for, manufacturing projection-shaped emitter and electron emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a projection-shaped emitter having uniform height and pitch. SOLUTION: The projection-shaped emitter 8 is manufactured by disposing silica beads 7 of a spherical particle on an emitter layer 3, forming the silica beads 7 into a mask 7a and etching the emitter layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a projecting emitter for emitting electrons and a method of manufacturing an electron-emitting device using the projecting emitter.

[0002]

2. Description of the Related Art In a conventional image forming apparatus such as a display device, in recent years, a flat panel display device using a liquid crystal has been
However, since it is not a self-luminous type, there is a problem that a backlight must be provided, and a self-luminous display device has been desired.

[0003] On the other hand, a field emission (FE) type electron-emitting device that emits electrons from a metal surface by applying a strong electric field of 10 ⁶ V / cm or more to a metal is one of the electron sources. It is attracting attention.

If an FE type electron source is put into practical use, a thin self-luminous image display device can be realized, which contributes to reduction in power consumption and weight.

As an example of a vertical (Spindt-type) FE type, as shown in the sectional view of FIG. 4, a projecting emitter 108 has a shape of a cone or a quadrangular pyramid in a substantially vertical direction from the substrate 101, for example, C.I. A. Spindt, "Physi
cal Properties of thin-Fi
1m Field emission cathode
s with molebdenium cone
s ", J. Appl. Phys., 47, 5248 (1
976) is known.

In FIG. 4, reference numeral 102 denotes a lower electrode, and 104 denotes an insulating layer.

When a voltage Vf is applied between the protruding emitter 108 and the upper electrode (gate electrode) 105, the electric field at the protruding tip of the protruding emitter 108 is increased, and electrons are taken out of the vicinity of the tip into a vacuum.

An example in which a large number of projecting emitters are provided,
A. A. G. FIG. Driskill-Smith, J. et al. Va
c. Sci. Technol. B15, 2773 (19
97). As a method of manufacturing the electron-emitting device, a process of depositing AuPd particles and using the mask as a mask to form a projecting emitter structure is shown.

This is obtained by the manufacturing process shown in FIG. On a GaAs substrate 101, W is used as an emitter layer 103 (film-like), SiO _{2 is used} as an insulating layer 104, and an upper electrode 1
As 05, W is laminated and the resist 106 is patterned (FIG. 5A).

Next, the upper electrode 105 and the insulating layer 104 are etched (FIG. 5B).

Subsequently, AuPd particles 107 are deposited. (FIG. 5 (c)).

Finally, etching is carried out using the AuPd particles 107 as a mask, and the resist 106 is peeled off. As a result, a projecting emitter is formed at the bottom of the hole of the insulating layer 104 and the upper electrode (gate electrode) 105 which are formed in a circular shape. 108 (FIG. 5D).

[0013]

However, when the above-described method for manufacturing an electron-emitting device is used, since there is variation in the particle size and interval of the deposited particles (AuPd particles 107) serving as a mask, these are used as masks. When a protruding emitter structure is manufactured by etching, there is a problem that the height and pitch of the protruding emitter become non-uniform, causing variations in electron emission characteristics.

An object of the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a method of manufacturing a projecting emitter capable of obtaining a projecting emitter structure having a uniform height and pitch, and an electron emission method. An object of the present invention is to provide a method for manufacturing an electron-emitting device capable of obtaining good electron-emitting characteristics without variation in characteristics.

[0015]

In order to achieve the above object, a method of manufacturing a projecting emitter according to the present invention comprises the steps of arranging spherical particles on an emitter layer, and using the spherical particles as a mask to form the emitter layer. Is characterized in that a protruding emitter is produced by a step of etching the substrate.

In the step of arranging the spherical particles on the emitter layer, it is preferable that the spherical particles are densely arranged in a single layer on the emitter layer.

It is also preferable that the spherical particles are silica beads.

In the step of arranging the spherical particles on the emitter layer, it is preferable to apply a solution in which silica beads are dispersed in water and alcohol so that the silica beads have a single layer on the emitter layer.

Preferably, the etching step is dry etching using a reactive gas.

It is also preferable that the ratio of the etching rate in the etching is emitter layer / mask = 2 or more.

Further, in the method of manufacturing an electron-emitting device using the projecting emitter manufactured by the above-described method, the method may further comprise, before disposing the spherical particles on the emitter layer, in a region where the spherical particles are not disposed. Water repellency treatment is performed.

A method of manufacturing an electron-emitting device having a convex structure including an insulating layer and an upper electrode on the insulating layer, a lower electrode on a substrate, and having a projecting emitter formed on the lower electrode. It is also preferable that the protruding emitter is formed near the side wall of the convex structure.

Before forming the spherical particles, it is preferable that at least the side wall of the convex structure is subjected to a water repellent treatment.

The material of the emitter layer and the lower electrode is carbon,
Metal, metal nitride, metal carbide, metal boride,
It is also preferable to be composed of either a semiconductor or a metal compound of a semiconductor.

According to the present invention, since the spherical particles are arranged on the emitter layer so as to form a dense single layer, the height and the pitch are made uniform by performing etching using this as a mask. A protruding emitter structure is obtained.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an example of a method for manufacturing a projecting emitter according to the present invention.

First, a lower electrode 2 and an emitter layer 3 (for example, formed in a film shape) are laminated on an insulating substrate 1 (FIG. 1A). Here, the film before being formed into a projection shape in a later step is simply called an emitter layer. In the configuration of FIG. 1, the emitter layer 3 can also serve as the lower electrode.

Examples of the emitter layer 3 include carbon, metal, metal nitride, metal carbide, metal boride, semiconductor, and metal compound of semiconductor. Preferably, W, Ta, M
heat-resistant material such as o, TiC, ZrC, Hf
Carbides such as C, TaC, SiC, WC, HfB ₂ , Zr
Borides such as B ₂ , LaB ₆ , CeB ₆ , YB ₄ , GdB ₄ ,
Preferred are nitrides such as TiN, ZrN, HfN, semiconductors such as Si and Ge, organic polymer materials, amorphous carbon, graphite, diamond-like carbon, and carbon and carbon compounds in which diamond is dispersed.

Next, a solution in which silica beads 7 as spherical particles having a uniform particle diameter are dispersed in water + alcohol is densely formed on the emitter layer 3 as a single layer (FIG. 1B).

As the silica beads 7, a silica sol using silicon alkoxide as a raw material may be used.

Here, by appropriately adjusting the concentration at which the silica beads 7 are dispersed, the silica beads 7 are densely formed as a single layer as a mask 7a by dip or spinner coating.

Subsequently, dry etching using a reactive gas such as CF ₄ or CHF ₃ is performed using the silica beads 7 as a mask 7 a until the silica bead mask disappears. The emitter is sharpened by incorporating a component that isotropically etched using a reactive gas.

FIG. 1 (c) shows a protruding emitter 8 obtained by stopping the etching when the mask 7a of the silica beads 7 has disappeared. At this time, the projecting emitter 8
Can be set to a desired height by changing the diameter of the silica beads 7 and the etching rate of the mask 7a and the emitter layer 3.

It is desirable that the ratio of the etching rate in the etching is emitter layer / mask = 2 or more, so that the projection-like emitter having a height of at least twice the diameter of the silica beads 7 used for the mask 7a. 8 can be produced. According to the present invention, a protruding emitter structure having a uniform height and pitch can be obtained.

Next, an example of a method of manufacturing the electron-emitting device 10 using the projecting emitter 8 according to the manufacturing method of the present invention is shown in FIG.
This will be described with reference to FIG.

Here, before explaining the manufacturing method, FIG. 2 schematically shows the cross-sectional structure of the completed electron-emitting device 10.
The element structure will be described with reference to FIG.

The electron-emitting device 10 has a convex structure comprising an insulating layer 4 and an upper electrode 5 (gate electrode) on the insulating layer, a lower electrode 2 on the substrate 1, and a projecting emitter 8 having a convex structure. It is formed on the lower electrode 2 near the side wall of the mold structure.

Since the protruding emitter 8 is formed near the side wall of the convex structure, the direction in which electrons are extracted is limited to a certain direction. Can be reduced.

Next, a method for manufacturing the electron-emitting device 10 will be described.

First, a lower electrode 2, an emitter layer 3, an insulating layer 4, an upper electrode 5, and a resist 6 are formed on an insulating substrate 1 (FIG. 2A). Here, photolithography and etching are used for patterning. Subsequently, a water-repellent silane coupling agent is applied.
Since the silane coupling agent is not formed on the electrode,
A film of a silane coupling agent (not shown) is formed on a portion where the insulating layer 4 and the resist 6 are exposed.

Next, a solution in which silica beads 7 as spherical particles having a uniform particle diameter are dispersed in water is densely formed on the emitter layer 3 to form a single layer (FIG. 2B). The mask 7a made of the silica beads 7 is not formed in the portion where the silane coupling agent film is formed and subjected to the water repellent treatment.

Here, by appropriately adjusting the concentration at which the silica beads 7 are dispersed, a single layer of the silica beads 7 is densely formed as a mask 7a by dip or spinner coating.

Subsequently, dry etching using a reactive gas such as CF ₄ or CHF ₃ is performed using the silica beads 7 as a mask 7 a until the mask 7 a of the silica beads 7 disappears. FIG. 2C shows the protruding emitter 8 obtained by stopping the etching when the mask 7a has disappeared. According to the present invention, a protruding emitter structure having a uniform height and pitch can be obtained.

Finally, the resist 6 is peeled off to complete the electron-emitting device 10, which is placed in a vacuum chamber (not shown), and an anode coated with a phosphor as shown in FIG. 9 and a device driving voltage Vf is applied between the lower electrode 2 and the upper electrode 5 and a high voltage Va is applied between the lower electrode 2 and the anode. Obtained.

As described above, according to the present invention, since spherical particles having a uniform particle size are formed on the emitter layer in a dense and single layer, etching is performed by using this as a mask to achieve a high level. Thus, a projecting emitter structure having a uniform pitch can be obtained, and good electron emission characteristics can be obtained.

[0046]

Embodiments of the present invention will be described below in detail.

(Embodiment 1) FIG. 1 is a view showing an example of a method of manufacturing a projecting emitter 8 according to the present invention.

First, on a substrate 1 made of quartz,
A 300 nm Al film is formed as the lower electrode 2 by sputtering and a Ta film is formed as the emitter layer 3 by a sputtering method.
nm deposited.

Next, a solution in which silica beads 7 as spherical particles having a uniform particle diameter of 10 nm are dispersed in water + alcohol is densely formed as a single layer on the emitter layer 3 (FIG. 1).
(B)). Here, by appropriately adjusting the concentration at which the silica beads 7 are dispersed, a single layer of the silica beads 7 was densely formed on the emitter layer 3 by spinner coating. The dispersion medium was removed by drying in a nitrogen atmosphere.

Subsequently, dry etching was performed using the silica beads 7 as a mask 7a and CF ₄ gas until the mask 7a formed of the silica beads 7 disappeared. In addition,
The etching power and gas pressure are appropriately selected from the particles of the silica beads 7 and the shape and film quality of the emitter layer 3.

Other conditions at the time of dry etching differ depending on the size and configuration of the apparatus and the substrate size. In this embodiment, a pressure of 4 Pa and a discharge power of 200 W were used. Under these conditions,
Since the ratio of the etching rate is emitter layer / mask = 3, the height is three times the diameter of the silica beads 7, that is, 3
A protruding emitter 8 having a height of 0 nm was produced (FIG. 1).
(C)).

As described above, according to the present invention, a protruding emitter structure having a uniform height and pitch can be obtained. The above-mentioned protruding emitter structure was placed in a vacuum chamber (not shown), an anode 9 coated with a phosphor was disposed on the protruding emitter structure, and a high voltage Va was applied between the lower electrode 2 and the anode 9.
Electron emission characteristics without luminance unevenness were obtained (FIG. 1).
(D)).

Embodiment 2 As a second embodiment, a method for manufacturing an electron-emitting device will be described with reference to FIGS.

First, a 300 nm Al film was deposited as a lower electrode 2 on a quartz substrate 1 by sputtering. Thereafter, by deposition, photolithography, etching and the like, a 30 nm Mo film as the emitter layer 3, a 50 nm SiO ₂ film as the insulating layer 4, a 20 nm Mo film as the upper electrode 5, and a resist 6 were formed (FIG. 2A). )).

Subsequently, a water-repellent silane coupling agent was applied. Since the silane coupling agent was not formed on the electrode, a film of the silane coupling agent (not shown) was formed on the portion where the insulating layer 4 and the resist 6 were exposed.

Next, a silica sol (silica beads 7) using silicon alkoxide having a particle size of 10 nm as a raw material
Was dispersed in water to form a dense single layer on the emitter layer 3 (FIG. 2B).

The silica beads 7 are not formed in the water-repellent portion where the silane coupling agent film is formed,
By appropriately adjusting the concentration at which the silica beads 7 were dispersed, the silica beads 7 were densely formed into a single layer by dip.

Subsequently, dry etching was performed using the silica beads 7 as a mask 7a and CF ₄ gas until the mask 7a formed of the silica beads 7 disappeared. In addition,
The etching power and gas pressure are appropriately selected based on the shapes and film quality of the mask particles and the emitter layer.

Other conditions at the time of dry etching differ depending on the size and configuration of the apparatus and the size of the substrate. In this embodiment, a pressure of 4 Pa and a discharge power of 200 W were used. Under these conditions,
Since the ratio of the etching rate is emitter layer / mask = 3, the height is three times the diameter of the silica beads 7, that is, 3
A protruding emitter 8 having a height of 0 nm was produced.
(C)).

As described above, according to the present invention, a protruding emitter structure having a uniform height and pitch can be obtained. Finally, the resist 6 is peeled off to complete the electron-emitting device 10, which is placed in a vacuum chamber (not shown).
As shown in (d), an anode 9 coated with a phosphor is arranged, and a device driving voltage Vf is applied between the lower electrode 2 and the upper electrode 5 and a high voltage Va is applied between the lower electrode 2 and the anode. Electron emission characteristics with a small beam diameter and no luminance unevenness were obtained.

Embodiment 3 As a third embodiment, a method for manufacturing another electron-emitting device will be described with reference to FIGS.

First, on the substrate 1 made of GaAs, 300 nm of W is deposited as the emitter layer 3, 30 nm of SiO ₂ is deposited as the insulating layer 4, and 30 nm of W is deposited as the upper electrode 5 by sputtering. The resist 6 was patterned (FIG. 3A).

Next, the upper electrode W and the insulating layer SiO ₂ were etched using the resist 6 as a mask (FIG. 3B).

Subsequently, a solution in which silica beads 7 having a uniform particle diameter of 7 nm were dispersed in water + alcohol was formed densely on the emitter layer 3 (FIG. 3C).

Here, by appropriately adjusting the concentration at which the silica beads 7 are dispersed, a single layer of the silica beads 7 was densely formed on the emitter layer 3 by spinner coating.
The dispersion medium was removed by drying in a nitrogen atmosphere.

Subsequently, dry etching was performed using the silica beads 7 as a mask 7a and CF ₄ gas until the mask 7a of the silica beads 7 disappeared. Note that the etching power and gas pressure are appropriately selected from the shapes and film quality of the mask particles and the emitter layer. Other conditions at the time of dry etching differ depending on the size and configuration of the apparatus and the substrate size, but in this embodiment, a pressure of 4 Pa and a discharge power of 200 W were used.

Under these conditions, since the ratio of the etching rate is 3 for the emitter layer / mask, a protruding emitter having a height three times the diameter of the silica beads, that is, a height of 21 nm was produced (FIG. 3). (D)).

As described above, according to the present invention, a protruding emitter structure having a uniform height and pitch can be obtained. Finally, the resist 6 is peeled off to complete the electron-emitting device. The electron-emitting device is placed in a vacuum chamber (not shown). When the element driving voltage Vf was applied between the electrodes and the high voltage Va was applied between the lower electrode 2 and the anode, electron emission characteristics without luminance unevenness were obtained.

[0069]

According to the present invention described above, since spherical particles having a uniform particle size are densely formed as a single layer on the emitter layer and arranged, the etching is performed using the mask as a mask. As a result, a protruding emitter having a uniform height and pitch was obtained.

In the electron-emitting device, good electron-emitting characteristics were obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for manufacturing a projecting emitter.

FIG. 2 is a diagram illustrating a method for manufacturing an electron-emitting device using a projecting emitter.

FIG. 3 is a diagram illustrating a method for manufacturing another electron-emitting device using a projecting emitter.

FIG. 4 is a view for explaining a conventional example of an electron-emitting device using a projecting emitter.

FIG. 5 is a view for explaining a method of manufacturing an electron-emitting device using a conventional projection-like emitter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Lower electrode 3 Emitter layer 4 Insulating layer 5 Upper electrode 6 Resist 7 Silica beads 7a Mask 8 Projection emitter 9 Anode 10 Electron emission element

Claims (10)

[Claims] 1. A method for manufacturing a projecting emitter, comprising: arranging spherical particles on an emitter layer; and etching the emitter layer using the spherical particles as a mask to produce a projecting emitter. 2. The method according to claim 1, wherein, in the step of arranging the spherical particles on the emitter layer, the spherical particles are densely arranged in a single layer on the emitter layer. . 3. The method according to claim 1, wherein the spherical particles are silica beads. In the step of arranging the spherical particles on the emitter layer, it is preferable that a solution in which silica beads are dispersed in water and alcohol is applied onto the emitter layer so that the silica beads are densely formed as a single layer. The method for manufacturing a projecting emitter according to claim 3. 5. The method according to claim 1, wherein the etching step is dry etching using a reactive gas. 6. The method according to claim 1, wherein an etching rate ratio in the etching is equal to or greater than an emitter layer / mask = 2. 7. A method of manufacturing an electron-emitting device using a projecting emitter manufactured by the method according to claim 1, wherein the spherical particles are arranged on an emitter layer. A method for manufacturing an electron-emitting device, wherein a water repellent treatment is performed on a region where the spherical particles are not arranged. 8. An electron-emitting device comprising: a projecting structure including an insulating layer and an upper electrode on the insulating layer; and a lower electrode on a substrate, and having a projecting emitter formed on the lower electrode. 8. The method according to claim 7, wherein the protruding emitter is formed near a side wall of the convex structure. 9. The method for manufacturing an electron-emitting device according to claim 7, wherein a water repellent treatment is performed on at least a side wall of the convex structure before forming the spherical particles. 10. The emitter layer and the lower electrode material are made of any one of carbon, metal, metal nitride, metal carbide, metal boride, semiconductor, and metal compound of semiconductor. The method for manufacturing an electron-emitting device according to claim 8.