JP3421549B2 - Vacuum micro device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission cold cathode device, a method for manufacturing the same, and a vacuum microdevice using the cold cathode device.

[0002]

2. Description of the Related Art In recent years, field emission type cold cathode devices utilizing semiconductor processing technology have been actively developed. As a typical example thereof, CA Spindt et al., Journal of Applied Phys.
ics, Vol. 47, 5248 (1976) is known. This field emission cold cathode device is
After forming a SiO ₂ layer and a gate electrode layer on a Si single crystal substrate, a hole with a diameter of about 1.5 μm is further formed, and a conical emitter for field emission is formed in this hole by vapor deposition. It was done. This concrete manufacturing method is shown in FIG.
This will be described with reference to 7 (a) to 7 (c).

First, a SiO ₂ layer 2 as an insulating layer is formed on a Si single crystal substrate 1 by a deposition method such as CVD. Next, a Mo layer 3 to be a gate electrode layer and an Al layer 4 to be used as a sacrificial layer are formed thereon by a sputtering method or the like. Next, holes 5 having a diameter of about 1.5 μm are formed in the layers 2, 3 and 4 by etching (FIG. 17A).

Next, a conical emitter 7 for field emission is formed in the hole 5 by vapor deposition (FIG. 17B). The emitter 7 is formed by vacuum-depositing a metal, which is a material of the emitter, such as Mo, in a direction perpendicular to the substrate 1 in a rotated state.
At this time, the pinhole diameter corresponding to the opening of the hole 5 decreases as the Mo layer 6 is deposited on the Al layer 4, and finally becomes 0. For this reason, the holes 5 deposited through the pinholes
The diameter of the emitter 7 in the inside gradually decreases and becomes a conical shape. The excess Mo layer 6 deposited on the Al layer 4 will be removed later (FIG. 17C).

[0005]

However, the above-mentioned manufacturing method and the field emission cold cathode device manufactured by the method have the following problems.

First, since the emitter is formed by utilizing the fact that the diameter of the pinhole corresponding to the opening of the hole 5 is gradually decreased by the rotary evaporation method, the height of the emitter, the shape of the tip end, etc. are varied. However, the uniformity of field emission deteriorates. Further, since the reproducibility of the shape and the yield are poor, the production cost becomes very high when a large number of field emission cold cathode devices with uniform characteristics are to be manufactured on the same substrate.

Further, since the sharpness of the tip of the emitter required for improving the field emission efficiency is lacking, the driving voltage becomes high, which causes problems such as a decrease in field emission efficiency and an increase in power consumption. When a high driving voltage is used, the shape of the tip of the emitter is apt to change under the influence of ionized residual gas due to this voltage, which causes problems in terms of reliability and life.

Further, since the SiO ₂ insulating layer is formed thick by the CVD method, the distance between the gate and the emitter, which largely influences the efficiency of field emission, cannot be accurately controlled, and the uniformity of field emission is not good. , Variations occur. Also,
A device having a smaller gate-emitter distance can be driven with a lower voltage, but it is difficult to bring the gate and the emitter close to each other with good control.

Further, due to the nature of the manufacturing method, it is difficult to set the ratio of the emitter height to the emitter base length, that is, the aspect ratio to 2 or more. When the aspect ratio of the emitter is higher, the electric field is concentrated on the tip of the emitter, so that the driving voltage and the power consumption are significantly reduced. One reason why the aspect ratio of the emitter cannot be increased is that the opening is gradually closed when controlling the height of the emitter, as described above. Another reason is that the base length of the emitter is almost the same as the mask diameter used for the stepper exposure, so that the base length smaller than the stepper exposure limit cannot be manufactured. This stepper exposure limit also limits the emitter base length, which causes another problem for high integration of the emitter.

The present invention has been made to solve the above problems, and provides a field emission cold cathode device having uniform field emission characteristics, capable of being driven at a low voltage, and high field emission efficiency, and a method of manufacturing the same. The purpose is to provide.

It is another object of the present invention to provide a field emission type cold cathode device which is easy to be highly integrated, has high productivity, and is capable of forming a large number of sharp emitters having the same shape, and a manufacturing method thereof. .

It is another object of the present invention to provide a vacuum micro device using the field emission cold cathode device having the above-mentioned excellent characteristics.

[0013]

The first aspect of the present invention is as follows.
In the field emission cold cathode device, a supporting member, an emitter for emitting electrons arranged on the supporting member,
And the emitter comprises a fullerene or a carbon nanotube.

A second aspect of the present invention is the field emission type cold cathode device according to the first aspect, characterized in that the emitter comprises a plurality of fullerenes or carbon nanotubes.

A third aspect of the present invention is the field emission type cold cathode device according to the first or the second aspect, further comprising a cathode wiring layer disposed on the supporting member, wherein the emitter is the cathode wiring. It is characterized by being arranged on a layer.

A fourth aspect of the present invention is the field emission type cold cathode device according to the third aspect, wherein the cathode wiring layer is M.
It is characterized in that it is basically formed of a material selected from the group consisting of o, Ta, W, Cr, Ni and Cu.

A fifth aspect of the present invention is the field emission type cold cathode device according to any one of the first to fourth aspects, wherein the emitter includes a conductive convex portion supported by the supporting member, The fullerene or carbon nanotube is supported by the tip of the conductive protrusion.

A sixth aspect of the present invention is characterized in that in the field emission cold cathode device according to the fifth aspect, the fullerene or carbon nanotube is partially embedded in the conductive convex portion.

A seventh aspect of the present invention is the field emission type cold cathode device according to the fifth or sixth aspect, wherein the conductive protrusions are Mo, Ta, W, Cr, Ni, Si, LaB ₆ , Al.
It is characterized in that it is basically formed of a material selected from the group consisting of N, GaN, graphite and diamond.

An eighth aspect of the present invention is characterized in that, in the field emission cold cathode device according to any one of the first to seventh aspects, a gate electrode facing the emitter is provided at a distance. And

A ninth aspect of the present invention is characterized in that, in the field emission type cold cathode device according to any one of the first to eighth aspects, the supporting member is basically formed of synthetic resin.

A tenth aspect of the present invention is the field emission type cold cathode device according to any one of the first to ninth aspects, wherein the carbon nanotubes are made of carbon having a period of a multiple of 0.426 nm or 0.738 nm. It is characterized by being basically composed of a series of 6-membered rings.

An eleventh aspect of the present invention is the first to tenth aspects.
In the field emission cold cathode device according to any one of the above aspects, the carbon nanotubes have a diameter of 30 nm or less.

A twelfth aspect of the present invention is the first to eleventh aspects.
In the field emission cold cathode device according to any one of the above aspects, the end portion of the carbon nanotube is closed by a graphite sheet including a carbon 5-membered ring, a carbon 6-membered ring, and a carbon 7-membered ring.

The thirteenth aspect of the present invention is the first to twelfth aspects.
In the field emission cold cathode device according to any one of items 1 to 3, the aspect ratio representing the ratio of the height to the bottom diameter of the carbon nanotubes forming the emitter is 3 or more and 1 × 10 ⁶ or less. To do.

A fourteenth aspect of the present invention is the field emission type cold cathode device according to the thirteenth aspect, wherein the aspect ratio is
It is characterized by being 3 or more and 1 × 10 ³ or less.

The fifteenth aspect of the present invention is the first to fourteenth aspects.
The field emission cold cathode device according to any one of the above aspects, further comprising a conductive filling layer capable of emitting electrons, which is disposed in the carbon nanotube.

A sixteenth aspect of the present invention is the field emission type cold cathode device according to the fifteenth aspect, wherein the filling layer is Mo or T.
a, W, Cr, Ni, Si, LaB ₆ , AlN, Ga
It is basically formed of a material selected from the group consisting of N, graphite and diamond.

A seventeenth aspect of the present invention is that, in a vacuum microdevice, a supporting member, an emitter for emitting electrons arranged on the supporting member, and the emitter comprising a fullerene or a carbon nanotube. When,
Due to the surrounding member that cooperates with the supporting member to form a vacuum discharge space surrounding the emitter, the extraction electrode arranged at a distance from the emitter, and the potential difference between the emitter and the extraction electrode. Electrons are emitted from the emitter.

An eighteenth aspect of the present invention is characterized in that, in the vacuum microdevice according to the seventeenth aspect, the extraction electrode comprises a gate electrode supported by the support member.

A nineteenth aspect of the present invention is characterized in that, in the vacuum microdevice according to the eighteenth aspect, an anode electrode is provided on the surrounding member at a position facing the emitter.

A twentieth aspect of the present invention is the vacuum microdevice according to the seventeenth aspect, wherein the extraction electrode comprises an anode electrode disposed on the surrounding member at a position facing the emitter. To do.

A twenty-first aspect of the present invention is a method for manufacturing a field emission type cold cathode device, comprising: a supporting member; and a plurality of emitters arranged on the supporting member for emitting electrons. Disposing a collecting member in the vacuum processing chamber, setting a vacuum atmosphere of the vacuum processing chamber in an inert gas atmosphere, sublimating carbon in the vacuum processing chamber, and depositing the carbon on the collecting member. And forming the carbon nanotubes by transferring the carbon nanotubes from the collecting member onto the supporting member to form the emitters including the carbon nanotubes.

A twenty-second aspect of the present invention is a method of manufacturing a field emission type cold cathode device comprising a support member and a plurality of emitters for emitting electrons arranged on the support member, Disposing the support member in a vacuum processing chamber, setting the vacuum processing chamber to a vacuum atmosphere of an inert gas, sublimating carbon in the vacuum processing chamber, and depositing the carbon on the support member. Forming the emitter having the carbon nanotubes by depositing as carbon nanotubes.

A twenty-third aspect of the present invention is the manufacturing method according to the twenty-first or twenty-second aspect, wherein the carbon sublimation is selected from the group consisting of resistance heating, electron beam, arc discharge, and laser light irradiation. It is performed by.

The twenty-fourth aspect of the present invention is the twenty-first to the second aspects.
3. The manufacturing method according to any one of 3) to 3), further comprising a step of forming a conductive filling layer capable of emitting electrons in the carbon nanotube.

A twenty-fifth aspect of the present invention is a method of manufacturing a field emission type cold cathode device, comprising a support member and an emitter for emitting electrons arranged on the support member. Forming a concave portion having a sharp bottom, a step of disposing fullerene or carbon nanotubes in the concave portion, a step of filling a conductive material in the concave portion to form a conductive convex portion, the conductive A step of joining the supporting member to the mold member so as to sandwich the convex portion; and a step of removing the mold member to form the emitter having the conductive convex portion and the fullerene or carbon nanotube on the supporting member. And a step of exposing.

A twenty-sixth aspect of the present invention is the manufacturing method according to the twenty-fifth aspect, which comprises a step of coating the inner surface of the recess with an insulating layer before filling the recess with the conductive material. Is characterized by.

The twenty-seventh aspect of the present invention is the twenty-first to the second aspects.
The manufacturing method according to any one of the aspects 6 to 6 includes a step of disposing a gate electrode so as to face the emitter and be supported on the support member via an insulating layer.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. In the following embodiments, corresponding members are designated by the same reference numerals, and overlapping description will be given only when necessary.

1A and 1B are schematic cross-sectional views showing the field emission type cold cathode device according to the embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 1 (b), the field emission type cold cathode device according to this embodiment includes a support substrate 12 and an emitter 1 arranged on the support substrate 12 for emitting electrons.
4 and. A plurality of or a single emitter 14 is arranged on the support substrate 12 according to the application of the field emission cold cathode device.

When the supporting substrate 12 itself also serves as the cathode wiring layer, the supporting substrate 12 is Mo, Ta, W, Cr, Ni, C.
It is basically formed of a conductive material such as u, carbon, or a semiconductor such as Si doped with impurities. When the cathode wiring layer is separately provided, the support substrate 12 is made of glass,
It is basically formed of an insulating material such as quartz or synthetic resin, or a semiconductor material such as Si.

Each of the emitters 14 is basically made of carbon 6
It is formed of a plurality of carbon nanotubes 16 formed by a series of member rings. Usually carbon nanotube 1
As shown in FIGS. 1A and 1B, 6 exists on the support substrate 12 in a state where the fallen trees overlap each other. However, in the following figures, for simplification of the figure, the carbon nanotubes 16 are shown in a state of standing up substantially vertically. It is also possible for each emitter 14 to consist of one carbon nanotube 16. 70 of all carbon nanotubes 16
% Or more has a diameter of 30 nm or less. The aspect ratio representing the ratio of the height to the bottom diameter of the carbon nanotubes 16 forming the emitter 14 is 3 or more and 1 × 10 ⁶
Below, it is desirably set to ³ or more and 1 × 10 ³ or less.

The carbon nanotube 16 is shown in FIG.
As shown in FIG. 2 (b), a graphite sheet 18 having a molecular structure basically composed of a series of 6-membered carbon rings
As shown in the figure, it is formed into a cylindrical shape. The graphite sheet 18 has a 6-membered ring in the direction B (having a period of 0.4
(26 nm), it exhibits metallic properties. The graphite sheet 18 also has a 6-membered ring in the direction A (having a period of 0.246n).
m) also, (3,0), (6,0), (9,0), etc., 3
When wound so as to connect the lattice points of × (1,0), a semiconductor property with a narrow bandgap is exhibited. Therefore, the carbon nanotube 16
The cycle of the 6-membered ring of carbon in is 0.42 in the cycle B direction.
6 nm or period A direction 0.246 nm × 3 = 0.73
It is a multiple of 8 nm.

The end portion of the carbon nanotube 16 may be closed as shown in FIG. 2 (b) or may be opened in a cylindrical shape without being closed. The graphite sheet 22 that closes the ends of the carbon nanotubes 16 has a structure in which a 5-membered ring of carbon and / or a 7-membered ring of carbon are interposed in a series of 6-membered rings of carbon. For example, in the example shown in FIG. 2 (b), a carbon 5-membered ring is interposed in the site 24. This is because the 6-membered ring of carbon cannot form the closed shape of the end portion.

Next, two examples of the method of manufacturing the field emission type cold cathode device according to this embodiment will be described.

In the first example of the manufacturing method, first, a pair of graphite electrodes having a diameter of 6.5 nm to 20 nm are prepared, and these are arranged in the vacuum processing chamber as an anode electrode (carbon source) and a cathode electrode (collecting member). Set up. next,
The vacuum processing chamber is evacuated, and an inert gas such as He or Ar is introduced into the vacuum processing chamber, and the vacuum processing chamber is heated to 20
The inert gas atmosphere is set to rr to 500 Torr, preferably about 500 Torr.

Next, a DC voltage of 10 V to 20 V is applied between the anode electrode and the cathode electrode, and an arc discharge is generated so that the current becomes about 100 A. In this way, while sublimating the carbon of the anode electrode, carbon is deposited on the cathode electrode to form carbon nanotubes. At this time, the carbon deposition conditions are adjusted so that the carbon nanotubes are basically composed of a series of carbon 6-membered rings and the period of the 6-membered rings is a multiple of 0.426 nm or 0.738 nm.

As described above, the diameter of the carbon nanotube can be reduced to 30 nm or less by adjusting the gas pressure or the voltage for generating arc discharge. Further, the shape of the carbon nanotubes formed varies depending on the process conditions and the like.
If it occupies at least%, there is no particular problem in terms of characteristics.

Next, the cathode electrode is immersed in ethanol and ultrasonic waves are applied to separate the carbon nanotubes from the cathode electrode and disperse them in ethanol. Next, the carbon nanotubes are taken out from the ethanol with a ceramic filter or filter paper and dried.
After separating the carbon nanotubes, the carbon nanotubes may be purified and classified so as to meet the usage conditions.

Next, carbon nanotubes are applied onto the support substrate 12 made of synthetic resin by a method such as coating, pressure bonding and embedding to form a carbon nanotube layer 26 (FIG. 1).
(A)). Here, as the material of the supporting substrate, polymethylmethacrylate, Teflon, polytetrafluoroethylene, polycarbonate, amorphous polyolefin, acrylic resin, epoxy resin can be used.

Next, a resist is applied to the emitter 14
The carbon nanotube layer 26 is lithographically patterned according to the layout of FIG. In this way
Emitter 14 composed of a plurality of carbon nanotubes 16
Is formed on the support substrate 12 (FIG. 1B).

In the first example of the above manufacturing method,
The electric power applied between the pair of graphite electrodes may be AC instead of DC. Further, the carbon nanotubes can be used together with the cathode electrode (collecting member) in a field emission cold cathode device without being separated from the cathode electrode (collecting member).

In the second example of the manufacturing method, first, a graphite rod having a diameter of 6.5 nm to 20 nm is placed in the vacuum processing chamber. Further, the support substrate 12 is directly placed in the vacuum processing chamber. Next, the vacuum processing chamber is evacuated and H
An inert gas such as e or Ar is introduced into the vacuum processing chamber, and the inside of the vacuum processing chamber is set to an inert gas atmosphere of 20 Torr to 500 Torr, preferably about 500 Torr.

Next, the graphite rod is energized to heat the graphite rod by resistance self-heating. In this way
While sublimating the carbon of the graphite rod, the supporting substrate 12
Carbon is deposited on the carbon nanotube layer 26 to form the carbon nanotube layer 26 (FIG. 1A). At this time, the carbon deposition condition is that the carbon nanotube is basically composed of a series of 6-membered rings of carbon, and the period of the 6-membered ring is 0.426 nm or 0.
Adjust to be a multiple of 738 nm.

As described above, the diameter of the carbon nanotube can be reduced to 30 nm or less by adjusting the gas pressure or the voltage for generating the arc discharge. Further, the shape of the carbon nanotubes formed varies depending on the process conditions and the like.
If it occupies at least%, there is no particular problem in terms of characteristics.

Next, a resist is applied to the emitter 14
The carbon nanotube layer 26 is lithographically patterned according to the layout of FIG. In this way
Emitter 14 composed of a plurality of carbon nanotubes 16
Is formed on the support substrate 12 (FIG. 1B).

As means for sublimating carbon in the vacuum processing chamber, electron beam, laser light irradiation, etc. may be used in addition to the arc discharge and resistance heating shown in the first and second examples of the manufacturing method. it can.

3 (a) and 3 (b) are schematic cross-sectional views showing a field emission type cold cathode device according to another embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 3B, in the field emission cold cathode device according to this embodiment, a cathode wiring layer 28 for supplying electrons to the emitter 14 is provided on the support substrate 12. This is different from the field emission type cold cathode device shown in FIG. The cathode wiring layer 28 is made of Mo, Ta,
It is basically formed of a conductive material such as W, Cr, Ni or Cu. The support substrate 12 is basically formed of an insulating material such as glass, quartz, synthetic resin, or a semiconductor material such as Si.

The field emission type cold cathode device shown in FIG. 3 (b) can be manufactured by substantially the same method as the field emission type cold cathode device shown in FIG. 1 (b). However, the following modifications are made to the first and second examples of the manufacturing method described with reference to FIG.

First, in the first example using the anode electrode (carbon source) and the cathode electrode (collection member), before the carbon nanotubes separated from the cathode electrode (collection member) are supplied onto the support substrate 12, the support is carried out. A patterned cathode wiring layer 28 is formed on the substrate 12. Then, the carbon nanotubes are attached to the support substrate 12 as described above.
Then, the carbon nanotube layer 26 is formed on the support substrate 12 and the cathode wiring layer 28 (FIG. 3).
(A)). Next, according to the layout of the emitter 14,
The carbon nanotube layer 26 is patterned by a lithography technique to form the emitter 14 composed of the plurality of carbon nanotubes 16 on the cathode wiring layer 28 (FIG. 3).
(B)).

In the second example in which carbon nanotubes are directly deposited on the support substrate 12, the support substrate 12
Before being placed in the vacuum processing chamber, a patterned cathode wiring layer 28 is formed on the support substrate 12. And
The support substrate 12 with the cathode wiring layer 28 is placed in the vacuum processing chamber, and the operation is performed as described above to deposit carbon on the support substrate 12 and the cathode wiring layer 28 to form the carbon nanotube layer 26 (FIG. 3). (A)). Next, according to the layout of the emitter 14, the carbon nanotube layer 26 is patterned by a lithography technique to form the emitter 14 composed of a plurality of carbon nanotubes 16 on the cathode wiring layer 28 (FIG. 3B).

FIGS. 4A to 4C are schematic sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 4 (c), the field emission cold cathode device according to this embodiment has the carbon nanotube 1
6 has a conductive filling layer 32 capable of emitting electrons.
Is provided, which is different from the field emission cold cathode device shown in FIG. The filling layer 32 is Mo, Ta, W, C
It is basically formed of a conductive material such as r, Ni, Si, LaB ₆ , AlN, GaN, graphite and diamond.

The field emission cold cathode device shown in FIG. 4 (c) can be manufactured by substantially the same method as the field emission cold cathode device shown in FIG. 1 (b), but with the following modifications. .

First, as described above, the carbon nanotube layer 26 is formed on the support substrate 12 (FIG. 4A). Next, the sublimated conductive material is deposited from above, or the entire completed structure is immersed in the molten conductive material to form the conductive material layer 34 on the entire surface of the support substrate 12. At this time, the filling layer 32 is formed mainly in the tip portion of the carbon nanotube (FIG. 4B). Here, theoretically, the conductive material sucked into the tube is likely to be formed in the center of the tube which is energetically most stable. However, the suction of the conductive material may stop in the middle of the tube due to various conditions such as the presence of gas in the tube.

Next, patterning is performed by a lithography technique according to the layout of the emitter 14 and the supporting substrate 12 is formed.
The portion of the conductive material layer 34 that is in direct contact with is removed, and the emitter 14 composed of a plurality of carbon nanotubes 16 is formed on the support substrate 12 (FIG. 4C). Since the carbon nanotubes 16 are firmly fixed on the supporting substrate 12 by the conductive material layer 34, the carbon nanotubes 16 shown in FIG.
(B) It is possible to provide a structure that is easier to handle and has higher reliability than the illustrated structure.

FIGS. 5A to 5C are schematic sectional views showing the field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 5C, the field emission type cold cathode device according to the present embodiment has the carbon nanotube 1
6 has a conductive filling layer 32 capable of emitting electrons.
3 is different from the field emission cold cathode device shown in FIG. 3B. The filling layer 32 is basically formed of the material described with reference to FIGS. The filling layer 32 may be formed of the same material as the cathode wiring layer 28.

The field emission type cold cathode device shown in FIG. 5C can be manufactured by the same method as that of the field emission type cold cathode device shown in FIG. 3B, but with the following modifications. .

First, as described above, the carbon nanotube layer 26 is formed on the support substrate 12 and the cathode wiring layer 28 (FIG. 5A). Next, the sublimated conductive material is deposited from above, or the entire completed structure is immersed in the molten conductive material to form the conductive material layer 34 on the entire surface of the support substrate 12. At this time, the filling layer 32 is formed mainly in the tip portion of the carbon nanotube (FIG. 5).
(B)). Next, according to the layout of the emitter 14,
The supporting substrate 12 is patterned by the lithography technique.
The part of the conductive material layer 34 that is in direct contact with is removed, and the emitter 14 composed of a plurality of carbon nanotubes 16 is formed on the cathode wiring layer 28 (FIG. 5).
(C)).

Incidentally, FIGS. 4 (a) to 4 (c) and FIG. 5 (a)
(C) In the illustrated embodiment, material selection or treatment of the surface of the supporting substrate 12 is performed in advance so that the peelability between the surface of the supporting substrate 12 and the conductive material of the filling layer 32 is good. You can Further, the filling layer 32 may be formed at the time of preparation before supplying the carbon nanotubes onto the supporting substrate 12. In this case, for example, the sublimated conductive material is deposited from above on the carbon nanotubes attached to the collecting member, or the carbon nanotubes attached to the collecting member or separated from each other are melted to form a conductive material. Layer 3 by immersing it in a conductive material
2 can be formed in carbon nanotubes.

The structure shown in FIG. 5C having the cathode wiring layer 28 and the filling layer 32 can also be formed by the manufacturing method shown in FIGS. 6A to 6D. Figure 6
The manufacturing method shown in (a) to (d) is an application of the first example of the manufacturing method using the anode electrode (carbon source) and the cathode electrode (collecting member), and is modified as follows.

First, as described above, carbon is deposited on the cathode electrode (collecting member) 42 to form the carbon nanotube layer 26 (FIG. 6A). Next, the carbon nanotube layer 26 is pressed against the synthetic resin layer 44 in the melted state while being attached to the cathode electrode (collecting member) 42 (FIG. 6B). Here, as the material of the synthetic resin layer 44, polymethylmethacrylate, Teflon, polytetrafluoroethylene, polycarbonate, amorphous polyolefin, acrylic resin, epoxy resin can be used.

After the synthetic resin layer 44 is dried to form the supporting substrate 12, the cathode electrode (collecting member) 42 is removed from the carbon nanotube layer 26. That is, the carbon nanotube layer 26 is transferred from the cathode electrode (collecting member) 42 onto the support substrate 12.

Next, the sublimated conductive material is deposited from above, or the entire completed structure is immersed in the molten conductive material to form the conductive material layer 46 to be the cathode wiring layer on the support substrate 12. Form. At this time, the filling layer 32 is formed mainly in the tip portion of the carbon nanotube (FIG. 6C). Next, a resist is applied to the emitter 14
The carbon nanotube layer 26 and the conductive material layer 46 are patterned by a lithographic technique according to the layout of FIG. In this way, a plurality of carbon nanotubes 16
The emitter 14 composed of is formed on the cathode wiring layer 28 (FIG. 6D).

As described above, according to the manufacturing method shown in FIGS. 6A to 6D, the filling layer 32 and the cathode wiring layer 28 are made of the same material.

FIGS. 7A and 7B are schematic sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention. In these embodiments, the fullerene 17 is used instead of the carbon nanotube to emit the emitter 14.
Is formed. 7 (a) and 7 (b)
These correspond to the structures shown in FIGS. 1B and 3B, respectively.

Fullerenes are allotropes of carbon as carbon nanotubes and are basically of the same quality. The extraordinary full-length fullerene forms carbon nanotubes. As shown in FIG. 2 (c), the basic type of fullerene is C ₆₀ composed of carbon 6-membered ring and carbon 5-membered ring, and its diameter is about 0.7 nm. C ₆₀ is a regular icosahedron having 12 or truncated icosahedron vertices have become 5 pyramid can by dropping all switching of (eventually 32 tetrahedral) carbon atoms of all the sp ² orbital hybridization vertices at It has a different structure.

In addition to C ₆₀ , higher fullerenes having more than 60 carbon atoms, such as C ₇₀ , C ₇₆ , C ₈₂ , C ₈₄ , C ₉₀ ,
C ₉₆ , ..., C ₂₄₀ , C ₅₄₀ , C _720, etc. are virtually infinite. However, the higher fullerenes are Euler's formula,
F + V = E + 2 (F: number of polygons, V: number of vertices, E:
The number of sides of a polygon) and p = s + 12 (p: number of 5-membered rings, s: number of 7-membered rings) are satisfied, and the carbon atoms are chemically stable.

Further, since the inside of the fullerene is hollow, there are onion type fullerenes in which multiple layers of the low-order fullerenes are entangled like onions in the high-order fullerenes.
These are called superfullerenes. The distance between layers in the superfullerene is 0.341 nm.
For example, it contains the C ₂₄₀ in the C _540, C ₆₀ further therein
The fullerene containing is represented by C ₆₀ @C ₂₄₀ @C ₅₄₀ . Here, the symbol "@" indicates that the molecule or atom described before is an endohedral fullerene.

Further, the fullerene can incorporate a metal inside the hollow. Examples of such metal-encapsulated fullerenes are La @ C ₆₀ , La @ C ₇₆ , La @ C ₈₄ , La.
₂ @ C ₈₀ , Y ₂ @C ₈₄ , Sc ₃ @C _82, etc. Furthermore,
Heterofullerenes in which elements other than carbon such as N, B and Si are incorporated in the skeleton of fullerenes have also been studied.

Fullerenes are produced by subjecting graphite to laser irradiation, arc discharge, resistance heating, etc.
It can be prepared by vaporizing carbon, allowing the vaporized carbon to pass through helium gas, cooling, reacting and aggregating, and collecting it by a collecting member.

The field emission type cold cathode device shown in FIGS. 7A and 7B is shown in FIGS. 1A, 1B and 3A, respectively.
It can be manufactured by applying the manufacturing method described with reference to (b).

That is, in the case of applying the first example of the manufacturing method described above, first, the fullerene 17 is separately prepared and collected in advance, and the supporting substrate 1 is applied by a method such as coating, pressure bonding and embedding.
2 or on the support substrate 12 and the cathode wiring layer 28 to form a fullerene layer. When applying the second example of the manufacturing method described above, first, the supporting substrate 12 or the supporting substrate 12 with the cathode wiring layer 28 is used as a collecting member, and the fullerene layer is formed thereon. next,
A resist is applied and the fullerene layer is lithographically patterned according to the layout of the emitter 14. As a result, the emitter 14 including the plurality of fullerenes 17 can be formed on the support substrate 14 or the cathode wiring layer 28.

Further, FIGS. 4A to 4C and 5A.
(C) As shown in the figure, when the conductive material layer 34 is used, the fullerene 17 is supported by the support substrate 14 or the cathode wiring layer 28.
Can be firmly fixed on top. In addition, FIG.
(A) to (d) By applying the manufacturing method shown in the drawings, the fullerene 17 can be transferred from the collecting member onto the supporting substrate 14.

8A to 8C are schematic sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 8C, the field emission type cold cathode device according to the present embodiment has the structure shown in FIG. It has an extraction electrode, that is, a gate electrode 54, made of a conductive material such as W. The gate electrode 54 faces the emitter 14 made of the carbon nanotubes 16 with a space.

The field emission type cold cathode device shown in FIG. 8C can be manufactured by the following method.

First, the patterned cathode wiring layer 28 is formed on the support substrate 12. As described above, the cathode wiring layer 28 is basically formed of a conductive material such as Mo, Ta, W, Cr, Ni or Cu. The support substrate 12 is made of an insulating material such as glass, quartz, synthetic resin, or S
It is basically formed from a semiconductor material such as i.

Next, the supporting substrate 12 and the cathode wiring layer 2
An insulating layer 52 made of SiO ₂ , SiN or the like is formed on the gate electrode 8, and a gate electrode layer 56 made of a conductive material such as W is further formed thereon (FIG. 8A). The insulating layer 52 can be formed by electron beam evaporation, a sputtering method, or a CVD method.

Next, the insulating layer 52 and the gate electrode layer 56 are patterned by the lithographic technique to form the gate electrode 54 and the gate wiring. At this time, the cathode wiring layer 28 is exposed in the recess 58 surrounded by the gate electrode 54 (FIG. 8B).

Next, a carbon nanotube layer is formed on the entire main surface of the object to be processed, that is, not only inside the recess 58 but also outside the recess 58. The carbon nanotube layer can be provided on the object to be treated by coating, printing or the like prepared in advance, or the object to be treated can be placed in a vacuum processing chamber and the carbon nanotubes can be directly deposited on the object. it can. Next, the carbon nanotube layer is patterned by a lithographic technique to form the cathode wiring layer 28.
Emitter 1 leaving carbon nanotubes 16 only on top
4 is formed (FIG. 8C).

In the present embodiment, fullerenes 17 can be used instead of carbon nanotubes. In this case, as shown in FIG. 8D, the structure and the manufacturing method are the same as those described with reference to FIGS. 8A to 8C, except that the emitter 14 is a fullerene 17. Becomes

FIGS. 9A to 9C are schematic sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

As shown in FIG. 9C, the field emission type cold cathode device according to this embodiment is also insulated on the support substrate 12 similarly to the field emission type cold cathode device shown in FIG. 8C. Membrane 6
2 has an extraction electrode, that is, a gate electrode 54 made of a conductive material such as W, which is disposed via the electrode 2. However, the device does not use the carbon nanotubes 16 that form the emitters 14.
Is partially embedded in the insulating film 62 and is firmly fixed, which is different from that shown in FIG. 8C.

The field emission cold cathode device shown in FIG. 9C can be manufactured by the following method.

First, the patterned cathode wiring layer 28 is formed on the support substrate 12. Next, the support substrate 12
A carbon nanotube layer is formed on the cathode wiring layer 28. The carbon nanotube layer can be provided on the object to be treated by coating, printing or the like prepared in advance, or the object to be treated can be placed in a vacuum processing chamber and the carbon nanotubes can be directly deposited on the object. it can. Next, the carbon nanotube layer is patterned by a lithography technique to form the emitter 14 while leaving the carbon nanotubes 16 only on the cathode wiring layer 28 (FIG. 9A).

Next, on the entire main surface of the object to be processed, Si
The insulating layer 62 made of O ₂ , SiN or the like is formed to a thickness such that the tip of the emitter 14 is exposed. The insulating layer 62 is
It can be formed by electron beam evaporation, sputtering, or CVD. The thickness of the insulating layer 62 can be controlled during film formation, or can be adjusted by slightly etching back after film formation. For example, the insulating layer 62 is S
In the case of iO _2, buffered hydrofluoric acid can be used for this etching.

Next, the resist layer 64 is formed on the entire main surface of the object to be processed, and the resist layer 64 is exposed so that the insulating layer 62 is exposed corresponding to the portion where the gate electrode 54 is formed.
Is patterned (FIG. 9B). Next, a gate electrode layer made of a conductive material such as W is formed on the entire main surface of the object to be processed. Next, the resist layer 64 is removed together with the unnecessary portion of the gate electrode layer by lift-off, so that the gate electrode 54 and the gate wiring having a predetermined pattern can be left on the insulating film 62 (FIG. 9C).

In the step shown in FIG. 9B, the insulating layer 62 may be formed thicker than the height of the emitter 14, and the recess 66 may be formed in a portion corresponding to the emitter 14 to expose the tip of the emitter. it can. The structure thus obtained is as shown in FIG. 9 (d). The gate electrode 54 is located above the tip of the emitter 14, which is a preferred arrangement for the extraction electrode.

In the present embodiment, fullerene 17 can be used instead of carbon nanotube. In this case, an outline of the structure and manufacturing method is shown in FIG. 9A, except that the emitter 14 is made of fullerene 17.
It is the same as that described with reference to (d).

FIG. 10A is a sectional view showing a flat panel image display device which is an example of a vacuum micro device according to still another embodiment of the present invention.

The display device shown in FIG. 10A is similar to that shown in FIG.
(C) It is formed by using the illustrated field emission cold cathode device. As shown in FIG. 10A, a plurality of gate lines forming the gate electrode 54 are arranged in a direction parallel to the paper surface,
A plurality of cathode lines forming the cathode wiring layer 28 are arranged in a direction perpendicular to the paper surface. An emitter group including a plurality of emitters 14 is arranged on the cathode line corresponding to each pixel.

A counter substrate 72 made of glass is arranged so as to face the support substrate 12 made of glass.
A vacuum discharge space 73 is formed therebetween. Both boards 12, 72
The spacing between is maintained by the peripheral frame and spacers 74. A transparent common electrode or anode electrode 76 and a phosphor layer 78 are provided on the surface of the counter substrate 72 facing the support substrate 12.

In this flat panel image display device, lighting or blinking of a pixel is selected by arbitrarily setting the voltage between the gate electrode 54 and the emitter 14 in each pixel via the gate line and the cathode line. can do. That is, the pixel selection is performed by so-called matrix driving, for example, by applying a predetermined potential as a selection signal to the cathode line in synchronization with line-sequential selection of gate lines and applying a predetermined potential. Can be done.

When one gate line and one cathode line are selected and given a predetermined potential, only the emitter group at the intersection of the gate line and the cathode line operates. The electrons emitted from the emitter group are attracted by the voltage applied to the anode electrode 76, and the phosphor layer 7 at the position corresponding to the selected emitter group.
It reaches 8 and emits light.

As shown in FIG. 10B, the display device can be constructed without using the gate electrode 54. The display device shown in FIG. 10B is formed using the field emission cold cathode device shown in FIG.

In this flat panel image display device, instead of the gate lines, a plurality of anode lines forming the transparent anode electrode 82 on the counter substrate 72 are arranged in a direction parallel to the paper surface. Therefore, lighting or blinking of the pixel can be selected by arbitrarily setting the voltage between the anode electrode 82 and the emitter 14 in each pixel via the anode line and the cathode line. When a certain anode line and a certain cathode line are selected and given a predetermined potential, only the emitter group at the intersection of the anode line and the cathode line operates.

The display device shown in FIGS. 10A and 10B is formed by using the field emission cold cathode device shown in FIGS. 8C and 3B, respectively. Embodiment of
For example, even when the field emission type cold cathode device having the emitter 14 made of the fullerene 17 is used, the display device can be similarly formed. Further, these field emission cold cathode devices can be used to form a vacuum microdevice other than a display device, such as a power conversion device such as a power switching device.

11 (a) and 11 (b) are a schematic sectional view showing a field emission type cold cathode device according to still another embodiment of the present invention and an enlarged schematic view showing its tip.

The field emission type cold cathode device according to this embodiment has a supporting substrate 112 and an emitter 115 arranged on the supporting substrate 112 via a cathode wiring layer 114 for emitting electrons. Each emitter 115 has a conductive protrusion 118 formed of a part of the conductive material layer 116, and a plurality of carbon nanotubes 122 partially buried in the tip of the conductive protrusion 118. Emitter 115
According to the application of the field emission cold cathode device, a plurality (only one is shown in the figure) or a single one is arranged on the support substrate 112.

The support substrate 112 is made of an insulating material such as Pyrex glass. The cathode wiring layer 114 is basically formed of a conductive material such as an ITO layer. The conductive material layer 116 and the conductive protrusion 118 are made of Mo, Ta, W, C.
It is basically formed of a conductive material such as r, Si, Ni, LaB ₆ , AlN, GaN, graphite and diamond. When the cathode wiring is formed using the conductive material layer 116, the cathode wiring layer 114 is omitted and the conductive material layer 116 is directly formed on the support substrate 112.

The carbon nanotube 122 is shown in FIG.
As described with reference to (a) and (b), it is basically composed of a continuous tube of carbon 6-membered rings. The carbon nanotubes 122 have a length of 3 nm to 10 μm, and 70% or more of them have a diameter of 30 nm or less. It suffices that the carbon nanotubes 122 be supported so that they can be electrically connected to the conductive protrusions 118, and they need not be partially buried. Although a plurality of carbon nanotubes 122 are arranged on the conductive convex portion 118 in the illustrated example, the number of the carbon nanotubes 122 may be one.

The carbon nanotube 122 is usually formed in a hollow cylindrical shape. However, if desired, a conductive fill layer 124 can be disposed within the carbon nanotubes 122, and particularly within the tip of the tube, as shown. The filling layer 124 is made of Mo, Ta, W, Cr, S.
i, Ni, LaB ₆ , AlN, GaN, graphite,
It is basically formed of a conductive material capable of emitting electrons such as diamond. The filling layer 124 can be formed of the same material as the conductive material layer 116 and the conductive convex portion 118 or a different material.

The structural characteristics and the preparation method of the carbon nanotube 122 other than the above are the same as those of the carbon nanotube 16 described above.

FIGS. 13A to 13F are views showing a method of manufacturing the field emission cold cathode device shown in FIG. 11A in the order of steps.

First, a concave portion having a sharp bottom is formed on one surface of a substrate made of, for example, a single crystal. As a method of forming such a recess, the following method utilizing anisotropic etching of a Si single crystal substrate can be used.

First, a p-type (10
0) A thickness of 0.1 on the Si single crystal substrate 131 having a crystal plane orientation.
A SiO ₂ thermal oxide layer 132 of μm is formed by a dry oxidation method. Next, a resist is applied on the thermal oxide layer 132 by spin coating to form a resist layer 133 (FIG. 13A).

Next, a stepper is used to perform processing such as exposure and development so as to obtain a plurality of openings 134 arranged in a matrix, for example, square openings of 1 μm square, and the resist layer 133 is formed. Perform patterning. Then, using the resist layer 133 as a mask, NH ₄ F.HF
The SiO ₂ film is etched with the mixed solution (FIG. 13B).

After removing the resist layer 133, anisotropic etching is performed using a 30 wt% KOH aqueous solution to form a recess 135 having a depth of 0.71 μm on the Si single crystal substrate 131. Next, using a NH ₄ F / HF mixed solution, S
Remove the iO ₂ oxide layer. By being etched with a KOH aqueous solution, the recess 135 has an inverted pyramid shape defined by the four slopes of the (111) plane.

In this case, the S in which the recess 135 is formed is formed.
i single crystal substrate 131 is thermally oxidized by a wet oxidation method,
A SiO ₂ thermal oxidation insulating layer may be formed on the entire surface including the recess 135. By forming the SiO ₂ thermal oxidation insulating layer, the tip of the conductive convex portion formed by using the concave portion 135 as a mold can be made sharper.

Next, the carbon nanotubes 136 are arranged on the bottom of the recess 135 (FIG. 13C). here,
For example, as described above, the carbon nanotubes deposited by the method using the anode electrode (carbon source) and the cathode electrode (collecting member) are separated from the cathode electrode by immersing them in ethanol and applying ultrasonic waves. Disperse in ethanol. Next, after pouring the suspension of ethanol into the recess 135 and drying,
The carbon nanotubes 136 can be arranged at the bottom of the recess 135. It does not matter if the carbon nanotubes are attached to the outside of the recess 135, but if there is any trouble, they are removed with an organic solvent after patterning.

As another method of disposing the carbon nanotubes 136 at the bottom of the recess 135, a graphite electrode may be provided near the substrate 131 and the carbon nanotubes may be deposited at the bottom of the recess 135. In this case, it is convenient because the carbon nanotubes are more likely to be deposited on the bottom than the top of the recess.

In FIGS. 13D to 13F below, the carbon nanotubes 136 are not shown for the sake of clarity.

Then, Si is filled so as to fill the recess 135.
A conductive material layer 137 made of a conductive material such as W is deposited on the single crystal substrate 131. The conductive material layer 137 is formed so that the recess 135 is filled and the portion other than the recess 135 has a uniform thickness, for example, 2 μm.

When forming the conductive material layer 137,
The conductive material layer 137 is not completely embedded in the bottom portion where the plurality of carbon nanotubes are arranged. Therefore, after separation from the substrate 131, a state in which the carbon nanotubes partially protrude from the tips of the conductive protrusions is obtained.

Furthermore, ITO is formed on the conductive material layer 137.
A layer, a conductive material layer 138 such as Ta is formed by the same sputtering method so as to have a thickness of 1 μm, for example (FIG. 13D). The conductive material layer 138 may be omitted depending on the material of the conductive material layer 137, and in that case, the conductive material layer 137 also serves as the cathode electrode layer.

On the other hand, the thickness of 0.4 on the back surface, which is a supporting substrate.
A Pyrex glass substrate (thickness 1 mm) 141 coated with an Al layer 142 of μm is prepared. And in FIG.
As shown in (e), the glass substrate 141 and the Si single crystal substrate 131 are bonded to each other with the conductive material layers 137 and 138 interposed therebetween. For this adhesion, for example, an electrostatic adhesion method can be applied. The electrostatic mounting method contributes to weight reduction and thickness reduction of the cold cathode device.

Next, the Al layer 14 on the back surface of the glass substrate 141.
2, is removed by mixed acid solution of _{HNO 3 · CH 3 COOH · HF} . Further, an aqueous solution containing ethylenediamine / pyrocatechol / pyrazine (ethylenediamine: pyrocatechol: pyrazine: water = 75 cc: 12 g: 3 mg: 10
In cc), the Si single crystal substrate 131 is removed by etching.
Thus, as shown in FIG. 13F, the carbon nanotubes 136 (not shown) and the conductive protrusions 143 are formed.
Expose.

If the filling layer 124 (see FIG. 11B) is provided in the carbon nanotube 136, the conductive convex portion 143 is exposed, and then the sublimated conductive material is placed above the carbon nanotube 136. Or deposit from
It can be formed by immersing the entire completed structure in a molten conductive material. Instead, when the carbon nanotubes 136 are prepared before being placed in the recesses 135, the sublimated conductive material is replaced with the carbon nanotubes 13.
Deposited from above 6 or carbon nanotubes 13
It can also be formed by immersing 6 in a molten conductive material.

In the field emission type cold cathode device shown in FIG. 11A manufactured by the manufacturing method shown in FIGS. 13A to 13F, the conductive protrusion 118 of the emitter 115 (see FIG. 1).
3 is indicated by the reference numeral 143), since it is formed by using the concave portion 135 as a mold, it has a pyramid shape that inherits the shape. A plurality of carbon nanotubes 122 (indicated by reference numeral 136 in FIGS. 13A to 13F) are supported at the tip of the conductive protrusion 118 while partially embedded in the conductive protrusion 118. It

When it is desired to cause the carbon nanotubes 122 to largely protrude from the tips of the conductive protrusions 118,
After placing the carbon nanotubes in the recess 135, the recess 1
A SiO ₂ layer is deposited on the surface of 35 by a sputtering method. Next, after backing with a conductive layer and removing the mold substrate, S
Only the iO ₂ layer is removed by a NH ₄ F / HF mixed solution. As a result, the protruding length of the carbon nanotube 122 from the conductive protrusion 118 is increased by the amount of the removed SiO ₂ layer.

FIG. 12 is a schematic sectional view showing a field emission type cold cathode device according to still another embodiment of the present invention.

The embodiment shown in FIG. 12 is different from the embodiment shown in FIG. 11A in that the gate made of a conductive material such as W is formed on the conductive material layer 116 with the insulating film 126 interposed therebetween. The electrode 128 is provided. The gate electrode 128 faces the emitter 115, that is, the conductive protrusion 118 and the carbon nanotube 122 with a space therebetween.

FIGS. 14A to 14H are views showing a method of manufacturing the field emission cold cathode device shown in FIG. 12 in the order of steps.

First, as described with reference to FIGS. 13 (a), 13 (b) and 13 (c), a p-type (10
0) (111) on the Si single crystal substrate 131 having a crystal plane orientation
A recess 135 having the shape of an inverted pyramid defined by four inclined surfaces is formed. Next, the Si single crystal substrate 131 in which the recess 135 is formed is thermally oxidized by the wet oxidation method, and the SiO ₂ thermal oxidation insulating layer 15 is formed on the entire surface including the recess 135.
1 is formed. At this time, the insulating layer 151 has a thickness of about 30 nm on the (111) surface of the substrate 131, that is, the side surface of the recess 135. Si single crystal (10
The thickness of the thermal oxide layer on the (0) plane matches the thickness on the (111) plane within ± 10%. Therefore, the thickness on the (111) plane can be estimated from the thickness of the oxide insulating layer on the (100) plane.

After forming the insulating layer 151, the carbon nanotubes 136 are arranged at the bottom of the recess 135 by the method described above (FIG. 14A). In addition, the following FIG. 14 (b)
In (h), the carbon nanotubes 136 are not shown for the sake of clarity.

Next, similar to the step of FIG. 13D, W is formed on the Si single crystal substrate 131 so as to fill the recess 135.
A conductive material layer 137 made of a conductive material such as is deposited. Further, a conductive material layer 138 such as an ITO layer is formed on the conductive material layer 137 by the same sputtering method (FIG. 14B).

Next, as in the step of FIG. 13E, a Pyrex glass substrate (thickness 1 mm) 141 having a 0.4 μm thick Al layer 142 coated on its back surface and conductive material layers 137, 138 are formed. It is adhered to the Si single crystal substrate 131 so as to be interposed (FIG. 14C).

Next, similar to the step of FIG. 13F, the Al layer 142 on the rear surface of the glass substrate 141 and the Si single crystal substrate 13 are formed.
1 and are removed by etching. In this way, the SiO ₂ thermal oxidation insulation layer 1 covering the pyramid-shaped conductive protrusions 152 is formed.
Expose 51.

Next, a conductive material layer 153 made of a conductive material such as W to be the gate electrode is formed on the insulating layer 151 by a sputtering method so as to have a thickness of about 0.5 μm. After that, a photoresist layer 153 is applied by a spin coating method to a thickness of about 0.9 μm, that is, a thickness such that the tip of the pyramid is slightly hidden (FIG. 14).
(E)).

Further, dry etching is performed by oxygen plasma, and the resist layer 154 is removed by etching so that the tip of the pyramid is exposed by about 0.7 μm (FIG. 14).
(F)). Then, the conductive material layer 153 at the tip of the pyramid is etched by reactive ion etching,
The opening 155 is formed (FIG. 14G).

After removing the resist layer 154, NH ₄ F
-The insulating layer 151 is selectively removed using an HF mixed solution. In this way, as shown in FIG. 14H, in the opening 155 of the conductive material layer 153 to be the gate electrode,
The carbon nanotubes 136 (not shown) and the conductive protrusions 152 are exposed.

In the field emission type cold cathode device shown in FIG. 12 manufactured by the manufacturing method shown in FIGS. 14A to 14H, the conductive protrusion 118 of the emitter 115 (see FIG. 14).
In (a) to (h), reference numeral 152 indicates a concave portion 135 which is sharpened by the formation of the SiO ₂ thermal oxidation insulating layer 151.
Since it is formed by using as a mold, the shape is succeeded to form a pyramid shape with a sharp tip. Conductive protrusion 118
A plurality of carbon nanotubes 122 (indicated by reference numeral 136 in FIG. 14) are partially formed on the tip of each of the conductive protrusions 1.
It is supported while being embedded in 18. Also, the emitter 1
15, the gate electrode 128 is opposed to the periphery of the conductive protrusion 118 and the carbon nanotube 122 with a space.

FIG. 15 is an enlarged schematic view showing the tip of a field emission type cold cathode device according to still another embodiment of the present invention. In this embodiment, instead of carbon nanotubes,
The fullerene 123 is arranged on the conductive convex portion 118. The structural characteristics and preparation method of fullerene 123 are the same as those of fullerene 17 described above.

The structure shown in FIG. 15 is shown in FIGS.
It can be applied to any of the field emission cold cathode devices shown in FIG. In addition, the manufacturing method of these application examples is shown in FIG.
The manufacturing method illustrated in (a) to (f) and FIGS. 14 (a) to (h) can be used substantially as it is. That is, in the step of arranging the carbon nanotubes at the bottom of the recess 135 shown in FIGS. 13C and 14A, it suffices to make a change in that the fullerenes 123 are arranged in place of the carbon nanotubes.

FIG. 16 is a sectional view showing a flat panel image display device which is an example of a vacuum micro device according to still another embodiment of the present invention.

The display device shown in FIG. 16 is formed by using the field emission cold cathode device shown in FIG. As shown in FIG. 16, a plurality of gate lines forming the gate electrode 128 are arranged in a direction perpendicular to the plane of the drawing, and the cathode wiring layer 11
A plurality of cathode lines forming 6 are arranged in a direction parallel to the paper surface. A plurality of emitters 11 corresponding to each pixel
An emitter group consisting of 5 is arranged on the cathode line.

A counter substrate 172 made of glass is arranged so as to face the support substrate 112 made of glass.
A vacuum discharge space 173 is formed between 2 and 172. The space between the substrates 112 and 172 is maintained by the peripheral frame and the spacer 174. A transparent common electrode or anode electrode 176 and a phosphor layer 178 are disposed on the surface of the counter substrate 172 facing the support substrate 112.

In this flat panel image display device, lighting or blinking of a pixel is selected by arbitrarily setting the voltage between the gate electrode 128 and the emitter 115 in each pixel via the gate line and the cathode line. can do. That is, the pixel selection is performed by so-called matrix driving, for example, by applying a predetermined potential as a selection signal to the cathode line in synchronization with line-sequential selection of gate lines and applying a predetermined potential. Can be done.

When a certain gate line and a certain cathode line are selected and given a predetermined potential, only the emitter group at the intersection of the gate line and the cathode line operates. The electrons emitted from the emitter group are attracted by the voltage applied to the anode electrode 176, reach the phosphor layer 178 at the position corresponding to the selected emitter group, and emit it.

The display device shown in FIG. 16 is formed by using the field emission type cold cathode device shown in FIG. 12, but another embodiment, for example, a field emission type device having an emitter 115 made of fullerene 123. Even when a cold cathode device is used, a display device can be similarly formed. Also,
These field emission cold cathode devices can also be used to form vacuum microdevices other than display devices, such as power conversion devices such as power switching devices.

Although the present invention has been described with reference to the embodiments shown in the accompanying drawings, the present invention can be implemented in various modes other than the illustrated embodiments within the scope of the concept. is there.

[0157]

According to the present invention, since an emitter is formed by using carbon nanotubes or fullerenes, a field emission cold cathode device having uniform field emission characteristics, capable of driving at a low voltage, and high field emission efficiency, and the same. A manufacturing method can be provided. Further, according to the present invention, it is possible to provide a field emission type cold cathode device which can easily be highly integrated, has high productivity, and can form a large number of sharp emitters having the same shape, and a manufacturing method thereof. In particular, when carbon nanotubes are used, the aspect ratio of the emitter can be increased.

[Brief description of drawings]

1A and 1B are schematic cross-sectional views showing a field emission cold cathode device according to an embodiment of the present invention in the order of manufacturing steps.

2A to 2C are diagrams showing details of carbon nanotubes and fullerenes.

3A and 3B are schematic cross-sectional views showing a field emission type cold cathode device according to another embodiment of the present invention in the order of manufacturing steps.

FIGS. 4A to 4C are schematic cross-sectional views showing a field emission cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

5A to 5C are schematic cross-sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

6A to 6D are schematic cross-sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps.

7A and 7B are schematic cross-sectional views showing a field emission cold cathode device according to still another embodiment of the present invention.

8A to 8C are schematic cross-sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps, and FIG. 8D is a schematic cross-sectional view showing a modification thereof. .

9A to 9C are schematic cross-sectional views showing a field emission type cold cathode device according to still another embodiment of the present invention in the order of manufacturing steps, and FIG. 9D is a schematic cross-sectional view showing a modification thereof. .

10A and 10B are cross-sectional views showing a flat panel image display device which is an example of a vacuum micro device according to still another embodiment of the present invention.

11A and 11B are a schematic cross-sectional view showing a field emission cold cathode device according to still another embodiment of the present invention and an enlarged schematic view showing a tip portion thereof.

FIG. 12 is a schematic sectional view showing a field emission cold cathode device according to still another embodiment of the invention.

13A to 13F are schematic cross-sectional views showing the field emission cold cathode device shown in FIG. 11A in the order of manufacturing steps.

14A to 14H are schematic cross-sectional views showing the field emission cold cathode device shown in FIG. 12 in the order of manufacturing steps.

FIG. 15 is an enlarged schematic view showing a tip portion of a field emission cold cathode device according to still another embodiment of the invention.

FIG. 16 is a cross-sectional view showing a flat panel image display device which is an example of a vacuum micro device according to still another embodiment of the present invention.

17A to 17C are schematic cross-sectional views showing a conventional field emission cold cathode device in the order of manufacturing steps.

[Explanation of symbols]

12 ... Support substrate 14 ... Emitter 16 ... Carbon tube 17 ... Fullerene 18 ... Graphite sheet 22 ... Graphite sheet 26 ... Carbon nanotube layer 28 ... Cathode wiring layer 32 ... Packed bed 34 ... Conductive material layer 42 ... Cathode electrode (collecting member) 44 ... Synthetic resin layer 46 ... Conductive material layer 52 ... Insulating layer 54 ... Gate electrode 62 ... Insulating layer 72 ... Counter substrate 73 ... Vacuum discharge space 74 ... Spacer 76 ... Anode electrode 78 ... Phosphor layer 82 ... Anode electrode 112 ... Support substrate 114 ... Cathode wiring layer 115 ... Emitter 116 ... Conductive material layer 118 ... Conductive protrusion 122 ... Carbon nanotube 123 ... Fullerene 124 ... Packed bed 126 ... Insulating layer 128 ... Gate electrode 131 ... Si single crystal substrate (molded substrate) 135 ... recess 136 ... Carbon nanotube 137, 138 ... Conductive material layer 141 ... Glass substrate 151 ... Oxide insulating film 153 ... Conductive material layer 154 ... Resist layer 155 ... Aperture 172 ... Counter substrate 173 ... Vacuum discharge space 174 ... Spacer 176 ... Anode electrode 178 ... Phosphor layer

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-7-201275 (JP, A) JP-A-7-192604 (JP, A) JP-A-7-11520 (JP, A) JP-A-7- 254370 (JP, A) JP 9-221309 (JP, A) JP 6-227806 (JP, A) JP 8-188406 (JP, A) JP 6-331309 (JP, A) Table 2000-500905 (JP, A) Walt A. de Heer, A Carbon Nanotube Field-Emission Electron Source, SCIENCE E, Vol. 270, No. 5239, p. 1179-1180 Morinobu Endo, Generation of Carbon Nanotubes, Structure and Properties, Surface, Volume 32, No. 5, p. 277-283 (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 1/304 H01J 9/02

Claims (17)

(57) [Claims] 1. A support member, an emitter disposed on the support member, for emitting electrons having carbon nanotubes to enhance field emission efficiency, and the support member in cooperation with the emitter. An enclosing member that forms an enclosing vacuum discharge space, and an extraction electrode that is arranged at a distance from the emitter and is arranged so that electrons are emitted from the emitter due to a potential difference between the emitter and the emitter. The carbon nanotube has a structure in which a graphite sheet made of a series of carbon 6-membered rings is wound in a cylindrical shape in a direction having a period of 0.426 nm, and the emitter is the support member. A conductive protrusion that is supported by the carbon nanotube, the carbon nanotube being supported by the tip of the conductive protrusion. Micro devices. 2. A support member, an emitter disposed on the support member and configured to emit electrons having carbon nanotubes to enhance field emission efficiency, and the support member in cooperation with the emitter. An enclosing member that forms an enclosing vacuum discharge space, and an extraction electrode that is arranged at a distance from the emitter and is arranged so that electrons are emitted from the emitter due to a potential difference between the emitter and the emitter. The carbon nanotube has a structure in which a graphite sheet made of a series of carbon 6-membered rings is wound into a cylindrical shape in a direction having a period of 0.738 nm, and the emitter is the support member. A conductive protrusion that is supported by the carbon nanotube, the carbon nanotube being supported by the tip of the conductive protrusion. Micro devices. 3. A vacuum micro device according to claim 1 or 2, characterized in that said emitter comprises a plurality of carbon nanotubes. Wherein comprising the supporting cathode wiring layer disposed on a member further either the emitter of claims 1 to 3, characterized in that it is arranged on the cathode wiring layer
Vacuum micro device according to any. 5. The cathode wiring layer is Mo, Ta, W, C
The vacuum microdevice according to claim 4 , wherein the vacuum microdevice is formed of a material selected from the group consisting of r, Ni, and Cu. 6. to claim 1, wherein the carbon nanotubes embedded in the part on the conductive projection
5. The vacuum microdevice according to any one of 5 above. 7. The conductive protrusions are Mo, Ta, W, Cr,
7. The vacuum microdevice according to claim 1 , wherein the vacuum microdevice is made of a material selected from the group consisting of Ni, Si, LaB ₆ , AlN, GaN, graphite and diamond. Wherein said supporting member is a vacuum micro device according to any one of claims 1 to 7, characterized in that it is formed from a synthetic resin. Wherein said emitter comprises a plurality of carbon nanotubes, a vacuum micro device according to any one of claims 1 to 8, characterized in that it has 70% or more below the diameter 30nm it like. 10. The end portion of the carbon nanotube is closed by a graphite sheet containing a 5-membered ring, a 6-membered ring and a 7-membered ring of carbon .
The vacuum microdevice according to any one of claims. 11. The carbon nanotube forming the emitter has an aspect ratio representing a height with respect to a diameter of a bottom portion of 3 or more and 1 × 10 ⁶ or less, according to any one of claims 1 to 10. The vacuum microdevice according to 1. 12. The aspect ratio is 3 or more and 1 × 10.
The vacuum microdevice according to claim 11 , wherein the vacuum microdevice is ³ or less. Wherein said disposed within the carbon nanotube, vacuum micro device according to any one of claims 1 to 12, characterized by further comprising a conductive filler layer capable of emitting electrons. 14. The filling layer is Mo, Ta, W, Cr, N.
i, Si, LaB ₆ , AlN, GaN, graphite,
14. The vacuum microdevice according to claim 13 , wherein the vacuum microdevice is formed of a material selected from the group consisting of diamond. 15. The extraction electrode to claim 1, characterized in that it consists supported gate electrode on the support member
15. The vacuum microdevice according to any one of 14 . 16. The vacuum microdevice according to claim 15 , further comprising an anode electrode disposed on the surrounding member at a position facing the emitter. 17. The extraction electrode vacuum micro device according to any one of claims 1 to 14, characterized in that an anode electrode disposed on said enclosing member at a position facing the emitter.