JP3526344B2 - Field emission device, electron emission source and flat display device using the field emission device, and method of manufacturing field emission 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 electron emission device utilizing vacuum microelectronics technology,
The present invention relates to an electron emission source and a flat display device to which the field electron emission device is applied, and a method for manufacturing the field emission device and the flat display device.

[0002]

2. Description of the Related Art In recent years, with the progress of semiconductor microfabrication technology, micron-sized micro vacuum tubes have been developed. The purpose is to review the vacuum as an electron transport medium,
It is to develop a field electron emission device that is super-high-speed and has excellent environmental resistance that overcomes the drawbacks of vacuum tubes driven by solid-state devices.

Typical examples of field electron emission devices which have been studied in recent years include Spindt type (Gray type), flat type, and MIM type (Metal-Insurate-Met).
al) etc. are known.

Spindt type and plane type field electron emission devices have an emitter electrode having a sharpened tip, and by applying an electric field from the adjacent gate electrode to the tip of the emitter electrode, the emitter electrode is formed. It draws (releases) electrons from.

On the other hand, the MIM type field emission device is a type in which an insulating film and a conductive film are thinly laminated on the surface of a conductor serving as an emitter electrode, and a strong electric field is applied from the conductive film to the surface of the emitter electrode. When applied, electrons are extracted by utilizing the quantum mechanical tunneling phenomenon.

[0006]

The significance of the development of the above-mentioned field electron emission device depends on how much the operating voltage of the field electron emission device can be lowered. For this purpose, it is necessary to improve the electron emission efficiency (emission current density) of the emitter electrode of the field electron emission device.

Further, it is considered that the field electron emission device is applied as an electron emission source of an electron beam drawing apparatus or a flat display. For this purpose, it is preferable that the above-mentioned electrons can be emitted in a plane and at a high density.

In the Spindt type or the planar type, the emitter electrode is formed into a pyramid or a cone (Spindt type),
By making it wedge-shaped (flat type), the tip is sharpened,
The electron emission efficiency is improved. However, since the shape accuracy of the tip of the emitter electrode depends on the resolution of a stepper or the like for mask patterning, there is a certain limit to sharpening and increasing the density.

On the other hand, it is not necessary to sharpen the above-mentioned MIM type electron-emitting device. Further, in the Spindt type described above, electrons could not be emitted in a plane unless the emitter electrode was formed in a high density, but in the MIM type, electrons (electron beam) were irrespective of such formation density. ) Can be discharged in a plane.
In addition, since it is not necessary to sharpen the emitter electrode, its production is very easy and the yield is high.

However, in order to improve the electron emission efficiency of this MIM type field emission device, the insulating film is made as thin as possible to reduce the distance (gap) between the surface of the emitter electrode and the conductive film. There is a need.

If the thickness of this insulating film cannot be reduced, the electron emission efficiency will be low, so that a high potential difference must be generated between the conductive film and the emitter electrode, and the operating voltage becomes high. Will end up.

In order to avoid such an inconvenience, the insulating film must be, for example, 100 angstroms or less. However, since this insulating film does not allow even one lattice defect, its formation is very difficult. Sometimes.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a field electron emission device which can fully utilize the advantages of the MIM type and have a high electron emission efficiency and a low operating voltage. It is intended.

[0014]

A first means is to use an emitter electrode that emits electrons based on a quantum mechanical tunneling phenomenon when an electric field is applied, an insulating film laminated on this emitter electrode, and this insulating film. in field electron emission device and an electron extraction electrode applying an electric field to said emitter electrode is laminated on, the emitter electrode Ri columnar crystal aggregate der comprising a plurality of columnar crystals formed on a surface of the conductor,
Each columnar crystal of the columnar crystal aggregate has a sharpened tip.
The electrons are emitted from this tip, and
The edge film is on the surface of the sharpened tip of each columnar crystal.
The electron extraction electrode is formed to have a substantially uniform thickness.
A conductive film that is applied to the surface of the edge film with a substantially uniform thickness.
Is a field emission element characterized by that.

[0015]

[0016]

A second means is that in the field electron emission device according to the first means, the columnar crystal aggregate is formed on the surface of a conductor by means of CVD (Chemical vapor deposition). It is a characteristic field electron emission device.

A third means is the field electron emission device according to the second means, wherein the columnar crystals are β-tungsten (W).
It is a field electron emission device characterized by including. Fourth
In the field electron emission device according to the first means, an insulating layer is provided on the surface of the conductor, and a through hole exposing the surface of the conductor is provided in the insulating layer.
The columnar crystal aggregate is a field electron emission device characterized in that it is formed on the surface of the conductor exposed in the through hole.

A fifth means is the field electron emission device according to the first means, which has an anode electrode for receiving the electrons emitted from the emitter electrode.

A sixth means is the field electron emission device according to the fifth means, wherein the anode electrode has a transparent conductive film, and the surface of the transparent conductive film on the electron extraction electrode side is covered with the emitter electrode. It is a field electron emission device characterized in that a phosphor that emits light upon receiving emitted electrons is provided.

The seventh means is the first, fourth or fifth means.
Is the electron-emitting source characterized by comprising by integrating field emission device means. The eighth means is the first or the first
4 means for emitting a field electron emission device arranged in a matrix on a substrate, and an electron emission source which is arranged so as to face the electron emission source and receives electrons emitted from the electron emission source. A flat display device having a display unit for performing the operation.

A ninth means is the flat display device according to the eighth means, wherein the display section is a transparent plate member and a transparent conductive film provided on a surface of the transparent plate member facing the electron emission source side. And a phosphor provided on the transparent conductive film.

A tenth means is the flat display device according to the ninth means, wherein the electron emission source divides the conductor into a plurality of strips and divides the electron extraction electrode into a plurality of strips orthogonal to the conductor. However, by using one of the strip-shaped conductor and the strip-shaped electron extraction electrode as an address line and the other as a data line, electrons are emitted from an emitter electrode provided at the intersection thereof. It is a display device.

According to an eleventh means, in the flat display device according to the ninth means, the transparent conductive film is divided into a plurality of strips, and the voltage applied to each transparent conductive film is controlled to control the light emission range. It is a flat display device characterized by:

A twelfth means is an emitter electrode which emits electrons based on a quantum mechanical tunneling effect when an electric field is applied, an insulating film laminated on the emitter electrode,
In a method of manufacturing a field electron emission device including an electron extraction electrode which is laminated on this insulating film and applies an electric field to the emitter electrode, a columnar crystal aggregate is formed on a conductor and a tip is sharpened into a needle shape. forming an emitter electrode made of are columnar crystals, the sharpened tip of each columnar crystal
The method includes a step of forming an insulating film with a substantially uniform thickness on the surface, and a step of forming a conductive film deposited on the surface of the insulating film with a substantially uniform thickness to form an electron extraction electrode. This is a method of manufacturing a field electron emission device.

A thirteenth means is an emitter electrode which emits electrons based on the quantum mechanical tunneling effect when an electric field is applied, and an insulating film laminated on the emitter electrode.
In a method of manufacturing a field electron emission device including an electron extraction electrode which is laminated on the insulating film and applies an electric field to the emitter electrode, a step of forming an insulating layer on a surface of a conductor and a predetermined portion of the insulating layer are formed. A step of removing and forming a through hole exposing the surface of the conductor, and forming a columnar crystal aggregate on the surface of the conductor exposed in the through hole, and the tip was sharpened into a needle shape. The step of forming an emitter electrode made of columnar crystals, and the surface of the sharpened tip of each columnar crystal described above.
A step of forming an insulating film with a substantially uniform thickness on the surface, and depositing a conductive film with a substantially uniform thickness on the surface of the insulating film,
And a step of forming an electron extraction electrode.

A fourteenth means is the method of manufacturing a twelfth or thirteenth field electron emission device, wherein in the step of forming the emitter electrode, the member containing the conductor is housed in a reaction chamber and the temperature is 120 ° C. to 500 ° C. The electric field electron is characterized in that the columnar crystal aggregate containing β-W is deposited on the surface of the conductor by keeping two degrees centigrade and introducing two kinds of reaction gases of WF ₆ and SiH ₄ into the chamber to react them. It is a method of manufacturing an emission element.

A fifteenth means is the method of manufacturing a field electron emission device according to the fourteenth aspect , wherein in the step of forming an insulating film on the surface of the columnar crystal aggregate, oxygen gas is introduced into the reaction chamber to form the columnar crystal. A method of manufacturing a field electron emission device, characterized in that an insulating metal oxide film is formed on the surface of the assembly.

[0029]

According to the first means , in the MIM (metal-insulation-metal) type field electron emission device, the emitter electrode is
It is possible to form a columnar crystal aggregate in which columnar crystals capable of emitting electrons from the sharpened tip are provided at a high density. Therefore, the electric field concentration on the emitter electrode is improved and the electron emission efficiency is improved.

Further, the electron extracting electrode by forming along the shape of the sharpened tip of the columnar crystal can further enhance the electric field concentration degree.

As in the second and third means, the aggregate of columnar crystals having the sharpened tip is C under certain conditions.
It can be formed by growing a columnar crystal containing β-W (β-tungsten) using a VD method or a sputtering method.

According to the fourth means, the range in which the emitter electrode is provided can be defined by providing the insulating layer having the through holes on the conductor. This through hole can have any shape such as a circle or a square.

According to the fifth means, a triode having an emitter electrode composed of a columnar crystal aggregate can be obtained. According to the sixth means, by providing the phosphor on the anode electrode of the triode, the phosphor can be made to emit light by the emitted electrons. At this time, since the electron emission efficiency is high, high brightness can be obtained with low power.

According to the seventh means, it is possible to obtain an electron emission source in which MIM type or SIM type field electron emission devices having columnar crystal aggregates as emitter electrodes are integrated, and electrons are provided in the insulating layer. It is emitted from the emitter electrode provided in the through hole.

With such a shape, the emitter electrode can be selectively formed only by CVD in the through hole, and therefore the manufacturing is very easy. According to eighth to eleventh means, it is possible to apply the MIM type electron emission source having an emitter electrode composed of a columnar crystal aggregate flat display, in this case, it requires a lower voltage Can be displayed.

According to the twelfth means, only the film forming technique is used.
Since a crystal aggregate composed of columnar crystals can be provided on the substrate to form an emitter electrode having a sharpened tip, a MIM type electron-emitting device having a high electron emission efficiency can be easily manufactured.

According to the thirteenth means, by first providing the insulating layer having the through hole on the conductor, the emitter electrode can be selectively formed only in the through hole.
Therefore, when the emitter electrodes are formed at a plurality of locations on the conductor, the emitter electrodes can be arranged very easily.

The columnar crystal aggregate can be easily formed under the conditions shown in the fourteenth means. Under this method, the columnar crystal aggregate is formed in a place other than the through hole. It will not be done. Furthermore, by using the fifteenth means, it is possible to easily form a thin and uniform insulating film on the surface of the columnar crystal aggregate.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 are schematic configuration diagrams of a field electron emission device 1 showing a first embodiment of the present invention.

Reference numeral 2 in the figure indicates a conductive substrate (conductor).
On this substrate 2, a columnar crystal aggregate 4 composed of a large number of fine columnar crystals 3 whose upper end is sharpened in a needle shape is formed. An insulating layer 5 is formed on the substrate 2 around the columnar crystal aggregate 4. An insulating film 6 and a conductive film 7 are stacked in this order on the columnar crystal aggregate 4 and the insulating layer 5.

As the material of the substrate 2, Si (silicon wafer) which is metal or semiconductor is adopted. The columnar crystal aggregate 4 is formed, for example, by a CVD (Chemical
Vapor Deposition) is an aggregate of tungsten crystals, and by performing this CVD under predetermined conditions, the columnar crystals 3 having sharpened upper ends are perpendicular to the surface of the substrate 2. It has been grown to. Such columnar crystals 3 include, for example, β-W (β-state tungsten).

The insulating layer 5 is made of, for example, SiO.
_{2. As} the material of the insulating film 6, for example, a thermal oxide film of tungsten can be used, and for the conductive film 7, a metal having general conductivity, such as Cu or Al, can be used.

Next, the operation of this field electron emission device 1 will be described. The columnar crystal aggregate 4 has conductivity,
It is electrically connected to the substrate 2. Therefore, for example, by applying a negative voltage to the substrate 2 and a positive voltage to the conductive film 7, the columnar crystal aggregates 4 and the conductive film 7 are provided.
When a potential difference is generated between the columnar crystal aggregates 4 and the conductive film 7, an electric field is applied from the conductive film 7 to the columnar crystal aggregate 4 through a gap secured by the thickness of the insulating film 6.

The applied electric field concentrates on the needle-shaped upper end of each columnar crystal 3. As a result, electrons (e ⁻ ) are extracted from the upper end of each columnar crystal 3 into the insulating film 6 based on the quantum mechanical tunneling phenomenon. That is, each columnar crystal 3
The (columnar crystal aggregate 4) acts as an emitter electrode, and the conductive film 7 acts as an electron extraction electrode.

The extracted electrons (-e) pass through the thin insulating film 6 and the conductive film 7 and are emitted into the vacuum above the field electron emission device 1, as shown in FIG. At this time, if an anode electrode (not shown) to which a voltage is applied is arranged at a position facing the field electron emission device 1, the emitted electrons will be attracted to this anode electrode.

The field electron emission device 1 is a so-called MIM type (Metal type) having a laminated structure of metal (tungsten: columnar crystal aggregate 4) -insulator 6 (tungsten oxide film) -metal (conductive film 7). -Insulater-Metal) electron-emitting device. Also, since electrons are emitted from a large number of fine columnar crystals 3 densely packed, they function as a planar electron beam emission source.

Next, a method of manufacturing the electron-emitting device 1 will be described with reference to FIG. First, as shown in FIG. 3A, the insulating layer 5 is formed on the substrate 2. This insulating layer 5
Is formed by, for example, thermal oxidation, sputtering, CVD, or the like. Then, a resist 9 is applied on the insulating layer 5 and patterned. The pattern of the resist 9 can be formed in any shape such as a circle or a square according to the area where the columnar crystal aggregate 4 is formed. Then, anisotropic etching such as RIE is performed by using the resist 9 as a mask to form a through hole 10 in the insulating layer 5 as shown in FIG. 3B.

Next, after the resist 9 is removed by washing,
As shown in FIG. 3C, the columnar crystal aggregate 4 is formed on the surface of the substrate 2 exposed in the through hole 10.
This film formation is performed by using, for example, CVD as described above.

That is, the substrate 2 is held in a decompression chamber (not shown), and the environmental temperature (substrate peripheral temperature) in the decompression chamber is 120 ° C. to 500 ° C., preferably about 32 ° C.
Set to 0 ° C.

Then, WF ₆ (tungst
en hexafluoride) and SiH ₄ (silane) are introduced and reacted. The flow ratio of these two kinds of reaction gases is controlled to 1: 1.

As a result, tungsten (W) is deposited on the surface of the substrate 2. Since there are no free electrons on the insulating film 5, no film is formed. Therefore, the columnar crystal aggregates 4 can be selectively formed only in the through holes 10.

Each tungsten crystal grown under the above-mentioned environment contains β-W (β-state tungsten), and grows into a substantially vertical column (columnar crystal 3) from the surface of the substrate 2. Has been confirmed. The upper end of each columnar crystal 3 is sharpened like a needle.

Further, the formation density of the columnar crystals 3 can be set depending on the setting of the film forming conditions, but under the conditions of this embodiment, the formation pitch is very fine with a forming pitch of 0.1 μm to 0.5 μm. Can be formed.

Further, the height of the columnar crystal aggregate 4 is
It can be set by adjusting the CVD time. In this embodiment, the height is set so as to slightly project from the upper end surface of the insulating layer 5.

After the columnar crystal aggregate 4 is formed in this way, next, inside the chamber, for example, 300
Maintaining an arbitrary temperature environment within a range of up to 400 ° C, a small amount of oxygen (vacuum degree: several mTorr) is introduced. With this,
As shown in FIG. 3D, an insulating film 6 made of a thin tungsten oxide film having a thickness of 100 Å or less is formed on the surface of the columnar crystal aggregate 4.

This insulating film 6 is deposited on the surface of the sharpened upper end of each columnar crystal 3 with a substantially uniform thickness. Therefore, the insulating film 6 is formed in a concavo-convex shape according to the shape of the upper end of the columnar crystal 3.

Next, as a final step, a thin conductive film 7 is deposited on the surfaces of the insulating layers 5 and 6 by, for example, sputtering. This completes the field electron emission device 1 shown in FIG.

Incidentally, FIG. 4 is an enlarged view showing the vicinity of the upper end of the columnar crystal 3. The upper end of the columnar crystal 3 is already sharp as shown in FIG. 4A when it is formed by CVD, and the insulating film 6 and the conductive film 7 are sharp as shown in FIG. It is applied according to the shape of the open part.

After the formation of the insulating film 6 and the conductive film 7 is completed and the temperature of the field electron emission device 1 is returned to room temperature, the columnar crystals 3 as shown in FIG.
It has been confirmed that the side surface of the upper end of the is deformed so as to be recessed inward, and the sharpness of the uppermost end becomes higher.

According to the field electron emission device 1 described above,
The effects described below can be obtained as compared with the conventional MIM type field electron emission device. That is, conventional MI
The M-type field electron emission device is formed by using a conductor having a substantially flat surface as an emitter electrode, and laminating an insulating film and a conductive film (electron extraction electrode) on the surface of the conductor. .

Then, a potential difference is generated between the conductive film and the emitter electrode, and a voltage is applied to the emitter electrode through the gap defined by the insulating film from the conductive film, whereby the quantum mechanical Electrons were extracted from this emitter electrode by the dynamic tunneling phenomenon. As a result, the conventional MIM-type field emission device has a planar electron beam.
It was functioning as a source.

By the way, in the field electron emission device,
The electron emission efficiency (emission current density) is determined by the distance between the emitter electrode and the electron extraction electrode (conductive film), and the geometrical amount such as the electric field concentration (sharpness) on the emitter electrode. , The smaller the distance between the emitter electrode and the electron extraction electrode, and the higher the sharpness of the emitter electrode, the larger.

In the above-mentioned conventional MIM type, since the surface of the emitter electrode is formed to be substantially flat in order to function as a planar electron beam emission source, its electron emission efficiency is
It depends on the thickness of the insulating film. Therefore, it is necessary to make the insulating film as thin as possible. However, since no single lattice defect is allowed in this insulating film, it is very difficult to make it thin.

On the other hand, in the present invention, attention is paid to the fact that an aggregate 4 of columnar crystals 3 having finely sharpened tips is obtained by a film forming technique such as CVD, and this is used as a MIM type field electron emission device. Was adopted as the emitter electrode of. As a result, the following effects can be obtained.

First, since the electric field concentration is improved, the electron emission efficiency can be improved without making the insulating film so thin. That is, in the conventional MIM type, the effect of electric field concentration cannot be obtained because the surface of the emitter electrode is substantially flat, but in the present invention, the emitter electrode is fine and the upper end is sharpened like a needle. Since the aggregate 4 of the columnar crystals 3 formed as described above can be formed, the electric field can be concentrated at the tips of the columnar crystals 3.

In addition, the conductive film 7 which becomes the above-mentioned electron extraction electrode.
Is formed along the sharpened upper end of each columnar crystal 3, so that the concentration of the electric field is further increased. The reason for this will be described with reference to FIG.

That is, the shape of the conductive film 7 is shown in FIG.
As shown in (a) to (c), the electric field concentration is compared by changing to three types. Considering the equipotential distribution for each shape, the equipotential lines shown in the figure are obtained. The electric field concentration factor increases as the equipotential line becomes steeper near the upper end.

Therefore, as shown in FIG. 5C, the electric field concentration is highest when the conductive film 7 is formed so as to cover the tip of the columnar crystal 3 (the present invention). .

Further, as described above, due to the residual stress generated in the insulating film 6, the needle-like upper end portion has a shape in which the side face is carved (see FIG. 4C), and the sharpness is further improved. Will increase. Therefore, the equipotential lines are steeper and the electric field concentration is higher.

Since the electric field concentration can be increased in this way, the electron emission efficiency can be improved without making the insulating film 6 so thin. Therefore, there is an effect that electrons can be emitted even at a low operating voltage.

In the columnar crystal aggregate 4 containing β-W described above, the distance between the tip ends of the columnar crystals 3 is very small, 0.1 μm or less. For this reason, the density of electron emission is high, and it sufficiently functions as a planar electron beam emission source.

Secondly, the manufacture of this field electron emission device is very easy. According to the present invention, the sharpened fine columnar crystals 3 (emitter electrodes) can be formed at a high density, and a field electron emission device that functions as a planar electron beam emission source can be obtained. , Its manufacture is very easy.

That is, conventionally, there existed field electron emission devices having sharpened emitter electrodes such as Spindt type and flat type, but they were produced by undergoing a complicated sharpening process. Further, since the formation density of the emitter electrode is limited by the resolution limit of the patterning and cannot be increased in density, it cannot be used as a planar electron emission source like the MIM type.

However, according to the field electron emission device of the present invention, it is possible to obtain the emitter electrode which is finely sharpened and integrated with high density as described above, only by the film forming step. Therefore, a complicated process for sharpening is unnecessary, and a high-resolution device may not be used. Therefore, it is possible to easily obtain the above-mentioned field electron emission device 1 having high electron emission efficiency.

Since the patterning resolution is not required as described above, a relatively low resolution used in the existing LCD (liquid crystal display) manufacturing process is not required even for a high resolution device used in the semiconductor manufacturing process. Can be used. Therefore, it is possible to manufacture a high-performance field electron emission device with a cheaper manufacturing facility.

Fourthly, since the columnar crystal 3 can be selectively formed only on the substance containing free electrons (the substrate 2 in the embodiment) by CVD, the patterning of the insulating layer 5 is performed. It is possible to form the emitter electrode in an arbitrary region on the substrate 2 only by changing Therefore, when a large number of field electron emission devices are integrated in an array on a single substrate, the manufacture thereof becomes easy.

In the first embodiment, the CVD is performed to deposit the columnar crystals 3 on the first conductive film, but the present invention is not limited to this.
For example, sputtering may be adopted instead of CVD.

Although the material containing β-W is used as the columnar crystal 3, the material is not limited as long as the columnar crystal 3 is obtained. For example, Al can be used as the material of the columnar crystals 3. Also in this case, CVD or sputtering can be adopted to deposit the columnar crystals.

Further, although the flow rate ratio of the reactive gas is set to 1: 1 in this embodiment, the flow rate ratio of the reactive gas may be arbitrarily set as long as a desired columnar crystal can be obtained. Also, the environmental temperature in the chamber can be changed.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The field electron emission device of the second embodiment is
As shown in FIG. 6, unlike the first embodiment, the base electrode 10 is provided on the substrate 2 '. That is, when an insulating material such as glass is used as the substrate 2 ', it is necessary to provide such a base electrode 10 as a base (conductor) in order to supply power to the columnar crystal aggregate 4. .

A method of manufacturing a field electron emission device including the base electrode 10 is shown in FIG. First, as shown in FIG. 7A, the base electrode 10 is formed on the substrate 2 '(eg, glass substrate).

The formation of this base electrode 10 is carried out by the above-mentioned substrate 2
After a metal such as Al or Cu is deposited on the surface of ′ by sputtering or the like, this metal film is formed into an arbitrary shape such as a square or a circle by etching. This makes the base electrode 1
You can get 0.

Then, as shown in FIGS. 7B to 7F, the electric field shown in FIG. 6 is obtained by going through the same manufacturing process as that of the first embodiment (FIGS. 3A to 3E). The electron-emitting device 1'can be obtained.

According to this structure, since the base electrode 10 and the columnar crystal aggregate 4 are electrically connected to each other, the space between the base electrode 10 and the conductive film 7 (electron extraction electrode) is increased. Electrons can be emitted from the upper ends of the columnar crystals 3 of the columnar crystal aggregate 4 by applying a potential difference to the columnar crystals.
Therefore, the same effect as that of the first embodiment can be obtained.

In the first and second embodiments described above, one field electron emission device has been described. However, when this field electron emission device is actually used, one field electron emission device such as a silicon wafer or a glass plate is used. A large number of field electron emission devices are integrated and used on a substrate. If necessary, the anode electrodes are arranged opposite to each other and used as a triode.

There are various possible uses for such an MIM type field electron emission device. For example, an example applied to a flat display device will be described as a third embodiment.

This flat display device is as shown in FIG. 8, and has an electron emission source 13 formed by integrating the electron emission elements 1 ′ of the second embodiment, and the electron emission source 13. The display unit 14 receives an electron and performs a light emission display.

The electron emission source 13 is manufactured as follows. First, the base electrode 11 formed on the substrate 2
Is divided into a number of strip-shaped base electrodes 11a adjacent to each other in the x direction by etching. This creates an address line.

Next, the insulating layer 5 is deposited on the substrate 2, and the through holes 10 are provided at predetermined intervals on each strip-shaped base electrode 11a. Thereafter, the above-mentioned CVD is applied to expose the base electrode 11a in the through hole 10.
The columnar crystal aggregate 4 is formed thereon.

As a result, the columnar crystal aggregates 4 functioning as the emitter electrodes are arranged in a matrix on the substrate 2. When CVD is used, the base electrode 1 described above is used.
The columnar crystal aggregate 4 is not formed in a portion where 1a is not exposed (a portion other than the through hole 10).

Next, by supplying a slight amount of oxygen into the chamber, an insulating film 6 (not shown in FIG. 8) made of a tungsten oxide film is formed on the surface of the columnar crystal aggregate 4. Next, a conductive film 7 is deposited over the surfaces of the insulating film 6 and the insulating layer 5, and then the conductive film 7 is etched or the like to form a large number of strip-shaped conductive films orthogonal to the base electrode 11a. Divide into membrane 7a. With this,
A tarline is created.

Through the above steps, the electron emission source 13 formed by integrating a large number of field electron emission devices 1'in a matrix.
Can be obtained. On the other hand, the display unit 14 includes a transparent substrate (quartz glass or the like) 15 and a transparent conductive film 16 (anodes) attached to the surface of the transparent substrate 15 on the electron emission source side.
Electrode) and the multicolor light emitting phosphor 17 attached to the surface of the transparent conductive film 16.

Here, as the transparent conductive film 16, for example, an ITO (Indium Tin Oxide) film is used. The ITO film is an indium oxide film doped with tin oxide and has conductivity and translucency.

The multicolor light emitting phosphor 17 is a phosphor for low acceleration electron beam, and ZnO: Zn is used, for example. The display portion 14 and the electron emission source 13 are joined to each other at an edge portion (not shown). This joining is performed using electrostatic joining in a vacuum atmosphere, for example, and
The space sandwiched between the electron emission source 13 and the electron emission source 13 is maintained in a vacuum.

In the flat panel display device thus constructed, each of the field electron emission devices 1'constitutes one pixel of the flat panel display device. In this flat display device, a method similar to that of an active matrix type liquid crystal display device using a TFT can be adopted as a driving method.

That is, the address lines formed by the base electrode 11a and the data lines formed by the conductive film 7a are driven by the drivers 18, 19 respectively.
It is connected to the.

Then, the drive drivers 18 and 19 are operated to select an arbitrary address line and a data line and apply a voltage to the field electron emission device 1'provided at the intersection of the lines. Emit an electron.

At this time, if a voltage higher than the voltage applied to the conductive film 7a is applied to the transparent conductive film 16 provided in the display section 14, the emitted electrons will be about 10 times.
0 percent It is attracted to the transparent conductive film 16 and collides with the phosphor 17 attached to the surface of the transparent conductive film 16. This allows the phosphor 17 to emit light.

According to such a flat display device, the following effects can be obtained. First,
It is possible to obtain a flat display device that works well even at a low operating voltage.

That is, the field electron emission device 1 of the present invention.
′ Is a planar electron beam emission source having a very high electron emission efficiency. Therefore, if the field emission devices are integrated at high density to form the electron emission source 13 of the flat display device, it is possible to obtain a flat display device that operates well even at a low operating voltage.

Further, in the present invention, as described above, the sharpened emitter electrode is obtained by utilizing the crystal shape of the columnar crystal aggregate 4, so that the emitter electrode is easy to form and the defect Also few. Therefore, it is also possible to improve the manufacturing yield of the flat panel display device.

Secondly, there is an effect that each pixel of the flat panel display device can be arranged very precisely. That is, in this flat display device, even if the field electron emission devices 1 ′ constituting each pixel are brought close to each other, the distance between the field electron emission devices 1 ′ is equal to the emitter electrode (the tip of the columnar crystal aggregate 4). There is no effect as long as it is slightly larger than the distance between the electron extraction electrodes (conductive film 7a).

In the case of the MIM type field emission device of the present invention, the emitter electrode (4) and the electron extraction electrode (7)
The distance a) is determined by the film thickness of the insulating film 6, and this film thickness is very thin, 100 angstroms or less. Moreover, since the tip of each emitter electrode is sharpened, the electric field concentration is very high.

Therefore, even if the distance between the field electron emission devices 1'is made extremely small and the pixels are densely arranged, and the address line and the data line are formed on the electron emission source 13 side as described above. Problems such as crosstalk do not occur.
Next, regarding the flat display device of the fourth embodiment,
This will be described with reference to FIG.

The flat panel display device of the fourth embodiment has a first field emission device as a field electron emission device used as an electron emission source.
In addition to using the field electron emission device 1 of the above embodiment, a data line is provided on the display section side.

That is, the electron emission source 13 'of this flat display device uses a conductive material (silicon wafer or the like) for the substrate 2. Then, an insulating layer 5 is provided on the substrate 2, and the through holes 10 are provided in the insulating layer 5 in a matrix shape. Then, a columnar column which acts as an emitter electrode is exposed on the surface of the substrate 2 in the through hole 10. Crystal aggregate 4 is C
The film is formed by VD.

Next, after the insulating film 6 made of a thermal oxide film is provided on the surface of the columnar crystal aggregate 4, the electron emission source 13 is formed.
The conductive film 7 is deposited over the entire surface of ′ ′. Then, the conductive film 7 is divided into a plurality of strip-shaped conductive films 7a 'by etching. This forms the address line.

That is, the conductive film 7a used as the data line in the third embodiment is used as the address line in this embodiment. On the other hand, as the display section 14 ', a transparent conductive film 16 made of ITO is deposited on the surface of the transparent substrate 15 made of quartz glass on the electron emission source 13' side. Then, the transparent conductive film 16 is divided into a plurality of strip-shaped transparent conductive films 16a orthogonal to the strip-shaped conductive film 7a 'of the electron emission source 13'. This forms a data line.

Then, a phosphor 17 capable of multicolor display is applied over the entire surface of the display portion. This completes the display unit 14 '. After that, as in the third embodiment, the display section 14 'and the electron emission source 13' are bonded to each other with a predetermined gap. This adhesion is performed, for example, by electrostatic bonding in a vacuum atmosphere.

As a result, the flat display device of the fourth embodiment is completed. In this flat display device, the driving drivers 18 and 1 are provided on the address line formed of the conductive film 7a 'of the electron emission source 13' and the data line formed of the transparent conductive film 16a of the display unit 14 ', respectively.
9 is connected and driven by the same method as that of a simple matrix type liquid crystal display device, for example.

At this time, if no voltage is applied to the substrate 2 and if the voltage is set to grand, electrons are emitted from any of the field electron emission devices 1 due to the voltage difference between the substrate 2 and the conductive film 7a. Will be. Further, the emitted electrons are attracted and converged to the data line (16a) to which a voltage is applied. As a result, the phosphor 17 at the desired position can be made to emit light, and the necessary display can be performed on the display unit 14 '.

According to this structure, substantially the same effect as in the third embodiment can be obtained, and in addition, the display section 1 can be obtained.
By providing the data line on the 4'side, the diverging electron beam can be converged, and the light emitting portion can be controlled more effectively.

Next, the flat display device of the fifth embodiment will be described with reference to FIG. The flat display device of the fifth embodiment uses the field electron emission device 1 of the first embodiment as the field electron emission device used for the electron emission source, similarly to the flat display device of the fourth embodiment. , A data line is provided on the display unit side.

However, the field electron emission element 1 provided in the flat display device 1 is the same as the insulating film 5 in the manufacturing process of the flat display device of the fourth embodiment.
The through-holes provided in are formed in a band shape instead of a circular shape. Therefore, as shown in FIG. 10, the field electron emission device 1 in this embodiment is formed linearly along the address line (conductive film 7a).

Even with such a structure, it is possible to obtain substantially the same effect as that of the fourth embodiment. The present invention is not limited to the first to fifth embodiments described above, and can be variously modified without changing the gist of the invention.

[0117]

As described above, the field electron emission device of the present invention is a MIM type (metal-insulating film-metal) field electron emission device using a columnar crystal aggregate as an emitter electrode. .

With such a structure, it is possible to provide a planar electron beam emission source which is easy to manufacture and has a high electron emission efficiency. Therefore, by integrating this field electron emission device to form a flat display device, it is possible to obtain a device capable of performing good display at a low operating voltage.

According to the method of manufacturing a field electron emission device of the present invention, the emitter electrode can be formed only by the film forming technique, and at the same time, the tip portion can be sharpened. Therefore, there is an effect that the above-described field electron emission device having high electron emission efficiency can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is likewise a process drawing showing a manufacturing process.

FIG. 4 is a schematic configuration diagram similarly showing an enlarged tip portion of an emitter electrode.

FIG. 5 is an explanatory diagram for explaining the degree of electric field concentration.

FIG. 6 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 7 is a process drawing that similarly shows the manufacturing process.

FIG. 8 is a flat display device showing a third embodiment of the present invention.

FIG. 9 is a flat panel display device showing a fourth embodiment of the present invention.

FIG. 10 is a flat display device showing a fifth embodiment of the present invention.

[Explanation of symbols]

1 (1 ') ... Field electron emission device, 2 ... Substrate (conductor),
2 '... Substrate, 3 ... Columnar crystal (emitter electrode), 4 ... Columnar crystal aggregate, 5 ... Insulating layer, 6 ... Insulating film, 7 ... Conductive film (electron extraction electrode), 7a ... Conductive film (data line) , 7a '
... conductive film (address line), 10 ... through hole, 11 ... base electrode (conductor), 13 ... electron emission source, 14 ... display part, 15 ... transparent substrate (transparent plate member), 16 ... transparent conductive film , 16a ... Transparent conductive film (data line), 17 ... Phosphor.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 1/312 H01J 1/30 H01J 9/02 H01J 17/49 H01J 31/12

Claims (15)

(57) [Claims] 1. An emitter electrode that emits electrons based on a quantum mechanical tunneling phenomenon when an electric field is applied, an insulating film laminated on the emitter electrode, and an electric field is applied to the emitter electrode laminated on the insulating film. in field electron emission device and an electron extraction electrode, the emitter electrode Ri columnar crystal aggregate der comprising a plurality of columnar crystals formed on a surface of the conductor, the columnar crystals collection
Each columnar crystal of the coalesced has a sharpened tip.
Electrons are emitted from the insulating film , and the insulating film has a sharpened tip portion of each columnar crystal.
The electron extraction electrode is formed with a substantially uniform thickness on the surface,
The conductive film is applied to the surface of this insulating film with a substantially uniform thickness.
A field electron emission device characterized by being a film . 2. The field electron emission device according to claim 1, wherein the columnar crystal aggregate is formed on a surface of a conductor by CVD (Chemica).
A field electron emission device characterized in that it is formed by means of vapor deposition). 3. The field electron emission device according to claim 2, wherein the columnar crystal contains β-tungsten (W). 4. The field electron emission device according to claim 1 , wherein an insulating layer is provided on a surface of the conductor, and a through hole exposing the surface of the conductor is provided in the insulating layer, A field electron emission device, wherein the columnar crystal aggregate is formed on the surface of a conductor exposed in the through hole. 5. A field electron emission device according to claim 1, further comprising an anode electrode for receiving electrons emitted from the emitter electrode. 6. The field electron emission device according to claim 5, wherein the anode electrode has a transparent conductive film, and an electron emitted from the emitter electrode is provided on a surface of the transparent conductive film on the electron extraction electrode side. A field electron emission device, comprising a phosphor that emits light upon receiving. 7. The method of claim 1, <br/> electron emission source characterized by comprising by integrating field emission device according to claim 4 or claim 5. 8. An electron emission source in which the field electron emission device according to claim 1 or 4 is arranged in a matrix on a substrate, and the electron emission source is arranged so as to face the electron emission source and is emitted from the electron emission source. A flat display device, comprising: a display unit that emits light by receiving the generated electrons. 9. The flat display device according to claim 8, wherein the display section includes a transparent plate member, a transparent conductive film provided on a surface of the transparent plate member facing the electron emission source side, and the transparent conductive film. A flat display device comprising: a phosphor provided on a conductive film. 10. The flat display device according to claim 9, wherein the electron emission source divides the conductor into a plurality of strips, and divides the electron extraction electrode into a plurality of strips orthogonal to the conductor. By using one of the conductor and the strip-shaped electron extraction electrode as an address line and the other as a data line,
A flat panel display device characterized in that electrons are emitted from an emitter electrode provided at a position where the two intersect. 11. The flat display device according to claim 9, wherein the transparent conductive film is divided into a plurality of strips, and a voltage applied to each strip of the transparent conductive film is controlled to control a light emission range. And a flat display device. 12. An emitter electrode which emits electrons based on a quantum mechanical tunneling effect when an electric field is applied, an insulating film laminated on the emitter electrode, and an electron which is laminated on the insulating film and gives an electric field to the emitter electrode. In a method of manufacturing a field electron emission device including an extraction electrode, a step of forming a columnar crystal aggregate on a conductor and forming an emitter electrode made of a columnar crystal having a needle-like sharpened tip. An insulating film is formed on the sharpened surface of each columnar crystal.
It has a step of forming a substantially uniform thickness and a step of forming a conductive film deposited on the surface of the insulating film with a substantially uniform thickness to form an electron extraction electrode. Method for manufacturing field electron emission device. 13. An emitter electrode which emits electrons based on a quantum mechanical tunneling effect when an electric field is applied, an insulating film laminated on the emitter electrode, and an electron which is laminated on the insulating film and gives an electric field to the emitter electrode. In a method of manufacturing a field electron emission device including an extraction electrode, a step of forming an insulating layer on the surface of a conductor, and a through hole that exposes the surface of the conductor by removing a predetermined portion of the insulating layer. forming, forming an emitter electrode made of the deposited columnar crystals aggregate to the surface of the exposed conductive material in the through hole, columnar crystals tip is sharpened to a needle-shaped, each An insulating film is formed on the surface of the sharpened tip of the columnar crystal.
A step of forming a substantially uniform thickness, and a step of depositing a conductive film on the surface of the insulating film with a substantially uniform thickness to form an electron extraction electrode. A method of manufacturing a characteristic field electron emission device. 14. The method of manufacturing a field electron emission device according to claim 12 or 13 , wherein the step of forming the emitter electrode includes the step of forming the emitter-containing member in a reaction chamber.
The temperature is kept at 0 ° C. to 500 ° C., and two kinds of reaction gases, WF ₆ and SiH ₄ , are introduced into the chamber and reacted to form a columnar crystal aggregate containing β-W on the surface of the conductor. And a method for manufacturing a field electron emission device. 15. The method of manufacturing a field electron emission device according to claim 14 , wherein in the step of forming an insulating film on the surface of the columnar crystal aggregate, oxygen gas is introduced into a reaction chamber to form the columnar crystal aggregate. A method of manufacturing a field electron emission device, which comprises forming an insulating metal oxide film on the surface of.