JPH0817365A - Field emission device and its manufacture - Google Patents

Abstract

PURPOSE:To avoid limiting temperature during degassing without breaking an electron emitting portion by opposing a cathode plate and an anode plate to each other with metallic spacers between them. CONSTITUTION:Metallic spacers 7 are provided on a cathode plate 1 and at a fixed distance and parallel to gate electrodes 3. The plate 1 is bonded to an opposite plate 8. Insulating spacers 9 are arranged on the plate 8 and between lines where emitter electrodes 2 on the plate 1 are formed, and anodes 10 are arranged on the electrodes 3 of the plate 1. A low melting point glass is usable for the insulating spacers. An organic material such as polyimide may be used if a degassing process at relatively low temperatures is sufficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission device and a method for manufacturing the same. More specifically, the present invention relates to a field emission device used for a high speed arithmetic device, a flat panel display, etc. and a method for manufacturing the same.

[0002]

2. Description of the Related Art An example of the structure of a field emission cathode is shown in FIGS. The field emission cathode of FIG. 9 is formed of a substrate 102 having an emitter electrode 101 laminated thereon, an insulating film 103 and a gate electrode 104 formed on the emitter electrode 101, and an insulating film 103 and a gate electrode 104. It is composed of a conical or wedge-shaped electron emitting portion (emitter tip) 105 existing in the opening (hereinafter referred to as a vertical field emission cathode). On the other hand, the field emission cathode of FIG. 10 is formed by planarly forming the emitter electrode 101, the gate electrode 104, and the electron emission portion 105 on the substrate 102,
The gate electrode 104 has a structure in which an apex portion of the electron emission portion 105 exists near the gap (hereinafter referred to as a planar field emission cathode).

FIG. 11 shows a schematic structure of a flat panel display, and the field emission cathode shown in FIGS. 9 and 10 is the entire surface of a substrate (hereinafter referred to as a cathode plate 106) as shown in FIG. Many are located in. The emitter electrode 108 and the gate electrode 107 are divided into a plurality of lines so as to be substantially orthogonal to each other with the insulating film 109 interposed therebetween, forming a matrix structure. In addition, the emitter electrode 10
A pair of field emission cathodes 110 at each intersection of 8 and the gate electrode 107 correspond to the pixel 111. The cathode plate 106 is arranged so as to face a substrate (hereinafter referred to as an anode plate 113) in which a phosphor 112 is applied on an electrode (anode electrode) on the substrate, and a high vacuum is maintained between the substrates. .

The operation of this display is performed as follows, for example. A gate line of the pixel 111 to be displayed is determined by inputting a positive address signal to a desired one of the gate electrodes 107, and the emitter electrode 1 of each pixel 111 is determined.
A signal negative voltage corresponding to the luminance is applied to 08. By cyclically performing such an operation on all the gate electrodes 107, an appropriate image can be displayed.

Generally, the distance between the anode plate and the cathode plate of a flat panel display is several tens to several hundreds of μm. Further, in the display, a spacer is usually inserted between the substrates in order to prevent a short circuit due to the contact between the anode plate and the cathode plate due to the warp of the substrate caused by the pressure difference between the inside and the outside. 12 and 13 show a conventional spacer example. In FIG. 12, the anode plate 1 is provided through the outer frame 114.
Glass beads 115 are used as spacers in the gap formed by 13 and the cathode plate 106 (I
DEM-91, (1991) p.197). On the other hand, in FIG. 13, several tens μm × several tens μm × several tens of μm formed by exposing a photosensitive resin applied to the cathode plate 106 on which the electron emitting portion 105, the gate electrode 117 and the emitter electrode 108 are formed. A rectangular parallelepiped is used as the spacer 116 (IEEE Trans. Electron Device Div.
ces, 36 (1989) p.225).

FIG. 14 shows a conventional example of a color flat panel display. According to FIG. 14, each pixel has an anode electrode 117 which is divided by coating blue, green, and red phosphors 118. When displaying a blue signal here, the blue anode electrode 117 can be selectively irradiated with an electron beam by setting the blue anode electrode 117 to be positive and the remaining two anode electrodes 117 to be negative. Bleeding can be prevented (in the figure, the arrow shows the flow of electrons).

[0007]

As shown in FIG. 12, when glass beads are used as a spacer, the spacer moves between the cathode plate and the anode plate when the spacer is not firmly fixed, and the electron emitting portion on the cathode plate side. Sometimes it comes to the top. In such a case, the spacer may destroy the electron emission portion, a short circuit may occur between the gate and the emitter at the destroyed portion, and the pixel or one line including the pixel does not emit light and becomes a defect. It will be.

On the other hand, when the spacer is formed by using the photosensitive resin as shown in FIG. 13, the above problem does not occur, but the adsorbed gas generated between the sealed substrates is degassed. Since the temperature cannot be raised, the deterioration of the characteristics due to the adsorbed gas cannot be avoided. In addition, since the interval in the display is as thin as several tens to several hundreds μm, the conductance is poor. Further, since the conventional getter for adsorbed gas is installed at the end of the display, there is a problem that degassing cannot be performed sufficiently. Therefore, it is desired to uniformly arrange the getters in the display in order to efficiently perform degassing.

[0009]

Thus, according to the present invention, the cathode plate having the field emission cathode composed of the electron emitting portion, the gate electrode and the emitter electrode and the anode plate having the anode electrode are opposed to each other via the metal spacer. A field emission device is provided.

Further, according to the present invention, after the spacer forming electrode is formed on the cathode plate having the field emission cathode composed of the electron emitting portion, the gate electrode and the emitter electrode,
There is provided a method for manufacturing a field emission device, which is characterized in that a metal spacer is formed on this electrode by a plating method. The substrate used in the present invention is not particularly limited,
Silicon substrates are preferred.

The field emission cathode of the present invention comprises an electron emission portion, a gate electrode and an emitter electrode. For example, both vertical and horizontal field emission cathodes shown in FIGS. 9 and 10 can be used. The electron emitting portion can be formed by vapor deposition or etching. The material of the gate electrode that can be used in the present invention is not particularly limited, and is made of molybdenum, chromium, tantalum, molybdenum silicide, or the like, and has a film thickness of 0.
It is set to about 2 to 0.4 μm. Further, it is preferable that the height of the gate electrode is about the height of the electron emitting portion because the electric field is well concentrated. The material of the emitter electrode can be the same as that of the gate electrode when it is formed by vapor deposition, and the semiconductor crystal can be used when it is formed by etching. It is preferable to use silicon among the semiconductor crystals from the viewpoint of ease of manufacturing.

A plurality of the above field emission cathodes are formed in a matrix on the anode plate, and a set of pixels composed of a plurality of field emission cathodes is formed at the intersection of the gate electrode and the emitter electrode. It This pixel is arranged so as to correspond to each dye formed on the anode electrode on the opposite anode plate side, and if a voltage is applied to the electrode, light emission of a desired color can be obtained.

Next, the metal spacer provided between the cathode plate and the anode plate, which is a feature of the present invention, is formed on the spacer forming electrode formed on the cathode plate by the plating means. The material that can be used for the spacer forming electrode is not particularly limited as long as it can be formed by vapor deposition and the like, and examples thereof include molybdenum, chromium, tantalum, molybdenum silicide and the like. Further, the spacer forming electrode may be arranged in parallel with the gate electrode or the emitter electrode. Further, if the pixels are arranged on the gate electrode so as not to be blocked, it is not necessary to provide a region for forming the spacer forming electrode, and accordingly the field emission cathodes for display can be arranged at high density.

On the other hand, the height of the metal spacer is tens to hundreds of μm. The material that can be used for the metal spacer is not particularly limited as long as it can be formed by a plating means, but a chemically base material such as molybdenum or iron is preferable because it can be used as a getter. At this time, if the metal spacer is porous, the surface area can be increased and the gettering ability is further improved, which is preferable. The plateable metal has a lower ability than titanium, zirconium, etc., which have been conventionally used as getters, but it can be uniformly arranged between narrow substrates of several tens to several hundreds μm. The capacity is better than before. Furthermore, although titanium, zirconium, etc. cannot be currently plated, if they can be plated in the future and can be used as a spacer, a higher getter ability can be obtained.

The same material as the cathode plate can be used for the opposing anode plates. Striped anode electrodes are formed on the anode plate. A transparent electrode material such as ITO or NESA is generally used for the anode electrode. The anode electrode is arranged in parallel with the gate electrode or the emitter electrode. It should be noted that when the cathode plate and the anode plate are opposed to each other, an insulating film may be interposed so that the metal spacer and the anode electrode are not electrically connected, and further, a desired phosphor may be applied to the anode electrode.

The above-described method for manufacturing a field emission device of the present invention is characterized in that a metal spacer is formed on the spacer-forming electrode by plating. Hereinafter, the method for manufacturing the field emission device of the present invention will be described by taking the vertical field emission device as an example. FIG. 2 is a schematic view of a method for manufacturing a field emission device formed by etching as disclosed in JP-A-4-94033.

First, an insulating film of silicon oxide or the like, which is difficult to be etched at the time of etching a subsequent semiconductor layer, is formed on a semiconductor layer made of silicon or the like which is a surface layer of a substrate and a photoresist process is performed. As a result, an etching resistant film made of an insulating film is formed on the electron emitting portion forming region and the spacer forming electrode forming region on the semiconductor layer. At this time, although not clearly shown in the drawing, the respective emitter electrodes are electrically separated by the substrate by the method described in JP-A-4-246662.

Next, the semiconductor layer is etched through the etching resistant film. The etching method is not particularly limited as long as it is isotropic, but reactive ion etching (R
IE) method, wet etching method and the like. Next, the entire surface is subjected to an oxidation treatment to oxidize the surface layer of the etched semiconductor layer to form an electron emitting portion having a sharp tip inside. Next, a conductive layer and an insulating film are formed on the etching resistant film and the oxide film. The spacer forming electrode and the gate electrode are formed by depositing.

Next, the oxide film is removed by a lift-off process to expose the electron emitting portion. At this time, since the insulating film under the spacer forming electrode has a sufficient width, it is not removed by the lift-off process. In the above etching resistant film forming step, if an etching resistant film that can be removed in a later lift-off step and has a width sufficiently smaller than the electron emitting portion forming area is formed along the spacer forming electrode forming area, It is more preferable because it is possible to prevent an abnormal discharge portion due to a protrusion that unexpectedly occurs on the electrode or the emitter electrode. If the cathode plate is manufactured in this way,
The spacer forming electrode can also be formed without increasing the number of steps.

Next, a mask having an opening is formed on the spacer forming electrode, then a plating process is performed through the mask to form a metal spacer on the spacer forming electrode, and the gate electrode is optionally patterned. As a result, the cathode plate is formed. A known method can be used as the plating method, and examples thereof include electrolytic plating and electroless plating. Further, the control of the film thickness of the metal spacer in the plating process can be easily controlled by the amount of electricity that has passed through the spacer forming electrode.

After that, the field emission device of the present invention can be obtained by making the anode plate, on which the anode electrode and optionally the insulating film are provided, face the cathode plate by a known method. Further, an insulating spacer for insulating the metal spacer may be provided on the anode electrode. The method for manufacturing the field emission device of the present invention is not limited to the above method. For example, in the method of forming a metal spacer, a method of forming a spacer forming electrode on a cathode plate on which a vertical or horizontal field emission cathode is formed in advance by a known method, and forming a metal spacer on the spacer forming electrode. Can also be used. Further, any method of forming the field emission cathode can also be used, such as vapor deposition or etching.

In the above description, the metal spacer is arranged on the cathode plate side, but it is naturally possible to arrange the metal spacer on the anode plate side.

[0023]

In the field emission device of the present invention, a cathode plate having a field emission cathode composed of an electron emission portion, a gate electrode and an emitter electrode and an anode plate having an anode electrode are opposed to each other with a metal spacer interposed therebetween, Since the spacer that defines the distance between the plate and the anode plate is made of a metal spacer, the electron emission portion is not destroyed unlike the conventional glass bead spacer, and degassing at a higher temperature than that of the resin spacer is possible.

Next, in the field emission device, a cathode plate having a field emission cathode composed of an electron emission portion, a gate electrode and an emitter electrode and an anode plate having an anode electrode are arranged to face each other via a spacer. Since the spacer is a superposed body of the metal spacer formed on the cathode plate and the insulating spacer formed on the anode plate, the metal spacer is easily insulated.

When the metal spacer is a metal having a getter function such as chromium, molybdenum or iron, the gas existing between the substrates can be adsorbed. Further, the anode electrode is divided into a plurality of comb-shaped thin wires, a shield electrode to which a negative potential is applied from the anode electrode is arranged between the thin wires, and a metal spacer is provided facing the shield. Color fringing is prevented.
Further, by applying the getter material on the shield electrode, the gas adsorption capacity of the device is enhanced.

Next, a spacer forming electrode is formed on a cathode plate having a field emission cathode composed of an electron emitting portion, a gate electrode and an emitter electrode, and then a metal spacer is formed on this electrode by a plating method. According to the method of manufacturing a field emission device as described above, a field emission device having a metal spacer can be easily manufactured. Further, the gate electrode is also used as the spacer forming electrode, and the metal spacer is formed on this electrode by the plating method, so that the region for forming the plating forming electrode is omitted.

Next, the cathode plate is formed with a semiconductor layer serving as an emitter electrode on the surface layer of the substrate, and an etching resistant film is formed on a region of the semiconductor layer where an electron emitting portion and a spacer forming electrode are formed. An oxide film is formed by etching the semiconductor layer through the etching resistant film and then oxidizing the surface layer of the etched semiconductor layer, and the insulating film and the conductive layer are formed on the etching resistant film and the oxide film. Since it is formed by the step of forming the spacer forming electrode and the gate electrode by depositing and the step of removing the oxide film by the lift-off process to expose the electron emitting portion,
The spacer forming electrode is formed without increasing the number of steps.

Further, since the etching resistant films for forming the adjacent plating spacer forming electrodes are connected to each other, the spacer forming electrodes are connected and a voltage can be applied during the plating process. A metal spacer is easily formed. Next, etching resistant films for forming adjacent plating spacer forming electrodes are connected to each other at both ends, and by having a step of forming gate electrodes in a self-aligned manner using the etching resistant films, The step of patterning the gate electrode is omitted.

Further, when forming the etching resistant film, there is a step of forming a plurality of narrow enclosures surrounding the gate electrode to form the gate electrode in a self-aligned manner. Field emission due to protrusions that are unexpectedly formed on the electrodes is prevented.

[0030]

【Example】

Example 1 FIG. 2 illustrates a method for manufacturing a cathode plate of a field emission device according to the present invention.
Further description will be given based on (a) to (f). The manufacturing method of the field emission cathode is mainly described in JP-A-4-94033 and JP-A-494033.
According to the method described in Japanese Patent Publication No. 246662.

First, a semiconductor layer to be an emitter electrode is formed on the surface layer of a silicon substrate. Next, the semiconductor layer is subjected to oxidation treatment to form a silicon oxide film. Then, a resist is applied, exposed, and developed to form a circle (diameter of 1 to several μm) on the electron emission portion forming region 12 and a strip (width of 10 to several tens of μm) on the spacer forming electrode forming region 13. μm) -shaped resist mask is formed.
Further, using this resist mask, etching is performed to leave the silicon oxide film 14 only on the electron emission portion forming region 12 and the spacer forming electrode forming region 13 (FIG. 2).
(See (a)). The silicon oxide film 14 functions as an etching resistant film in a later etching process.
When an element that enables matrix driving is created, the lines of the emitter electrodes are separated by diffusing impurities in advance. In FIG. 2, for simplicity, the state in which the emitter electrode layers are separated is omitted. Here, the silicon oxide film formed by oxidizing the substrate is used as the etching resistant film, but it can be formed by the CVD method, and not only the silicon oxide film but also a silicon nitride film or the like is used. be able to.

Next, the substrate is etched by the RIE method using the silicon oxide film 14 as an etching resistant film (FIG. 2).
(B)). At this time, the etching is completed before the silicon oxide film 14 formed on the electron emission portion forming region 12 is removed. Note that wet etching can also be used as another etching method. Next, the entire surface is subjected to an oxidation treatment to oxidize the exposed region of the substrate to sharpen the electron emitting portion 4 (see FIG. 2C).

Next, the gate electrode 3 and the spacer forming electrode 6 are simultaneously formed by stacking an insulating film 15 made of silicon oxide and a conductive film such as chromium on the entire surface by vacuum evaporation (see FIG. 2D). ). Next, the insulating film 15 around the electron emitting portion 4 is removed by wet etching by lift-off to expose the electron emitting portion 4. here,
A hydrofluoric acid buffer solution or the like can be used as the etchant. The insulating film under the spacer forming electrode 6 has a sufficiently wide width and is not removed (FIG. 2 (e)).
reference).

Further, a region other than the spacer forming electrode 6 is covered with a photoresist having a film thickness of about several tens of μm, and the spacer forming electrode 6 is immersed in an electrolytic plating solution while applying a negative potential to the plating treatment. Then, a metal spacer 7 made of nickel or the like is formed on the spacer forming electrode 6.
To form. Further, the gate electrode 3 is also patterned (see FIG. 2 (f)). I did electrolytic plating here,
Other plating methods such as electroless plating can also be used. In this way, the cathode plate is formed.

On the other hand, an insulating spacer made of resin is provided on the anode plate so as to be substantially perpendicular to the gate electrode, and a line having a height of several tens to several hundreds of μm and a width of several to 100 μm is formed using a thick film printing technique or the like. To form. Next, the field emission device of the present invention is obtained by making the cathode plate and the anode plate face each other.

In the field emission device obtained by the above manufacturing method, it is possible to prevent the electron emission portion from being destroyed because the spacer is fixed on the substrate. Fig.3 (a)-
2D shows the pattern of the silicon oxide film 14 shown in FIG. 2A as viewed from above. In FIG. 3A, the silicon oxide film 14 used for forming the spacer forming electrode 6 is separated. In this case, it is troublesome to supply power to each spacer forming electrode 6 in the same manner during the plating process, and thus it is difficult to control the film thickness, but it is preferable to perform electroless plating.

In FIG. 3B, the exposure is performed so that the silicon oxide film 14 is left so as to surround the portion to be the gate electrode 3 and the spacer forming electrode 6 is electrically connected. In this case, since the portion to be the gate electrode 3 is formed in a self-aligned manner by the process of FIG. 2, the patterning process of the gate electrode 3 can be omitted. In FIG.
This is a case where a plurality of thin enclosures made of a silicon oxide film having a width of about 1 μm are arranged between the gate electrode 3 and the spacer forming electrode 6 in (b). 3D is shown in FIG.
It is sectional drawing at the time of the completion of the element of the AA line of (c). As can be seen from FIG. 3D, the gap of several μm or more can be surely secured between the gate electrode 3 and the spacer forming electrode 6, so that the gate electrode 3 and the spacer forming electrode 6 were unexpectedly formed. It is possible to prevent field emission due to the protrusions. Further, since the metal spacer is uniformly arranged between the anode plate and the cathode plate, a getter effect can be expected by plating a chemically base metal such as molybdenum, chromium or iron.

Example 2 As a pattern for forming a metal spacer, for example, as shown in FIG.
The configurations illustrated in FIGS. 4A and 4B can be used, but are not limited thereto. The figure will be briefly described below. In FIG. 1, 1 is a cathode plate, 2 is an emitter electrode, 3 is a gate electrode, 4 is an electron emitting portion, 5 is a pixel, 6 is a spacer forming electrode, 7 is a metal spacer, 8 is an anode plate, and 9 is an insulating spacer. Reference numerals 10 and 10 denote anode electrodes, respectively.

In FIG. 1, a metal spacer 7 is provided on the cathode plate 1 in parallel with the gate electrode 3 at a constant distance. The cathode plate 1 is attached so as to face the anode plate 8. An insulating spacer 9 is arranged on the anode plate 8 between the lines on the cathode plate 1 where the emitter electrode 2 is formed, and an anode electrode 10 is arranged on the gate electrode 3 of the cathode plate 1. There is. Low melting point glass can be used for the insulating spacer. Further, an organic material such as polyimide may be used as long as the degassing process is performed at a relatively low temperature.

When the present invention is used as a display device, a phosphor is coated on the anode electrode 10. However, in order to improve the display contrast ratio, a reflective film such as carbon is formed between the anode electrodes 10 to form an outer layer. You may suppress reflection of light. Next, FIGS. 4A and 4B are a plan view and a perspective view of the metal spacer. In the configuration as shown in these figures, a line where the gate electrode 3 is formed and a line where the metal spacer 7 is formed are shown. Are common, and the number of emitters can be increased as much as the region for forming the spacer forming electrode 6 can be omitted, so that the burden on the electron emitting portion can be reduced and the image resolution can be improved, which is preferable. .
The configuration of FIG. 4A is a configuration in which the line other than the pixel 5 formed by the field emission portion 4 on which the gate electrode is formed is covered with the metal spacer 7, and the configuration of FIG. The structure is shown in which the island-shaped metal spacers 7 are provided on the line where the gate electrodes 3 are formed and between the adjacent pixels 5.

By applying a voltage to the metal spacer, it can also be used as a lens electrode (see FIG. 5A) and a deflection electrode (see FIG. 5B).
The arrows in the figure indicate the flow of electrons. In the conventional field emission device, the lens electrode and the deflection electrode are used also as the gate electrode as described in JP-A-5-313600, but it is necessary to drive them by pulse or AC voltage in order to use them as a gate electrode. Power consumption is required for charging and discharging due to the parasitic capacitance between the emitter electrode and the emitter electrode.
However, in the present invention, since it is not used for both purposes, a DC voltage can be applied to the metal spacer, and low power consumption can be achieved.

Example 3 As the combination pattern of the anode electrode and the metal spacer, for example, the constitutions shown in FIGS. 6 and 7 can be used, but the present invention is not limited thereto. The figure will be briefly described below. First, as shown in FIG. 6A, the anode electrodes 10 may be arranged in strips, and the shield electrodes 11 in strips may be commonly connected between them. With such a structure, leakage of electrons between the anode electrodes 10 can be prevented. Also,
Since the anode electrode 10 and the shield electrode 11 can have a comb-shaped electrode structure facing each other, it is easy to supply power to each electrode. The anode electrode 10 and the shield electrode 1
Reference numeral 1 is parallel to either the gate electrode 3 or the emitter electrode 2, and the anode electrode 10 is formed on the gate electrode 3 or the emitter electrode 2 and the shield electrode 11 is formed on the metal spacer 7.

The structure of FIG. 6A has the following advantages. That is, when a potential larger than the gate electrode is applied to the anode electrode 10 and a potential lower than the gate electrode is applied to the shield electrode 11 and the metal spacer 7, the deflection effect by the metal spacer 7 and the shield electrode 11 as shown in FIG. Due to the synergistic effect of the convergence effect, a negative potential wall is formed in the space between the metal spacer 7 and the shield electrode 11,
The electron beam (arrow in the figure) can be concentrated on the anode electrode 10 as compared with the case where the metal spacer 7 is not provided (see FIG. 6C). Therefore, the wall of negative potential between the metal spacer 7 and the shield electrode 11 makes it possible to loosen the overlay accuracy of the anode plate and the cathode plate. Further, since DC voltage can be applied to the anode electrode and the shield electrode, it is not necessary to swing the anode potential by AC or the like, and the circuit configuration is simple and the power consumption can be reduced. When a color display is performed, color bleeding can be prevented by separately applying a phosphor to each anode electrode. The dotted line in the figure shows the potential distribution when the metal spacer 7 and the shield electrode 11 have the same potential.
Further, since the shield electrode is negatively applied and is not irradiated with the electron beam, if a getter material or the like is applied to the shield electrode, degassing due to electron beam irradiation can be avoided, and high gas adsorption capacity can be expected. .

Further, as shown in FIG. 7, the insulating spacer in the field emission device of FIG. 1 can be omitted. In this figure, the anode electrode 10 and the metal spacer 7 have the same potential. When manufacturing a color display with such a configuration, the RGB phosphors are separately coated so as to be parallel to the gate electrode, and the metal spacer serves to prevent color fringing. It is also possible to combine the configuration of FIG. 7 with the configuration of FIG. 4 and / or FIG.

Example 4 FIGS. 8A to 8F use the pattern of the silicon oxide film 14 formed in FIG. 2 (see FIG. 2A) and have a width of 10 μm around the electron emission portion. This is an embodiment in which an enclosure that does not separate the inside and the outside is formed to some extent. In this case, the width of the enclosure is sufficiently larger than the etching amount in the lift-off step in FIG. 2E, so that the fuse 16 can be formed at the boundary between the inside and the outside and the silicon oxide film 1 can be formed.
4, the insulating film 15 and the spacer forming electrode 6 remain,
As shown in FIG. 8B, an enclosure having a height of several μm is formed.

The enclosure shown in FIG. 8 (b) does not attract particles larger than the enclosure size to the electron emitting portion.
This is effective in preventing short circuit due to particles as in (c) and (d). In addition to FIG.
Various patterns such as (e) and (f) are possible. FIG. 8F shows an embodiment in which circular patterns having a diameter of about 10 μm are mixed in the array. In this embodiment, FIG.
It is possible to prevent a short circuit due to finer particles than those in (a) and (e).

The metal spacers can be formed not only by plating treatment but also by thin film such as vapor deposition or printing method. In this case, the spacer forming electrode can be omitted.

[0048]

The field emission device of the present invention comprises an electron emission portion,
Since the cathode plate having the field emission cathode composed of the gate electrode and the emitter electrode and the anode plate having the anode electrode are opposed to each other through the metal spacer, the electron emitting portion is not destroyed unlike the conventional glass bead spacer. The temperature is not limited during degassing like a resin spacer.

Next, in the field emission device, a cathode plate having a field emission cathode composed of an electron emission portion, a gate electrode and an emitter electrode and an anode plate having an anode electrode are arranged to face each other with a spacer interposed therebetween. Since the spacer is composed of a metal spacer formed on the cathode plate and an insulating spacer formed on the anode plate, the metal spacer can be easily insulated.

Further, when the metal spacer is made of a metal having a getter function such as chromium, molybdenum or iron, the gas existing between the substrates can be adsorbed. Further, the anode electrode is divided into a plurality of comb-shaped thin wires, a shield electrode to which a negative potential is applied from the anode electrode is arranged between the thin wires, and a metal spacer is provided facing the shield. Color fringing can be prevented.

Next, a spacer forming electrode is formed on a cathode plate having a field emission cathode composed of an electron emitting portion, a gate electrode and an emitter electrode, and then a metal spacer is formed on this electrode by a plating method. According to the method of manufacturing a field emission device as described above, a field emission device having a metal spacer can be easily manufactured. Further, the gate electrode is also used as the spacer forming electrode, and the metal spacer is formed on this electrode by the plating method, whereby the region for forming the plating forming electrode can be omitted.

Next, the cathode plate is formed with a semiconductor layer serving as an emitter electrode on the surface layer of the substrate, and an etching resistant film is formed on a region of the semiconductor layer where an electron emitting portion and a spacer forming electrode are formed. An oxide film is formed by etching the semiconductor layer through the etching resistant film and then oxidizing the surface layer of the etched semiconductor layer, and the insulating film and the conductive layer are formed on the etching resistant film and the oxide film. Since it is formed by the step of forming the spacer forming electrode and the gate electrode by depositing and the step of removing the oxide film by the lift-off process to expose the electron emitting portion,
The spacer forming electrode can be formed without increasing the number of steps.

Further, since the etching resistant films for forming the adjacent plating spacer forming electrodes are connected to each other, the spacer forming electrodes are connected and a voltage can be applied during the plating process. The metal spacer can be easily formed. Next, etching resistant films for forming adjacent plating spacer forming electrodes are connected to each other at both ends, and by having a step of forming gate electrodes in a self-aligned manner using the etching resistant films, The step of patterning the gate electrode can be omitted.

Further, when forming the etching resistant film, there is a step of forming multiple narrow enclosures surrounding the gate electrode to form the gate electrode in a self-aligned manner. It is possible to prevent field emission due to protrusions that are unexpectedly formed on the electrodes.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a field emission device of the present invention.

FIG. 2 is an example of a manufacturing process of the field emission device of the present invention.

FIG. 3 is a schematic plan view of an etching resistant film when forming a spacer forming electrode of the present invention.

FIG. 4 is a schematic plan view and a schematic perspective view of a metal spacer of the present invention.

FIG. 5 is a schematic diagram for explaining a flow of electrons when a voltage is applied to the metal spacer of the present invention.

FIG. 6 is a schematic diagram for explaining a structure of an anode plate that can be used in the field emission device of the present invention and a flow of electrons by the substrate.

FIG. 7 is a schematic perspective view of a field emission device of the present invention.

FIG. 8 is a schematic diagram showing a specific example of a pattern of an etching resistant film.

FIG. 9 is a schematic sectional view of a vertical field emission cathode.

FIG. 10 is a schematic sectional view of a horizontal field emission cathode.

FIG. 11 is a schematic perspective view of a conventional field emission device.

FIG. 12 is a schematic cross-sectional view of a conventional field emission device.

FIG. 13 is a schematic perspective view of a conventional field emission device.

FIG. 14 is a schematic diagram for explaining a flow of electrons in a conventional field emission device.

[Explanation of symbols]

 1 Cathode Plate 2 Emitter Electrode 3 Gate Electrode 4 Electron Emitting Part 5 Pixel 6 Spacer Forming Electrode 7 Metal Spacer 8 Anode Plate 9 Insulating Spacer 10 Anode Electrode 11 Shield Electrode 12 Field Emission Cathode Forming Region 13 Spacer Forming Electrode Forming Region 14 Oxidation Silicon film 15 Insulation film 16 Fuse 17 Particle 101 Cathode electrode 102 Substrate 103 Insulation film 104 Gate electrode 105 Electron emission part 106 Cathode plate 107 Gate electrode 108 Emitter electrode 109 Insulation film 110 Field emission cathode 111 Pixel 112 Phosphor 113 113 Anode plate 114 Outside Frame 115 Glass beads 116 Spacer 117 Anode electrode 118 Phosphor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H01J 29/94 31/15 C (72) Inventor Tadashi Nakatani 1015 Kamitadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Inventor Osamu Toyoda 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Within Fujitsu Limited

Claims (10)

[Claims] 1. A field emission device characterized in that a cathode plate having a field emission cathode composed of an electron emission portion, a gate electrode and an emitter electrode and an anode plate having an anode electrode are opposed to each other with a metal spacer interposed therebetween. . 2. A field emission device in which a cathode plate having a field emission cathode composed of an electron emission portion, a gate electrode and an emitter electrode and an anode plate having an anode electrode are arranged to face each other via a spacer, and the spacer is a cathode plate. A field emission device comprising a superposed body of a metal spacer formed on the anode plate and an insulating spacer formed on the anode plate. 3. The field emission device according to claim 1, wherein the metal spacer is made of a metal having a getter function. 4. The anode electrode is divided into a plurality of comb-shaped thin wires, a shield electrode to which a negative potential is applied from the anode electrode is arranged between the thin wires, and a metal spacer is provided facing the shield. The field emission device according to claim 2. 5. A cathode plate having a field emission cathode composed of an electron emission portion, a gate electrode and an emitter electrode is provided with a spacer forming electrode, and then a metal spacer is formed on the electrode by a plating method. The method for manufacturing a field emission device according to claim 1 or 2. 6. The method of manufacturing a field emission device according to claim 5, wherein the gate electrode also serves as a spacer forming electrode, and a metal spacer is formed on the electrode by a plating method. 7. The step of forming a semiconductor layer, which becomes an emitter electrode, on the surface layer of the substrate by the cathode plate according to claim 5,
An etching resistant film is formed in a region where an electron emitting portion and a spacer forming electrode are formed on the semiconductor layer, the semiconductor layer is etched through the etching resistant film, and then the surface layer of the etched semiconductor layer is oxidized. A step of forming an oxide film by processing, forming an insulating film and a conductive layer on the etching resistant film and the oxide film to form a spacer forming electrode and a gate electrode, and removing the oxide film by a lift-off process to emit electrons. The method for manufacturing a field emission device according to claim 5, wherein the method is formed by a step of exposing the portion. 8. The method for manufacturing a field emission device according to claim 7, wherein the etching resistant films for forming adjacent plating spacer forming electrodes are connected to each other. 9. An etching resistant film for forming adjacent plating spacer forming electrodes is connected to each other at both ends, and a step of forming a gate electrode in a self-aligned manner using the etching resistant film. Item 7. A method for manufacturing a field emission device according to Item 7. 10. The field emission device according to claim 9, further comprising the step of forming a plurality of narrow enclosures surrounding the gate electrode to form the gate electrode in a self-aligned manner when forming the etching resistant film. Manufacturing method.