JP2000357448A - Cold cathode field electron emitting element, its manufacture, and cold cathode field electron emission display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold cathode field electron emitting element capable of enhancing the durability of an electron emission part, assuring easy manufacture, and working well with a large-sized screen of display device. SOLUTION: A cold cathode field electron emitting element is furnished with a cathode electrode 11 formed on a support 10, an insulating layer 12 formed on the support 10 and cathode electrode 11, a gate electrode 13 formed on the insulating layer 12, an opening 14 penetrating the gate electrode 13 and insulating layer 12, and an electron emission part 16e which is formed on the cathode electrode 11 positioned at the bottom of the opening 14 and whose forefront has a conical shape and is made of a crystalline electroconductive material wherein the forefront of the electron emission part 16e has a crystal grain boundary approx. perpendicular to the cathode electrode 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold cathode field emission device, a method of manufacturing the same, and a cold cathode field emission display, and more particularly, to a cold cathode field emission device having a conical tip. The present invention relates to a device and a method for manufacturing the same, and a flat-type cold cathode field emission display in which such cold cathode field emission devices are arranged in a two-dimensional matrix.

[0002]

2. Description of the Related Art Various types of flat-panel (flat-panel) display devices have been studied as image display devices to replace the current mainstream cathode ray tube (CRT). Examples of such a flat display device include a liquid crystal display device (LCD), an electroluminescence display device (ELD), and a plasma display device (PDP). In addition, a cold cathode field emission display device capable of emitting electrons from a solid into a vacuum without thermal excitation, a so-called field emission display (FED), has been proposed. Attention is drawn from the viewpoint of power consumption.

A display device of a cold cathode field emission type (hereinafter, referred to as a cold cathode field emission type)
Generally, a display device is simply referred to as a display device). In general, a collision between a cathode panel having an electron emission portion corresponding to each pixel arranged in a two-dimensional matrix and electrons emitted from the electron emission portion. And an anode panel having a phosphor layer that emits light when excited by the above. In each pixel on the cathode panel, usually, a plurality of electron emitting portions are formed, and further, a gate electrode for extracting electrons from the electron emitting portion is formed. The portion having the electron emission portion and the gate electrode will be referred to as a field emission device.

In the structure of such a display device, in order to obtain a large emission electron current at a low driving voltage, the tip of the electron emission portion is formed to have a sharp point, and each electron emission portion is miniaturized. It is necessary to increase the density of the electron-emitting portions in the section corresponding to one pixel, and to shorten the distance between the tip of the electron-emitting portion and the gate electrode. Therefore, in order to realize these, field emission devices having various configurations have been conventionally proposed.

As one of typical examples of the field emission device used in such a conventional display device, a so-called Spindt-type field emission device in which an electron emission portion is formed of a conical conductor is known. FIG. 51 shows a conceptual diagram of this Spindt-type display device. The Spindt-type field emission device formed on the cathode panel CP includes a cathode electrode 201 formed on a support 200, an insulating layer 202, and an insulating layer 2.
02 and the gate electrode 2
03 and the opening 20 provided through the insulating layer 202
4 is formed of a conical electron emitting portion 205 formed inside. A predetermined number of the electron emission units 205 are arranged in a two-dimensional matrix to form one pixel. On the other hand, the anode panel AP has a structure in which a phosphor layer 211 is formed on a transparent substrate 210 in a predetermined pattern, and the phosphor layer 211 is covered with an anode electrode 212.

When a voltage is applied between the electron-emitting portion 205 and the gate electrode 203, electrons e are extracted from the tip of the electron-emitting portion 205 by the resulting electric field. This electron e is supplied to the anode electrode 212 of the anode panel AP.
The anode electrode 212 and the transparent substrate 210
And the phosphor layer 211, which is a light emitting layer formed between the two. As a result, the phosphor layer 211 is excited to emit light, and a desired image can be obtained. The operation of the field emission device is basically controlled by the voltage applied to the gate electrode 203.

An outline of a method of manufacturing a field emission device in such a display device will be described below with reference to FIGS. This manufacturing method is basically a method of forming the conical electron emitting portion 205 by vertical vapor deposition of a metal material. That is, the vapor deposition particles enter the opening 204 perpendicularly, but the amount of the vapor deposition particles reaching the bottom of the opening 204 by utilizing the shielding effect of the overhanging deposit formed near the opening end. Is gradually reduced, and the electron emission portion 205 which is a conical deposit is formed in a self-aligned manner. Here, a method in which a release layer 206 is formed in advance on the gate electrode 203 in order to facilitate removal of unnecessary overhang-like deposits will be described.

[Step-10] First, a cathode electrode 201 made of niobium (Nb) is formed on a support 200 made of, for example, a glass substrate, and then an insulating layer 202 made of SiO ₂ and a conductive material are formed thereon. The gate electrode 203 is formed sequentially, and then the gate electrode 203 and the insulating layer 20 are formed.
An opening 204 is formed by patterning 2 (see FIG. 52A).

[Step-20] Next, as shown in FIG. 52B, a release layer 206 is formed by obliquely depositing aluminum on the gate electrode 203 and the insulating layer 202. At this time, the incident angle of the vapor deposition particles with respect to the normal line of the support 200 is selected to be sufficiently large, so that aluminum is hardly deposited on the bottom surface of the opening 204, and the aluminum is peeled off on the gate electrode 203 and the insulating layer 202. Layer 2
06 can be formed. The peeling layer 206 protrudes in an eave shape from the opening end of the opening 204, whereby the diameter of the opening 204 is substantially reduced.

[Step-30] Next, for example, molybdenum (Mo) is vertically deposited as a conductive material on the entire surface. At this time, as shown in FIG. 53A, as the conductive material layer 205A having an overhang shape grows on the separation layer 206, the substantial diameter of the opening 204 is gradually reduced. The deposition particles contributing to deposition at the bottom of the portion 204 gradually become limited to those passing near the center of the opening 204. As a result, a conical deposit is formed at the bottom of the opening 204, and the conical deposit becomes the electron-emitting portion 205.

[Step-40] Thereafter, as shown in FIG. 53B, the separation layer 206 is separated from the surface of the gate electrode 203 by an electrochemical process and a wet process, and the conductive layer above the gate electrode 203 is removed. The material layer 205A is selectively removed.

[0012]

By the way, the electron emission characteristics of the field emission device having the structure shown in FIG. It largely depends on the distance to the tip of the portion 205. This distance is equal to the opening 204
Processing accuracy and diameter dimensional accuracy, film thickness accuracy and coverage (step coverage) of the conductive material layer 205A formed in [Step-30], and further, the release layer 2 serving as a base thereof.
06 greatly depends on the shape accuracy.

Therefore, in order to manufacture a display device composed of a plurality of field emission devices having uniform characteristics, the conductive material layer 205A must be formed uniformly over the entire surface of the film-forming body. No. However, since the conductive material particles are emitted from the evaporation source installed at one point with a certain spread angle in the ordinary vapor deposition apparatus, the layer thickness is symmetric with respect to the coverage in the vicinity of the central portion and the peripheral portion of the film to be formed. Sex is different. For this reason, the height of the electron-emitting portion is likely to vary, or the position of the vertex of the electron-emitting portion is likely to be shifted from the center of the opening portion 204, and the variation in the distance from the tip of the conical electron-emitting portion 205 to the gate electrode 203 is reduced. Difficult to control. Moreover, this variation in distance occurs not only within the same manufacturing lot but also between manufacturing lots, and causes image display characteristics of the display device, for example, unevenness in image brightness. Further, since the conductive material layer 205A is usually formed to a thickness of about 1 μm or more, the deposition method requires a film formation time of several tens of hours, and it is difficult to improve the throughput. There is also a problem that a device is required.

It is also extremely difficult to form the peeling layer 206 uniformly over the entire surface of the film-forming body having a large area by oblique evaporation. Opening 20 provided in gate electrode 203
It is also very difficult to deposit the peeling layer 206 with high precision so that the peeling layer 206 extends like an eave from the edge of the fourth.
In addition, the film formation of the release layer 206 not only varies in the plane of the support, but also tends to vary from lot to lot. Furthermore, in order to manufacture a display device having a large area, it is extremely difficult to peel the release layer 206 over the entire support 200 having a large area, and the peeling of the release layer 206 causes contamination. As a result, the manufacturing yield of the display device is reduced.

In addition, since the height of the conical electron emitting portion 205 is mainly determined by the thickness of the conductive material layer 205A, the degree of freedom in designing the electron emitting portion 205 is low. In addition, since it is difficult to arbitrarily set the height of the electron-emitting portion 205, when the distance from the electron-emitting portion 205 to the gate electrode 203 is reduced, the thickness of the insulating layer 202 must be reduced. Not get. However, when the thickness of the insulating layer 202 is reduced, the capacitance between the wirings (between the gate electrode 203 and the cathode electrode 201) cannot be reduced.
Not only does the load on the electric circuit of the display device increase, but also the in-plane uniformity and image quality of the display device deteriorate.

Further, in the electron-emitting portion 205 having the above-mentioned conical shape, the electron-emitting characteristics may be different depending on the orientation of the crystal grain boundaries of the conductive material constituting the electron-emitting portion 205. In a method for manufacturing a field emission device, a technique of using a region having an optimum orientation in a region of a conductive material layer as the electron-emitting portion 205 is not known.

Accordingly, the present invention can solve the manufacturing problem of the conventional Spindt-type cold cathode field emission device, and provides a plurality of cold cathode field emission devices having uniform and good electron emission characteristics. (Hereinafter, referred to as a field emission device) and a method for manufacturing the same, and a cold cathode field emission display device (hereinafter, referred to as a field emission device) using the field emission device. ,
(Referred to as a display device).

[0018]

According to a first aspect of the present invention, there is provided a cold-cathode field-emission device comprising: (A) a cathode electrode formed on a support;
An insulating layer formed on the support and the cathode electrode, (C)
A gate electrode formed on the insulating layer, (D) an opening penetrating the gate electrode and the insulating layer, and (E) a cathode electrode formed on the cathode electrode located at the bottom of the opening, the tip of which is conical A cold cathode field emission device having an electron emission portion having a tip made of a crystalline conductive material, wherein the tip of the electron emission portion has crystal grains substantially perpendicular to the cathode electrode. Characterized by having a field.

The method for manufacturing a cold cathode field emission device according to the first aspect of the present invention (hereinafter referred to as the manufacturing method according to the first aspect) includes the cold cathode field emission device according to the first aspect of the present invention. This is a method for manufacturing an emission device and a cold cathode field emission device according to a second embodiment of the present invention described below.
That is, (a) a step of forming a cathode electrode on a support, (b) a step of forming an insulating layer on a support including the cathode electrode, and (c) a step of forming a gate electrode on the insulating layer (D) a step of forming at least an opening in which the cathode electrode is exposed at the bottom in the insulating layer; and (e) a step of forming a conductive material layer for forming an electron-emitting portion on the entire surface including the inside of the opening. F) forming a mask material layer on the conductive material layer so as to shield a region of the conductive material layer located at the center of the opening, and (g) a direction perpendicular to the support of the conductive material layer. By etching the conductive material layer and the mask material layer under anisotropic etching conditions in which the etching rate in the mask material layer is faster than the etching rate in the direction perpendicular to the support, the conductive material is formed in the opening. Consisting of layers, Part is characterized by comprising the step, of forming the electron emission portion having a conical form. The above step (g) is a kind of etch-back process in which the difference between the etching rates of the mask material layer and the conductive material layer is skillfully used. In the present specification, the “etching rate in the direction perpendicular to the support” is simply referred to as “etching rate”.

A cold cathode field emission display according to a first aspect of the present invention is a cold cathode field emission display to which the cold cathode field emission device according to the first aspect of the invention is applied. That is, each pixel is composed of a plurality of cold cathode field emission devices, an anode electrode and a phosphor layer provided on a substrate facing the plurality of cold cathode field emission devices. , Each cold cathode field emission device
(A) a cathode electrode formed on a support, (B) an insulating layer formed on the support and the cathode electrode, (C) a gate electrode formed on the insulating layer, (D) a gate electrode and an insulating layer And (E) an electron emission portion formed on the cathode electrode located at the bottom of the opening, the tip portion having a conical shape, and the tip portion made of a crystalline conductive material. , Wherein the tip of the electron-emitting portion has a crystal grain boundary substantially perpendicular to the cathode electrode.

In the cold cathode field emission device according to the first aspect of the present invention, the method for manufacturing the same, and the cold cathode field emission display device, the electron emission portion has a conical shape at the tip, and The part is made of a crystalline conductive material. The electron emitting portion may be entirely conical, or may have only a conical shape like a sharpened pencil. The conical shape includes a conical shape or a pyramid shape. Since the tip of the electron-emitting portion is a place where a high electric field is concentrated and the size of the electron-emitting portion is on the order of microns, physical damage to the tip is likely to occur during repeated electron emission. In the first aspect of the present invention, the fact that the tip of the electron emitting portion is made of a crystalline conductive material and the direction of the crystal grain boundary is substantially perpendicular to the cathode electrode means that the tip of the electron emitting portion is Means that the electron flow at does not cross the grain boundaries. Therefore, disorder of the crystal structure at the tip is less likely to occur, and the durability of the electron-emitting portion that emits electrons when exposed to a high electric field can be increased. Therefore, it is possible to extend the life of the cold-cathode field emission device and the cold-cathode field emission display device incorporating the same.

The tip of the electron-emitting portion may be made of any material, for example, a high melting point material such as tungsten, titanium, niobium, molybdenum, tantalum, and chromium, as long as the orientation of the crystal grain boundaries can be made substantially perpendicular to the cathode electrode. A metal or a compound thereof (for example, a nitride such as TiN, or a silicide such as WSi ₂ , MoSi ₂ , TiSi ₂ , or TaSi ₂ ) may be formed by any method. It is particularly preferable that the layer be made of a tungsten layer formed by the following method. CV
The advantages of the method D over the vapor deposition method are that the film formation speed is high and the throughput can be greatly improved, and the vapor deposition that deposits vapor particles flying from a single evaporation source. Unlike the CVD method, in the CVD method, film formation can proceed at any point as long as the point comes into contact with the source gas existing in the film formation atmosphere. Therefore, it is relatively easy to form a film with a uniform film thickness and coverage. The film formation process of the tungsten layer by the CVD method is well established technically, and is a high melting point metal layer, so that it is suitable as a constituent material of the tip of the electron emitting portion.

It is to be noted that a conductive member is provided between the electron emitting portion and the cathode electrode.
An electrically conductive adhesion layer may be provided. As an adhesion layer
Is a so-called barrier metal layer in a normal semiconductor process.
Can be used as a single layer
Even if it is a kind of material layer, multiple kinds of material layers are combined
It may be a combined layer. However, the first of the present invention
Manufacturing method according to an aspect of the present invention and a second aspect of the present invention described below
In the method for manufacturing a cold cathode field emission device according to
The electron emitting portion and the sharp portion are formed of a conductive material layer or a second conductive material layer (hereinafter, referred to as a second conductive material layer).
Lower, electron emitting portion, sharp portion, conductive material layer and second conductive material
Layers are sometimes collectively referred to as conductive material layers, etc.)
Considering that the conductive material layer is formed by
And the adhesion layer under the same etching conditions.
Can be removed at approximately the same etch rate
Or the etching rate R of the conductive material layer, etc. ₁Is faster
However, the etching rate R of the adhesion layer_TwoSelect within 5 times of
(R_Two≤R₁≦ 5R_TwoIs particularly preferred. this is,
Etching of the conductive material layer etc. progresses and the etched surface
The adhesion layer is largely exposed, and the etching reaction of the adhesion layer occurs.
A large amount of product is generated and a part of it is on the surface of conductive material layer etc.
If adhered, the vapor pressure of this etching reaction product becomes excessive.
Lower, the etching reaction product itself is
It functions as a mask and etches the conductive material layer
This is because there is a great risk of hindering the operation. At its simplest, the
When the electrical material layer etc. and the adhesion layer are made of the same conductive material
If both layers have the same etching rate,
You. However, the conductive material layer etc. and the adhesion layer are made of the same conductive material.
In this case, the adhesion layer is formed by sputtering and
It is particularly preferable to form the electric material layer and the like by the CVD method.
New

Further, in the cold cathode field emission device or the cold cathode field emission display device according to the first aspect of the present invention, a second insulation layer is further formed on the gate electrode and the insulation layer, and the second insulation layer is formed. A focusing electrode may be formed on the layer. In a so-called high voltage type cold cathode field emission display device, the focusing electrode has a potential difference between the anode electrode and the cathode electrode of the order of several thousand volts and the distance between the two electrodes is relatively long. This is a member provided to prevent the trajectory of the electrons emitted from the divergence. By improving the convergence of emitted electron trajectories, optical crosstalk between pixels is reduced, preventing color turbidity particularly when performing color display, and further miniaturizing pixels to achieve higher definition of a display screen. It becomes possible.

In the manufacturing method according to the first aspect of the present invention,
In step (d), the surface of the cathode electrode was used as a reference.
Wall inclination angle θ_wAn opening having a hole is formed in the insulating layer.
In the process (g), the slope of the cathode electrode
Tilt angle θ_eIs θ_w<Θ _eConical tip satisfying <90 ° relationship
An end may be formed. By this method, the book
Fabrication of a cold cathode field emission device according to the second aspect of the invention
can do. The process (g) is a kind as described above
The etching back process is
When perpendicular to the surface of the sword electrode, the corner of the opening
The etching residue of the conductive material layer remains in the part,
Depending on the case, the electron emission section having a conical tip and the game
May be shorted by the etching residue.
You. To avoid this short circuit, make sure that the etching residue is
If the etch back continues for a long time until it is removed,
Decreases the height of the electron-emitting portion at the same time.
The distance from the end of the gate electrode to the tip of the electron emission section.
The separation becomes longer, and the electron emission efficiency decreases.

However, when the inclination angle θ _w of the wall surface of the opening is defined as described above, the etching species enter the conductive material layer on the wall surface as compared with the case where the wall surface is perpendicular to the surface of the cathode electrode. Easier to do. The etch-back process usually employs anisotropic etching conditions in which ions, which are the etching species, are incident almost perpendicularly to the object to be etched. And the wall surface of the opening is exposed within a short time. Therefore, it is possible to prevent a short circuit between the gate electrode and the electron emission portion without reducing the height of the electron emission portion in the opening (that is, without lowering the electron emission efficiency).

As a method of forming an opening in the insulating layer,
The anisotropic etching method is the most common, and in this etching method, the wall surface of the opening can be inclined by utilizing the effect of lowering the etching rate due to deposition by-products. In particular, when a silicon compound such as a silicon oxide-based material or a silicon nitride-based material is assumed as a constituent material of the insulating layer, a fluorocarbon-based etching gas is generally used as an etching gas, and a carbon-based polymer is used as a deposition material. Can be. In order to increase the deposition amount of the carbon-based polymer in such an etching reaction system, the flow rate of the fluorocarbon-based etching gas is increased, or the flow rate of the etching gas that can be a supply source of the oxygen-based chemical species that promotes the combustion of the carbon-based polymer. Reduce the mean free path of ions by increasing the gas pressure, decrease the RF power for plasma excitation, or increase the frequency of the RF power supply for plasma excitation to increase the carbon by the ion sputtering effect. Measures such as lowering the vapor pressure of the carbon-based polymer by suppressing the removal of the system-based polymer or lowering the temperature of the object to be etched can be taken. However, if the deposition amount of the carbon-based polymer is too large, the etching does not proceed at a practical rate,
The above measures must be taken to the extent that a practical etching rate can be achieved.

In the cold cathode field emission device according to the first embodiment of the present invention, the opening penetrates the gate electrode and the insulating layer. In the step (d) of the manufacturing method according to the first aspect of the present invention, the expression that "at least" an opening in which the cathode electrode is exposed at the bottom is formed in the insulating layer is as follows.
This is because it is assumed that it is not necessary to simultaneously form the opening in the gate electrode and the opening in the insulating layer. The case where it is not necessary to simultaneously perform the formation of the opening in the gate electrode and the formation of the opening in the insulating layer means that, for example, a gate electrode provided with the opening from the beginning is formed on the insulating layer, and the inside of the opening is formed. In this case, an opening is formed by removing a part of the insulating layer.
Note that the meaning of “at least” also applies to step (d) of the manufacturing method according to the second embodiment of the present invention described later.

The manufacturing method according to the first aspect of the present invention can be further roughly classified from the first aspect to the first aspect according to the variation of the step (e). That is, the method of manufacturing the cold cathode field emission device according to the first embodiment (A) of the present invention (hereinafter referred to as the manufacturing method according to the first embodiment (A)).
In the step (e), when forming a conductive material layer for forming an electron emission portion on the entire surface including the inside of the opening, a concave portion based on a step between an upper end surface and a bottom portion of the opening is formed in the conductive material layer. After forming a mask material layer on the entire surface of the conductive material layer in the following step (f), the mask material layer is removed until the flat surface of the conductive material layer is exposed. It is characterized by leaving. The surface of the mask material layer left in the recess is preferably substantially flat. Therefore, when the surface of the mask material layer is substantially flat at the stage where the mask material layer is formed over the entire surface of the conductive material layer, the removal of the mask material layer can be performed by an etch-back method, a polishing method under anisotropic etching conditions, or any of these methods. The combination may be performed. In the case where the surface of the mask material layer is not substantially flat at the stage when the mask material layer is formed over the entire surface of the conductive material layer, the removal of the mask material layer may be performed by a polishing method.

The mask material layer in the manufacturing method according to the embodiment 1A is a material whose etching rate in the next step (g) can be set to be lower than the etching rate of the conductive material layer, and whose surface has It is made of a material that can have fluidity at an appropriate stage of formation so that it can be planarized. As a material constituting the mask material layer, for example, a resist material, SOG (spin-on-glass),
A polyimide resin can be used, and these materials can be easily applied by a spin coating method. Alternatively, a material such as BPSG (boron / phosphorus silicate glass) that can be heated and reflowed after the film formation to flatten the surface may be used.

In the method for manufacturing a cold cathode field emission device according to the first and second aspects of the present invention, the region of the conductive material layer shielded by the mask material layer is formed by the method according to the first aspect. It is possible to make it narrower than in. That is, in the method for manufacturing the cold cathode field emission device according to the 1B aspect of the present invention (hereinafter, referred to as the manufacturing method according to the 1B aspect), in the step (e), the upper end surface and the bottom portion of the opening are formed. A substantially funnel-shaped concave portion composed of a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is generated on the surface of the conductive material layer based on the step between them. After forming the mask material layer, the mask material layer and the conductive material layer are removed in a plane parallel to the surface of the support to leave the mask material layer in the columnar portion.

In the method of manufacturing a cold cathode field emission device according to the first aspect of the present invention (hereinafter referred to as the manufacturing method according to the first aspect of the present invention), the step (e) includes the step of: A substantially funnel-shaped concave portion including a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed on the surface of the conductive material layer based on a step between the base material and the bottom portion. After forming a mask material layer on the entire surface of the above, by removing the mask material layer on the conductive material layer and in the enlarged portion,
The method is characterized in that a mask material layer is left on the columnar portion.

In the manufacturing methods according to the first embodiment and the first embodiment, in order to form a substantially funnel-shaped concave portion on the surface of the conductive material layer, the conductive material layer which grows almost vertically from the wall surface of the opening is formed. The formation of the conductive material layer may be stopped shortly before the surface comes into contact at the substantially central portion of the opening. For example, if the opening is cylindrical, the thickness of the conductive material layer needs to be set smaller than the radius of the opening, and thus a columnar column is formed. At this time, the diameter of the columnar portion is approximately 5 to 30% of the diameter of the opening, more preferably approximately 5 to 1%.
It is good to select in the range of 0%. 1B embodiment and 1C
In any of the manufacturing methods according to the embodiments, the minute mask material layer finally left in a very narrow region (ie, a columnar portion) substantially at the center of the opening functions as a mask for the etch-back process. Therefore, the tip of the formed electron-emitting portion is further sharpened. However, such a small mask material layer needs to have sufficient etching resistance. Generally, when the etching rate of the mask material layer is R ₃ and the etching rate of the conductive material layer is R ₁ ,
It is preferable that the relationship of 10R ₃ ≦ R ₁ is satisfied. That is, the etching rate R ₃ of the mask material layer is about _one tenth or less than the etching rate R ₁ of the conductive material layer. For example, the conductive material layer is made of a high melting point metal such as tungsten (W), titanium (Ti), niobium (Nb), molybdenum (Mo), tantalum (Ta), and chromium (Cr), or a compound thereof (for example, nitride such as TiN). Object, WSi ₂ , MoSi ₂ , TiSi ₂ , TaS
When the mask material layer is made of silicide such as i ₂ , at least one of copper (Cu), gold (Au), and platinum (Pt) can be used.

When the mask material layer is formed on the entire surface of the conductive material layer in the manufacturing method according to the first embodiment and the first embodiment, the film can be formed into the narrow columnar portion. It is necessary to adopt a method. Electroplating and electroless plating are preferred methods. When a sputtering method or a CVD method is adopted, it is particularly preferable to take measures to improve the step coverage. For example, when using a sputtering method, it is desirable to perform so-called high-temperature reflow sputtering at a film forming temperature of about 300 ° C. or higher, or to perform high-pressure sputtering. Also, CVD
When employing the method, it is desirable to use a bias ECR (Electron Cyclotron Resonance) plasma CVD apparatus.

In the method for manufacturing a cold cathode field emission device according to the first aspect of the present invention (hereinafter referred to as the manufacturing method according to the first aspect), in step (e), a conductive material for forming an electron emitting portion is formed. Before forming the material layer, a conductive adhesion layer is formed on the entire surface including the inside of the opening, and in step (g), the etching rate of the conductive material layer and the etching rate of the adhesion layer are lower than the etching rate of the mask material layer. The conductive material layer, the mask material layer, and the adhesion layer are etched under anisotropic etching conditions that increase the speed.

The etching rates of the conductive material layer and the adhesion layer are as follows:
Not be the same, practically if the difference to some extent has been described above to the effect that is acceptable, the etching step (g) the etching rate R ₁ and the adhesive layer of the conductive material layer for an electron emitting portion formed in It is preferable that the speed R ₂ satisfies the relationship of R ₂ ≦ R ₁ ≦ 5R ₂ . In particular, when the conductive material layer for forming the electron-emitting portion and the adhesion layer are made of the same conductive material, R ₂ can be approximately equal to R ₁ .

In the manufacturing method according to Embodiments 1A to 1D, it is necessary to form a concave portion on the surface of the conductive material layer based on the step between the upper end surface and the bottom portion of the opening. It is particularly preferable to form the layer by a CVD method having excellent step coverage (step coverage).

The cold cathode field emission device according to the second aspect of the present invention comprises: (A) a cathode electrode formed on a support; (B) an insulating layer formed on the support and the cathode electrode; C) a gate electrode formed on the insulating layer, (D) an opening penetrating the gate electrode and the insulating layer, and (E) a cathode electrode formed on the cathode electrode located at the bottom of the opening, the tip of which is conical. A cold cathode field emission device having an electron emission portion having a shape of a circle, wherein the inclination angle of the wall surface of the opening with respect to the surface of the cathode electrode is θ _w , and the tip portion with respect to the surface of the cathode electrode when the tilt angle of the slope was θ _e, θ _w
<Θ _e <90 °.

A cold cathode field emission display according to a second aspect of the present invention is a cold cathode field emission display to which the cold cathode field emission element according to the second aspect of the invention is applied. That is, each pixel is composed of a plurality of cold cathode field emission devices, an anode electrode and a phosphor layer provided on a substrate facing the plurality of cold cathode field emission devices. , Each cold cathode field emission device
(A) a cathode electrode formed on a support, (B) an insulating layer formed on the support and the cathode electrode, (C) a gate electrode formed on the insulating layer, (D) a gate electrode and an insulating layer And (E) an electron-emitting portion formed on the cathode electrode located at the bottom of the opening, and having a tip portion having a conical shape. When the inclination angle of the wall surface of the opening with respect to the surface of the cathode electrode is θ _w and the inclination angle of the slope of the tip end with respect to the surface of the cathode electrode is θ _e , θ _w <θ _e <9
It is characterized by satisfying a relationship of 0 °.

As described above, the inclination angle θ _w of the wall surface of the opening with respect to the surface of the cathode electrode is smaller than the inclination angle θ _e of the slope of the tip end with respect to the surface of the cathode electrode (θ _w <Θ _e ) is selected, the second aspect of the present invention
The cold cathode field emission device according to the aspect and the cold cathode field emission display device according to the second aspect of the present invention include the gate electrode and the electron emission portion while having the electron emission portion having a sufficient height. The short circuit between them is surely prevented.
The method for manufacturing the cold cathode field emission device according to the second aspect of the present invention is as described above.

The cold cathode field emission device according to the third aspect of the present invention comprises: (A) a cathode electrode formed on a support; (B) an insulating layer formed on the support and the cathode electrode; C) a gate electrode formed on the insulating layer, (D) an opening penetrating the gate electrode and the insulating layer, and (E) an electron emitting portion formed on a cathode electrode located at the bottom of the opening. , Wherein the electron-emitting portion comprises a base and a conical sharpened portion formed on the base.

The method for manufacturing a cold cathode field emission device according to the second aspect of the present invention (hereinafter referred to as the manufacturing method according to the second aspect) is directed to the cold cathode field emission device according to the third aspect of the present invention. 5 is a method for manufacturing an emission device. That is, a method of manufacturing a cold cathode field emission device having an electron emission portion comprising a base and a conical sharpened portion formed on the base, wherein (a) forming a cathode electrode on a support When,
(B) forming an insulating layer on a support including on the cathode electrode; (c) forming a gate electrode on the insulating layer; and (d) opening the cathode electrode at the bottom at least. (E) embedding the bottom of the opening with a base made of the first conductive material layer,
(F) forming a second conductive material layer on the entire surface including the remainder of the opening; and (g) forming a mask material layer so as to shield a region of the second conductive material layer located at the center of the opening. Forming the second conductive material layer on the second conductive material layer; and (h) etching the second conductive material layer in a direction perpendicular to the support in a direction perpendicular to the support of the mask material layer. 2nd under anisotropic etching condition
Forming a sharpened portion made of the second conductive material layer on the base portion by etching the conductive material layer and the mask material layer.

A cold cathode field emission display according to a third aspect of the present invention is a cold cathode field emission display to which the cold cathode field emission device according to the third aspect of the invention is applied. That is, each pixel is composed of a plurality of cold cathode field emission devices, an anode electrode and a phosphor layer provided on a substrate facing the plurality of cold cathode field emission devices. , Each cold cathode field emission device
(A) a cathode electrode formed on a support, (B) an insulating layer formed on the support and the cathode electrode, (C) a gate electrode formed on the insulating layer, (D) a gate electrode and an insulating layer And (E) an electron emission portion formed on a cathode electrode located at the bottom of the opening, wherein the electron emission portion is a base portion. And a conical sharp part formed on the base.

In the manufacturing method according to the second aspect of the present invention, in the step (e), after forming the first conductive material layer on the entire surface including the inside of the opening, the first conductive material layer is etched to form the opening. Preferably, the bottom is embedded in the base. Alternatively, when it is desired to planarize the surface of the base, in the step (e), a first conductive material layer is formed on the entire surface including the inside of the opening, and a flattening layer is further formed on the entire surface of the first conductive material layer. The bottom of the opening is buried with a base having a flat top surface by being formed so as to be substantially flat and etching both the flattening layer and the first conductive material layer under the condition that the etching rates thereof are substantially equal. Can be.

In the cold cathode field emission device or the cold cathode field emission display according to the third aspect of the present invention, the base of the electron emission portion and the sharp portion may be made of different conductive materials. Note that such a configuration may be referred to as a cold cathode field emission device or a cold cathode field emission display according to the third embodiment of the present invention. In order to form such a cold cathode field emission device, in the manufacturing method according to the second aspect, different types of conductive materials are used as the first conductive material layer for forming the base and the second conductive material layer for forming the sharpened portion. What is necessary is just to select a layer. At this time, the sharp portion exposed to the high electric field is preferably made of a high melting point metal material, such as tungsten (W),
Titanium (Ti), molybdenum (Mo), niobium (N
b), a simple substance such as tantalum (Ta), chromium (Cr), or an alloy containing these metal elements, or a compound containing these metal elements (for example, nitride such as TiN, WSi
₂ , silicide such as MoSi ₂ , TiSi ₂ , TaSi ₂ )
Can be exemplified. In particular, it is preferable to form the sharp portion by etching a tungsten (W) layer formed by a CVD method. The base may be formed by selecting a high-melting-point metal different from that constituting the sharpened portion from the above-mentioned high-melting-point metals, or a semiconductor material such as a polysilicon layer containing impurities may be used. . In order to form such a sharpened portion, a first conductive material layer for forming a base portion and a second conductive material layer for forming a sharpened portion are formed by a CVD method. A portion having a substantially vertical crystal grain boundary may be left as a sharp portion.

In the cold cathode field emission device or the cold cathode field emission display according to the third embodiment of the present invention, the base and the sharp portion of the electron emission portion may be made of the same conductive material. . Incidentally, such a configuration may be referred to as a cold cathode field emission device or a cold cathode field emission display device according to the 3B mode of the present invention. In order to form such a cold cathode field emission device, in the manufacturing method according to the second aspect, the same type of conductive material is used as the first conductive material layer for forming the base and the second conductive material layer for forming the sharp portion. You just have to select It is preferable that the sharp portion of the electron-emitting portion has a crystal grain boundary substantially perpendicular to the cathode electrode and is made of a crystalline conductive material. To form such a sharpened portion, a first conductive material layer for forming a base portion and a second conductive material layer for forming a sharpened portion are formed.
The conductive material layer may be formed by a CVD method, and a portion having a crystal grain boundary substantially perpendicular to the cathode electrode may be left as a sharpened portion when the second conductive material layer is etched.

In the cold cathode field emission device, the method for manufacturing the same, or the cold cathode field emission display according to the embodiment 3B of the present invention, the first conductive material layer and the second conductive material layer are made of tungsten (W), A metal layer made of a high melting point metal such as niobium (Nb), tantalum (Ta), titanium (Ti), molybdenum (Mo), chromium (Cr), an alloy layer containing these metal elements, or these metal elements Containing compounds (for example, nitrides such as TiN, WSi ₂ , MoS
i _2, TiSi _2, can be formed using a TaSi silicide _2, etc.) layer. Particularly, a tungsten layer is preferable.

A cold cathode field electron according to the third embodiment of the present invention
In emission devices or cold cathode field emission displays
Is the inclination of the wall of the opening with respect to the surface of the cathode electrode.
Bevel angle θ_wOf the sharp part based on the surface of the cathode electrode
The slope angle of the slope is θ_pAnd θ_w<Θ_p<90 °
The clerk may be satisfied. In addition, such a configuration was originally developed.
The cold cathode field emission device according to the third C mode of the present invention
May be referred to as a cold cathode field emission display. Heel
To form a cold cathode field emission device according to the second embodiment
In the manufacturing method according to
Angle of inclination θ of wall surface with reference to pole surface_wOpening with
Is formed on the insulating layer, and in step (h), the surface of the cathode electrode is
Slope angle θ with respect to surface_pIs θ_w<Θ _p<90 °
What is necessary is just to form a conical sharp part which satisfies the relationship. For this reason
About the manufacturing method according to the second aspect of the present invention,
As described above.

The manufacturing method according to the second aspect of the present invention can be further roughly classified from the second aspect to the second aspect by the variation of the step (f). That is, the method of manufacturing the cold cathode field emission device according to the second aspect (A) of the present invention (hereinafter referred to as the manufacturing method according to the second aspect (A)).
In forming the second conductive material layer for forming a sharp portion on the entire surface including the remaining portion of the opening in the step (H), the concave portion based on the step between the upper end surface and the bottom of the opening is sharpened. In the step (g), after a mask material layer is formed on the entire surface of the second conductive material layer, the mask material layer is formed on the flat surface of the second conductive material layer. It is characterized in that the mask material layer is left in the recess by removing it until it is exposed. The surface of the mask material layer embedded in the recess is preferably substantially flat. Therefore, when the surface of the mask material layer is substantially flat when formed on the entire surface of the second conductive material layer, the removal of the mask material layer can be performed by an etch-back method or a polishing method under anisotropic etching conditions, or any of these methods. It may be performed by a combination of methods. If the surface of the mask material layer is not substantially flat at the stage when the mask material layer is formed over the entire surface of the second conductive material layer, the removal of the mask material layer may be performed by a polishing method. Materials that can constitute the mask material layer include:
It is as described above with respect to the manufacturing method according to the first embodiment.

According to the method of manufacturing a cold cathode field emission device according to the second embodiment 2B and the second embodiment 2C, the region of the second conductive material layer shielded by the mask material layer is formed according to the second embodiment A. It is possible to make it narrower than in the manufacturing method. That is, in the method of manufacturing the cold cathode field emission device according to the 2B aspect of the present invention (hereinafter, referred to as the manufacturing method according to the 2B aspect), in the step (f), the upper end surface and the bottom portion of the opening are formed. A substantially funnel-shaped concave portion including a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed on the surface of the second conductive material layer for forming a sharp portion based on the step between Forming a mask material layer on the entire surface of the second conductive material layer, and removing the mask material layer and the second conductive material layer in a plane parallel to the surface of the support to form a mask material layer on the columnar portion. It is characterized by leaving a layer.

Further, in the method for manufacturing a cold cathode field emission device according to the 2C aspect of the present invention (hereinafter referred to as the manufacturing method according to the 2C aspect), in the step (f), the upper end face of the opening is provided. A substantially funnel-shaped concave portion including a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed on the surface of the second conductive material layer for forming a sharpened portion based on the step between the bottom and the bottom portion. And g) forming a mask material layer on the entire surface of the second conductive material layer, and then removing the mask material layer on the second conductive material layer and in the enlarged portion, thereby leaving the mask material layer on the columnar portion. And

In the manufacturing method according to the second embodiment 2B and the second embodiment 2C, conditions necessary for forming a substantially funnel-shaped concave portion on the surface of the second conductive material layer and materials usable as the mask material layer are as follows. , 1B and 1C.

In the cold cathode field emission device or the cold cathode field emission display according to the third aspect of the present invention, it is preferable that a conductive adhesion layer is formed between the base and the sharp portion. . In this case, when R ₂ etch rate in the direction perpendicular to the substrate of the adhesion layer, the etch rate in the direction perpendicular to the substrate of the conductive material layer constituting the sharpened tip was R _1, R ₂ It is preferable that the adhesion layer is formed of a conductive material satisfying the relationship of ≦ R ₁ ≦ 5R ₂ . In addition, it is desirable that the adhesive layer and the sharp portion are made of the same conductive material.

In the method of manufacturing a cold cathode field emission device according to the second aspect, in the step (f), before forming the second conductive material layer for forming the sharp portion, the entire surface including the remaining portion of the opening is formed. A conductive adhesion layer may be formed. As this adhesion layer, the above-mentioned adhesion layer usable between the cathode electrode and the electron-emitting portion can be used. Generally, when the etching rate of the mask material layer in the direction perpendicular to the support is R ₃ and the etching rate of the conductive material layer in the direction perpendicular to the support is R ₁ , 10R ₃ ≦ R ₁
Is preferably satisfied. As the mask material layer, at least one of copper (Cu), gold (Au), and platinum (Pt) can be used.

In the method for manufacturing a cold cathode field emission device according to the 2D aspect of the present invention (hereinafter referred to as the manufacturing method according to the 2D aspect), an adhesion layer is formed on the entire surface including the remaining portion of the opening. In this case, in the step (h), the second conductive material layer and the mask material under an anisotropic etching condition in which the etching rate of the second conductive material layer and the etching rate of the adhesion layer are faster than the etching rate of the mask material layer. The method is characterized in that the layer and the adhesion layer are etched.

Although the etching rate of the second conductive material layer and that of the adhesion layer are not the same, but a difference of a certain degree is practically acceptable as described above, It is preferable that the etching rate R ₁ of the second conductive material layer for formation and the etching rate R _{2 of the} adhesion layer satisfy the relationship of R ₂ ≦ R ₁ ≦ 5R ₂ . In particular, when the second conductive material layer for forming the sharpened portion and the adhesion layer are made of the same conductive material, R ₂ can be approximately R ₁ .

In the manufacturing method according to the embodiments 2A to 2D, since it is necessary to form a concave portion based on the step between the upper end surface and the bottom portion of the opening on the surface of the second conductive material layer, It is particularly preferable to form the conductive material layer by a CVD method having excellent step coverage (step coverage).

In the cold cathode field emission device or the cold cathode field emission display according to the third aspect of the present invention, a second insulating layer is further formed on the gate electrode and the insulating layer, and the second insulating layer is formed. A focusing electrode may be formed thereon.

The support constituting the cold-cathode field emission device according to all aspects of the present invention only needs to have at least a surface made of an insulating member, and a glass substrate and a glass substrate having an insulating film formed on the surface. , A quartz substrate, a quartz substrate having an insulating film formed on its surface, and a semiconductor substrate having an insulating film formed on its surface can be used. Also, in the cold cathode field emission display of the present invention, the substrate only needs to have at least the surface made of an insulating member, and the glass substrate, the glass substrate having the insulating film formed on the surface, the quartz substrate,
A quartz substrate having an insulating film formed on its surface and a semiconductor substrate having an insulating film formed on its surface can be used.

As the constituent material of the insulating layer, SiO ₂ , S
iN, SiON, or a cured product of glass paste can be used alone or appropriately laminated. Known processes such as a CVD method, a coating method, a sputtering method, and a printing method can be used for forming the insulating layer.

The gate electrode, cathode electrode and focusing electrode are made of tungsten (W), niobium (Nb), tantalum (Ta), titanium (Ti), molybdenum (Mo), chromium (Cr), aluminum (Al), copper ( Cu), a metal layer such as silver (Au), or an alloy layer containing these metal elements, or a compound containing these metal elements (for example, TiN
Nitride, such as WSi ₂ , MoSi ₂ , TiSi ₂ , Ta
(Silicide such as Si ₂ ) or a semiconductor layer such as diamond. However, in the present invention, these electrodes may be exposed when the electron-emitting portion is formed by etching, so it is necessary to select a material that can secure an etching selectivity with respect to the conductive material layer forming the electron-emitting portion. There is.

[0062]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments of the present invention (hereinafter, abbreviated as embodiments).

(Embodiment 1) In Embodiment 1, the field emission device according to the first aspect of the present invention, the display device according to the first aspect of the present invention provided with such a field emission device, and the present invention And a method of manufacturing the field emission device according to the first aspect A. FIG. 1A is a schematic partial end view of the field emission device of the first embodiment, and FIG. 1B is a schematic diagram of an electron emission portion and members near the electron emission portion. FIG. 2 is a schematic partial end view of the display device. Further, a method of manufacturing the field emission device is shown in FIGS.

This field emission device has, for example, a support 10 made of a glass substrate, a cathode electrode 11 made of chromium (Cr), an insulating layer 12 made of SiO ₂ , a gate electrode 13 made of chromium, and a conical shape. And an electron emitting portion 16e made of a tungsten (W) layer. Here, the cathode electrode 11 is provided on the support 10. The insulating layer 12 is formed on the support 10 and the cathode electrode 11, and the gate electrode 13 is formed on the insulating layer 12. Gate electrode 13 and insulating layer 1
An opening 14 is provided in 2, and the side wall surface of the opening provided in the insulating layer 12 is recessed from the opening end of the gate electrode 13. The electron emission portion 16 e is formed on the cathode electrode 11 at substantially the center of the bottom of the opening 14.
The cathode electrode 11 is exposed at a part of the bottom of the opening 14. The entire electron emitting portion 16e as well as the tip of the electron emitting portion 16e has a conical shape, specifically, a conical shape. The electron emitting portion 16e is made of a crystalline conductive material. Note that a conductive adhesive layer 15e is formed between the electron emitting portion 16e and the cathode electrode 11, but this is not a member indispensable for the operation of the field emission device, but is formed for manufacturing reasons. The electron emission portions 16e remain when they are formed by etching.

The display device according to the first embodiment is composed of a plurality of pixels as shown in FIG. Each pixel includes a plurality of the above-described field emission devices, and an anode electrode 162 and a phosphor layer 161 provided on the substrate 160 so as to face each other. The anode electrode 162 is made of aluminum, and is formed so as to cover a phosphor layer 161 formed in a predetermined pattern on a substrate 160 made of glass. Phosphor layer 161 on substrate 160
The stacking order of the anode electrode 162 and the anode electrode 162 may be reversed, but in this case, the anode electrode 162 is located in front of the phosphor layer 161 when viewed from the observation surface side of the display device. It must be made of a transparent conductive material such as (indium / tin oxide).

In the actual configuration of the display device, the field emission element is a component of the cathode panel CP, the anode electrode 162 and the phosphor layer 161 are components of the anode panel AP, and these cathode panel CP and anode panel AP Are joined via a frame (not shown), and the space surrounded by both panels and the frame is evacuated to high vacuum. A relatively negative voltage is applied to the electron emitting portion 16 e from the scanning circuit 163 through the cathode electrode 11 and the gate electrode 13
, A positive voltage is relatively applied from the control circuit 164, and a positive voltage higher than that of the gate electrode 13 is applied to the anode electrode 162 from the acceleration power supply 165. When display is performed on the display device, a video signal is input to the control circuit 164 and a scanning signal is input to the scanning circuit 163. Electrons e are extracted from the tip of the electron emitting portion 16e by an electric field generated when a voltage is applied to the cathode electrode 11 and the gate electrode 13. When the electrons e are attracted to the anode electrode 162 and collide with the phosphor layer 161, the phosphor layer 161
Emits light, and a desired image can be obtained.

By the way, the tip of the electron emitting portion 16e made of a tungsten layer, and the whole of the electron emitting portion 16e have a conical shape, and the direction of the crystal grain boundary of the tungsten layer is as shown in FIG. As shown by an arrow in FIG. This direction substantially coincides with an ideal electron emission direction, that is, a direction perpendicular to the anode electrode 162 when the field emission device is incorporated in a display device. Thus, even when electron emission is repeated under a high electric field, the electron emission portion 16e
The crystal structure of is hardly broken, and the life of the field emission device and the display device can be extended.

The surface of the electron emitting portion 16e is ideally a growth boundary GB. This growth interface GB
When the conductive material layer for forming the electron emission portion is grown in the opening portion 14, it is inevitably formed. That is, a portion where the growth front surfaces of the conductive material layers that have grown substantially perpendicularly from the bottom portion and the side wall surface of the opening 14 collides with each other is the growth boundary surface GB, and the growth boundary surface GB is sandwiched therebetween. In each region of the adjacent conductive material layer, the direction of the crystal grain boundary is different from each other. Therefore, the fact that the surface of the electron-emitting portion 16e is the growth boundary surface means that the orientation of the crystal grain boundaries is almost single inside the electron-emitting portion 16e, and therefore it can be said that it is ideal. .

Hereinafter, a method of manufacturing the field emission device according to the first embodiment will be described with reference to FIGS.

[Step-100] First, as one example, a cathode electrode 11 made of chromium (Cr) is provided on a support 10 having a SiO ₂ layer having a thickness of about 0.6 μm formed on a glass substrate. Specifically, a plurality of strip-shaped cathode electrodes 11 extending in parallel with the row direction are formed by depositing a chromium layer on the support 10 by, for example, a sputtering method or a CVD method, and patterning the chromium layer. be able to. The width of the cathode electrode 11 is, for example, 50 μm, and the space between the electrodes is, for example, 30 μm. Thereafter, an insulating layer 12 made of SiO _{2 is} formed on the support 10 including the cathode electrode 11 by a plasma CVD method. Table 1 shows an example of CVD conditions when TEOS (tetraethoxysilane) is used as a source gas. Insulation layer 1
2 has a thickness of about 1 μm. Next, a conductive layer made of chromium is formed on the entire surface of the insulating layer 12 by sputtering, and the conductive layer is patterned to form a plurality of strips extending parallel to the column direction, that is, the direction orthogonal to the cathode electrode 11. Of the gate electrode 13 is formed. An example of the sputtering conditions is shown in Table 2 below. Table 3 below shows an example of etching conditions for patterning the conductive layer.

[Table 1] TEOS flow rate: 800 SCCM O ₂ flow rate: 600 SCCM Pressure: 1.1 kPa RF power: 0.7 kW (13.56 MHz) Film forming temperature: 40 ° C.

[Table 2] Ar flow rate: 100 SCCM Pressure: 5 Pa DC power: 2 kW Sputtering temperature: 200 ° C

[Table 3] Cl ₂ flow rate: 100 SCCM O ₂ flow rate: 100 SCCM Pressure: 0.7 Pa RF power: 0.8 kW (13.56 MHz) Etching temperature: 60 ° C.

Next, the cathode electrode 11 and the gate electrode 13
In the overlapping region with the gate electrode 1, that is, in one pixel region.
An opening 14 penetrating through the insulating layer 3 and the insulating layer 12 is formed. The planar shape of the opening 14 is a circle having a diameter of 0.3 μm.
This opening 14 is usually provided in a pixel area of 500 to 500
About 0 are formed. In order to form the opening 14, first, an opening is formed in the gate electrode 13 by a RIE (Reactive Ion Etching) method using a chlorine-based etching gas, using a resist layer formed by ordinary photolithography as a mask. Then, an opening is formed in the insulating layer 12 by RIE using a fluorocarbon-based etching gas. The RIE conditions for forming the opening 14 in the gate electrode 13 may be as shown in Table 3. Table 4 shows an example of RIE conditions when forming the opening 14 in the insulating layer 12. After the RIE, the resist layer
It is removed by ashing. An example of the ashing condition is:
It is shown in Table 5 below. Thus, the structure shown in FIG. 3A can be obtained.

[Table 4] Etching apparatus: Parallel plate type RIE apparatus C ₄ F ₈ flow rate: 30 SCCM CO flow rate: 70 SCCM Ar flow rate: 300 SCCM Pressure: 7.3 Pa RF power: 1.3 kW (13.56 MHz) Etching temperature: 20 ° C

[Table 5] O ₂ flow rate: 1200 SCCM Pressure: 75 Pa RF power: 1.3 kW (13.56 MHz) Ashing temperature: 300 ° C.

[Step-110] Next, as shown in FIG. 3B, a conductive adhesion layer 15 is preferably formed on the entire surface by a sputtering method. This adhesion layer 15 is formed on the gate electrode 1.
3 and an insulating layer 12 exposed on the side wall surface of the opening 14 and a conductive material layer 16 entirely formed in the next step.
This is a layer provided to enhance the adhesion between the layer. Here, it is assumed that the conductive material layer 16 is formed of tungsten, and an adhesion layer 15 made of titanium nitride (TiN) having excellent adhesion to tungsten is formed to a thickness of 0.07 μm by a sputtering method. An example of sputtering conditions at this time is shown in Table 6 below.

[Table 6] Ar flow rate: 30 SCCM N ₂ flow rate: 60 SCCM Pressure: 0.67 Pa DC power: 3 kW Sputtering temperature: 200 ° C

[Step-120] Next, as shown in FIG. 4A, a conductive material layer 16 for forming an electron-emitting portion is formed on the entire surface including the inside of the opening 14. Here, a tungsten layer having a thickness of about 0.6 μm is formed as the conductive material layer 16 by a hydrogen reduction reduced pressure CVD method. The film forming conditions are illustrated in Table 7 below. On the surface of the formed conductive material layer 16,
A recess 16A is formed based on a step between the upper end surface of the opening 14 and the bottom.

[Table 7] WF ₆ flow rate: 95 SCCM H ₂ flow rate: 700 SCCM Pressure: 1.2 × 10 ⁴ Pa Film formation temperature: 430 ° C.

[Step-130] Next, the region of the conductive material layer 16 located at the center of the opening 14 (specifically, the recess 1
A mask material layer 17 is formed so as to shield 6A).
That is, first, as shown in FIG.
A mask material layer 17 is formed on 6. The mask material layer 17 absorbs the recess 16A of the conductive material layer 16 and achieves a substantially flat surface. Here, a resist layer having a thickness of 0.35 μm formed by spin coating is used as the mask material layer 17. Next, as shown in FIG.
The mask material layer 17 is etched by RIE using an oxygen-based gas. An example of the RIE conditions at this time is shown in Table 8 below. This etching is completed when the flat surface of the conductive material layer 16 is exposed. As a result, the mask material layer 17 remains so as to fill the recess 16A of the conductive material layer 16 substantially flat.

[Table 8] O ₂ flow rate: 100 SCCM Pressure: 5.3 Pa RF power: 0.7 kW (13.56 MHz) Etching temperature: 20 ° C.

[Step-140] Next, as shown in FIG. 5B, the conductive material layer 16, the mask material layer 17, and the adhesion layer 15 are etched to form a conical electron emitting portion 16e. . These layers are etched by the conductive material layer 16.
Is performed under an anisotropic etching condition in which the etching rate of the mask material layer 17 is higher than the etching rate of the mask material layer 17. Table 9 below shows the etching conditions at this time.

[Table 9] SF ₆ flow rate: 150 SCCM O ₂ flow rate: 30 SCCM Ar flow rate: 90 SCCM Pressure: 35 Pa RF power: 0.7 kW (13.56 MHz)

[Step-150] After that, when the side wall surface of the opening 14 provided in the insulating layer 12 is receded under isotropic etching conditions, the field emission device shown in FIG. 1A is completed. Is done. The isotropic etching can be performed by dry etching using radicals as a main etching species, such as chemical dry etching, or wet etching using an etchant. As an etching solution, for example, a 49% hydrofluoric acid aqueous solution and pure water 1:
A 100 (volume ratio) mixture can be used. Next, a display device is manufactured by combining the cathode panel CP on which many such field emission elements are formed with the anode panel AP. Specifically, a frame of about 1 mm height made of ceramics or glass is prepared,
A sealing material made of frit glass is applied between the frame body and the anode panel AP and between the frame body and the cathode panel CP, and the sealing material is dried and then fired at about 450 ° C. for 10 to 30 minutes. do it. Thereafter, the inside of the display device is evacuated to a degree of vacuum of about 10 ^-4 Pa, and sealed by an appropriate method.

Here, the mechanism for forming the electron-emitting portion 16e in [Step-140] will be described with reference to FIG. FIG. 6A is a schematic diagram showing how the surface profile of the object to be etched changes at regular time intervals as the etching progresses, and FIG. 9 is a graph showing the relationship between the thickness of an object to be etched at the center of an opening. The thickness of the mask material layer in the aperture center h _p, the height of the electron emission portion of the aperture center and h _e.

Under the etching conditions shown in Table 9, the etching rate of the conductive material layer 16 is naturally higher than the etching rate of the mask material layer 17 made of the resist material.
In a region where the mask material layer 17 does not exist, the conductive material layer 1
6 begins to be etched immediately, and the surface of the object to be etched quickly descends. On the other hand, the mask material layer 1
In the region where the mask material layer 7 exists, the etching of the conductive material layer 16 thereunder does not start unless the mask material layer 17 is first removed, so that the thickness of the object to be etched is reduced while the mask material layer 17 is being etched. The speed is low (h _p reduction section), and only when the mask material layer 17 disappears,
Rate of decrease in the thickness of the object to be etched is increased similarly to the nonexistent areas of the mask material layer 17 (h _e decreasing segment). h _p
The start time of the decreasing section is the latest at the center of the opening where the thickness of the mask material layer 17 is the largest, and earlier toward the periphery of the thin opening of the mask material layer 17. Thus, a conical electron emitting portion 16e is formed.

The ratio of the etching rate of the conductive material layer 16 to the etching rate of the mask material layer 17 made of the resist material will be referred to as “resist selectivity”.
The fact that the resist-to-resist selectivity is an important factor in determining the height and shape of the electron-emitting portion 16e will be described with reference to FIG. FIG. 7A shows a case where the resist selectivity is relatively small, and FIG. 7C shows a case where the resist selectivity is relatively large, and FIG. In this case, the shape of the electron emission portion 16e is shown. As the selectivity with respect to the resist increases, the thickness of the conductive material layer 16 decreases more than the thickness of the mask material layer 17, so that the electron-emitting portion 16e is higher and sharper. The resist selectivity decreases as the ratio of the O ₂ flow rate to the SF ₆ flow rate increases. When using an etching apparatus that can change the incident energy of ions by using the substrate bias, the resist bias can be selected by increasing the RF bias power or decreasing the frequency of the AC power supply for bias application. The ratio can be reduced.

The value of the resist selectivity is selected to be 1.5 or more, preferably 2 or more, and more preferably 3 or more. However, as shown in FIG. 1B, in the case where only the region in which the direction of the crystal grain boundaries is substantially perpendicular to the region of the conductive material layer 16 is used as the electron emitting portion 16e, the conductive material It is necessary to predict in advance the inclination of the growth boundary surface GB based on the film formation speed of the layer 16 and the size of the opening 14, and to set a resist selectivity to obtain this inclination.

In the above-described etching, it is naturally necessary to ensure a high selectivity with respect to the gate electrode 13 and the cathode electrode 11, but there is no problem at all under the conditions shown in Table 9. This is because chromium constituting the gate electrode 13 and the cathode electrode 11 is hardly etched by the fluorine-based etching species, and a chromium-to-chromium selectivity of about 10 or more can be obtained under the above conditions.

(Embodiment 2) Embodiment 2 relates to a method for manufacturing a field emission device according to Embodiment 1B of the present invention. 8 to 11 show a manufacturing method according to the second embodiment.
Note that the reference numerals in these drawings are partially common to those in FIG.

[Step-200] First, the cathode electrode 11 is formed on the support 10. The cathode electrode 11 is made of, for example, a TiN layer (thickness 0.1 μm), a Ti layer (thickness 5 nm), and an Al—Cu layer (thickness 0.4 μm) by a DC sputtering method according to sputtering conditions shown in Table 10 below. ), Ti layer (5 nm thickness), TiN layer (0.02 μm thickness) and T
An i-layer (0.02 μm) is stacked in this order to form a stacked film, and then the stacked film is formed by patterning.
In the figure, the cathode electrode 11 is shown as a single layer. Next, an insulating layer 12 is formed on the support 10 and the cathode electrode 11.
To form The insulating layer 12 is formed by a plasma CVD method using TEOS (tetraethoxysilane) as a source gas.
It is formed to a thickness of 0.7 μm. Next, the gate electrode 13 is formed on the insulating layer 12. The gate electrode 13 is formed by patterning a 0.1 μm thick TiN layer formed by a sputtering method. The patterning of the TiN layer can be performed by the RIE method. Table 11 below shows an example of the RIE conditions at this time.

[Table 10] Ar flow rate: 30 SCCM N ₂ flow rate: 60 SCCM (only when forming a TiN layer) Pressure: 0.67 Pa DC power: 3 kW Sputtering temperature: 200 ° C.

[Table 11] Etching apparatus: Parallel plate type RIE apparatus BCl ₃ flow rate: 30 SCCM Cl ₂ flow rate: 70 SCCM Pressure: 7 Pa RF power: 1.3 kW (13.56 MHz) Etching temperature: 60 ° C.

Further, an etching stopper layer 21 made of, for example, SiO ₂ and having a thickness of 0.2 μm is formed on the entire surface. The etching stop layer 21 is not an indispensable member for the function of the field emission device, and serves to protect the gate electrode 13 when the conductive material layer 26 is etched in a later step.
The conditions for forming the etching stop layer 21 are as shown in Table 1 above. However, if the gate electrode 13 can have sufficiently high etching resistance with respect to the etching conditions of the conductive material layer 26, the etching stop layer 21 may be omitted. Thereafter, an opening 24 that penetrates the etching stop layer 21, the gate electrode 13, and the insulating layer 12 and exposes the cathode electrode 11 at the bottom is formed by RIE. The RIE conditions for the etching stop layer 21 and the insulating layer 12 are as shown in Table 4. An example of the RIE conditions for the gate electrode 13 is shown in Table 12 below. Thus, the state shown in FIG. 8A is obtained.

[Table 12] Cl ₂ flow rate: 30 SCCM Ar flow rate: 300 SCCM Pressure: 5.3 Pa RF power: 0.7 kW (13.56 MHz) Etching temperature: 20 ° C.

[Step-210] Next, as shown in FIG. 8B, a conductive adhesive layer 2 is formed on the entire surface including the inside of the opening 24.
5 is formed. Here, for example, a titanium nitride (TiN) layer having a thickness of 0.03 μm is formed as the adhesion layer 25. Subsequently, a conductive material layer 26 for forming an electron-emitting portion is formed on the entire surface including the inside of the opening 24. However, the thickness of the conductive material layer 26 in the second embodiment is selected so that a concave portion 26A deeper than the concave portion 16A described in the first embodiment is formed on the surface. Here, the thickness of the conductive material layer 26 is set to 0.25.
By setting the thickness to μm, the substantially funnel-shaped concave portion 26 </ b> A formed of the columnar portion 26 </ b> B and the enlarged portion 26 </ b> C communicating with the upper end of the columnar portion 26 </ b> B is conductive based on the step between the upper end surface and the bottom portion of the opening 24. It is formed on the surface of the material layer 26.

[Step-220] Next, as shown in FIG. 9A, a mask material layer 27 is formed on the entire surface of the conductive material layer. Here, as an example, a copper (Cu) layer having a thickness of about 0.5 μm is formed by an electroless plating method. An example of electroless plating conditions is shown in Table 13 below.

[0099] [Table 13] Plating liquid: copper sulfate _{(CuSO 4 · 5H 2 O)} 7g / liter Formalin (37% HCHO) 20ml / l sodium hydroxide (NaOH) 10 g / l potassium sodium tartrate 20 g / l plating bath temperature ： 50 ℃

[Step-230] Next, as shown in FIG. 9B, the mask material layer 27 and the conductive material layer 26 are removed in a plane parallel to the surface of the support 10. Then, the mask material layer 27 is left on the columnar portion 26B. This removal can be performed by, for example, a chemical mechanical polishing (CMP) method under the conditions exemplified in Table 14 below. In the following conditions, the term “wafer” is conventionally used, but the member corresponding to the wafer in the present invention is the support 10.

[Table 14] Wafer pressing pressure: 3.4 × 10 ⁴ Pa (= 5 ps)
i) Delta pressure: 0 Pa Platen rotation speed: 280 rpm Wafer holding table rotation speed: 16 rpm Slurry flow rate: 150 ml / min

[Step-240] Next, under anisotropic etching conditions in which the etching rate of the conductive material layer 26 and the adhesion layer 25 is higher than the etching rate of the mask material layer 27,
The conductive material layer 26, the mask material layer 27, and the adhesion layer 25 are etched. The etching conditions at this time are illustrated in Table 15 below. As a result, as shown in FIG. 10A, a conical electron emission portion 26e is formed in the opening 24.
Is formed. When the mask material layer 27 remains at the tip of the electron emission portion 26e, the mask material layer 27 can be removed by wet etching using a diluted hydrofluoric acid solution.

[Table 15] Etching apparatus: Microwave plasma etching apparatus with magnetic field SF ₆ flow rate: 100 SCCM Cl ₂ flow rate: 100 SCCM Ar flow rate: 300 SCCM Pressure: 3 Pa Microwave power: 1.1 kW (2.45 GHz) RF bias power: 40W (13.56MHz) Upper coil current: 13A Middle coil current: 17A Lower coil current: 5.5A Etching temperature: -40 ° C

[Step-250] Then, when the side wall surface of the opening 24 provided in the insulating layer 12 is receded under isotropic etching conditions, the field emission device shown in FIG. 10B is completed. You. The isotropic etching is as described in the first embodiment. Using such a field emission device, a display device can be formed in the same manner as described in Embodiment 1.

Incidentally, in the electron emitting portion 26e formed in the second embodiment, a sharper conical shape is achieved in the electron emitting portion formed in the first embodiment as compared with 16e. This is due to the difference between the shape of the mask material layer 27 and the ratio of the etching rate of the conductive material layer 26 to the etching rate of the mask material layer 27. This difference will be described with reference to FIG. FIG. 11 is a diagram showing how the surface profile of the object to be etched changes at regular time intervals. FIG. 11A shows a case where a mask material layer 27 made of copper is used. B) shows the case where a mask material layer 17 made of a resist material is used, respectively. Here, for simplicity, the conductive material layer 2
6 is assumed to be equal to the etching rate of the adhesion layer 25, and the etching rate of the conductive material layer 16 is equal to the etching rate of the adhesion layer 15.
In FIG. 1, the illustration of the adhesion layers 25 and 15 is omitted.

When the mask material layer 27 made of copper is used (see FIG. 11A), the etching rate of the mask material layer 27 is sufficiently lower than the etching rate of the conductive material layer 26. The mask material layer 27 does not disappear in the inside, so that the sharp electron emission portion 2
6e can be formed. On the other hand, when the mask material layer 17 made of a resist material is used (see FIG. 11B), the etching rate of the mask material layer 17 is not so slow as compared with the etching rate of the conductive material layer 16. During the etching, the mask material layer 17 is easily lost, so that the electron emission portion 1 after the mask material layer 17 is lost.
The conical shape of 6e tends to be dull.

Further, the mask material layer 2 remaining on the columnar portion 26B
7 also has the advantage that the shape of the electron emitting portion 26e is unlikely to change even if the depth of the columnar portion 26B slightly changes.
That is, the depth of the columnar portion 26B can change due to the thickness of the conductive material layer 26 and variations in step coverage.
Since the width of the columnar portion 26B is substantially constant irrespective of the depth, the width of the mask material layer 27 is also substantially constant, and there is no great difference in the shape of the finally formed electron emission portion 26e. On the other hand, in the mask material layer 17 remaining in the recess 16A,
Since the width of the mask material layer changes between the case where the recess 16A is shallow and the case where the recess 16A is deep, the electron emitting portion 16 is earlier as the recess 16A is shallower and the thickness of the mask material layer 17 is smaller.
The conical shape of e begins to blunt. The electron emission efficiency of the field emission device is determined by the potential difference between the gate electrode and the cathode electrode, the distance between the gate electrode and the electron emission portion, the work function of the constituent material of the electron emission portion, and the tip of the electron emission portion. Also changes depending on the shape of. For this reason, it is preferable to select the shape and etching rate of the mask material layer as described above as necessary.

(Embodiment 3) Embodiment 3 relates to a method for manufacturing a field emission device according to Embodiment 1C of the present invention. The manufacturing method according to the third embodiment will be described with reference to FIGS. Note that the reference numerals in these drawings are partially common to those in FIGS. 8 to 10, and a detailed description of the common portions will be omitted.

[Step-300] First, the steps up to the formation of the mask material layer 27 shown in FIG. 9A are performed in the same manner as in [Step-200] to [Step-220] of the second embodiment, and then, By removing only the mask material layer 27 on the material layer 26 and in the enlarged portion 26C, as shown in FIG.
The mask material layer 27 is left on the columnar portion 26B. At this time, for example, by performing wet etching using a diluted hydrofluoric acid aqueous solution, only the mask material layer 27 made of copper can be selectively removed without removing the conductive material layer 26 made of tungsten. The height of the mask material layer 27 remaining in the columnar portion 26B depends on the etching time. This etching time is not so long as the portion of the mask material layer 27 embedded in the enlarged portion 26C is sufficiently removed. Does not require strictness. This is because the discussion regarding the height of the mask material layer 27 is substantially the same as the discussion regarding the shallow depth of the columnar portion 26B described above with reference to FIG. This is because the shape of the formed electron emitting portion 26e is not significantly affected.

[Step-310] Next, the conductive material layer 26, the mask material layer 27, and the adhesion layer 25 are etched in the same manner as in the second embodiment, and the electron emission portion as shown in FIG. 26e is formed. As a matter of course, the electron emitting portion 26e may have a conical shape as shown in FIG. 10A, but only the tip portion has a conical shape in FIG. 12B. Modified examples having the above are shown. Such a shape may occur when the height of the mask material layer 27 buried in the columnar portion 26B is low or the etching rate of the mask material layer 27 is relatively high. No problem.

[Step-320] Then, when the side wall surface of the opening 24 provided in the insulating layer 12 is receded under isotropic etching conditions, the field emission device shown in FIG. 13 is completed. The isotropic etching is as described in the first embodiment. Using such a field emission device, a display device can be formed in the same manner as described in Embodiment 1.

(Embodiment 4) Embodiment 4 is directed to a field emission device according to the second embodiment of the present invention, and a method of manufacturing the field emission device according to the first embodiment A for manufacturing such a field emission device. About the method. First, the technical background leading to the proposal of the field emission device of the fourth embodiment will be described with reference to FIG. 14, and subsequently, FIG. 15 shows a conceptual diagram of the field emission device of the fourth embodiment. FIG. 16 shows a process chart of the method for manufacturing the field emission device. Note that the reference numerals in these drawings are partially common to those in FIG.

The process shown in FIG. 5A and FIG. 5B is the same as [Step-130] in the first embodiment.
4 to [Step-140], that is, the case where the etching of the conductive material layer 16 and the adhesion layer 15 has ideally progressed. However, in an actual process, due to subtle variations in etching conditions, FIG.
As shown in FIG.
In some cases, r may remain. In the illustrated example, since the gate electrode 13 and the cathode electrode 11 are short-circuited by the etching residue 16r, it is necessary to reduce the etching residue 16r to such an extent that the short-circuit is eliminated. However, if the etching of the conductive material layer 16 is continued for this purpose, then, as shown in FIG.
The height of 6e is reduced. That is, the distance between the end of the gate electrode 13 and the tip of the electron emitting portion 16e increases, which causes a reduction in electron emission efficiency and an increase in power consumption.

The field emission device according to the fourth embodiment solves this problem by inclining the wall surface of the opening 44 as shown in FIG. That is, the cathode electrode 11
_W The inclination angle of the wall surface of the opening 44 where the surface relative to the of theta,
Electron emission portion 46e based on the surface of cathode electrode 11
When the inclination angle of the inclined surface of the tip portion and _{θ e, θ w <θ e} <
The relationship of 90 ° is satisfied. Hereinafter, a method for manufacturing such a field emission device will be described.

[Step-400] First, after the steps up to the formation of the insulating layer 12 are performed in the same manner as in the first embodiment, the gate electrode 13 made of TiN is formed in the same manner as in the second embodiment. Next, the gate electrode 13 is etched in accordance with the above-described etching conditions in Table 12, and the etching of the insulating layer 12 is performed under the conditions shown in Table 16 below as an example. As a result,
As shown in FIG. 16A, the cathode electrode 11 is provided at the bottom.
Is exposed, and an opening 44 whose wall is inclined is formed. At this time, the opening 4 based on the surface of the cathode electrode 11 is used.
The inclination angle θ _w of the wall surface of No. 4 is about 75 °.

[Table 16] C ₄ F ₈ flow rate: 100 SCCM CO flow rate: 70 SCCM Ar flow rate: 100 SCCM Pressure: 7.3 Pa RF power: 0.7 kW (13.56 MHz) Etching temperature: 20 ° C.

[Step-410] Next, a conductive adhesion layer 45 made of TiN is formed according to the sputtering conditions shown in Table 6 above. Subsequently, a conductive material layer 46 for forming an electron-emitting portion is formed on the entire surface including the inside of the opening 44. Here, a tungsten layer having a thickness of about 0.3 μm is formed as the conductive material layer 46 by a silane reduction low-pressure CVD method. An example of the CVD conditions is shown in Table 17 below. On the surface of the formed conductive material layer 46, a concave portion 46A is formed based on a step between the upper end surface and the bottom portion of the opening 44. Further, as in the first embodiment, the mask material layer 47 is left in the concave portion 46A. FIG. 16B shows a state in which the processes up to this point have been completed.

[Table 17] WF ₆ flow rate: 10 SCCM SiH ₄ flow rate: 70 SCCM H ₂ flow rate: 1000 SCCM Pressure: 26.6 Pa Film formation temperature: 430 ° C.

[Step-420] Next, as shown in FIG. 16C, the conductive material layer 46, the mask material layer 47, and the adhesion layer 45 are etched to form a conical electron emission portion 46e.
To form These layers are etched by the conductive material layer 4.
6 and the adhesion rate of the adhesive layer 45
The etching is performed under anisotropic etching conditions in which the etching speed is higher than the etching speed. An example of the etching conditions is shown in Table 18 below. Electron emission part 4 based on the surface of cathode electrode 11
The inclination angle θ _e of the slope at the tip of 6e is about 80 °, which is larger than the inclination angle θ _w (about 75 °) of the wall surface of the opening 44 with reference to the surface of the cathode electrode 11. Both inclination angles are θ _w <
By satisfying the relationship of θ _e, an etching residue (FIG. 1) is formed on the wall surface of the opening 44 during the etching.
4 (A), the electron emission portion 46e having a sufficient height is formed.

[Table 18] SF ₆ flow rate: 30 SCCM Cl ₂ flow rate: 70 SCCM Ar flow rate: 500 SCCM Pressure: 3 Pa Microwave power: 1.3 kW (2.45 GHz) RF bias power: 20 W (8 MHz) Etching temperature: -30 ° C

Thereafter, when the side wall surface of the opening 44 provided in the insulating layer 12 is receded under isotropic etching conditions,
The field emission device shown in FIG. 15 is completed. The isotropic etching is as described in the first embodiment. The display device according to the second aspect of the present invention can be configured using such a field emission device. The method for configuring the display device according to the second aspect is the same as the method described in Embodiment 1.

(Fifth Embodiment) A fifth embodiment is a modification of the fourth embodiment. The field emission device of the fifth embodiment is different from the field emission device of the fourth embodiment in that a second insulating layer is further formed on the gate electrode and the insulating layer, and a focusing electrode is formed on the second insulating layer. That is the point. Embodiment 5
FIG. 17 is a conceptual diagram of the field emission device of FIG.
20 to 20 show process diagrams of a manufacturing method according to the first embodiment of the present invention for manufacturing the field emission device. still,
The reference numerals in these drawings are partially common to those in FIG.

In the field emission device of the fifth embodiment, a second insulation layer 50 is formed on the gate electrode 13 and the insulation layer of the field emission device shown in FIG. ) Is formed. The focusing electrode 51 is emitted from the electron emission portion in a so-called high voltage type display device in which the potential difference between the anode electrode and the cathode electrode is on the order of several thousand volts and the distance between the two electrodes is relatively long. This member is provided to prevent the divergence of the electron trajectory, and a relative negative voltage is applied from a converging power supply (not shown). By improving the convergence of emitted electron trajectories, optical crosstalk between pixels is reduced, preventing color turbidity particularly when performing color display, and further miniaturizing pixels to achieve higher definition of a display screen. It becomes possible. The tip of the focusing electrode 51 is recessed from the tip of the gate electrode 13. Focusing electrode 5
The original purpose of (1) is to correct only the trajectories of electrons that are likely to deviate greatly from the direction perpendicular to the cathode electrode 11. There is a possibility that it will decrease. However, as described above, the tip of the focusing electrode 51 is
Retreating from the tip portion is extremely preferable from the viewpoint that only a necessary convergence effect can be obtained without hindering electron emission.

An opening 54 is provided in the focusing electrode 51, the second insulating layer 50, the gate electrode 13 and the insulating layer 12 so as to expose the cathode electrode 11 at a part of the bottom.
The side wall surface of the opening 54 is formed by the processing surfaces of the focusing electrode 51, the second insulating layer 50, the gate electrode 13, and the insulating layer 12. The upper end of the opening provided in the second insulating layer 50 is recessed from the tip of the focusing electrode 51, and the upper end of the opening provided in the insulating layer 12 is recessed from the tip of the gate electrode 13. Accordingly, the structure is such that an electric field of a desired intensity can be efficiently formed in the opening 54.
The electron emitting portion 56e is formed in the opening 54, and a conductive adhesive layer 55e made of titanium nitride (TiN) is formed between the electron emitting portion 56e and the cathode electrode 11. The inclination angle θ _w of the wall surface of the opening 54 provided in the insulating layer 12 with respect to the surface of the cathode electrode 11 is
Electron emitting portion 56e based on the surface of cathode electrode 11
The tip portion is smaller than the inclination angle theta _e of slope (θ _w <θ _e <
90 °).

Hereinafter, a method of manufacturing the field emission device according to the fifth embodiment will be described with reference to FIGS.

[Step-500] First, a plurality of strip-shaped cathode electrodes 11 extending in parallel with the row direction are formed on the support 10. The cathode electrode 11 is made of, for example, TiN
Layer, Ti layer, Al-Cu layer, Ti layer, TiN layer and Ti
It consists of a laminated film of layers. In the figure, the cathode electrode 11 is shown as a single layer. Subsequently, the insulating layer 12 is formed on the support 10 including the cathode electrode 11. Further, the insulating layer 12
Above, a plurality of strip-shaped gate electrodes 13 extending in parallel with the column direction are formed to obtain the state shown in FIG.
The gate electrode 13 is made of, for example, TiN. The steps so far can be performed as described in [Step-200] of the second embodiment.

[Step-510] Next, a second insulating layer 50 made of SiO ₂ and having a thickness of about 1 μm is formed on the entire surface by the CVD method. Furthermore, a thickness of about 0.0
A 7 μm TiN layer is formed by a sputtering method, and a predetermined patterning is performed to form a focusing electrode 51. Further, an etching stop layer 52 made of SiO ₂ is formed to a thickness of about 0.2 μm on the second insulating layer 50 including the focusing electrode 51, and the state shown in FIG. 18B is obtained. Second insulating layer 5
0 and the formation of the etching stop layer 52 can be performed under the same conditions as those for forming the insulating layer 12. Further, the formation of the focusing electrode 51 can be performed under the same conditions as those for forming the gate electrode 13.

[Step-520] Next, an etching stop layer
A resist layer 53 having a predetermined pattern is formed on
Etching stop using this resist layer 53 as a mask.
Stop layer 52, focusing electrode 51, second insulating layer 50, gate electrode
13 and the insulating layer 12 are sequentially etched. This etch
As shown in FIG. 19 (A), the bottom is
Forming a circular opening 54 exposing the cathode electrode 11.
Can be. Here, the focusing electrode 51 and the gate electrode 13
Etching may be performed according to the conditions shown in Table 12 above.
it can. Also, the etching stop layer 52 and the second insulating layer 50
The etching of the insulating layer 12 is shown in Table 16 above.
It can be done according to the conditions. At this time, the cathode
The opening provided in the insulating layer 12 with respect to the surface of the pole 11
The inclination angle θ of the wall surface of the mouth 54 _wIs about 75 °.

[Step-530] Next, the resist layer 53 is removed, and the entire surface including the inside of the opening 54 is covered with, for example, the above-described Table 6.
A conductive adhesion layer 55 made of TiN is formed in accordance with the sputtering conditions described above. Subsequently, on the entire surface including the inside of the opening 54,
For example, a conductive material layer 56 for forming an electron emission portion made of tungsten is formed according to the reduced pressure CVD conditions in Table 17 described above. An opening 5 is formed on the surface of the conductive material layer 56 thus formed.
A concave portion 56A is formed based on a step between the upper end surface and the bottom portion of No. 4. Further, similarly to the first embodiment, the conductive material layer 5
A mask material layer 57 is formed on 6. FIG. 19B shows a state in which the processes up to this point have been completed.

[Step-540] Next, the mask material layer 57
Is etched, and as shown in FIG.
The mask material layer 57 is left on 6A. The process of leaving the mask material layer 57 in the concave portion 56A is the same as the [Step-1 of the first embodiment.
30].

[Step-550] Next, as shown in FIG. 20B, the conductive material layer 56, the mask material layer 57, and the adhesion layer 55 are etched to form a conical electron emitting portion 56e.
To form These layers are etched according to the fourth embodiment.
Can be performed in the same manner as in [Step-420]. The inclination angle θ _e of the slope of the tip of the electron-emitting portion 56 e with respect to the surface of the cathode electrode 11 is about 80 °, and the opening 54 formed in the insulating layer 12 with respect to the surface of the cathode electrode 11. It is larger than the wall inclination angle θ _w (about 75 °).
Since both inclination angles satisfy the relationship of θ _w <θ _e <90 °, an etching residue (see reference numeral 16r in FIG. 14A) remains on the wall surface of the opening 54 during the above-described etching. Electron emitting portion 5 having a sufficient height without any
6e is formed.

Thereafter, when the side wall surfaces of the openings 54 provided in the insulating layer 12 and the second insulating layer 50 are retreated under isotropic etching conditions, the field emission device shown in FIG. 17 is completed. Embodiment 1 about isotropic etching
Is as described above. Using such a field emission device,
The display device according to the second embodiment of the present invention can be configured. The method for configuring the display device according to the second aspect is the same as the method described in Embodiment 1.

(Embodiment 6) Embodiment 6 relates to a method for manufacturing a field emission device according to Embodiment 1D of the present invention. First, the technical background leading to the proposal of the method for manufacturing the field emission device of the sixth embodiment will be described with reference to FIG. 21. Next, the method for manufacturing the field emission device according to the 1D mode will be described with reference to FIGS. This will be described with reference to FIG. Note that the reference numerals in these drawings are partially common to those in FIG.

The process shown in FIG. 5A and FIG. 5B is the same as the [Step-130] in the first embodiment.
4 to [Step-140], that is, the case where the etching of the conductive material layer 16 has ideally progressed. However, in an actual process, the conical shape of the electron-emitting portion 16e may become dull as the etching proceeds, or an etching residue may remain on the side wall of the opening 14 due to subtle variations in etching conditions.
One of the causes is that the conductive material layer 16 and the adhesion layer 15
It is conceivable that an etching reaction product derived from the adhesion layer 15 inhibits the etching of the conductive material layer 16 depending on the combination of the constituent materials described above. For example, the conductive material layer 16
FIG. 21 conceptually shows a phenomenon that may occur when the adhesive layer 15 is made of titanium nitride (TiN) and these are etched using fluorine-based chemical species. FIG. 21 shows SF ₆ as an etching gas.
Using, illustrate the state of SF _x ⁺ is generated as a fluorine-based species, NF _x ⁺ By using NF ₃ as the etching gas, CF _x ⁺ is the use of the fluorocarbon gas,
Each is generated as a fluorine-based chemical species. FIG. 21A shows an object to be etched as the etching proceeds (that is, the conductive material layer 16, the adhesion layer 15, and the mask material layer 17).
FIG. 21B schematically shows a phenomenon that can occur when the surface profile c is achieved. Here, it is assumed that the ratio between the etching rates of the conductive material layer 16 and the mask material layer 17 is 2: 1 and the ratio between the etching rates of the conductive material layer 16 and the adhesion layer 15 is 10: 1.

In the initial stage of this etching, the area of the conductive material layer 16 made of tungsten occupies most of the area of the object to be etched, and the surface profile is a →
It changes to b. At this time, the conductive material layer 16 is made of W +
xF → WFx (where x is a natural number of 6 or less, typically x = 6), and is quickly removed. However, when the surface profile c is achieved, the area of the adhesion layer 15 made of TiN occupies most of the area of the object to be etched.
The ratio of the area of 6 to the area of the object to be etched is only 1% or less in a normal field emission device design. However, titanium fluoride (TiFx; where x is a natural number of 3 or less, typically x = 3) generated by the reaction between TiN and a fluorine-based species has a low vapor pressure, and thus is a conductive material. It adheres to the surface of the layer 16 and hinders the progress of the etching. Therefore, looking at the surface profile after the disappearance of the mask material layer 17, the conical shape becomes blunter as d → e → f → g, and the opening 14
There is a possibility that an etching residue may remain on the side wall of the substrate. This causes inconveniences such as a reduction in electron emission efficiency and a short circuit between the gate electrode and the cathode electrode due to an etching residue.

[0136] In the production method of the field emission device of the sixth embodiment, the conductive material layer 16 or nearly aligned with the etch rate R ₁ and the etching rate R ₂ of the contact layer 15 of, or the etching rate of the conductive material layer 16 R even better _one is faster, by selecting within 5 times the etch rate R ₂ of the adhesive layer _{15 (R 2 ≦ R 1 ≦} 5R 2), to solve the above problems. In order to make the etching rates of the conductive material layer 16 and the adhesion layer 15 uniform under the same etching conditions, it is most simple to configure both layers using the same conductive material. Even if the conductive material constituting both layers is the same, by selecting a film forming method, good step coverage required for the conductive material layer and good adhesiveness required for the adhesive layer are achieved. It is possible to do. Hereinafter, a method for manufacturing the field emission device of the sixth embodiment will be described.

[Step-600] First, the steps up to the formation of the opening 14 are performed in the same manner as in [Step-100] of the first embodiment.
Next, a conductive adhesion layer 15 made of tungsten and having a thickness of about 0.07 μm is formed on the entire surface including the inside of the opening 14 by a DC sputtering method. Table 1 below shows an example of the sputtering conditions.
It is shown in FIG. The tungsten layer formed by the sputtering method can sufficiently function as the adhesion layer 15. Thereafter, a conductive material layer 16 made of tungsten is formed, and a mask material layer 17 is formed in a concave portion 16A on the surface of the conductive material layer 16.
Is the process from [Step-120] of the first embodiment.
It can be performed in the same manner as in [Step-130]. FIG. 22A shows a state in which the steps so far have been completed.

[Table 19] Ar flow rate: 100 SCCM Pressure: 0.67 Pa RF power: 3 kW (13.56 MHz) Sputtering temperature: 200 ° C

[Step-610] Next, the conductive material layer 16 and the mask material layer 17 are etched in the same manner as in [Step-140] of the first embodiment. FIG. 22B shows the adhesion layer 1.
FIG. 5 shows the point in time when just exposed. In the sixth embodiment, since the material occupying most of the area of the object to be etched at this point is still tungsten, FIG.
No etching reaction product having a low vapor pressure as described with reference to No. 1 is generated, and the etching continues rapidly.

[Step-620] Further, when the etching proceeds with the adhesion layer 15 added to the object to be etched, finally, as shown in FIG. 23A, electrons having a good conical shape are formed. An emission part 16e can be formed. FIG. 23B shows changes in the surface profiles a to f of the object to be etched (that is, the conductive material layer 16, the adhesion layer 15, and the mask material layer 17) as the etching proceeds. Here, the conductive material layer 16 and the mask material layer 17 are used here.
Is assumed to be 2: 1 and the conductive material layer 1
It is assumed that the ratio of the etching rate of 6 to the adhesion layer 15 is 1: 1. Even after the mask material layer 17 has disappeared,
It is clear that the dulling of the conical shape of the electron emitting portion 16e and the remaining etching residue are effectively suppressed.

Thereafter, when the side wall surface of the opening 14 provided in the insulating layer 12 is receded under isotropic etching conditions,
The field emission device shown in FIG. 1 is completed. The isotropic etching is as described in the first embodiment. The display device according to the first embodiment and the second embodiment of the present invention can be configured using such a field emission device. The method for configuring the display device according to the first mode and the second mode is the same as the method described in the first embodiment.

(Embodiment 7) Embodiment 7 relates to the third mode of the present invention, more specifically, the field emission device according to mode 3A, and the second mode of the present invention, more specifically. Specifically, the present invention relates to the manufacturing method according to the second aspect. Embodiment 7
FIG. 24 shows a schematic partial end view of the field emission device of FIG.
The manufacturing method is shown in FIGS. The reference numerals in these figures are partially common to FIG. 1, and detailed description of the components common to FIG. 1 will be omitted.

The field emission device of the seventh embodiment is significantly different from the field emission devices of the first to sixth embodiments in that the electron emission portion 78 includes a base 73e and a base portion 7e.
3e and a conical pointed portion 76e formed on 3e. Here, the base 73e and the sharp portion 76e are made of different conductive materials. Specifically, the base 73e is a member for adjusting the substantial height of the electron-emitting portion 78, and here is formed of a polysilicon layer containing impurities. The sharp portion 76e is a member mainly contributing to electron emission, and is formed of a tungsten layer having a crystal grain boundary substantially perpendicular to the cathode electrode 11, and has a conical shape, more specifically, a conical shape. Note that TiN is provided between the base 73e and the sharp portion 76e.
A conductive adhesion layer 75e made of is formed. Here, the adhesive layer 75e is also included in the electron-emitting portion 78 for convenience, but is not a component essential for the function of the electron-emitting portion 78, and is formed for manufacturing reasons. The opening 14 is formed by digging the insulating layer 12 from immediately below the gate electrode 13 to the upper end of the base 73e.

Hereinafter, a method of manufacturing the field emission device according to the seventh embodiment will be described with reference to FIGS.

[Step-700] First, the steps up to the formation of the opening 14 are performed in the same manner as in [Step-100] of the first embodiment. Subsequently, as shown in FIG.
A first conductive material layer 73 for forming a base is formed on the entire surface including the inside. As the first conductive material layer 73, a polysilicon layer containing phosphorus (P) as an impurity on the order of 10 ¹⁵ / cm ³ is formed by a plasma CVD method. Further, a flattening layer 74 is formed on the entire surface so that the surface is substantially flat. Here, a resist layer formed by spin coating is used as the flattening layer 74. Next, the planarization layer 74 and the first conductive material layer 7
Both layers are etched under the condition that the etching rates in Step 3 are substantially equal to each other, and as shown in FIG. 25B, the bottom of the opening 14 is filled with a base 73e having a flat upper surface. Etching can be performed by an RIE method using an etching gas containing a chlorine-based gas and an oxygen-based gas. First
Since the etching is performed after the surface of the conductive material layer 73 is once flattened by the flattening layer 74, the upper surface of the base 73e becomes flat.

[Step-710] Next, as shown in FIG. 26A, a conductive adhesive layer 75 is formed on the entire surface including the remaining portion of the opening 14 and further includes the remaining portion of the opening 14. A second conductive material layer 76 for forming a sharp portion is formed on the entire surface, and the opening 1 is formed.
4 is filled with the second conductive material layer 76. Adhesion layer 75
Is a 0.07 μm thick T formed by sputtering.
The second conductive material layer 76 is an iN layer, and is a 0.6 μm thick tungsten layer formed by a low pressure CVD method.
The sputtering conditions for forming the adhesion layer 75 are shown in Table 6
The CVD conditions for forming the conductive material layer 76 may be the same as those shown in Table 7 or Table 17, respectively. On the surface of the second conductive material layer 76, a concave portion 76A is formed based on a step between the upper end surface of the opening 14 and the bottom.

[Step-720] Next, as shown in FIG. 26B, a mask material layer 77 is formed on the entire surface of the second conductive material layer 76 so that the surface is substantially flat. The mask material layer 77 is made of a resist layer formed by a spin coating method, and has a concave portion 76A on the surface of the second conductive material layer 76.
To achieve a flat surface. Next, the mask material layer 77 is etched by RIE using an oxygen-based gas. This etching ends when the flat surface of the second conductive material layer 76 is exposed. As a result, as shown in FIG. 27A, the concave portion 76A of the second conductive material layer 76 is formed.
The mask material layer 77 is left flat. This mask material layer 7
7 denotes a second conductive material layer 7 located at the center of the opening 14.
6 is formed so as to shield the area.

[Step-730] Next, as in [Step-140] of the first embodiment, the second conductive material layer 76,
When both the mask material layer 77 and the adhesion layer 75 are etched, as shown in FIG. 27B, the sharp portion 76e having a conical shape according to the magnitude of the resist selectivity and the adhesion layer 75e are formed according to the above-described mechanism. Are formed, and the electron emission portions 7 are formed.
8 is completed. Thereafter, when the side wall surface of the opening 14 provided in the insulating layer 12 is retracted, the field emission device shown in FIG. 24 can be obtained. Using such a field emission device, a display device according to the third embodiment of the present invention, more specifically, the display device according to embodiment 3A can be configured. The method for configuring the display device according to the third embodiment is the same as the method described in the first embodiment.

(Eighth Embodiment) An eighth embodiment is a modification of the seventh embodiment. The field emission device of the eighth embodiment is different from the field emission device of the seventh embodiment in that a second insulating layer is further formed on the gate electrode and the insulating layer, and a focusing electrode is formed on the second insulating layer. That is the point. Embodiment 8
FIG. 28 shows a schematic partial end view of the field emission device of FIG.
The manufacturing method is shown in FIGS. The reference numerals in these figures are partially common to those in FIG. 17, and the detailed description of the components common to those in FIG. 17 is omitted.

As shown in FIG. 28, the field emission device according to the eighth embodiment includes a support 10 made of a glass substrate, for example.
A cathode electrode 11 made of chromium (Cr) and SiO ₂
Insulating layer 12 of chromium and gate electrode 13 of chromium
, A second insulating layer 50 made of SiO ₂ , a focusing electrode 51 made of chromium, and an electron emitting portion 88. Here, a plurality of cathode electrodes 11 are arranged on the support 10 in a strip shape. The insulating layer 12 is formed on the support 10 and the cathode electrode 11, and the gate electrode 13 is formed on the insulating layer 12. The second insulating layer 50 is formed on the gate electrode 13 and the insulating layer 12, and the focusing electrode 51 is formed on the second insulating layer 50. Focusing electrode 5
1 is a so-called high-voltage type display device in which the potential difference between the anode electrode and the cathode electrode is on the order of several thousand volts and the distance between the two electrodes is relatively long. A member provided to prevent divergence of the orbit, and a relative negative voltage is applied from a converging power supply (not shown). By increasing the convergence of the emitted electron trajectories, optical crosstalk between pixels is reduced,
In particular, it is possible to prevent color turbidity in the case of performing color display, and to further reduce the size of pixels to achieve higher definition of a display screen. Note that an etching stop layer 52 as shown in FIG. 18B may be formed on the focusing electrode 51.

An opening 54 is provided in the focusing electrode 51, the second insulating layer 50, the gate electrode 13 and the insulating layer 12. The side wall surface of the opening 54 is formed by the processed surfaces of the focusing electrode 51, the second insulating layer 50, the gate electrode 13 and the insulating layer 12, but in order to realize a smooth emitted electron trajectory as a whole. It is preferable that the opening size is reduced from the upper side toward the bottom side. The side wall surface of the opening provided in the second insulating layer 50 is recessed from the tip of the focusing electrode 51, and the side wall surface of the opening provided in the insulating layer 12 is recessed from the tip of the gate electrode 13. In addition, since the focusing electrode 51 and the gate electrode 13 are reduced in thickness toward the distal end, an electric field having a desired intensity can be efficiently formed in the opening 54. The electron emission section 88 is formed in the opening 54,
It comprises a base 83 and a conical (specifically, conical) sharpened portion 86 formed on the base 83. Base 83
Is a polysilicon layer containing impurities, and the sharp portion 86 is a tungsten layer. The base 8
An electrically conductive adhesive layer 85 is formed between 3 and the sharp portion 86. Although this adhesion layer 85 is made of TiN, it is not an essential component for the function of the electron emission section 88, and is formed for manufacturing reasons.

Hereinafter, a method of manufacturing the field emission device according to the eighth embodiment will be described with reference to FIGS. In each of the processes described in the following embodiments of the present specification, including the eighth embodiment, for the processes that do not particularly describe the process conditions, the conditions shown in the above table can be appropriately selected and applied. it can.

[Step-800] First, steps from [Step-500] to [Step-800] of the fifth embodiment are performed until the focusing electrode 51 is formed.
510]. Next, a resist layer 53 is formed in a predetermined pattern on the focusing electrode 51, and the focusing layer 51, the second insulating layer 50, the gate electrode 13, and the insulating layer 12 are sequentially etched using the resist layer 53 as a mask. As shown in FIG. 29A, a circular opening 54 with the cathode electrode 11 exposed at the bottom can be formed. The diameter of the opening 54 is not uniform in the depth direction, and is about 0.5 μm in the vicinity of the focusing electrode 51 and 0.35 μm in the vicinity of the gate electrode 13. FIG.
9A, the side wall surface of the opening 54 provided in the second insulating layer 50 and the insulating layer 12 is perpendicular to the surface of the support 10. If adopted, the side wall surface can be inclined.

[Step-810] Next, as shown in FIG. 29B, the bottom of the opening 54, more specifically, the bottom of the portion of the opening 54 that penetrates the insulating layer 12 is buried. A base portion 83 is formed. The formation of the base 83 is performed in the same manner as in [Step-700] of the seventh embodiment.
The conductive material layer can be formed by a process in which film formation over the entire surface, planarization by a planarizing layer, and etching are combined. Here, a polysilicon film containing phosphorus (P) is used as the first conductive material layer.

[Step-820] Next, as shown in FIG. 30, a contact layer 85 and a conical sharpened portion 86 made of tungsten are formed on the base 83 to complete the electron emitting portion 88. The formation of the sharp portion 86 is performed in the same manner as in [Step-710] to [Step-730] of the seventh embodiment, by forming the entire surface of the conductive adhesive layer 85 and forming a second conductive material layer for forming the sharp portion (see FIG. (Not shown), formation of a mask material layer (not shown), embedding of the mask material layer in a concave portion (not shown), and etching of the second conductive material layer, the mask material layer, and the adhesion layer 85. Can be formed by a process combining the above. Thereafter, by performing isotropic etching to retreat the side wall surfaces of the openings 54 provided in the insulating layer 12 and the second insulating layer 50, the field emission device shown in FIG. 28 is obtained. Using such a field emission device, a display device according to the third embodiment of the present invention, more specifically, the display device according to embodiment 3A can be configured. The method for configuring the display device according to the third embodiment is the same as the method described in the first embodiment.

Ninth Embodiment A ninth embodiment relates to a field emission device according to the third aspect of the present invention, more specifically, the field emission device according to the 3B aspect, and a manufacturing method according to the second aspect of the present invention. About the method. In Embodiment 7 described above, the base and the sharp portion constituting the electron emitting portion are made of different conductive materials, whereas in Embodiment 9, the base and the sharp portion are made of the same conductive material. Become. FIG. 31 is a schematic partial end view of the field emission device according to the ninth embodiment, and FIGS. The reference numerals in these figures are partially common to FIG. 1, and detailed description of the components common to FIG. 1 will be omitted.

The field emission device according to the ninth embodiment has a base 93e made of tungsten as shown in FIG.
And an electron emitting portion 9 also made of tungsten and having a conical sharp portion 96e laminated on the base portion 93e.
8 A conductive adhesive layer 25e is formed between the base 93e and the cathode electrode 11. An opening 94 is formed in the insulating layer 12 by being cut from immediately below the gate electrode 13 to the upper end of the base 93e.

FIG. 31B is a schematic diagram showing the direction of the crystal grain boundary of the electron emitting portion 98. FIG. CV for tungsten layer
When formed by the D method, tungsten generally grows in a direction substantially perpendicular to the growth surface. Therefore, inside the opening, a region (c) where a crystal grain boundary is formed substantially horizontally from the side wall surface and a region (d) where a crystal grain boundary is formed substantially vertically from the bottom portion are generated. In a narrow space such as an opening, the respective regions grown from the side wall surface and the bottom eventually collide with each other, and the collision surface becomes a growth boundary surface. The growth boundary surface is shown by a broken line in FIG. The profile of the growth interface between region (c) and region (d) is:
Almost equal to the surface of a cone. In the electron emitting portion 98, a portion mainly contributing to electron emission is a sharp portion 96e.
In the field emission device of the ninth embodiment, the sharp portion 96e is formed of a region (D) in which the direction of the crystal grain boundary is substantially vertical.
This is extremely advantageous from the viewpoint of electron emission efficiency and lifetime.

Hereinafter, a method of manufacturing the field emission device of the ninth embodiment will be described with reference to FIGS.

[Step-900] Steps from [Step-200] to [Step-200] of the second embodiment are performed up to the formation of the conductive adhesion layer 25.
210]. However, the reference numeral of the opening is 94 (see FIG. 32A). Next, a first conductive material layer 93 for forming a base is formed on the entire surface including the inside of the opening 94.
The first conductive material layer 93 has a thickness of 0.7 μm by a low pressure CVD method.
Is a tungsten (W) layer formed to a thickness of. FIG.
2B shows the direction of the crystal grain boundary of the first conductive material layer 93 for forming the base. At the bottom of the opening 94, as described above, a region (d) surrounded by the conical growth boundary and having the crystal grain boundaries oriented substantially vertically is formed, and the portion along the side wall surface of the opening 94 is formed. Region (c) in which the grain boundaries are oriented substantially horizontally
Is formed. In addition, outside the opening 94, the insulating layer 12
(A) where the grain boundaries are oriented substantially perpendicular to the surface of
Is formed. Further, a transition region (b) between the region (a) and the region (c) is formed at a corner of the opening 94, and the orientation direction of the crystal grain boundary is oblique.

[Step-910] Next, as shown in FIGS. 33A and 33B, the first conductive material layer 93 is etched to have a thickness of about 0.1 mm so as to bury the bottom of the opening 94. 5
A μm base 93e is formed. On the surface of the base 93e,
As shown in FIG. 33B, the region (c) is exposed.

[Step-920] Next, a second conductive material layer 96 for forming a sharp portion is formed on the entire surface including the remaining portion of the opening 94. The second conductive material layer 96 is formed by a low pressure CVD method.
This is a tungsten layer formed to a thickness of 7 μm. FIG.
FIG. 4B shows the direction of the crystal grain boundary of the second conductive material layer 96 for forming a sharpened portion. In this [Step-920], since the surface of the base 93e becomes a new bottom surface of the opening 94, the surface of the base 93e is surrounded by a conical growth boundary surface and the crystal grain boundaries are oriented substantially vertically. (D) is formed.
The formation of each of the other regions (A), (B), and (C) is as follows.
This is the same as the case of each of the regions (a), (b), and (c) in the first conductive material layer 93 for forming the base. In addition, the concave portion 96 based on the step between the upper end surface of the opening portion 94 and the bottom portion.
A is generated on the surface of the second conductive material layer 96. Subsequently, a mask material layer 97 is formed in the recess 96A on the surface of the second conductive material layer 96. This mask material layer 97 is formed by removing a mask material layer (not shown) formed on the entire surface from the second conductive material layer 96.
Can be formed by etching until the flat surface is exposed (see FIGS. 34A and 34B).

[Step-930] Next, the second conductive material layer 9
6. When both the mask material layer 97 and the adhesion layer 25 are etched, as shown in FIGS. 35A and 35B, a sharpened portion having a conical shape corresponding to the magnitude of the resist selectivity according to the mechanism described above. 96e are formed, and the electron emission portion 98 is formed.
Is completed. At this time, by optimizing the etching selectivity between the second conductive material layer 96 and the mask material layer 97, the surface of the sharp portion 96e can be made to coincide with the growth boundary surface, but some inconsistency is allowed. . That is, when the conical shape of the sharp portion 96e becomes more gentle, the sharp portion 96e is still formed only of the region (D), but when the conical shape becomes steeper, the region (C) is added to the sharp portion 96e. Will be mixed. The adhesion layer 25e remains between the base 93e and the cathode electrode 11. Thereafter, when the side wall surface of the opening 94 formed in the insulating layer 12 is retracted,
The field emission device shown in FIG. 31 can be obtained. The display device according to the third mode of the present invention, more specifically, the mode 3B mode can be constituted by using such a field emission device. The method of configuring the display device according to the 3B mode is the same as the method described in Embodiment 1.

(Embodiment 10) Embodiment 10 is a modification of embodiment 9. The field emission device of the tenth embodiment differs from the field emission device of the ninth embodiment in that an adhesion layer is also formed between the base and the sharp portion.
FIG. 36 is a schematic partial end view of the field emission device according to the tenth embodiment, and FIGS. The reference numerals in these figures are partially common to those in FIG. 31, and detailed description of components common to FIG. 31 is omitted.

The field emission device of the tenth embodiment is shown in FIG.
As shown in FIG. 5, an electron emission portion 108 includes a base 93e made of tungsten, and a conical (specifically, conical) sharpened portion 106e formed on the base 93e. Note that a conductive adhesion layer 25e made of TiN is provided between the base 93e and the cathode electrode 11.
Is formed, and a conductive adhesion layer 105e made of TiN is formed between the base 93e and the sharpened portion 106e. Here, the contact layer 105e is referred to as the electron emitting portion 1 for convenience.
08, it is not an indispensable member for the operation of the field emission device, but is formed for manufacturing reasons. An opening 94 is formed in the insulating layer 12 by being cut from immediately below the gate electrode 13 to the upper end of the base 93e. The sharp portion 106e of the electron emitting portion 108 is made of a crystalline conductive material, and has a region (D) in which crystal grain boundaries are oriented substantially vertically.
This region (D) includes a base portion 93e
Is separated from the region (c) constituting the surface by the adhesion layer 105e, so that the region (c) grows almost without being affected by the orientation. Therefore, as compared with the ninth embodiment, the region (D) has more excellent orientation and the durability against repeated electron emission is improved.

Hereinafter, a method for manufacturing the field emission device of the tenth embodiment will be described with reference to FIGS. still,
In these drawings, (A) is a schematic cross-sectional view of the field emission device, and (B) is a schematic diagram for explaining a direction of a crystal grain boundary of an electron emission portion.

[Step-1000] First, the same steps as [Step-900] to [Step-910] in the ninth embodiment are performed, and a conductive adhesive layer 25 made of TiN is After forming a first conductive material layer 93 for forming a base made of tungsten, the adhesion layer 25 and the first conductive material layer 93 are formed.
The adhesion layer 25 and the first conductive material layer 93 are etched under the condition that the etching rates of the conductive material layer 93 become substantially equal. Thereby, as shown in FIG. 37A, a base 93e is formed so as to bury the bottom of the opening 94.
As shown in FIG. 37B, a region (c) where the crystal grain boundaries are oriented in a substantially horizontal direction is exposed on the surface of the base 93e. Here, since the adhesion layer 25 is also etched, the adhesion layer 25e remains only between the base 93e and the opening 94 and between the base 93e and the cathode electrode 11.

[Step-1010] Next, as shown in FIG. 38, a conductive adhesive layer 105 made of TiN is formed on the entire surface including the remaining portion of the opening 94, and a second conductive material for forming a sharpened portion made of tungsten. The material layers 106 are sequentially formed. Second
The conductive material layer 106 grows by considering the surface of the adhesive layer 105 formed above the base 93e, more precisely, on the base 93e as a new bottom surface of the opening.
Is a region (D) in which crystal grain boundaries are oriented in a substantially vertical direction. Subsequently, in the same manner as in [Step-920] of the ninth embodiment, the mask material layer 107 is left in the concave portion 106A on the surface of the second conductive material layer 106.

[Step-1020] Next, when the second conductive material layer 106, the mask material layer 107, and the adhesion layer 105 are all etched together, as shown in FIG. The sharpened portion 106e having a corresponding conical shape is formed, and the electron emitting portion 108 is completed. Thereafter, when the side wall surface of the opening 94 formed in the insulating layer 12 is retracted, the field emission device shown in FIG. 36 can be obtained. The display device according to the third mode of the present invention, more specifically, the mode 3B mode can be constituted by using such a field emission device. The method of configuring the display device according to the 3B mode is the same as the method described in Embodiment 1.

(Eleventh Embodiment) The eleventh embodiment is another modification of the ninth embodiment. The field emission device of the eleventh embodiment differs from the field emission device of the ninth embodiment in that the surface of the base is once flattened by etching. That is, the electron emission portion 11 of the field emission device
8, a base 113e having a flat upper surface, as shown in FIG.
f, and a conical sharpened portion 116e formed on the base 113ef. Since the upper surface of the base portion 113ef is flat, the adhesion layer 1 as in Embodiment 10 described above is provided.
Even if the base portion 93e and the sharp portion 106e are not divided by using 05e, the orientation control of the crystal grain boundary of the sharp portion 116e in a substantially vertical direction becomes easy. Note that a conductive adhesion layer 25e is formed between the base 113ef and the cathode electrode 11. An opening 94 is formed in the insulating layer 12 by being cut from immediately below the gate electrode 13 to the upper end of the base 113ef.

Hereinafter, a method of manufacturing the field emission device according to the eleventh embodiment will be described with reference to FIGS. still,
In these drawings, (A) is a schematic cross-sectional view of the field emission device, and (B) is a schematic diagram for explaining a direction of a crystal grain boundary.

[Step-1100] First, similarly to [Step-900] of the ninth embodiment, a conductive adhesive layer 25 made of TiN and a first conductive layer for forming a base are formed on the entire surface including the inside of the opening 94. A material layer 113 is formed. First conductive material layer 1
13 is a tungsten layer formed by the CVD method. Subsequently, a planarizing layer 11 made of a resist material is formed on the entire surface.
4 is formed so that the surface becomes flat (see FIG. 41).

[Step-1110] Next, the planarization layer 114
The etching is performed under the condition that the etching rates of the first conductive material layer 113 and the first conductive material layer 113 are substantially equal. Thereby, as shown in FIG. 42, the base 113e having a flat upper surface is formed at the bottom of the opening 94.
f is embedded. A region (c) where the crystal grain boundaries are oriented in a substantially horizontal direction is exposed on the surface of the base 113ef.
Here, the second step for forming a sharp portion to be formed in the next step is described.
Insulating layer 12 of conductive material layer 116 and etching stop layer 2
1 in order to maintain good adhesion to
Leave.

[Step-1120] Next, as shown in FIG. 43, a second conductive material layer 116 for forming a sharp portion is formed on the entire surface including the remaining portion of the opening 94. Second conductive material layer 116
Is a tungsten layer formed by a CVD method,
Since the growth is performed by regarding the flat upper surface of the base 113ef as a new bottom surface of the opening 94, the region of the second conductive material layer 116 formed on the base 113ef is a region where the crystal grain boundary is oriented in a substantially vertical direction. (D). Subsequently, the second conductive material layer 1 is formed in the same manner as in [Step-920] of the ninth embodiment.
The mask material layer 117 is left in the concave portion 116A on the surface of the substrate 16.

[Step-1130] Next, when the second conductive material layer 116, the mask material layer 117, and the adhesion layer 25 are all etched together, as shown in FIG. A sharpened portion 116e having a corresponding conical shape is formed, and the electron emitting portion 118 is completed. Thereafter, when the side wall surface of the opening 94 formed in the insulating layer 12 is retracted, the field emission device of FIG. 40 is completed. The display device according to the third mode of the present invention, more specifically, the mode 3B mode can be constituted by using such a field emission device. The method of configuring the display device according to the 3B mode is the same as the method described in Embodiment 1.

(Embodiment 12) Embodiment 12 relates to a field emission device according to the third aspect of the present invention and a method for manufacturing a field emission device according to the second aspect of the present invention.
FIG. 45 is a schematic partial end view of the field emission device according to the twelfth embodiment, and FIG. 46 shows a manufacturing method thereof. The reference numerals in these figures are partially common to FIG. 1, and detailed description of the components common to FIG. 1 will be omitted.

The field emission device of the twelfth embodiment is similar to that of FIG.
As shown in FIG. 7, the electron emission portion 12 includes a base portion 123 and a conical sharp portion 126e formed on the base portion 123.
8 In the twelfth embodiment, both the base 123 and the sharpened portion 126e are made of tungsten, but may be made of different conductive materials. Base 12
A conductive adhesive layer 122 made of TiN is formed between the base 3 and the cathode electrode 11, and a conductive adhesive layer 12 made of TiN is formed between the base 123 and the sharpened portion 126e.
5e are formed. Here, the adhesion layer 125e is included in the electron emission portion 128 for convenience, but is not a member indispensable for the operation of the field emission device, and is formed for manufacturing reasons. Opening 12 based on surface of cathode electrode 11
The inclination angle θ _w of the wall surface of No. 4 is smaller than the inclination angle θ _p of the inclined surface of the sharp portion 126 e of the electron emission portion 128 with reference to the surface of the cathode electrode 11 (θ _w <θ _p <90 °). Insulation layer 1
2, an opening 124 is formed by being excavated from immediately below the gate electrode 13 to the upper end of the base 123.

Hereinafter, a method of manufacturing the field emission device of the twelfth embodiment will be described with reference to FIG.

[Step-1200] First, the process up to the formation of the etching stop layer 21 is the same as the [Step-200] of the second embodiment.
Perform in the same manner as described above. Next, by sequentially etching the etching stop layer 21, the gate electrode 13, and the insulating layer 12,
An opening 124 having an inclined wall is formed. At this time, the etching of the etching stopper layer 21 and the insulating layer 12 was performed as shown in Table 1.
6 can be applied, and the gate electrode 13
The conditions shown in Table 12 can be applied to the etching. Opening 1 based on surface of cathode electrode 11
The inclination angle θ _w of the wall surface of the 24 is about 75 °. Next, a conductive adhesive layer 122 and a first conductive material layer (not shown) for forming a base are formed on the entire surface including the inside of the opening 124, and these two layers are etched. By this etching, the base 123 burying the bottom of the opening 124 is formed.
Although the illustrated base 123 has a flattened upper surface, the upper surface may be depressed like the base 93e in the tenth embodiment. The base 123 having the flattened upper surface is the same as [Step-1100] to [Step-1100] of Embodiment 11.
It can be formed by the same process as [Step-1110]. Further, a conductive adhesive layer 125 and a second conductive material layer 126 for forming a sharpened portion are sequentially formed on the entire surface including the remaining portion of the opening 124 in the same manner as in Embodiment 11, and the second conductive material layer 126 is formed. The mask material layer 12 is formed in the concave portion 126A on the surface.
Leave 7. FIG. 46A shows a state in which the process up to this point has been completed.

[Step-1210] Next, when the second conductive material layer 126, the mask material layer 127, and the adhesion layer 125 are etched, as shown in FIG. A sharpened portion 126e having a conical shape corresponding to the size is formed, and the electron emitting portion 128 is completed. These layers are etched according to the fourth embodiment.
Can be performed in the same manner. The inclination angle θ _p of the slope of the sharp portion 126e with respect to the surface of the cathode electrode 11 is about 80.
°, which is larger than the inclination angle θ _w (about 75 °) of the wall surface of the opening 124 with reference to the surface of the cathode electrode 11.
Since the two inclination angles satisfy the relationship of θ _w <θ _p <90 °, the electron emission portion 128 having a sufficient height does not leave an etching residue on the wall surface of the opening 124 during the above-described etching. Is formed.

Thereafter, when the side wall surface of the opening 124 formed in the insulating layer 12 is retreated under isotropic etching conditions, the field emission device shown in FIG. 45 is completed. The isotropic etching is as described in the first embodiment. The display device according to the third mode of the present invention, more specifically, the mode 3C can be constituted by using such a field emission device. The method of configuring the display device according to the third embodiment is the same as the method described in the first embodiment.

(Thirteenth Embodiment) A thirteenth embodiment relates to a method for manufacturing a field emission device according to the second aspect of the present invention. This manufacturing method will be described with reference to FIGS.

[Step-1300] First, the steps up to the formation of the opening 94 are performed in the same manner as in [Step-900] of the ninth embodiment. Next, the conductive adhesive layer 1 is formed on the entire surface including the inside of the opening 94.
32 and a first conductive material layer (not shown) for forming the base are formed, and both layers are etched. By this etching, a base 133 burying the bottom of the opening 94 is formed. The adhesion layer 132 remains between the base 133 and the cathode electrode 11. Although the illustrated base 133 has a flattened upper surface, the upper surface may be depressed like the base 93e in the tenth embodiment. The base 133 having the flattened upper surface can be formed by a process similar to [Step-1100] to [Step-1110] of the eleventh embodiment. Further, a conductive adhesive layer 135 and a second conductive material layer 136 for forming a sharpened portion are sequentially formed on the entire surface including the remaining portion of the opening 94. At this time,
A substantially funnel-shaped concave portion 136A including a columnar portion 136B based on a step between the upper end surface and the bottom portion of the remaining portion of the opening 94 and an enlarged portion 136C communicating with the upper end of the columnar portion 136B has a second conductive material layer 136. The second surface as produced on the surface of
The thickness of the conductive material layer 136 is selected. Next, a mask material layer 137 is formed over the second conductive material layer 136. The mask material layer 137 is formed using, for example, copper. FIG.
FIG. 7A shows a state in which the process up to this point has been completed.

[Step-1310] Next, FIG.
As shown in the figure, the mask material layer 137 and the second conductive material layer 1
36 is removed in a plane parallel to the surface of the support 10 to leave the mask material layer 137 on the columnar portion 136B. This removal can be performed by a chemical mechanical polishing (CMP) method as in [Step-230] of the second embodiment.

[Step-1320] Next, when the second conductive material layer 136, the mask material layer 137 and the adhesion layer 135 are etched, a sharp point having a conical shape corresponding to the magnitude of the resist selectivity is obtained according to the above-described mechanism. A part 136e is formed. Etching of these layers can be performed in the same manner as in [Step-240] of the second embodiment. Sharp point 1
36e and base 133e, and sharp portion 136e and base 13
The electron-emitting portion 138 is formed by the adhesive layer 135e remaining between 3e. Needless to say, the electron emitting portion 138 may have a conical shape as a whole, but FIG. 48A shows a state in which a part of the base 133 e remains so as to bury the bottom of the opening 94. Was. Such a shape can occur when the height of the mask material layer 137 embedded in the columnar portion 136B is low or the etching rate of the mask material layer 137 is relatively high.
Function does not hinder at all.

[Step-1330] After that, when the side wall surface of the opening 94 formed in the insulating layer 12 is receded under isotropic etching conditions, the field emission device shown in FIG. 48B is completed. Is done. The isotropic etching is as described in the first embodiment. The display device according to the third mode of the present invention, more specifically, the mode 3B mode can be constituted by using such a field emission device. The method of configuring the display device according to the 3B mode is the same as the method described in Embodiment 1.

(Embodiment 14) Embodiment 14 relates to a method for manufacturing a field emission device according to Embodiment 2C of the present invention. This manufacturing method will be described with reference to FIG.

[Step-1400] Second conductive material layer 136
Are performed in the same manner as in [Step-1300] of the thirteenth embodiment. Next, a mask material layer 147 is formed over the second conductive material layer 136. Next, by removing only the mask material layer 147 on the second conductive material layer 136 and in the enlarged portion, the mask material layer 147 is left on the columnar portion 136B as shown in FIG. Here, only the mask material layer 147 made of copper can be selectively removed without removing the second conductive material layer 136 made of tungsten, for example, by performing wet etching using a diluted hydrofluoric acid aqueous solution. After this, the second conductive material layer 136 and the mask material layer 14
Processes such as etching 7 and isotropic etching of the insulating layer 12 can all be performed in the same manner as in the thirteenth embodiment.

(Embodiment 15) Embodiment 15 relates to a method of manufacturing a field emission device according to the 2D mode of the present invention. This manufacturing method will be described with reference to FIG.

[Step-1500] The steps up to the formation of the base 133 are performed in the same manner as in [Step-1300] of the thirteenth embodiment.
Next, a conductive adhesion layer 155 made of tungsten and having a thickness of about 0.07 μm is formed on the entire surface including the inside of the opening 94 by the DC sputtering method in the same manner as in [Step-600] of the sixth embodiment. . Thereafter, in the same manner as in the thirteenth embodiment, a second conductive material layer 156 made of tungsten is formed, and the mask material layer 15 is formed in a concave portion on the surface of the second conductive material layer 156.
7, the second conductive material layer 156 and the mask material layer 157 are etched. FIG. 50 (A) illustrates a point in time when the adhesion layer 155 has just been exposed. In the fifteenth embodiment, since the material occupying most of the area of the object to be etched at this point is still tungsten, an etching reaction product having a low vapor pressure as described with reference to FIG. Etching continues rapidly.

[Step-1510] Further, when the etching proceeds with the adhesion layer 155 added to the object to be etched, finally, as shown in FIG. 50B, a sharp point having a good conical shape is obtained. A portion 156e is formed. The electron emitting portion 158 is formed by the sharp portion 156e and the base portion 133 and the adhesive layer 155e remaining between the sharp portion 156e and the base portion 133. The display device according to the third mode of the present invention, more specifically, the mode 3B mode can be constituted by using such a field emission device. The method of configuring the display device according to the 3B mode is the same as the method described in Embodiment 1.

Although the present invention has been described based on the embodiments of the present invention, the present invention is not limited to these embodiments. The details of the structure of the field emission device, the details of the processing conditions and the materials used in the method of manufacturing the field emission device, and the details of the structure of the display device to which the field emission device is applied are examples, and may be appropriately changed, selected, and combined. It is possible. For example, the field emission device described in the first to third embodiments and the sixth embodiment may be provided with the focusing electrode described in the fifth embodiment. Further, the field emission device described in Embodiments 9 to 13 and 15 includes:
The focusing electrode described in Embodiment 8 may be provided. The field emission device described in Embodiments 2 to 5 may be provided with the adhesion layer described in Embodiment 6. Further, the field emission device described in Embodiments 7 to 13 may be provided with the adhesion layer described in Embodiment 15. In Embodiments 4 and 5, the manufacturing method according to Embodiment 1A of the present invention has been illustrated, but the manufacturing methods according to Embodiments 1B, 1C, and 1D are also applicable. It is. Further, in the seventh to twelfth embodiments, the manufacturing method according to the second embodiment A of the present invention has been exemplified. However, the manufacturing methods according to the second embodiment B, the second embodiment C, and the second embodiment D are also the same. Applicable.

[0193]

As is clear from the above description, the field emission device according to the first aspect of the present invention is a crystalline conductive material in which the tip of the electron emission portion has a crystal grain boundary oriented substantially vertically. , The durability of the electron-emitting portion that repeatedly emits electrons under a high electric field is improved, and the life of the display device according to the first embodiment using the field-emitting device is extended. In the field emission device according to the second aspect of the present invention, by satisfying the relationship of θ _w <θ _e <90 °, a configuration in which a residue hardly remains in the opening is adopted, and high electron emission efficiency is achieved. However, a short circuit between the gate electrode and the cathode electrode is prevented, and the power consumption and high reliability of the display device according to the second embodiment using the field emission device are achieved. Further, in the field emission device according to the third aspect of the present invention, since the electron-emitting portion is composed of the base and the sharp portion formed thereon, the electron-emitting portion can be selected by appropriately selecting the height of the base. , The distance between the tip of the device and the gate electrode can be finely adjusted, and the degree of freedom in designing the field emission device, and furthermore, the display device according to the third embodiment using the field emission device is increased.

In the method of manufacturing the field emission device according to the second aspect of the present invention, the electron emission portion is formed by dividing the electron emission portion into a base portion and a sharp portion on the base portion. In the case where the sharp portion is formed using the conductive material layer, the sharp portion can be formed using the region of the conductive material layer in which the crystal grain boundaries are oriented substantially vertically right above the base, so that the tip of the electron emitting portion can be formed. In addition to enabling precise control of the distance between the portion and the gate electrode, the durability of the electron-emitting portion can be improved.

In the method of manufacturing the field emission device according to the first and second aspects of the present invention, the tip portion or the sharp portion constituting the electron emission portion can be formed by a series of self-aligned processes. . Accordingly, not only the complexity of the process is reduced, but also in the case where a large-area cathode panel is to be manufactured, an electron-emitting portion having a uniform size and shape is formed over the entire surface of the cathode panel. Accordingly, it is possible to easily cope with the enlargement of the screen of the display device. Since a self-aligned process can be applied, the number of photolithography steps can be reduced, and further, the investment in manufacturing equipment can be reduced, the processing time can be shortened, and the manufacturing cost of a field emission device and a display device can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a field emission device according to a first embodiment;
(A) is a schematic end view, (B) is a schematic diagram for explaining the direction of the crystal grain boundary of the electron emitting portion.

FIG. 2 is a schematic end view showing a configuration example of a display device of the present invention.

FIGS. 3A and 3B are schematic end views illustrating a method for manufacturing the field emission device according to the first embodiment, in which FIG.
(B) represents the step of forming the adhesion layer.

4A and 4B are schematic end views illustrating the method for manufacturing the field emission device according to the first embodiment, following FIG. 3; FIG. 4A is a step of forming a conductive material layer for forming an electron emission portion; Represents a step of forming a mask material layer.

5A and 5B are schematic end views illustrating the method for manufacturing the field emission device according to the first embodiment, following FIG. 4; FIG. 5A is a step of leaving a mask material layer in a concave portion; Respectively.

FIG. 6 is a diagram for explaining a formation mechanism of an electron emission portion;
(A) is a conceptual diagram showing a change in a surface profile of an object to be etched with progress of etching, and (B) is a graph showing a relationship between an etching time and a thickness of the object to be etched at the center of an opening.

FIG. 7 is a schematic end view showing a change in shape of an electron-emitting portion depending on the selectivity of a conductive material layer to resist.

8A and 8B are schematic end views illustrating a method for manufacturing the field emission device according to the second embodiment, in which FIG.
(B) shows the step of forming the adhesion layer and the conductive material layer, respectively.

FIGS. 9A and 9B are schematic end views illustrating the method for manufacturing the field emission device according to the second embodiment, wherein FIG. 9A is a process for forming a mask material layer, and FIG. Steps of leaving a layer are respectively shown.

FIGS. 10A and 10B are schematic end views illustrating the method for manufacturing the field emission device according to the second embodiment, following FIG. 9, wherein FIG. 10A is a step of forming an electron emission portion, and FIG. Respectively represents the step of retreating.

11A and 11B are schematic diagrams for explaining a change in the shape of an electron-emitting portion due to the shape of a mask material layer, wherein FIG. 11A shows a mask material layer remaining in a columnar portion, and FIG. Respectively.

12A and 12B are schematic end views illustrating a method for manufacturing the field emission device according to the third embodiment, in which FIG. 12A shows a step of leaving a mask material layer on a columnar portion, and FIG. 12B shows a step of forming an electron emission portion. Respectively.

FIG. 13 is a schematic end view illustrating the method for manufacturing the field emission device according to the third embodiment, following FIG. 12, and illustrates a step of retracting the side wall surface of the opening.

FIGS. 14A and 14B are schematic end views for explaining the technical background of the fourth embodiment, in which FIG.
(B) shows a state in which the electron-emitting portion is reduced with the removal of the etching residue.

FIG. 15 is a schematic end view showing a field emission device according to a fourth embodiment.

FIG. 16 is a schematic end view showing the method for manufacturing the field emission device of Embodiment 4, in which (A) is a step of forming an opening,
(B) shows a step of leaving a mask material layer in a concave portion, and (C) shows a step of forming an electron-emitting portion.

FIG. 17 is a schematic end view showing a field emission device of a fifth embodiment.

FIGS. 18A and 18B are schematic end views showing a method for manufacturing the field emission device of the fifth embodiment, wherein FIG. 18A shows a step of forming a gate electrode, and FIG. 18B shows a step of forming a focusing electrode and an etching stop layer. .

FIG. 19 is a schematic end view showing the method of manufacturing the field emission device according to the fifth embodiment, following FIG. 18, (A) showing an opening forming step, and (B) showing a conductive material layer and a mask material layer. Respectively.

FIG. 20 is a schematic end view showing the method of manufacturing the field emission device according to the fifth embodiment, following FIG. 19, wherein (A) shows a step of leaving a mask material layer in a concave portion, and (B) shows an electron emission portion. The forming steps are respectively shown.

21A and 21B are diagrams illustrating a technical background of the sixth embodiment, in which FIG. 21A is a conceptual diagram illustrating a change in a surface profile of an object to be etched with progress of etching, and FIG. Each figure is represented.

FIGS. 22A and 22B are schematic end views showing a method of manufacturing the field emission device of Embodiment 6, wherein FIG. 22A shows a step of leaving a mask material layer in a concave portion, and FIG. Respectively.

FIGS. 23A and 23B are schematic end views illustrating the method of manufacturing the field emission device of Embodiment 6 following FIG. The change in the surface profile of the etched product is shown.

FIG. 24 is a schematic end view showing the field emission device of the seventh embodiment.

FIG. 25 is a schematic end view for explaining the method of manufacturing the field emission device according to the seventh embodiment, wherein FIG.
The step of forming the conductive material layer and the flattening layer and the step (B) of FIG.

FIG. 26 is a schematic end view illustrating the method for manufacturing the field emission device according to the seventh embodiment, following FIG. 25, wherein FIG. 26 (A) is a step of forming a second conductive material layer for forming a sharpened portion, and FIG. ) Respectively indicate a step of forming a mask material layer.

27A and 27B are schematic end views illustrating the method of manufacturing the field emission device according to the seventh embodiment, following FIG. 26, wherein FIG. 27A shows a step of leaving a mask material layer in a concave portion, and FIG. Respectively.

FIG. 28 is a schematic end view showing the field emission device of the eighth embodiment.

FIGS. 29A and 29B are schematic end views illustrating a method for manufacturing the field emission device according to the eighth embodiment, in which FIG. 29A illustrates a step of forming an opening, and FIG. 29B illustrates a step of forming a base.

FIG. 30 is a schematic end view illustrating the method of manufacturing the field emission device according to the eighth embodiment, following FIG. 29, illustrating a step of forming an electron-emitting portion;

31A and 31B are diagrams illustrating a field emission device according to a ninth embodiment, in which FIG. 31A is a schematic end view, and FIG. 31B is a schematic diagram illustrating the direction of a crystal grain boundary of an electron emission portion.

FIG. 32 is a schematic end view illustrating the method for manufacturing the field emission device according to the ninth embodiment, where (A) is a first view for forming a base.
FIG. 4B is a schematic diagram illustrating a direction of a crystal grain boundary of the first conductive material layer, in which the conductive material layer is formed.

FIG. 33 is a schematic end view illustrating the method for manufacturing the field emission device according to the ninth embodiment, following FIG. 32, wherein (A) is a base forming step, and (B) is a direction of a crystal grain boundary of the base. FIG.

FIG. 34 is a schematic end view illustrating the method for manufacturing the field emission device according to the ninth embodiment, following FIG. 33, wherein (A) illustrates a recess formed in the second conductive material layer for forming a sharp portion; FIG. 4B is a schematic diagram illustrating a step of leaving a mask material layer, and FIG. 4B is a diagram illustrating a direction of crystal grain boundaries of a base and a second conductive material layer.

FIG. 35 is a schematic end view illustrating the method of manufacturing the field emission device according to the ninth embodiment, following FIG. 34, wherein FIG. 35 (A) shows a step of forming a sharpened portion by etching, and FIG. It is a schematic diagram explaining the direction of a crystal grain boundary.

36A and 36B are diagrams showing a field emission device according to a tenth embodiment, wherein FIG. 36A is a schematic end view, and FIG. 36B is a schematic diagram for explaining the direction of a crystal grain boundary of an electron emission portion.

FIGS. 37A and 37B are schematic end views illustrating the method for manufacturing the field emission device according to the tenth embodiment. FIG. 37A is a schematic diagram illustrating a base forming step, and FIG. It is.

FIG. 38 is a schematic end view illustrating the method for manufacturing the field emission device according to the tenth embodiment, following FIG. 37, wherein FIG. 38 (A) illustrates a recess formed in a second conductive material layer for forming a sharp portion; FIG. 4B is a schematic diagram illustrating a step of leaving a mask material layer, and FIG. 4B is a diagram illustrating a direction of crystal grain boundaries of a base and a second conductive material layer.

FIG. 39 is a schematic end view illustrating the method of manufacturing the field emission device according to the tenth embodiment, following FIG. 38, wherein (A) is a step of forming a sharp portion, and (B) is a crystal grain of an electron emission portion. It is a schematic diagram explaining the direction of a field.

FIGS. 40A and 40B are diagrams showing a field emission device of an eleventh embodiment, in which FIG. 40A is a schematic end view, and FIG.

FIGS. 41A and 41B are schematic end views illustrating the method for manufacturing the field emission device according to the eleventh embodiment, in which FIG. 41A is a step of forming a first conductive material layer for forming a base and a planarizing layer, and FIG. FIG. 3 is a schematic diagram illustrating a direction of a crystal grain boundary of a first conductive material layer.

42 is a schematic end view illustrating the method for manufacturing the field emission device according to the eleventh embodiment, following FIG. 41, wherein (A) a step of forming a base having a flat upper surface, and (B) a crystal grain of the base; It is a schematic diagram explaining the direction of a field.

FIG. 43 is a schematic end view illustrating the method for manufacturing the field emission device according to the eleventh embodiment, following FIG. 42, wherein (A) illustrates a concave portion formed in the second conductive material layer for forming a sharp portion; FIG. 4B is a schematic diagram illustrating a step of leaving a mask material layer, and FIG. 4B is a diagram illustrating a direction of crystal grain boundaries of a base and a second conductive material layer.

FIGS. 44A and 44B are schematic end views illustrating the method of manufacturing the field emission device according to the eleventh embodiment, in which FIG. 44A is a step of forming a sharp portion, and FIG. It is a schematic diagram explaining the direction of a field.

FIG. 45 is a schematic end view showing the field emission device of the twelfth embodiment.

FIG. 46 is a schematic end view showing the method of manufacturing the field emission device according to the twelfth embodiment, in which (A) is a second example for forming a sharp portion.
The step of leaving the mask material layer in the recess formed in the conductive material layer and the step (B) represent the step of forming the electron-emitting portion, respectively.

FIGS. 47A and 47B are schematic end views showing the method of manufacturing the field emission device of the thirteenth embodiment. FIG. 47A shows a step of forming a mask material layer, and FIG. 47B shows a step of leaving a mask material layer in a columnar portion. Represent.

48 is a schematic end view showing the method of manufacturing the field emission device according to the thirteenth embodiment, following FIG. 47, wherein FIG. 48 (A) shows a step of forming an electron emission portion, and FIG. Steps of retracting are respectively shown.

FIG. 49 is a schematic end view showing the method for manufacturing the field emission device of the fourteenth embodiment, showing a step of leaving a mask material layer on the columnar portion.

FIG. 50 is a schematic end view showing the method of manufacturing the field emission device of the fifteenth embodiment, wherein (A) shows a state in the middle of etching of the second conductive material layer, and (B) shows a step of forming an electron emission portion. Respectively.

FIG. 51 is a partial schematic end view showing a general configuration of a conventional display device.

FIGS. 52A and 52B are schematic end views for explaining an example of a conventional method for manufacturing a Spindt-type field emission device, wherein FIG. 52A shows a state in which an opening is formed, and FIG. The state in which the release layer is formed is shown.

FIG. 53 is a schematic end view for explaining an example of a conventional method for manufacturing a Spindt-type field emission device following FIG. 52, wherein (A) shows a conical electron emission accompanying the growth of a conductive material layer; (B) shows a state in which an unnecessary conductive material layer is removed together with a peeling layer.

[Explanation of symbols]

10 ... Support, 11 ... Cathode, 12 ...
.Insulating layer, 13 ... gate electrode, 14, 24, 44,
54, 94, 124 ... openings, 16, 26, 46,
56... Conductive material layer (for forming an electron emitting portion), 16A,
26A, 46A, 56A, 76A, 96A, 106A,
116A, 126A, 136A ... recess, 26B, 1
36B: columnar portion, 26C, 136C: enlarged portion,
16e, 26e, 46e, 56e, 78, 88, 98,
108, 118, 128, 138, 158... Electron-emitting portion, 17, 27, 47, 57, 77, 97, 107,
117, 127, 137, 147, 157: mask material layer, 73, 93, 113: first conductive material layer (for forming base portion), 73e, 83, 93e, 113ef, 12
3, 133, 133e ... base, 74, 114 ...
Planarization layer, 76, 96, 106, 116, 126, 13
6, 156... Second conductive material layer (for forming a sharp portion), 7
6e, 86, 96e, 106e, 116e, 126e,
136e, 156e: sharp part, 12: insulating layer,
50: second insulating layer, 51: focusing electrode, CP
・ Cathode panel, AP ・ ・ ・ Anode panel, 1
60 ... substrate, 161 ... phosphor layer, 162 ...
Anode electrode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Kikuchi 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C031 DD17 DD19 5C036 EE01 EE14 EF01 EF06 EF09 EG12 EG19 EH08 EH21

Claims (49)

[Claims] (A) a cathode electrode formed on a support; (B) an insulating layer formed on the support and the cathode electrode; (C) a gate electrode formed on the insulating layer; (E) an opening formed through the gate electrode and the insulating layer; and (E) a conductive material formed on the cathode electrode located at the bottom of the opening, the tip having a conical shape, and the tip being a crystalline conductive material. A cold cathode field emission device comprising: an electron emission portion comprising: a cold cathode field emission device having a crystal grain boundary substantially perpendicular to a cathode electrode. element. 2. The cold cathode field emission device according to claim 1, further comprising a conductive adhesion layer between the cathode electrode and the electron emission portion. 3. An etching rate in a direction perpendicular to the support of the adhesion layer as R ₂ , and an etching rate in a direction perpendicular to the support of the conductive material layer constituting the electron emission portion as R _1. 3. The cold cathode field emission device according to claim 2, wherein the adhesion layer is formed of a conductive material satisfying a relationship of R ₂ ≦ R ₁ ≦ 5R ₂ . 4. The cold cathode field emission device according to claim 3, wherein the adhesion layer and the electron emission portion are made of the same conductive material. 5. The cold cathode field emission device according to claim 1, wherein a second insulating layer is further formed on the gate electrode and the insulating layer, and a focusing electrode is formed on the second insulating layer. element. 6. The cold cathode field emission device according to claim 1, wherein the tip of the electron emission portion is made of a tungsten layer formed by a CVD method. (A) a cathode electrode formed on the support, (B) an insulating layer formed on the support and the cathode electrode, (C) a gate electrode formed on the insulating layer, (D) A cold cathode field electron comprising: an opening penetrating through the gate electrode and the insulating layer; and (E) an electron-emitting portion formed on the cathode electrode located at the bottom of the opening and having a conical tip. When the inclination angle of the wall surface of the opening with respect to the surface of the cathode electrode is θ _w , and the inclination angle of the slope of the tip end with respect to the surface of the cathode electrode is θ _e , θ _w < A cold cathode field emission device which satisfies the relationship of θ _e <90 °. (A) a cathode electrode formed on the support, (B) an insulating layer formed on the support and the cathode electrode, (C) a gate electrode formed on the insulating layer, (D) A cold cathode field emission device comprising: an opening penetrating through a gate electrode and an insulating layer; and (E) an electron emission portion formed on a cathode electrode located at the bottom of the opening. The cold cathode field emission device is characterized in that the portion comprises a base and a conical sharpened portion formed on the base. 9. The cold cathode field emission device according to claim 8, wherein the base portion and the sharp portion are made of different conductive materials. 10. The cold cathode field emission device according to claim 8, wherein the base portion and the sharp portion are made of the same conductive material. 11. The cold cathode field emission device according to claim 10, wherein the conductive material is tungsten. 12. The cold cathode field emission device according to claim 8, wherein the sharp portion has a crystal grain boundary substantially perpendicular to the cathode electrode and is made of a crystalline conductive material. 13. The cold cathode field emission device according to claim 8, wherein a conductive adhesive layer is formed between the base and the sharpened portion. 14. An etching rate in a direction perpendicular to the support of the adhesion layer as R ₂ , and an etching rate in a direction perpendicular to the support of the conductive material layer constituting the sharp portion as R ₁ . _{2. The} adhesion layer is made of a conductive material satisfying a relationship of R ₂ ≦ R ₁ ≦ 5R _2.
4. The cold cathode field emission device according to item 3. 15. The cold cathode field emission device according to claim 14, wherein the adhesion layer and the sharp portion are made of the same conductive material. 16. The cold cathode field electron according to claim 8, wherein a second insulating layer is further formed on the gate electrode and the insulating layer, and a focusing electrode is formed on the second insulating layer. Emission element. 17. An opening based on the surface of a cathode electrode.
Angle of the wall of _w, Based on the surface of the cathode electrode
The angle of inclination of the slope of the sharp part_pAnd θ _w<Θ_p<
9. The method according to claim 8, wherein the relationship of 90 ° is satisfied.
Cold cathode field emission device. 18. A step of forming a cathode electrode on a support, (b) a step of forming an insulating layer on a support including the cathode electrode, and (c) forming a gate electrode on the insulating layer. (D) a step of forming at least an opening in which the cathode electrode is exposed at the bottom in the insulating layer; and (e) a step of forming a conductive material layer for forming an electron-emitting portion on the entire surface including the inside of the opening. (F) forming a mask material layer on the conductive material layer so as to shield a region of the conductive material layer located at the center of the opening; and (g) forming a mask on the support of the conductive material layer. The conductive material layer and the mask material layer are etched under anisotropic etching conditions in which the etching rate in the vertical direction is higher than the etching rate in the direction perpendicular to the support of the mask material layer. Consisting of Part manufacturing method of a cold cathode field emission device characterized by comprising the step, of forming an electron emitting portion in the opening portion having a conical form. In the step (d), the surface of the cathode electrode is
The reference wall inclination angle θ_wOpenings with insulation
In step (g), the slope based on the surface of the cathode electrode
Angle of inclination θ_eIs θ_w<Θ _eConical shape satisfying the relationship of <90 °
19. The method of claim 18, wherein the tip is formed.
A method for manufacturing a cold cathode field emission device. 20. In the step (e), a concave portion is formed on the surface of the conductive material layer based on a step between the upper end surface and the bottom portion of the opening. In the step (f), a mask is formed on the entire surface of the conductive material layer. 19. The cold cathode field emission device according to claim 18, wherein after forming the material layer, the mask material layer is removed until the flat surface of the conductive material layer is exposed, thereby leaving the mask material layer in the concave portion. Manufacturing method. 21. In the step (e), a substantially funnel-shaped concave portion including a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed on the conductive material layer based on a step between the upper end surface of the opening and the bottom portion. In the step (f), after forming a mask material layer on the entire surface of the conductive material layer, the mask material layer and the conductive material layer are removed in a plane parallel to the surface of the support. 19. The method according to claim 18, wherein the mask material layer is left on the columnar portion by the method. 22. In the step (e), a substantially funnel-shaped concave portion including a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed on the basis of a step between the upper end surface and the bottom portion of the opening. In the step (f), a mask material layer is formed on the entire surface of the conductive material layer, and then the mask material layer on the conductive material layer and in the enlarged portion is removed. 19. The method of manufacturing a cold cathode field emission device according to claim 18, wherein: 23. When the etching rate of the mask material layer in the direction perpendicular to the support is R ₃ , and the etching rate of the conductive material layer in the direction perpendicular to the support is R ₁ , 10R ₃ ≦ R 23. The method according to claim 22, wherein the relationship of ₁ is satisfied. 24. The method according to claim 23, wherein the mask material layer is made of at least one of copper, gold and platinum. 25. The method according to claim 18, wherein the step (e) comprises forming a conductive material layer by a CVD method.
5. The method for manufacturing a cold cathode field emission device according to item 1. 26. In the step (e), before forming a conductive material layer for forming an electron-emitting portion, a conductive adhesion layer is formed on the entire surface including the inside of the opening, and in the step (g), the conductive material layer is formed. The etching rate in the direction perpendicular to the support and the etching rate in the direction perpendicular to the support of the adhesion layer are higher than the etching rate in the direction perpendicular to the support of the mask material layer 20. The method according to claim 18, wherein the conductive material layer, the mask material layer, and the adhesion layer are etched under the condition of the reactive etching. 27. In step (g), the etching rate R _{1 in the} direction perpendicular to the support of the conductive material layer for forming the electron-emitting portion and the etching rate R _{1 in the} direction perpendicular to the support of the adhesion layer. ₂ and is a manufacturing method of a cold cathode field emission device according to claim 26, characterized in that satisfy the relationship _{R 2 ≦ R 1 ≦ 5R 2} . 28. The conductive material layer for forming an electron emitting portion and the adhesion layer are made of the same conductive material.
8. The method for manufacturing a cold cathode field emission device according to item 7. 29. A method for manufacturing a cold cathode field emission device having an electron emission portion comprising a base portion and a conical sharp portion formed on the base portion, comprising: (a) forming a cathode electrode on a support; Forming; (b) forming an insulating layer on the support including on the cathode electrode; (c) forming a gate electrode on the insulating layer; and (d) exposing the cathode electrode at the bottom. Forming the opening at least in the insulating layer; (e) embedding the bottom of the opening with the base made of the first conductive material layer; and (f) forming the second conductive material layer on the entire surface including the remaining portion of the opening. (G) forming a mask material layer on the second conductive material layer so as to shield a region of the second conductive material layer located at the center of the opening; Etching rate in the direction perpendicular to the support of the two conductive material layers By etching the second conductive material layer and the mask material layer under an anisotropic etching condition in which the etching rate of the mask material layer in a direction perpendicular to the support is higher, the sharpness of the second conductive material layer is increased. Forming a portion on a base portion. A method for manufacturing a cold cathode field emission device, comprising: 30. In the step (e), after forming a first conductive material layer on the entire surface including the inside of the opening, the first conductive material layer is etched to fill the bottom of the opening with the base. Item 30. The method for producing a cold cathode field emission device according to Item 29. 31. In the step (e), a first conductive material layer is formed on the entire surface including the inside of the opening, and a flattening layer is formed on the entire surface of the first conductive material layer so that the surface is substantially flat. By etching both the planarizing layer and the first conductive material layer under conditions that the etching rates in the direction perpendicular to the support are substantially equal, the bottom of the opening is filled with a base having a flat top surface. The method for manufacturing a cold cathode field emission device according to claim 29. 32. The cold cathode field emission device according to claim 29, wherein the first conductive material layer for forming the base portion and the second conductive material layer for forming the sharp portion are made of different conductive materials. Production method. 33. A first conductive material layer for forming a base portion and a second conductive material layer for forming a sharp portion are formed by a CVD method, and in etching the second conductive material layer, the second conductive material layer is substantially perpendicular to the cathode electrode. The method for manufacturing a cold cathode field emission device according to claim 32, wherein a portion having a crystal grain boundary is left as a sharp portion. 34. The cold cathode field emission device according to claim 29, wherein the first conductive material layer for forming the base portion and the second conductive material layer for forming the sharp portion are made of the same conductive material. Manufacturing method. 35. A first conductive material layer for forming a base portion and a second conductive material layer for forming a sharp portion are formed by a CVD method, and in etching the second conductive material layer, the second conductive material layer is substantially perpendicular to the cathode electrode. The method according to claim 34, wherein a portion having a crystal grain boundary is left as a sharp portion. 36. The cold cathode field emission device according to claim 34, wherein the first conductive material layer for forming the base portion and the second conductive material layer for forming the sharp portion are tungsten layers. Method. 37. In the step (d), the surface of the cathode electrode is
The reference wall inclination angle θ_wOpenings with insulation
In the step (h), the slope based on the surface of the cathode electrode
Angle of inclination θ_pIs θ_w<Θ _pSharp part that satisfies <90 ° relationship
30. The cold cathode according to claim 29, wherein
A method for manufacturing a field emission device. 38. In the step (f), a concave portion based on the step between the upper end surface and the bottom portion of the opening is formed on the surface of the second conductive material layer for forming the sharp portion. After forming a mask material layer on the entire surface of the second conductive material layer, the mask material layer is removed until a flat surface of the second conductive material layer is exposed, thereby leaving the mask material layer in the concave portion. Item 30. The method for producing a cold cathode field emission device according to Item 29. 39. In the step (f), based on a step between the upper end surface of the opening and the bottom, a substantially funnel-shaped concave portion including a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed into a sharpened portion. In the step (g), after forming a mask material layer on the entire surface of the second conductive material layer, the mask material layer and the second conductive material layer are formed on the support. 30. The mask material layer is left in the columnar portion by removing in a plane parallel to the surface.
5. The method for manufacturing a cold cathode field emission device according to item 1. 40. In the step (f), a substantially funnel-shaped recess comprising a columnar portion and an enlarged portion communicating with the upper end of the columnar portion is formed into a sharp portion based on a step between the upper end surface of the opening and the bottom portion. In the step (g), after forming a mask material layer on the entire surface of the second conductive material layer, the mask material layer on the second conductive material layer and in the enlarged portion is formed. 30. The method of manufacturing a cold cathode field emission device according to claim 29, wherein the mask material layer is left on the columnar portion by removing. 41. The etching rate of the mask material layer in the direction perpendicular to the support is R ₃ , and the etching rate of the second conductive material layer in the direction perpendicular to the support is R _1.
41. The method according to claim 40, wherein a relationship of 10R ₃ ≦ R ₁ is satisfied. 42. The method according to claim 41, wherein the mask material layer is made of at least one of copper, gold and platinum. 43. In the step (f), before forming the second conductive material layer for forming the sharpened portion, a conductive adhesion layer is formed on the entire surface including the remaining portion of the opening. 2
10. The method for producing a cold cathode field emission device according to item 9. 44. In the step (h), the etching rate of the second conductive material layer in the direction perpendicular to the support and the etching rate of the adhesion layer in the direction perpendicular to the support are supported by the mask material layer. 42. The cold cathode according to claim 41, wherein the second conductive material layer, the mask material layer, and the adhesion layer are etched under anisotropic etching conditions in which the etching speed is higher than an etching rate in a direction perpendicular to the body. A method for manufacturing a field emission device. 45. A second step for forming a sharpened portion in the step (h).
The etching rate R _{1 in the} direction perpendicular to the support of the conductive material layer and the etching rate R _{2 in the} direction perpendicular to the support of the adhesion layer satisfy the relationship of R ₂ ≦ R ₁ ≦ 5R _2. The method for manufacturing a cold cathode field emission device according to claim 44, wherein: 46. A structure according to claim 4, wherein the second conductive material layer for forming the sharpened portion and the adhesion layer are made of the same conductive material.
6. The method for producing a cold cathode field emission device according to item 5. 47. A plurality of pixels, each pixel comprising: a plurality of cold cathode field emission devices; an anode electrode and a phosphor layer provided on the substrate so as to face the plurality of cold cathode field emission devices. Each of the cold cathode field emission devices comprises: (A) a cathode electrode formed on a support, (B) an insulating layer formed on the support and the cathode electrode, and (C) an insulating layer formed on the insulating layer. (D) an opening penetrating the gate electrode and the insulating layer, and (E) a cathode electrode formed on the cathode electrode located at the bottom of the opening, the tip having a conical shape, and A cold cathode field emission display device having an electron-emitting portion having a tip made of a crystalline conductive material, wherein the tip of the electron-emitting portion has a crystal grain boundary substantially perpendicular to the cathode electrode. A cold cathode field emission display. 48. Each pixel includes a plurality of cold cathode field emission devices, and an anode electrode and a phosphor layer provided on a substrate facing the plurality of cold cathode field emission devices. Each of the cold cathode field emission devices comprises: (A) a cathode electrode formed on a support, (B) an insulating layer formed on the support and the cathode electrode, and (C) an insulating layer formed on the insulating layer. (D) an opening penetrating through the gate electrode and the insulating layer; and (E) an electron-emitting portion formed on the cathode electrode located at the bottom of the opening, the tip having a conical shape. Wherein the inclination angle of the wall surface of the opening with respect to the surface of the cathode electrode is θ _w , and the inclination angle of the slope of the tip portion with respect to the surface of the cathode electrode is θ _w when the _{θ e, θ w <θ e} <90 ° relationship Cold cathode field emission display, characterized by satisfying. 49. Each pixel includes a plurality of cold cathode field emission devices, an anode electrode and a phosphor layer provided on a substrate facing the plurality of cold cathode field emission devices. Each of the cold cathode field emission devices comprises: (A) a cathode electrode formed on a support, (B) an insulating layer formed on the support and the cathode electrode, and (C) an insulating layer formed on the insulating layer. Cold-cathode field electrons comprising: a gate electrode formed; (D) an opening penetrating through the gate electrode and the insulating layer; and (E) an electron-emitting portion formed on the cathode electrode located at the bottom of the opening. A cold-cathode field emission display device according to claim 1, wherein the electron-emitting portion comprises a base and a conical sharpened portion formed on the base.