JP2000195448A - Manufacture of electric field emission type cathode and flat surface type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure easy manufacture of an electric field emission type cathode using material, such as carbon material, capable of emitting electrons in an electric field of a low threshold. SOLUTION: This manufacture includes a process for forming an insulating layer 7 and a second electrode 12 thereon on a first electrode 11, both having an opening 25 in parts for forming an electron emitting element, a process for forming a resist layer 26 on an area including on a second electrode 12 except for the opening 25 and forming an electron emitting material layer 27 (such as a carbon material layer) on an area including the resist layer 26 and in the opening 25 facing to the first electrode 11, a process for forming an electron emitting element 28 of an electron emitting material layer on the first electrode 11 in the opening 25 by lifting off the resist layer 26 and the electron emitting layer 27 thereon, and a process for etching and eliminating an insulating layer wall in the opening 25 so as to separate the insulating layer wall from the electron emitting element 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a flat display device and a method of manufacturing a field emission cathode.

[0002]

2. Description of the Related Art As a flat display device, a flat display device having a field emission type cathode having a cold cathode structure has been developed. Such a conventional flat display device 15 is, for example, shown in FIG.
As shown in a perspective view in which a part thereof is a cross section, first and second substrates 1 each constituted by a glass substrate, for example,
And 2 are opposed to each other via a reinforcing spacer 3 at a predetermined interval, and the peripheral portions of the opposing substrates 1 and 2 are made of, for example, glass via an insulating outer peripheral frame 14 made of ceramic or the like. Airtightly sealed by a frit, an airtight flat space is formed between the two substrates 1 and 2, a field emission cathode 4 is arranged on the first substrate 1 side, and a field emission cathode 4 is arranged on the second substrate 2 side. A fluorescent screen 5 is formed.

On the first substrate 1, a plurality of first electrodes (so-called cathode electrodes) 11 each having, for example, a stripe shape are provided.
And a second electrode (a so-called gate electrode) 12 are arranged in parallel in a direction crossing each other, and the crossing portion is formed by the insulating layer 7.
Are formed so as to be electrically insulated through the substrate.

[0004] For example, a field emission cathode 4 is formed corresponding to the intersection of the first and second electrodes 11 and 12, respectively. These field emission cathodes 4
FIG. 9 shows a perspective view in which a part of the main part is cross-sectional and a cross-sectional view of the main part. Through holes 8 penetrating the layer 7 and the upper second electrode 12 are formed, and in these through holes 8, a so-called Spindt-type, for example, a conical sharp shape is formed on the lower first electrode 11. An electron-emitting device (so-called emitter) 9 is arranged. In this case, a plurality of field emission devices 9 are arranged for one pixel.

A metal back layer 6 of a thin film conductive layer is formed on the fluorescent screen 5 on the second substrate 2 side, and a high accelerating voltage is supplied to the metal back layer 6.

Then, the first and second electrodes 11 and 12
When a required voltage is applied between the selected electrodes, electrons are taken out from each electron-emitting device 9 of the field emission type cathode 4 arranged at the intersection, and the electrons are accelerated by the above-described acceleration voltage. By penetrating through the metal back layer 6 and impacting the fluorescent screen 5, this portion is excited and emits light,
An intended light emission display, for example, an image display is performed.

The above-mentioned field emission type cathode utilizes the tunneling effect of a substance due to a strong electric field instead of thermionic emission. As a so-called emitter material for the electron-emitting device, a refractory metal such as molybdenum (Mo), nickel (Ni), and tungsten (W), or silicon (Si) is used (for example, Japanese Patent Application Laid-Open No. 7-176264, See JP-A-8-264112).

In the field emission cathode, the Spindt-type electron emission element is specifically configured, for example, as follows. That is, the through hole 8 shown in FIG. 9 is formed with a diameter of 1 μm or less, and the radius of curvature of the tip of the through hole 8 is made several tens nm by a lift-off method or the like using the high melting point metal or silicon. It has a conical shape, and is formed so that the tip is directed to the second electrode 12 side. Conical height is also 1
μm or less, and the distance between the first electrode 11 and the second electrode 12 is also 1 μm or less via the insulating layer 7. When a positive voltage of several tens of volts is applied to the second electrode 12 with respect to the first electrode 11, the tip of the conical electron-emitting device 9 has an electric field of approximately 10 ⁷ V / cm, and this electron-emitting device 9 Field emission occurs from the tip of the.

In the flat display device 15 described above, such a field emission type cathode 4 is placed at a distance of 0.1 mm from the fluorescent screen 5.
They are arranged facing each other with a distance of about 2 mm to 1.0 mm.

Incidentally, such a Spindt-type field emission cathode has the following problems. (1) The threshold electric field at which field emission of refractory metals such as Mo, Ni and W or Si occurs is as high as about 10 ⁷ V / cm, so that the gate voltage supplied to the second electrode 12 must be reduced. The diameter of the through-hole of the second electrode 12 and the distance between the first electrode 11 and the second electrode 12 need to be set to submicron or less, and a submicron or less production accuracy is required. (2) Refractory metals such as Mo, Ni, and W and Si are weak to ion bombardment and easily deteriorated by residual gas or ion bombardment generated from a phosphor. For this reason, in order to secure the life of the cathode, the degree of vacuum of the normal flat display device is set to 1
It is necessary to maintain a degree of vacuum that is at least one order of magnitude lower than 0 ^-6 to 10 ^-7 torr.

On the other hand, a field emission cathode using a carbon-based material having a small threshold electric field, such as diamond, diamond-like carbon, and graphite, as an emitter instead of the high melting point metal having such a problem has been disclosed. However, the etching of carbon-based materials is 80
There are processing problems such as the necessity of performing at a high temperature of 0 ° C. or higher and a low etching rate.

Instead of this, PCT / GB96 / 01
No. 858 (WO 97/06549), conductive particles such as graphite are arranged on a conductive layer provided on a substrate with a dielectric layer interposed therebetween, and a dielectric layer is provided on the conductive particles. The thickness of the dielectric layer on the conductive particles and the thickness of the dielectric layer on the conductive layer provided on the substrate are set to 1/1 of the conductive particles.
A field emission type cathode having a structure from 0 to 1/100 has been proposed.

[0013] US Patent 5,608,
Reference numeral 283 denotes a field emission cathode in which particles of graphite, amorphous carbon, and silicon carbide are arranged on a high-resistance column formed on a conductive layer on a substrate or on this conductive layer via an adhesive layer. Plates have been proposed.

[0014]

However, the former PCT / GB96 / 01858 (WO97 / 0654)
9) is characterized in that the conductive particles are arranged via a dielectric layer, and in particular, the thickness of the dielectric layer is limited to the order of several hundreds of square meters. However, it is difficult to control the thickness of the dielectric layer on the order of several hundreds of square meters.

The latter US Patent 5,608,
283 is characterized in that the conductive particles are attached to the high resistance layer by a conductive adhesive layer, but there is a risk that the adhesive layer covers the conductive particles, in which case no field emission occurs. There was a problem.

The present invention has been made in view of the above circumstances, and provides a flat-panel display device capable of emitting electrons at a low threshold electric field and easily manufactured.

Another object of the present invention is to provide a method of manufacturing a field emission cathode which enables the use of a material capable of emitting electrons at a low threshold electric field, for example, a carbon-based material and facilitates the manufacture. .

[0018]

According to the flat display device of the present invention, the first and second substrates are opposed to each other while maintaining a required interval, and the peripheral portion of the opposed portion of the first and second substrates is provided. Is hermetically sealed, a field emission cathode is disposed on the first substrate side, a phosphor screen is formed on the second substrate side, and electrons extracted from the field emission cathode are accelerated to form a phosphor screen on the phosphor screen. What is claimed is: 1. A flat-panel display device which emits light and emits light on a phosphor screen to perform display, wherein a field emission cathode is provided on a lower first electrode separated from a second electrode via an insulating layer. An electron-emitting device made of a material capable of emitting electrons with a threshold electric field smaller than 10 ⁷ V / cm formed by a lift-off method, wherein a wall surface of an insulating layer in an opening facing the electron-emitting device is recessed from the electron-emitting device. I do.

In this flat display device, 10 ⁷ V
/ Cm can be emitted in a low threshold electric field. During manufacturing, it is possible to manufacture under favorable conditions, such as allowing a sufficient margin in the production accuracy such as the distance between the first electrode and the second electrode, the size of the opening diameter of the second electrode, and a large degree of vacuum. Becomes

In addition, the field emission cathode is formed by a lift-off method using a material having a small threshold electric field, and the insulating layer wall surface in the opening is recessed from the electron-emitting device. The reliability of the emission cathode is increased. Therefore, it is possible to provide a highly reliable flat display device capable of emitting electrons with a low threshold electric field.

In the method of manufacturing a field emission cathode according to the present invention, a step of forming an insulating layer having an opening on a portion where an electron-emitting device is to be formed on a first electrode and a second electrode thereon Forming a resist layer on a region including the second electrode except for the opening, and forming an electron emission material layer on the region including the resist layer and the opening facing the first electrode; Lifting off the resist layer and the electron-emitting material layer thereon to form an electron-emitting device with the electron-emitting material layer on the first electrode in the opening; and removing the insulating layer wall surface in the opening from the electron-emitting device. And a step of etching away so as to leave.

In this manufacturing method, after the resist layer and the electron-emitting material layer thereabove are lifted off to form an electron-emitting device in the opening, the insulating layer wall surface in the opening is removed by etching away from the electron-emitting device. Thus, the electron-emitting device and the second electrode are completely separated. Then, by this manufacturing method, for example, 10 ⁷ V / c of carbon-based material or the like is obtained.
It is possible to manufacture a field emission cathode using a material having a low threshold electric field smaller than m.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

First, a method of manufacturing a field emission cathode according to the present embodiment will be described with reference to FIGS. In addition,
FIG. 5 to FIG. 7 showing the respective steps correspond to cross sections taken along the line BB of FIG. 4 (plan view after completion).

First, as shown in FIG. 5A, a first electrode (so-called cathode electrode) 11 patterned in a stripe shape is formed on one surface of a base substrate 21 made of an insulating substrate such as glass. The entire surface including the upper surface of the first electrode 11 (excluding the terminal portion of the first electrode 11)
An insulating layer 7 made of O ₂ , glass, polyimide, or the like is coated with a chemical vapor deposition method such as a hot filament CVD method or a plasma CVD method (Chemical Vaper Deposition), a physical vapor deposition method (Physical Vaper Deposition), spin coating, and printing. It is formed using a technique or the like. Next, a metal electrode material layer 121 of gold (Au) / chromium (Cr), tungsten (W), gold (Au) / titanium (Ti), or the like is formed on the entire surface of the insulating layer 7 by vapor deposition, sputtering, or the like. accumulate.

Next, as shown in FIG. 5B, the first and second electrodes (so-called gate electrodes) to be formed on the metal electrode material layer 121 at right angles to the first electrode 11 have the same stripe pattern as that of the first electrode 11. A plurality of openings 24 are provided at the intersection of the second electrodes.
The photoresist layer 23 having a predetermined pattern having the following is formed.

Next, as shown in FIG. 5C, using the photoresist layer 23 as a mask, the metal electrode material layer 121 is selectively etched by using an etching technique such as a wet method or a dry method to be formed later. A stripe-shaped second electrode 12 having an opening (through hole) 25 at a position corresponding to the electron-emitting device is formed.

Further, as shown in FIG. 6D, using the same photoresist layer 23 as a mask, the lower insulating layer 7 is selectively etched using an etching technique such as a wet method or a dry method to form the second insulating layer 7 into a second layer. It is formed in the same pattern as the electrode 12. That is, openings (through holes) are formed in the insulating layer 17 at positions corresponding to the electron-emitting devices to be formed later.
25 are formed.

Next, as shown in FIG. 6E, the photoresist layer 23 is removed, and again, as shown in FIG. 6F, a photoresist layer 26 is coated on the entire surface except for the opening 25 by photolithography. Form.

Next, as shown in FIG. 7G, an electron-emitting material layer, for example, a material capable of emitting electrons with a threshold electric field smaller than 10 ⁷ V / cm, for example, a carbon-based material, is formed on the entire surface of the opening 25 and on the photoresist layer 26. A layer 27 is deposited, and then the photoresist layer 26 and the carbon-based material layer 27 thereon are lifted off as shown in FIG.
An electron-emitting device (so-called emitter) 28 made of a carbon-based material is formed on the first electrode 11 inside. As the carbon-based material, for example, carbon graphite, diamond, DLC, or the like can be used. The threshold electric field of the carbon-based material is about 10 ⁴ to 10 ⁵ V / cm.

In this state, the carbon-based material is
There is a possibility that the electron-emitting device 28 (therefore, the first electrode 11) and the second electrode 12 may be short-circuited by adhering to the inner wall surface of the device.

For this reason, as shown in FIG. 7I, the wall surface of the insulating layer 7 in the opening 25 is selectively etched together with the carbon-based material attached thereto, and the wall surface of the insulating layer 7 is Away from Thereby, the electron-emitting device 28
Is reliably separated from the second electrode 12, and a crown-shaped electron-emitting device 28 whose peripheral tip projects sharply upward is formed. Thus, the intended field emission cathode 30 having the cold cathode structure shown in FIGS. 4 and 7I is obtained.

According to the method of manufacturing a field emission cathode according to the present embodiment, a material having a small threshold electric field, for example, a carbon-based material such as carbon graphite particles is formed on the first electrode 11 in the opening 25 by a lift-off method. By forming the electron-emitting device 28, a material that emits electrons at a low threshold electric field, for example, a carbon-based material, for example, in the manufacture of a cold cathode field emission cathode of a three-pole (so-called cathode, gate, anode) emission device Can be used, and a field emission cathode having a low threshold electric field can be easily formed.

After the lift-off, the inner wall surface of the insulating layer 7 is removed by etching together with an electron-emitting material, for example, a carbon-based material attached thereto, to completely separate the second electrode 12 and the electron-emitting device 28. As a result, a field-emission cathode made of a low-threshold-field electron-emitting material having a sharp crown at the peripheral tip by self-alignment can be formed. The amount of electron emission can be controlled by the second electrode 12.

Next, an embodiment of the flat display device of the present invention provided with the field emission type cathode 30 manufactured by the above-described method will be described. FIG. 1 is a perspective view in which a part of a main part of the flat display device according to the present embodiment is sectioned, FIG. 2 is a perspective view of the main part, and FIG. 3 shows a cross section.

The flat panel display 35 according to the present embodiment is
A first and a second respectively constituted by a glass substrate, for example.
Substrates 1 and 2 are opposed to each other via a reinforcing spacer 3 having a required height with a required space therebetween,
The periphery of these opposing substrates 1 and 2 is hermetically sealed with, for example, a glass frit via an insulating peripheral frame 14 made of ceramic or the like, so that an airtight flat space is formed between the two substrates 1 and 2. A field emission cathode 30 is provided on the first substrate 1 side.
And a fluorescent screen 5 is formed on the second substrate 2 side.

On the first substrate 1, a plurality of first electrodes (so-called cathode electrodes) 11 each having, for example, a stripe shape are provided.
And a second electrode (a so-called gate electrode) 12 are arranged in parallel in a direction crossing each other, and the crossing portion is formed by the insulating layer 7.
Are formed so as to be electrically insulated through the substrate.

For example, a field emission type cathode 30 having a cold cathode configuration is formed corresponding to each intersection of the first and second electrodes 11 and 12.

The field emission cathode 30 has a first electrode 11 in an opening (through hole) 25 formed through the second electrode 12 and the insulating layer 7 so as to reach the first electrode 11.
An electron-emitting device 28 made of a material capable of emitting electrons with a threshold electric field smaller than 10 ⁷ V / cm formed thereon by a lift-off method, for example, a carbon-based material can be used. In this case, the electron-emitting device 28 is formed in a crown shape such that the peripheral tip projects sharply upward, and the opening 2
The wall surface of the insulating layer 7 in 5 is formed so as to recede away from the electron-emitting device 28. This ensures that the electron-emitting device 28 is electrically separated from the second electrode 12.

The field emission cathode 30 has a plurality of electron emission elements 2 per pixel as shown in FIG.
8 can be arranged and configured.

The fluorescent screen 5 on the side of the second substrate 2 is not shown, for example, in the case of forming a flat display device by color display, but is not shown, for example, each of red, green and blue phosphors R, G and B.
Are formed in a predetermined arrangement order, for example, a so-called black matrix is formed between the phosphors R, G, and B by a light absorbing layer.

A metal back layer 6 made of a thin film conductive layer having the function of an accelerating electrode is formed on the phosphor screen 5. A high accelerating voltage (so-called anode voltage), for example, 5 KV, is applied to the metal back layer 6. Supplied.

In the flat display device 35, a required voltage is applied between selected ones of the first and second electrodes 11 and 12, so that the field emission type cathode 30 disposed at the crossing portion is used. Electrons are taken out, accelerated by the above-mentioned acceleration voltage, penetrated through the metal back layer 6 and impacted on the phosphor screen 5 to excite this portion to emit light, thereby performing a desired light emission display, for example, image display.

According to the flat display device 35 according to the present embodiment, by providing the field emission type cathode 30 made of a material which emits electrons with a low threshold electric field formed by the lift-off method, for example, a carbon-based material, 10 ⁷ V / c
Electrons can be emitted with a low threshold electric field smaller than m. With this, it is possible to provide a margin in the accuracy of forming the distance between the first electrode 11 and the second electrode 12, the size of the opening diameter of the second electrode 12, and the like, and to increase the degree of vacuum in the flat space. For example, the production under preferable conditions becomes possible. The configuration of the field emission cathode 30 is also simplified. Therefore, it is easy to manufacture a flat-panel display device that can emit electrons with this kind of low threshold electric field.

The field emission type cathode 30 is formed by a lift-off method using a material having a small threshold electric field, for example, a carbon-based material, and the wall surface of the insulating layer 7 in the opening 25 is recessed from the electron-emitting device 28. As a result, electrical separation between the second electrode 12 and the electron-emitting device 28 (that is, the first electrode 11) is ensured, and a highly reliable flat-panel display device capable of emitting electrons with a low threshold electric field is provided. it can.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the field emission type cathode 30 of the present invention will be described. In the present embodiment, in the step of FIG. 5A, a printed insulating paste (for example, glass paste) is
1 is printed on the glass substrate 21 on which
By baking for 20 minutes, an insulating layer 7 having a thickness of about 5 μm is formed. Further, chromium (Cr) is deposited on the insulating layer 7 by using an electron beam evaporation apparatus at a thickness of 200 °, and then gold ( Au) is deposited to a thickness of 2000 mm to form a metal electrode material layer 12
Form one.

In the step of FIG. 5B, a positive resist layer 23 is formed, and in the step of FIG. 5C, chromium (Cr) is converted to ceric ammonium nitrate: hydrogen peroxide: pure using this positive resist layer 23 as a mask. Using a solution in which water was mixed at a ratio of 10:20:70, gold (Au) was etched using a solution in which iodine: potassium iodide: pure water was mixed at a ratio of 1: 20: 100, respectively. , An opening 25 is formed. The formation of the positive resist mask 23 was performed using the photolithography technique under the conditions shown in Table 1.

[0048]

[Table 1]

In the step of FIG. 6D, the insulating layer 7 made of the printed insulating paste (glass paste) is etched with, for example, a nitric acid-based etching solution to form the opening 25.

Next, in the step of FIG. 6F, the negative resist layer 2 patterned by photolithography is used.
Then, carbon graphite particles of a carbon-based material, for example, carbon graphite particles are deposited by vapor deposition or spin coating, the negative resist layer 26 is dissolved in a solvent, lift-off is performed, and the carbon graphite particles are embedded in the openings 25. In this example, the negative resist layer 26 was patterned using the photolithography technique under the conditions shown in Table 2.

The carbon graphite particles were obtained by spin-coating a carbon graphite particle paint under the conditions shown in Table 3,
The film is baked at 180 ° C., and then fired at 530 ° C. to deposit. Further, the carbon graphite particle paint used here contains submicron graphite particles and a terpene resin.

[0052]

[Table 2]

[0053]

[Table 3]

When the carbon graphite particles are merely buried in the coating material, the carbon graphite particles adhere to the inner wall surface of the insulating layer 7, and the second electrode 12 and the first electrode 11 are short-circuited. Does not work as cathode. Therefore, an electron-emitting device 28 made of carbon graphite particles is formed at a desired position of the opening 25 while etching the inner wall surface of the insulating layer 7 to remove the carbon graphite particles attached to the inner wall surface.
As the etching of the insulating layer 7, nitric acid: pure water is used in a ratio of 1:
Etching is performed at an etching rate of 2 μm / sec using a solution mixed at a ratio of 1000. The electron-emitting device 28 made of carbon graphite particles thus formed functions as the field emission cathode 30 without short-circuiting with the second electrode 12.

[0055]

According to the flat display device of the present invention, it is possible to provide a field emission type flat display device capable of emitting electrons at a low threshold electric field. In addition, it is possible to form the first electrode, the second electrode, and the field emission cathode under preferable conditions with a margin of production accuracy, and to set a preferable degree of vacuum in a flat space. High reliability and easy manufacture of a flat display device capable of emitting electrons in an electric field can be achieved.

According to the method of manufacturing a field emission cathode of the present invention, an electron emission material that can emit electrons with a low threshold electric field, such as a carbon-based material, can be used. Can be manufactured. In addition, a field emission cathode capable of emitting electrons by a low threshold electric field can be produced under conditions that are not strictly accurate. Therefore, the present invention can be suitably applied to, for example, the manufacture of a field emission cathode for a flat display device.

[Brief description of the drawings]

FIG. 1 is a perspective view, partially in section, of a main part showing an embodiment of a flat panel display according to the present invention.

FIG. 2 is a perspective view showing a field emission cathode of the flat panel display of FIG. 1;

FIG. 3 is a sectional view taken on line AA of FIG. 2;

FIG. 4 is a plan view of a main part showing one embodiment of a field emission cathode according to the present invention.

FIGS. 5A to 5C are views showing a manufacturing process of a field emission cathode according to the present invention.

6A to 6F are manufacturing process diagrams of the field emission cathode according to the present invention.

7A to 7G are views showing a manufacturing process of a field emission cathode according to the present invention.

FIG. 8 is a perspective view showing a cross section of a part of a main part of a conventional flat display device.

FIG. 9 is a perspective view showing a field emission cathode of a conventional flat display device.

[Explanation of symbols]

1,2,21 substrate, 3 spacer, 5 fluorescent screen, 6 metal back, 7 insulating layer, 11 and 12
{Electrode, 121} metal electrode material layer, 23, 26 photoresist layer, 25 opening, 27 electron emitting material layer, 28 electron emitting device, 4, 30 field emission cathode, 25,35 ‥‥ flat panel display

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 29, 1999 (1999.1.2
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction contents]

[0048]

[Table 1]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0054

[Correction method] Change

[Correction contents]

When the carbon graphite particles are merely buried in the coating material, the carbon graphite particles adhere to the inner wall surface of the insulating layer 7, and the second electrode 12 and the first electrode 11 are short-circuited. Does not work as cathode. Therefore, an electron-emitting device 28 made of carbon graphite particles is formed at a desired position of the opening 25 while etching the inner wall surface of the insulating layer 7 to remove the carbon graphite particles attached to the inner wall surface.
As the etching of the insulating layer 7, nitric acid: pure water is used in a ratio of 1:
Etching is performed at an etching rate of 2 μm / min using a solution mixed at a ratio of 1000. The electron-emitting device 28 made of carbon graphite particles thus formed functions as the field emission cathode 30 without short-circuiting with the second electrode 12.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jiro Yamada 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5C031 DD09 DD17 DD19 5C036 EE01 EE14 EF01 EF06 EF09 EG12 EH06 EH08 EH11

Claims (4)

[Claims] A first substrate facing the first substrate and a second substrate facing the first substrate at a predetermined interval; a peripheral portion of a facing portion between the first substrate and the second substrate being hermetically sealed; A field emission cathode is disposed on the side, a phosphor screen is formed on the second substrate side, and electrons extracted from the field emission cathode are accelerated and irradiated on the phosphor screen to excite the phosphor screen to emit light. Wherein the field emission cathode is formed by a lift-off method on a lower first electrode separated from a second electrode via an insulating layer. An electron-emitting device made of a material capable of emitting electrons with a threshold electric field smaller than 10 ⁷ V / cm, wherein an insulating layer wall surface in an opening facing the electron-emitting device is recessed from the electron-emitting device. Flat panel display. 2. The flat display device according to claim 1, wherein said electron-emitting device is formed of a carbon-based material. A step of forming an insulating layer having an opening on a portion where an electron-emitting device is to be formed on the first electrode and a second electrode on the insulating layer; Forming a resist layer on a region including on the electrode, and forming an electron emitting material layer on the region including the opening and the resist layer facing the first electrode; and forming the resist layer and the resist layer. Lifting off the upper electron-emitting material layer to form an electron-emitting device using the electron-emitting material layer on the first electrode in the opening; and removing an insulating layer wall surface in the opening from the electron-emitting device. Etching away so as to separate them from each other. 4. The method according to claim 3, wherein the electron-emitting material is a carbon-based material layer.