JP2000251625A - Electron emitting element, electron source, image forming device, and manufacture of the electron emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an element having high electron emitting efficiency and stable electron emitting characteristic over a long time by increasing the conductivity of a pair of films, having carbon which are connected to a pair of electrodes, respectively, and partitioned by a first clearance part toward the first clearance part. SOLUTION: A pair of films having carbon is electrically connected to electrodes via a conductive thin film 4 arranged between the electrodes, and the conductive thin film 4 has a second clearance part between the electrodes. A first clearance part 8 is arranged within the second clearance part, and the narrowest part in the vertical direction to a base body surface of the first clearance part 8 is preferably located on the end part distant from the base body surface. An electron emission part 5 is formed of films 21 and 22 having carbon, which are opposed with the first clearance part 8 between, and a substrate recessed part 23 having carbon atom by passing through activation process. The film present in the narrowest position of the first clearance part 8 has a thickness of 100 nm or less, the carbon is graphite carbon, and a Pd fine particle film is suitably used as the conductive thin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron-emitting device, an electron source, an image forming apparatus, and a method for manufacturing an electron-emitting device.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction type electron emission element.

As an example of the FE type, W. P. Dyke &
W. W. Dolan, "Fielddemissio
n ", Advance in Electron Ph
ysics, 8, 89 (1956) or C.I. A. S
pindt, "PhysicalProperties"
of thin-film field emiss
ion cathodes with mollybde
nium cones ", J. Appl. Phys.,
47, 5248 (1976).

As an example of the MIM type, C.I. A. Mead,
“Operation of Tunnel-Emis
Sion Devices ", J. Apply. Phys.
s. 32, 646 (1961) and the like are known.

As an example of the surface conduction electron-emitting device,
M. I. Elinson, RadioEng. Elec
Tron Phys. , 10, 1290, (1965)
Etc.

[0006] The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using a SnO2 thin film by Elinson et al. And a device using an Au thin film [G. Dimmer, Thin Solid Fil
ms, 9, 317 (1972)], In2 O3 / SnO
2 Thin film [M. Hartwell and
C. G. FIG. Fonsted, IEEE Trans. ED
Conf. , 519 (1975)], and those using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)], and the like.

As a typical configuration of these surface conduction type emission devices, the above-mentioned M.D. Figure 1 shows the device configuration of Hartwell
FIG. In FIG. 1, reference numeral 1 denotes an insulating substrate. Reference numeral 4 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and a linear electron-emitting portion 5 is formed by an energization process called forming described later. In the drawing, the element electrode interval L is set to 0.5 to 1 mm, and W is set to 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, before the electron emission, the electron-emitting portion 5 is generally formed by applying a current to the conductive thin film 4 by a process called forming. That is, forming means applying a DC voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 4 and energizing the conductive thin film 4 to locally break, deform or alter the conductive thin film, thereby increasing the electrical resistance. This is to form the electron-emitting portion 5 in a resistance state. In the electron emitting portion 5, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface-conduction type electron-emitting device that has been subjected to the forming process is configured to apply a voltage to the conductive thin film 4 and cause a current to flow through the device, thereby causing the electron-emitting portion 5 to emit electrons.

On the other hand, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-235255, there is a case where an element which has been formed is subjected to a process called an activation process. The activation processing step means that the element current I
f, a step in which the emission current Ie changes significantly.

[0010] The activation step can be performed by applying a voltage to the element in an atmosphere containing an organic substance, similarly to the forming process. By this treatment, carbon or a carbon compound is deposited from the organic substance present in the atmosphere at the electron emission portion of the device and in the vicinity thereof, and the device current If and the emission current Ie are remarkably changed. Obtainable.

FIG. 18 shows a cross-sectional shape of the electron-emitting device disclosed in Japanese Patent Application Laid-Open No. 7-235255. In this figure, 1, 4 and 5 are the same as those in FIG. 17, and represent an insulating substrate, a conductive thin film, and an electron-emitting portion, respectively.
Reference numerals 2 and 3 denote device electrodes for applying a voltage to the conductive thin film 4, and a voltage is applied by using 2 as a low potential side electrode and 3 as a high potential side electrode. The electron emitting portion 5 has a structure in which carbon or the carbon compound 6 is deposited by performing the above-described activation step, and realizes good electron emission characteristics.

An image forming apparatus can be constructed by using an electron source substrate on which a plurality of electron-emitting devices as described above are formed and combining it with an image forming member made of a phosphor or the like.

[0013]

However, with the rapid progress of multimedia with the advancement of information in recent years, higher performance is required for image forming apparatuses such as displays. That is, the screen size of the display device is increased, the power consumption is reduced, the definition is increased, the image quality is increased, and the space is saved.

Therefore, in the above-mentioned electron-emitting device, the image forming apparatus to which the electron-emitting device is applied keeps a stable and high-emission characteristic for a longer period of time so that a bright display image can be stably provided. Technology is desired.

Here, the efficiency refers to a current (hereinafter, referred to as an element current If) flowing in a vacuum when a voltage is applied between a pair of opposing element electrodes of the surface conduction electron-emitting element. (Hereinafter referred to as emission current Ie).

That is, it is desirable that the device current If be as small as possible and the emission current Ie be as large as possible.

If high-efficiency electron emission characteristics can be stably controlled over a long period of time, for example, in an image forming apparatus using a phosphor as an image forming member, a low-power, bright, high-quality image forming apparatus such as a flat TV can be realized.

However, the above-mentioned M.P. In the case of Hartwell's electron-emitting devices, satisfactory electron-emitting characteristics and electron-emitting efficiencies have not always been obtained. The fact is that it is extremely difficult to provide

In other words, for use in such applications, a sufficient emission current Ie can be obtained at a practical voltage (for example, 10 V to 20 V), and the emission current Ie and the device current If do not fluctuate significantly during driving. It is necessary that the emission current Ie and the device current If do not deteriorate for a long time. However, the conventional surface conduction electron-emitting device has the following problems.

As shown in FIG. 17, the surface conduction electron-emitting device has a linear electron-emitting portion 5 substantially perpendicular to the voltage application direction.

The electron emitting portion 5 is constituted by a gap formed in the conductive thin film by forming as described above, but the gap is not necessarily formed with a uniform width and shape over the entire area as shown in FIG. Not always. In the case of such a non-uniform electron emission portion configuration, a sufficient emission current Ie
May not be obtained, or the characteristics may fluctuate or deteriorate significantly during driving.

On the other hand, according to the above-described activation step, a film having carbon, such as carbon or a carbon compound, is deposited on the substrate in the gap formed in the conductive thin film and on the conductive thin film in the vicinity thereof. A narrower gap is formed (FIG. 1).
8). The activation step increases the emission current Ie and the device current If. However, the device characteristics such as the electron emission efficiency and lifetime depend on the shape, structure, and structure of the carbon-containing film deposited by the activation step. It depends on the stability.

In particular, since a high electric field is applied to the above-mentioned narrow gap formed in the deposit, the behavior when electrons are emitted between the deposits sandwiching this gap, and the behavior when discharging is regarded as discharge. It is important for stability to control the phenomenon that occurs. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its main objects to increase the electron emission efficiency of an electron-emitting device and to stabilize the electron emission characteristics.

[0024]

In view of the above problems, the present inventors have studied and found that a pair of electrodes disposed on the surface of a substrate are connected to the pair of electrodes, respectively. A film having a pair of carbons separated by a gap, and using the electron-emitting device, wherein the conductivity of the film having the carbon increases toward the first gap. An object of the present invention is to provide an electron-emitting device having high electron emission efficiency and stable electron emission characteristics for a long time.

The present invention is further characterized in that the film having a pair of carbons is electrically connected to the electrodes via a conductive thin film disposed between the pair of electrodes. Preferably, the conductive thin film has a second gap between the pair of electrodes, and a first gap of the film having the pair of carbons is arranged in the second gap. In the first gap portion of the film having a pair of carbons, the narrowest portion in a direction perpendicular to the surface of the substrate is located at an end of the film having the pair of carbons away from the substrate surface. Is preferable, and the substrate is
It is preferable that the first gap portion has a concave portion, and that the concave portion surface has carbon, and that an extension line connecting the narrowest portion of the first gap portion in a direction perpendicular to the substrate surface. The thickness of the existing film having a pair of carbons is 1
The thickness is preferably not more than 00 nm, the carbon in the film having a pair of carbons is preferably graphite-like carbon, and the conductive thin film is preferably a Pd fine particle film.

The present invention further has the following features.
An electron source, wherein a plurality of the above-described electron-emitting devices are formed on a substrate, and electrons are emitted from at least one of the electron-emitting devices in response to an input signal. And an image forming member that forms an image by irradiating electrons emitted from the electron source.

In the method of manufacturing an electron-emitting device, a voltage is applied between a pair of conductive thin films having a gap in an atmosphere containing an organic substance to remove carbon from the organic substance present in the atmosphere. In a method of manufacturing an electron-emitting device in which a film having an active layer is formed around the gap and the gap is activated, the activation is performed while the gap is extremely heated. .

It is preferable that the extreme heating of the gap is not performed in the initial stage of the formation of the carbon-containing film, but is performed during the formation of the carbon-containing film and thereafter. Suitable heating is preferably performed by laser light irradiation.

According to the electron-emitting device of the present invention thus configured, since the conductivity of the carbon-containing film increases toward the first gap, the potential distribution change near the electron-emitting portion is small. Become. Therefore, when the electron-emitting device is driven with the gap as a boundary, the electron-emitting device falls on a carbon-containing film or conductive thin film or a device electrode on the side to which a higher voltage is applied and is absorbed and is partially absorbed by the device current (If) Decreases, while the amount of electrons reaching the anode electrode (emission current Ie) increases.

Further, when the substrate exposed in the first gap has a recess, the creeping distance between the films having carbon opposed to each other with the gap therebetween increases depending on the depth of the recess. This suppresses a discharge phenomenon and an element current If, which are considered to be caused by a strong electric field between the films having carbon opposed to each other with the gap therebetween (gap).

Further, it is assumed that the substrate surface (insulating) exposed between the gaps is irradiated with the emitted electrons, but the electrons are irradiated by having carbon in the concave portions. This suppresses the charging phenomenon caused by such a phenomenon, and as a result, the fluctuation and deterioration of the element characteristics, which are considered to be caused by the charging phenomenon, are also suppressed, and the above-described discharge phenomenon is further suppressed.

Further, according to the method for manufacturing an electron-emitting device, it is possible to obtain an electron-emitting device in which the conductivity of a film having carbon increases toward the first gap, and the electron emission device has high efficiency and high stability. An element is obtained.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

First, the basic structure of the electron-emitting device according to the present invention will be described.

FIGS. 1 (a) and 1 (b) are a plan view and a sectional view, respectively, showing the structure of a basic planar electron-emitting device according to the present invention. 2 (a), (b),
(C) is a plan view, a cross-sectional view, and a schematic diagram showing a conductivity distribution of a film having carbon, respectively, in which the structure in the vicinity of the electron emission portion of the surface conduction electron-emitting device according to the present invention is enlarged and schematically shown. It is. The basic structure of the device according to the present invention will be described with reference to FIGS.

In FIG. 1, 1 is a substrate as a base, 2 and 3 are device electrodes as a pair of electrodes, 4 is a conductive thin film,
Denotes an electron emission portion.

2A and 2B, reference numeral 1 denotes a substrate;
4 is a conductive thin film, 5 is an electron emitting portion, 21 and 22 are deposits having carbon deposited on the substrate 1 and the conductive thin film 4 in a gap (second gap) formed in the conductive thin film. (Film: film having a pair of carbon), and reference numeral 23 denotes a substrate altered portion (recess) having carbon atoms. Note that the deposits are opposed to the substrate surface in the lateral direction (parallel to the substrate surface) with the gaps 8 (first gaps) as boundaries, and
Although they are schematically shown as being divided into 1 and 22, they may be partially connected. The deposit 21 is also deposited on the conductive thin film 4 on the side of the element electrode 2 and the deposit 22
Are also deposited on the conductive thin film on the element electrode 3 side. FIG. 2C shows a direction (F-A) crossing the gap in FIG.
5 schematically shows the conductivity distribution of a film having carbon (portion indicated by F ′), and the feature of the present invention is that the conductivity increases toward the gap 8.

With the above arrangement, the deposits (21, 22)
Are electrically connected to the device electrodes (2, 3). In the drawings, the deposits (21, 22) which are films containing carbon are:
When connected to the device electrodes (2, 3) via the conductive thin film, the deposits (21, 22) are respectively deposited on the device electrodes (2, 3) and are directly electrically connected. There is also.

The substrate 1 is made of quartz glass, blue plate glass, blue plate glass, or the like formed by sputtering or the like.
And a ceramic substrate such as alumina. These substrates are desirably made of a material containing SiO2, so that an electron emitting portion 5 having a substrate altered portion 23 more suitable for the present invention can be formed in an activation step described later.

The material of the opposing device electrodes 2 and 3 may be any material as long as it has conductivity. For example, Ni, Cr, Au, Mo, W, Pt,
Metals or alloys such as Ti, Al, Cu, Pd and Pd;
A printed conductor made of a metal such as Ag, Au, RuO2, Pd-Ag or a metal oxide and glass; ln2 O3
A transparent conductor such as -SnO2 and a semiconductor conductor material such as polysilicon.

The distance L between the device electrodes, the length W of the device electrode, and the shape thereof are appropriately designed depending on the application form of the electron-emitting device. For example, in a display device such as a television described later, a pixel corresponding to the screen size is used. The size is designed. In particular, a high-definition television requires a small pixel size and high definition. Therefore, in order to obtain a sufficient luminance even when the size of the electron-emitting device is limited, it is designed so that a sufficient emission current is obtained.

The distance L between the device electrodes is several tens nm to several hundred μm.
Yes, the photolithography technology that is the basis of the device electrode manufacturing method, i.e., the performance of the exposure device and the etching method, etc., and is set by the voltage applied between the device electrodes, preferably, from several μm to several tens μm is there.

The length W of the device electrode and the device electrode 2,
The film thickness d of 3 is appropriately designed in consideration of the resistance value of the electrode, the connection with the X and Y wirings described above, and the arrangement of a large number of electron sources. μm to several hundred μm, and the film thickness d of the device electrodes 2 and 3 is several μm to several μm.

In addition to the structure shown in FIG.
A configuration in which the conductive thin film 4 and the opposing device electrodes 2 and 3 are laminated on the above in this order can also be adopted.

As the conductive thin film 4, a fine particle film composed of fine particles is preferably used in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of the step coverage for the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, a forming condition described later, and the like.

Further, since the magnitudes of the device current If and the emission current Ie depend on the width W of the conductive thin film 4, as in the case of the shape of the device electrode, it is sufficient when the size of the electron emission device is limited. It is designed to obtain an emission current.

In general, the thermal stability of the conductive thin film 4 may dominate the life of the electron emission characteristics, and it is desirable to use a material having a higher melting point as the material of the conductive thin film 4. However, usually, as the melting point of the conductive thin film 4 is higher, larger electric power is required for energization forming described later.

Further, an applied voltage (threshold voltage) at which electrons can be emitted depends on the shape of the resulting electron emitting portion.
In some cases, a problem occurs in the electron emission characteristics such as an increase in

In the present invention, the material of the conductive thin film 4 is not particularly required to be a material having a high melting point, and a material / form capable of forming a good electron emission portion with a relatively low forming power is selected. Can be.

Examples of materials satisfying the above conditions include Ni,
It is preferable to use a conductive material such as Au, PdO, Pd, or Pt formed with a film thickness having a resistance value of Rs (sheet resistance) of 102 to 107 Ω / □. Rs is a value that appears when a resistance R measured in the length direction of a thin film having a thickness t, a width w, and a length 1 is R = Rs (l / w). Then, Rs = ρ / t. The film thickness showing the above-mentioned resistance value is in the range of about 5 nm to 50 nm, and in this film thickness range, the thin film of each material has the form of a fine particle film.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure in a state in which the fine particles are individually dispersed and arranged or in a state in which the fine particles are adjacent to each other or overlap each other (some fine particles are formed). To form an island-like structure as a whole).

The particle diameter of the fine particles is in the range of several hundred pm to several hundred nm, preferably in the range of 1 nm to 20 nm.

Now, among the materials exemplified above, Pd
O can be easily formed into a thin film by baking an organic Pd compound in the air, has a relatively low electric conductivity because it is a semiconductor, has a wide process margin of film thickness for obtaining the resistance value Rs in the above range, and has a conductive thin film. This is a preferable material because it can be easily reduced to metal Pd after forming a gap portion in, for example, and the film resistance can be reduced. However, the effect of the present invention is not limited to PdO,
Further, the material is not limited to the above-mentioned materials.

The length of the electron emitting portion 5 is substantially determined by the width W ′ of the conductive thin film 4.

The electron emitting portion 5 faces the first gap 8 narrower than the second gap formed in the conductive thin film as shown in FIG. Composed of films 21 and 22 having carbon and substrate concave portions 23 having carbon atoms.

The films 21 and 22 containing carbon are mainly made of graphite-like carbon, but may contain elements constituting the conductive thin film 4. As shown in FIG. 2, the shapes of the deposits 21 and 22 containing carbon as a main component in the present invention have a height H1 from the surface of each conductive thin film 4 and
High potential side deposit 2 to which higher voltage is applied during driving
2, and the gap 8 of the deposit is characterized by having a narrower portion above the surface of the substrate and the surface of the conductive thin film.

Strictly speaking, the height H1 depends on the deposits 21 and 22.
When the potential difference is applied so that the side of the deposit 22 has a high potential during the period, the position where the electric field is strongest (points A and B) is defined by the height from the surface of the conductive thin film 4, and D1 is When the deposit 22 is cut along an extension line connecting the point A and the point B, the thickness is defined by the thickness (length) of the deposit existing there. In a broad sense, the positions where the electric field is strongest (points A and B) are where the deposits 21 and 22 are closest (the gap 8 is the narrowest).
Position.

In order to describe the electron-emitting device of the present invention in detail, first, a measurement and evaluation device will be described with reference to FIG.

FIG. 3 is a schematic configuration diagram of a measurement evaluation apparatus for measuring the electron emission characteristics of the device having the configuration shown in FIG. In FIG. 3, 1 is a base, 2 and 3 are device electrodes, 4 is a conductive thin film, and 5 is an electron emitting portion. Also,
31 is a power supply for applying the element voltage Vf to the element, 30
Is a device current I flowing through the conductive thin film 4 between the device electrodes 2 and 3.
f, an ammeter for measuring f, an anode electrode for capturing an emission current Ie emitted from the electron-emitting portion of the device, a high-voltage power supply for applying a voltage to the anode electrode, and a reference numeral 32 for the device. This is an ammeter for measuring the emission current Ie emitted from the electron emission section 5.

In measuring the device current If and the emission current Ie of the current emitting device, the power source 31 is connected to the device electrodes 2 and 3.
And an ammeter 30, and an anode 34 connected to a power supply 33 and an ammeter 32 is disposed above the electron-emitting device. Further, the electron-emitting device and the anode electrode 34
Is installed in a vacuum device.

In FIG. 3, when a voltage is applied between the device electrodes 2 and 3 so that the device electrode 3 has a high potential, the deposits 21 and 22 shown in FIG.
And a potential difference is generated according to the voltage applied between them. At this time, a strong electric field is generated around the point A on the deposit 21 and the point B on the deposit 22. If this electric field is large enough to allow tunneling of electrons from the deposit 21 to the deposit 22, the electrons tunnel from the vicinity of the point A on the deposit 21 to the vicinity of the point B on the deposit 22. Conceivable.

Here, it is considered that the electrons tunneled from the vicinity of the point A are partially scattered in the vicinity of the point B of the deposit 22, and the remaining part enters the deposit 22. here,
The electrons partially scattered in the vicinity of the point B of the deposit 22 enter the deposit 22 or the conductive thin film 4 again, and the element current I
It is presumed that there are some that become a part of f and those that fly in vacuum and are captured by the anode electrode 34 and observed as the emission current Ie. Therefore, in the electron-emitting device of the present invention, since the position where the electric field is considered to be the strongest and the position where the gap portion 8 is the narrowest is higher than the surface of the conductive thin film 4 connected to the device electrode 3, scattering is caused. After that, it is considered that the ratio of electrons that enter the conductive thin film 4 and become a part of the device current If decreases, and as a result, the ratio of the emission current Ie increases and the electron emission efficiency improves. In the present invention,
It is also characterized by the fact that the conductivity of the film containing carbon is higher toward the gap, and therefore, the change in the potential distribution in the vicinity is small. That is, since the potential rise toward the element electrode 3 is gradual, the force of the scattered electrons in the direction toward the substrate is reduced,
It is considered that this also further reduces the proportion of electrons that enter the conductive thin film 4 after being scattered and become a part of the device current If. As a result, the proportion of the emission current Ie increases, and the electron emission efficiency increases. Is improved.

On the other hand, the electrons that have entered the deposit 22 flow directly to the device electrode 3 through the conductive thin film 4 and are observed by the ammeter 30 as a device current If. Since the thickness D1 is formed to be thin, it is considered that a part of the entered electrons is transmitted through the deposit 22 and released into the vacuum.

Therefore, it is considered that the emission current Ie of the electron-emitting device of the present invention includes the emission current due to the electrons scattered by the deposit 22 and the emission current due to the electrons transmitted through the deposit 22.

The transmittance Te of the electrons passing through the deposit 22
Can be represented by the following equation.

Te = exp (−D1 / La) (1) where La is the decay length of electrons in the deposit 22.

It is known that the attenuation length of an electron having energy of 10 eV to 20 eV in a substance (metal) is about 3 to 10 atomic layers. Thus, for example, the deposit 22
In the case where the carbon spacing d002 is 0.38 nm and the direction of incidence of electrons coincides with the c-axis of carbon, the decay length of electrons is about 1 to 4 nm.

The thickness D1 of the deposit 22 necessary for the transmittance Te of the electrons passing through the deposit 22 to be, for example, 0.1%.
By substituting La = 4 nm and Te = 0.001 into equation (1), D1 = 28 nm. Normally, the current caused by the electrons scattered by the deposit 22 is about 0.1% of the element current If.
It is considered that the total emission current Ie almost doubles by setting the value to.

In the present invention, it is more preferable to set the value to about D1 or less, but it is known that when the density of free electrons in a substance is small (semiconductor or insulator), the decay length of electrons becomes long. D1 varies depending on the orientation of graphite-like carbon constituting the deposit 22, interplanar spacing, carrier concentration and the like, and is not strictly limited to this value, and is preferably 100 nm or less.

On the other hand, the electrons transmitted through the deposit 22 also enter the deposit 22 or the conductive thin film 4 again like the scattered electrons and become a part of the device current If. It is considered that there are some which are captured by the electrode 34 and observed as the emission current Ie.

In the present invention, since the shapes of the deposits 21 and 22, which are films containing carbon, are configured as described above,
Efficient electron emission characteristics can be obtained.

Various methods are conceivable as a method for manufacturing the above-mentioned electron-emitting device. One example is shown in FIG.

Hereinafter, the manufacturing method will be described with reference to FIGS.
A description will be given based on FIG. 2 and FIG.

1) After sufficiently washing the substrate 1 with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum deposition method, a sputtering method or the like, and then the device electrodes 2, 3 are formed by a photolithography technique ( FIG. 4 (a).

2) An organic metal film is formed between the element electrodes 2 and 3 provided on the substrate 1 by applying and drying an organic metal solution. The organic metal solution is a solution of an organic metal compound containing a metal such as Pd, Ni, Au, or Pt as a main element. Thereafter, the organic metal film is heated and baked, and patterned by lift-off, etching, or the like to form a conductive thin film 4 (FIG. 4).
(B)). Note that, here, the description has been made with the application method of the organometallic solution, but the present invention is not limited thereto, and is formed by a vacuum evaporation method, a sputtering method, a CVD method, a dispersion coating method, a dipping method, a spinner method, an inkjet method, or the like. In some cases.

3) Subsequently, an energizing process called forming is performed by applying a pulse voltage or a rising voltage between the element electrodes 2 and 3 by using a power supply (not shown).
A gap 7 is formed in a part of the conductive thin film 4, and the conductive thin film is disposed to face the substrate surface in the lateral direction with the gap 7 interposed therebetween (FIG. 4C). The gap 7 may be partially connected.

The electrical processing after the forming processing is performed in the measurement and evaluation apparatus shown in FIG.

Although the measurement and evaluation apparatus shown in FIG. 3 is a vacuum apparatus, the vacuum apparatus is provided with equipment necessary for a vacuum apparatus such as an exhaust pump (not shown) and a vacuum gauge. The device can be measured and evaluated below.
The exhaust pump includes a high-vacuum system such as a magnetic levitation turbo pump and a dry pump that does not use oil, and an ultra-high vacuum system including an ion pump. In addition, a gas introduction device (not shown) is attached to the measurement device,
The vapor of the desired organic substance can be introduced into the vacuum at the desired pressure. The entire vacuum device and the electron-emitting device can be heated by a heater (not shown).

In the forming process, there are a case where a pulse having a constant pulse peak value is applied and a case where a voltage pulse is applied while increasing the pulse peak value. First, FIG. 5A shows a voltage waveform in a case where a pulse having a pulse peak value of a constant voltage is applied.

In FIG. 5A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec to 1 μs.
0 msec, T2 is set to 10 μsec to 100 msec, and the peak value of the triangular wave (peak voltage at the time of forming) is appropriately selected.

Next, FIG. 5B shows a voltage waveform when a voltage pulse is applied while increasing the pulse peak value.

In FIG. 5B, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec to 1 μs.
0 msec, T2 is 10 μsec to 100 msec, and the peak value of the triangular wave (peak voltage at the time of forming)
Is increased by, for example, about 0.1 V steps.

Note that the forming process ends when the conductive thin film 4 is locally destroyed during the forming pulse.
A voltage that does not deform, for example, a pulse voltage of about 0.1 V is inserted, and the element current is measured to obtain a resistance value.
When the resistance was 1 MΩ or more, the forming was terminated.

In forming the gap 7 described above, the forming process is performed by applying a triangular wave pulse between the electrodes of the element, but the waveform applied between the electrodes of the element is not limited to the triangular wave. A desired waveform such as a rectangular wave may be used, and the peak value, pulse width, pulse interval and the like are not limited to the above-mentioned values. Select an appropriate value according to the value.

4) Next, an activation process is performed on the element for which the forming has been completed. The activation treatment is performed by introducing a gas of an organic substance into the vacuum apparatus shown in FIG. 3 and applying a voltage between the electrodes of the element under an atmosphere containing the organic substance.
By this treatment, a film having carbon is deposited on the element from the organic substance existing in the atmosphere with the deterioration of the substrate,
The element current If and the emission current Ie change remarkably.

In the present invention, the shape of the carbon-containing film deposited by the activation treatment is changed to the shape shown in FIG.
It must be formed with good control. The shape of the film containing carbon, which is a deposit, depends on the voltage waveform applied to the element, the pressure of the introduced organic substance, the diffusion mobility on the element surface, the average residence time on the element surface, and the like. It is also important to have easy handling such as easy introduction into a vacuum device and easy exhaustion after activation. From the above viewpoints, as a result of examining various organic substances, it was found that a nitrile compound was effective, and particularly when tolunitrile (toluene cyanide) or acrylonitrile was used, it had good controllability. Although the reason why these organic substances are preferably used is not strictly understood, a nitrile group (—C≡) is preferred.
This is probably because the state of adsorption to the element surface via N) conforms to the above conditions.

Hereinafter, a process of forming a deposit, which is a film containing carbon, in the activation process of the present invention will be described with reference to FIGS. In FIG. 6, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, 7 is a second gap formed in the conductive thin film, 21 and 22 are deposits which are films containing carbon, 23 Denotes a deteriorated portion (concave portion) of the substrate. FIG. 7 shows an example of voltage application to the active device electrode used in the present invention. The maximum voltage value to be applied (the constant voltage value in FIG. 7) is appropriately selected in the range of 10 to 20V. Since the discharge may occur if the constant voltage is applied from the beginning of the activation, it is preferable to have a process of increasing the voltage from a low voltage to a constant voltage as shown in FIG. Further, it is preferable that the initial voltage value of the activation is larger than the maximum voltage value applied in the forming.

FIG. 6A schematically shows the vicinity of the electron emission portion of the electron emission element before the activation process. The element was once reduced in pressure to the order of 10 @ -6 Pa, and then placed in a vacuum device into which a gas of an organic substance was introduced (FIG. 3). Here, a case where tolunitrile is used as an organic substance will be described as an example. The preferred pressure of tolunitrile to be introduced is slightly affected by the shape of the vacuum device, the members used in the vacuum device, etc.
About 10-3 Pa. At a pressure of 1 × 10 −5 Pa or less, the progress of the activation becomes extremely slow, and the activation may not proceed sufficiently depending on the composition and partial pressure of the remaining gas. On the other hand, at a pressure of 1 × 10 −3 Pa or more, the progress of activation becomes extremely fast, and it becomes difficult to form a desired deposit shape with good reproducibility. The preferred range of the introduced partial pressure depends on the saturated vapor pressure of the organic substance at that temperature, and in the case of acrylonitrile, 1 × 10 -1 Pa to 1
About 10-3 Pa.

In the activation step (the step of depositing a film containing carbon), the voltages shown in FIG.
It is applied between the gaps (gap 7). Thus, the organic substance in the atmosphere starts to deposit on the conductive thin film 4 in the gap 7 and in the vicinity thereof (FIG. 6B). In this process, sediment 2
1, 22 are simultaneously deposited in the direction perpendicular to the paper surface.

Further, when the activation process is continued, the deposition of the deposit increases with the alteration of the substrate (digging described later) and grows above the surface of the conductive thin film (FIG. 6).
(C)). Then, the activation process ends when the configuration finally becomes as shown in FIG.

FIG. 19 shows the state of the current (device current If) flowing between the device electrodes 2 and 3 during the activation step.
It is.

In FIG. 19, (a) and (b) of FIG. 6 show how the film having carbon is deposited in the region I. FIGS. 6C and 6D show how the film having carbon is deposited in the region II.

In the region II where the rise of the device current is slow, the substrate 21 is deteriorated and the deposition of the carbon-containing films 21 and 22 proceeds upward from the substrate surface along with the digging of the substrate. Therefore, when the end of the activation step is determined while measuring the device current, after the voltage applied to the device electrode at the time of activation enters a region of a constant voltage (const voltage in FIG. 7), the device current is reduced as described above. After confirming that it has entered the region II, the activation step is terminated.

When the voltage shown in FIG. 7 is applied only to the device electrode 3 so that the device electrode 3 becomes positive during the activation process shown in FIG. Membrane 2
It is possible to make an asymmetric structure in which the heights 22 from the substrate surface of the substrates 1 and 22 are higher.

In the case of an element having such an asymmetric structure, the potential applied at the time of driving should be higher to the electrode to which the film having carbon, which is higher from the substrate surface, is electrically connected. Is preferred. By driving in this manner, higher electron emission efficiency can be obtained.

As shown in FIG. 6D, in order to make the heights of the carbon-containing films 21 and 22 from the substrate surface uniform, the potential of the waveform shown in FIG. Device electrode 3
Of the device electrode 3
Can be formed by applying a voltage such that the potential of the negative electrode becomes negative.

As described above, by performing the step of applying a potential whose polarity has been inverted during the activation step, the carbon-containing film 2 is formed.
Since the quality of the carbon constituting the first and second films 22 and 22 can be made substantially the same, preferential alteration or loss of one of the films 21 and 22 having carbon exposed to a high temperature when the electron-emitting device is driven. , And as a result, the electron emission characteristics can be made more stable.

The following is considered regarding the alteration (digging) of the substrate.

When the temperature rises under the condition where SiO 2 (substrate material) exists near carbon, Si is consumed.

SiO2 + C → SiO {+ CO} It is considered that Si in the substrate is consumed by such a reaction and the substrate has a hollow (recessed) shape. The electron-emitting portion 5 forms a shape having a carbon deposit that has been removed from the substrate and protruded upward, so that the electric field is concentrated at the tip portion, thereby enabling more stable electron emission.

The recess 23 formed in the substrate is separated from the deposit 2 by the first gap 8 formed in the deposit.
The creepage distance between 1 and 22 is increased. It is considered that an increase in the creepage distance suppresses a discharge phenomenon between the deposits 21 and 22 even under a high electric field applied between the deposits 21 and 22.

Since carbon is present on the surface of the concave portion, charging of the substrate exposed in the gap portion 8 is suppressed, and as a result, more stable electron emission characteristics are considered to be obtained.

Next, the carbon of the deposits 21 and 22, which are the films having carbon in the present invention, will be described.

The graphite-like carbon in the present invention is:
One having a perfect graphite crystal structure (a so-called HOPG), one having a crystal grain of about 20 nm and a slightly disordered crystal structure (PG), and one having a crystal grain of about 2 nm and having a further disordered crystal structure (GC) ), Amorphous carbon (refers to amorphous carbon and a mixture of amorphous carbon and the microcrystals of graphite). That is, it can be preferably used even if there is a layer disorder such as a grain boundary between graphite particles.

6) The electron-emitting device thus manufactured is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum vessel. Although it is desirable to eliminate the organic substance in the vacuum vessel as much as possible, the partial pressure of the organic substance is preferably 1 to 3 × 10 −8 Pa or less. Further, the pressure including other gases is preferably 1 to 3 × 10 −6 Pa or less, and more preferably 1 × 10 −7 Pa or less. As the vacuum exhaust device for exhausting the vacuum container, a device that does not use oil is used so that oil generated from the device does not affect the characteristics of the element. Specifically, a sorption pump,
A vacuum exhaust device such as an ion pump can be used.
Further, when the inside of the vacuum vessel is evacuated, the entire vacuum vessel is heated so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device are easily evacuated. The heating condition at this time is desirably as long as possible at 150 to 350 ° C., preferably 200 ° C. or more, for as long as possible. However, the heating condition is not particularly limited thereto. This is performed under conditions appropriately selected according to various conditions. After performing the stabilization step, it is preferable that the atmosphere at the time of driving maintain the atmosphere at the end of the stabilization process,
However, the present invention is not limited to this. If the organic substance is sufficiently removed, it is possible to maintain sufficiently stable characteristics even if the pressure itself slightly increases.

By adopting such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, so that the shape of the film having carbon of the present invention is maintained. As a result, the device current If and the emission current Ie are stable. I do.

The basic characteristics of the electron-emitting device manufactured by the above-described manufacturing method to which the present invention can be applied will be described with reference to FIGS.

The emission current Ie and the device current I of the device after the stabilization process were measured by the measurement and evaluation apparatus shown in FIG.
FIG. 8 shows a typical example of f and the device voltage Vf. In FIG. 8, since the emission current Ie is significantly smaller than the element current If, the emission current Ie is shown in an arbitrary unit, and each is a linear scale. As is clear from FIG. 8, the electron-emitting device has three properties with respect to the emission current Ie.

First, when an element voltage higher than a certain voltage (called a threshold voltage, Vth in FIG. 8) is applied to the present element, the emission current Ie sharply increases, while the threshold voltage Ve is increased.
Below th, the emission current Ie is hardly detected. That is, a clear threshold voltage Vt for the emission current Ie
h is a non-linear element.

Second, since the emission current Ie depends on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf.

Third, the emission charge captured by the anode electrode 34 depends on the time during which the device voltage Vf is applied. That is, the amount of charge captured by the anode electrode 34 can be controlled by the time during which the device voltage Vf is applied.

By using the characteristics of the electron-emitting device as described above, the electron-emitting characteristics can be easily controlled according to the input signal. Furthermore, since the electron-emitting device according to the present invention has stable and high-luminance electron-emitting characteristics, it can be expected to be applied to various fields.

An application example of the electron-emitting device to which the present invention can be applied will be described below.

By arranging a plurality of electron-emitting devices according to the present invention on a substrate, for example, an electron source or an image forming apparatus can be constructed.

For the arrangement of the elements on the substrate, for example,
A large number of electron-emitting devices are arranged in parallel, and both ends of each element are connected by wiring. A large number of electron-emitting device rows are arranged (referred to as a row direction). ), A control electrode (called a grid) installed in a space above the electron source to control and drive the electrons (called a ladder type), and n An example is an arrangement in which the Y-directional wiring is provided via an interlayer insulating layer, and the X-directional wiring and the Y-directional wiring are connected to a pair of device electrodes of the surface conduction electron-emitting device, respectively. Hereinafter, this is referred to as a simple matrix arrangement.

Next, the simple matrix arrangement will be described in detail.

According to the characteristics of the above-mentioned three basic characteristics of the surface conduction electron-emitting device according to the present invention, when the electrons emitted from the surface conduction electron-emitting device are equal to or higher than the threshold voltage, the opposing device electrode It can be controlled by the peak value and width of the pulse voltage applied between them. On the other hand, when the voltage is equal to or lower than the threshold voltage, it is hardly emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged, if the pulse-like voltage is appropriately applied to each of the devices, the surface-conduction electron-emitting device is selected according to an input signal, and the electron is selected. The amount of release can be controlled.

Hereinafter, the structure of the electron source substrate formed based on this principle will be described with reference to FIG.

The m X-direction wirings 102 are DX1, DX
.., DXm, formed on the substrate 1 by a vacuum evaporation method, a printing method, a sputtering method, or the like, and made of a conductive metal or the like having a desired pattern, and is substantially equivalent to a large number of surface conduction electron-emitting devices. The material, the film thickness, the wiring width, and the like are designed so that an appropriate voltage is supplied. These m X-directional wirings 102 and n
An interlayer insulating layer (not shown) is provided between the Y-directional wirings 103 and electrically separated to form a matrix wiring (m and n are both positive integers).

The interlayer insulating layer (not shown) is made of SiO 2 or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. In particular, the film thickness and the thickness are set so as to withstand the potential difference at the intersection of the X-direction wiring 102 and the Y-direction wiring 103.
The material and manufacturing method are appropriately set. X direction wiring 102 and Y
The direction wiring 103 is drawn out as an external terminal. Further, in the same manner as described above, opposing electrodes (not shown) of the surface conduction electron-emitting device 104 are composed of m X-directional wirings 102 (DX1, DX2,..., DXm) and n Y-directional wirings 103 (DY1). , DY2,..., DYn) are electrically connected to each other by a connection 105 made of a conductive metal or the like.

Here, the conductive metal of the element electrode opposed to the m X-directional wirings 102, the n Y-directional wirings 103, and the connection 105 has the same structure as that of the element metal even if some or all of the constituent elements are the same. Moreover, each may be different. These materials are appropriately selected, for example, from the above-described materials for the device electrodes.

As will be described in detail later, the X-direction wiring 102 has a surface conduction type emission element 9 arranged in the X-direction.
The four rows are electrically connected to a scanning signal applying unit (not shown) for applying a scanning signal for scanning in accordance with an input signal, and are arranged in the Y direction on the Y direction wiring 103. Each row of the surface conduction electron-emitting devices 104 is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulating each row according to an input signal.

Further, a driving voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element.

Next, an example of an electron source using the electron source substrate manufactured as described above and an example of an image forming apparatus used for display and the like will be described with reference to FIGS. FIG. 10 is a basic configuration diagram of the image forming apparatus, and FIG. 11 is a fluorescent film.

In FIG. 10, reference numeral 101 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 111, a rear plate on which the electron source substrate 101 is fixed; 116, a fluorescent film 114 and a metal back 115 formed on the inner surface of a glass substrate 113; This is the finished face plate. Reference numeral 112 denotes a support frame, and the rear plate 111, the support frame 112, and the face plate 1
16 is coated with frit glass and baked in air or nitrogen at 400 to 500 ° C. for 10 minutes or more to be sealed to form an envelope 118.

In FIG. 10, reference numeral 104 corresponds to the surface conduction electron-emitting portion shown in FIG. 1 or FIG. 10
Reference numerals 2 and 103 are an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device. Further, the wiring to these device electrodes may be referred to as a device electrode when the material of the device electrode and the wiring material are the same.

As described above, the envelope 118 is composed of the face plate 116, the support frame 112, and the rear plate 111. Since the rear plate 111 is provided mainly for the purpose of reinforcing the strength of the substrate 101, If it has sufficient strength, the separate rear plate 111 is unnecessary, and the support frame 112 is directly sealed to the substrate 101, and the envelope 118 is constituted by the face plate 116, the support frame 112, and the substrate 101. You may.

On the other hand, by installing a support (not shown) called a spacer between the face plate 116 and the rear plate 111, an envelope 118 having sufficient strength against atmospheric pressure can be formed. .

FIG. 11 shows a fluorescent film. Phosphor film 114
Is composed of only a phosphor in the case of a monochrome, but is composed of a black conductive material 121 called a black stripe or a black matrix and a phosphor 122 depending on the arrangement of the phosphor in the case of a color phosphor film. The purpose of providing the black stripe and black matrix is
Each phosphor of three primary color phosphors required for color display 1
The purpose is to make the color mixture and the like inconspicuous by making the painted portion between 22 black, and to suppress a decrease in contrast due to reflection of external light on the fluorescent film 114. The material of the black stripe is not limited to the commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection.

The method of applying the fluorescent substance to the glass substrate 113 is not limited to monochrome or color, and a precipitation method, a printing method, or the like is used.

A metal back 115 is usually provided on the inner side of the fluorescent film 114. The purpose of metal back is
The face plate 1 emits light toward the inner surface side of the phosphor emission.
To improve the brightness by specular reflection to the 16 side, to act as an electrode for applying electron beam acceleration voltage, to protect the phosphor from damage due to the collision of negative ions generated in the envelope, etc. is there. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after producing the phosphor film, and then depositing Al by vacuum evaporation or the like.

In the face plate 116, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 114 in order to further increase the conductivity of the fluorescent film 114.

When the above-mentioned sealing is performed, in the case of color, the phosphors of each color must correspond to the electron-emitting devices, so that it is necessary to perform sufficient alignment.

The envelope 118 is passed through an exhaust pipe (not shown)
After the degree of vacuum is set to about 1.times.10@-7 Torr, sealing is performed. In addition, getter processing may be performed in order to maintain the degree of vacuum of the envelope 118 after sealing. this is,
Immediately before or after sealing the envelope 118, the envelope 11 is heated by a heating method such as resistance heating or high-frequency heating.
8 is a process of heating a getter arranged at a predetermined position (not shown) in 8 to form a deposited film. Getter is usually B
a is a main component, and maintains a degree of vacuum of, for example, 1 × 10 −5 or 1 × 10 −7 Torr by the adsorption action of the deposited film.

In the image display device of the present invention completed as described above, a voltage is applied to each electron-emitting device through external terminals Dox1 to Doxm and Doy1 to Doyn, thereby emitting electrons. Metal back 115 or transparent electrode (not shown)
A high voltage of several kV or more is applied to accelerate the electron beam, collide it with the fluorescent film 114, and excite and emit light to display an image.

The configuration described above is a schematic configuration necessary for producing a suitable image forming apparatus used for display and the like, and detailed portions such as materials of each member are limited to those described above. Instead, it is appropriately selected so as to be suitable for the use of the image forming apparatus. Next, a configuration example of a driver circuit for performing television display based on an NTSC television signal on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG.

FIG. 12 is a block diagram showing an example of a drive circuit for performing display in accordance with NTSC television signals. In FIG. 12, reference numeral 131 denotes a display panel, 132 denotes a scanning signal generation circuit, and 133 denotes timing. The control circuit 134 is a shift register. 135 is a line memory, 136
Is a synchronization signal separation circuit, 137 is a modulation signal generation circuit, Vx
And Va are DC voltage sources.

The display panel 131 has terminals Dox1 to Dox1
oxm, terminals Doy1 to Doyn, and high voltage terminal Hv
Connected to an external electric circuit via Terminal Dox1
Scanning for sequentially driving electron sources provided in the display panel, that is, a group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns, one row at a time (n elements). A signal is applied. Terminals Doy1 to Do
To yn, a modulation signal for controlling an output electron beam of one row of surface conduction electron-emitting devices selected by the scanning signal is applied. A DC voltage source Va is connected to the high voltage terminal Hv.
Thus, for example, a DC voltage of 10 kV is supplied, which is an accelerating voltage for applying sufficient energy to the electron beam emitted from the surface conduction electron-emitting device to excite the phosphor.

The scanning signal generating circuit 132 has m switching elements therein (S1 to S1 in the drawing).
m). Each switching element selects either the output voltage of the DC voltage source Vx or 0 V (ground level) and is electrically connected to the terminals Dox1 to Doxm of the display panel 131. S
Each of the switching elements 1 to Sm operates based on the control signal Tscan output from the control circuit 133, and can be configured by combining switching elements such as FETs, for example.

In the case of the present embodiment, the DC voltage source Vx uses a drive voltage applied to an element that is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction type electron emission element. It is set to output a constant voltage that is equal to or lower than the voltage.

The timing control circuit 133 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. The timing control circuit 133 sends Tscan to each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 136.
And Tsft and Tmry control signals.

The synchronizing signal separation circuit 136 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 136 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience. The DATA signal is input to the shift register 134.

The shift register 134 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and a control signal Tsft sent from the timing control circuit 133.
(Ie, the control signal Tsft can be said to be a shift clock of the shift register 134). The data for one line of the image that has been subjected to the serial / parallel conversion (corresponding to drive data for N electron-emitting devices) is output from the shift register 134 as N parallel signals ld1 to ldn.

The line memory 135 is a storage device for storing data for one line of an image for a required time only, and a control signal T sent from the timing control circuit 133.
The contents of ld1 to ldn are stored as appropriate according to mry. The stored contents are output as l'd1 to l'dn and input to the modulation signal generator 107.

The modulation signal generator 137 outputs the image data l '
The signal source is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of d1 to l'dn. Applied to the emitting element.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie. That is, a clear threshold voltage Vth is required for electron emission.
And electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the device.

From this, when a pulse-like voltage is applied to the present element, for example, when a voltage lower than the electron emission threshold is applied, no electron emission occurs, but when a voltage higher than the electron emission threshold is applied, An electron beam is output. At that time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. In addition, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw. Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method of modulating the electron-emitting device according to the input signal.

In implementing the voltage modulation method, the modulation signal generator 137 generates a voltage pulse of a fixed length, and modulates the peak value of the pulse appropriately according to input data. A circuit can be used.

When implementing the pulse width modulation method,
As the modulation signal generator 137, a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data can be used.

The shift register 134 and the line memory 13
5 can be either a digital signal type or an analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 136 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronization signal separation circuit 136. Just do it. In this connection, the circuit used for the modulation signal generator 137 is slightly different depending on whether the output signal of the line memory 135 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 137 includes:
For example, a D / A conversion circuit is used, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 137 includes, for example, a high-speed oscillator, a counter (counter) for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. (Comparator) is used. If necessary, an amplifier for voltage-amplifying the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, the modulation signal generator 137 may employ an amplifier circuit using, for example, an operational amplifier, and may add a bell shift circuit and the like as necessary. In the case of the pulse width modulation method, for example, a voltage-controlled oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the drive voltage of the surface conduction electron-emitting device can be added as necessary.

In the image display apparatus to which the present invention can be applied, which has such a configuration, by applying a voltage to each electron-emitting device via the external terminals Dox1 to Doxm and Doy1 to Doyn, the electron-emitting device can emit electrons. Occurs.
A high voltage is applied to the metal back 115 or a transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 114 and emit light to form an image. The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. Although the NTSC system has been described as the input signal, the input signal is not limited to this, and PAL, SECA
In addition to the M type, a TV with a larger number of scanning lines
Signal (for example, high quality T including MUSE method)
V) system can also be adopted. The image forming apparatus of the present invention can be used not only as a display device for television broadcasting, a display device such as a video conference system or a computer, but also as an image forming device as an optical printer including a photosensitive drum or the like. it can.

[0154]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 The basic structure of an electron-emitting device according to this example is a plan view and a sectional view of FIGS. 1A and 1B, and FIGS. 2A and 2B. ) And (c) are the same as the enlarged plan view, cross-sectional view, and conductivity distribution diagram of the film containing carbon.

The method for manufacturing the surface conduction electron-emitting device according to this embodiment is basically the same as that shown in FIGS. Hereinafter, a basic configuration and a manufacturing method of the element according to the present embodiment will be described with reference to FIGS. 1, 2, 4, and 6.

Hereinafter, the manufacturing method will be described in order with reference to FIG.
This will be described with reference to FIGS. 2, 4, and 6.

Step-a First, on the cleaned quartz substrate 1, a pattern to be a gap L between the device electrodes 2, 3 and a desired device electrode is formed by a photoresist (RD-2000N-41 manufactured by Hitachi Chemical Co., Ltd.). Then, a 5 nm-thick Ti,
Pt having a thickness of 30 nm was sequentially deposited. The photoresist pattern was dissolved with an organic solvent, the Pt / Ti deposited film was wrist-off, the element electrode interval L was 3 μm, and the element electrode width W was 5 μm.
The device electrodes 2 and 3 having a thickness of 00 μm were formed (FIG.
(A)).

Step-b: A Cr film having a thickness of 100 nm is deposited by vacuum evaporation, patterned so as to have an opening corresponding to the shape of a conductive thin film described later, and an organic palladium compound solution (c
cp4230 manufactured by Okuno Pharmaceutical Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 12 minutes. The conductive thin film 4 formed of fine particles of Pd as the main element thus formed had a thickness of 10 nm and a sheet resistance Rs of 2 × 10 4 Ω / □. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated as described above.

Step-c The Cr film and the baked conductive thin film 4 are etched with an acid etchant so that the width W ′ of the conductive thin film 4 is 30 or less.
A conductive thin film 4 having a desired pattern was formed to have a thickness of 0 μm (FIG. 4B).

The device electrodes 2 and 3 and the conductive thin film 4 were formed on the substrate 1 by the above steps.

Note that, in exactly the same steps, Comparative Examples 1 and 2
Was manufactured.

Step-d Next, the apparatus was set in the measurement and evaluation apparatus shown in FIG. 3, evacuated by a vacuum pump, and after reaching a degree of vacuum of 1 × 10 −6 Pa, a power supply for applying an element voltage Vf to the element. From 31, a voltage is applied between the device electrodes 2 and 3 of the device to perform a forming process,
The first gap 7 was formed in the conductive thin film. The voltage waveform of the forming process is shown in FIG. 5B (FIGS. 4C and 6A).

In FIG. 5 (b), T1 and T2 are the pulse width and pulse interval of the voltage waveform, and in this embodiment, T1 is 1
msec, T2 was set to 16.7 msec, the peak value of the rectangular wave was raised in 0.1 V steps, and the forming process was performed. Also, during the forming process, at the same time, 0.1 V
At a voltage of, a resistance measurement pulse was inserted between the forming pulses, and the resistance was measured. The forming process was terminated when the value measured by the resistance measurement pulse became about 1 MΩ or more, and at the same time, the application of the voltage to the element was terminated.
The maximum voltage applied during the forming was about 5V.

Step-e Subsequently, to perform the activation step, tolunitrile was introduced into the vacuum apparatus through a slow leak valve, and 1.3 ×
A -4 Pa of 10 was maintained. Next, an activation voltage waveform as shown in FIG. 7B is repeatedly applied to the formed element through the element electrodes 2 and 3. Specifically, the element electrode 2 is set to 0 V, a positive rectangular wave having a pulse width of T3 = 1 msec is applied to the element electrode 3, and then a negative rectangular wave having the same pulse width is applied thereto. Is applied repeatedly. FIG. 7 shows the absolute value of the peak value of the pulse applied at that time.
As shown in (a), the voltage was raised at a constant rate from 6 V to 15 V, and then maintained at 15 V to perform an activation process.
At this time, the voltage applied to the device electrode 3 is positive, and the direction of the device current If flowing from the device electrode 3 to the device electrode 2 is positive. About 60 minutes later, after it was confirmed that the vehicle had entered the region II in FIG. 19, the power supply was stopped, the slow leak valve was closed, and the activation process was completed.

On the other hand, the devices of Comparative Examples 1 and 2 which were subjected to the same forming step as the device of this example were subjected to an activation process under the following conditions.

Element of Comparative Example 1 Same as the element of this example except that the partial pressure of tolunitrile was 1.3 × 10 −2 Pa. Element of Comparative Example 2: The partial pressure of tolunitrile was 1.3 ×. 1
Step-f Subsequently, a stabilization step is performed as in the device of this example except that the pressure was set to -6 Pa of 0. While the vacuum device and the electron-emitting device were heated by the heater and maintained at about 250 ° C., the evacuation of the vacuum device was continued. After 20 hours, the heating by the heater was stopped and the temperature was returned to room temperature.
It reached about -8 Pa of × 10.

Subsequently, the electron emission characteristics were measured.

The distance H between the anode 34 and the electron-emitting device was 4 mm, and the anode 3
4 was given a potential of 1 kV. In this state, a rectangular pulse voltage having a peak value of 15 V is applied between the device electrodes 2 and 3 using the power supply 31, and the current of the device of the present example and the device of the comparative example are measured by the ammeter 30 and the ammeter 32. The current If and the emission current Ie were measured, respectively. In the device of this example, the device current If was almost the same as that of Comparative Example 1, but the emission current I
e shows a value larger than that of Comparative Example 1, and an element having good efficiency was obtained. In the device of Comparative Example 2, the device current If was extremely low, and a sufficient emission current Ie could not be obtained.

From these results, it was found that the device of this example had a larger emission current Ie and an excellent electron emission efficiency η as compared with the device of the comparative example.

For the device of the present example and the device of the comparative example manufactured in the above steps, observation by a scanning tunneling microscope (STM), observation by an atomic force microscope (AFM) and observation by a transmission electron microscope (TEM) were performed. went.

First, the potential distribution of the carbon-containing film near the electron-emitting portion was observed using a scanning tunneling microscope while applying a voltage lower than that for emitting electrons to the device fabricated as described above. As a result, the potential of the carbon-containing film increases as the distance from the gap increases in any element, but in the element of this embodiment, the potential rise near the gap is small, and the potential increases as the distance from the gap increases. The rate was found to be rising. That is, in the device of this example, as shown in FIG. 2C, the conductivity of the film containing carbon was increased toward the gap. Therefore, a change in the potential distribution near the electron emitting portion, specifically, a rise in the potential is suppressed. As a result, the carbon on the side to which a higher voltage is applied when the electron emitting element is driven, with the gap as a boundary. The amount of electrons that fall on the film or the conductive thin film or the device electrode having the above and are absorbed and become a part of the device current (If) decreases, while the amount of electrons reaching the anode electrode (emission current Ie) increases. We think that there is.

Next, the shape of the plane including the electron-emitting portion 5 of the device was observed using an atomic force microscope. The shape of the element of this example was similar to the planar shape shown in FIG. That is, the deposits 21 and 22 were observed on both sides of the gap 7 formed in the conductive thin film 4. Also, from the height information obtained from the atomic force microscope, the height at the highest part of the deposit is about 80 nm higher than the surface of the conductive thin film 4, and the deposit at that height has a width of 500 nm. It had a band-like shape of a degree. On the other hand, in the device of Comparative Example 1, deposits were observed on both sides of the gap formed in the conductive thin film 4 as in the device of the present example, but the height of the deposits was almost uniform. However, a belt-like shape like the element of this example was not observed. Further, when the device of Comparative Example 2 was observed, places where deposits existed and places where no deposits exist were found on both sides of the gap formed in the conductive thin film 4.

Next, a cross section including a deposit of each element was observed with a transmission electron microscope.

As a result, the deposit near the gap 8 of the device of this embodiment has the same shape as that shown in FIG.
The height of the portion corresponding to the deposits 21 and 22 was about 80 nm. The deposit 21 is connected to the device electrode 2 of FIG. 1 via the conductive thin film 4, and the deposit 22 is connected to the device electrode 3 of FIG. 1 via the conductive thin film 4. A film containing carbon was also deposited on the conductive film 4, and its height was about 20 nm. Further, when the thickness of the portion corresponding to the thickness D1 was measured, it was about 25 nm.

The depth of the degenerated portion (concave portion) of the substrate is about 30 nm.
The presence of carbon atoms was also confirmed in the altered part. A cavity was observed in the center.

On the other hand, the deposit of the device of Comparative Example 1 had a large thickness covering the entire gap formed in the conductive thin film, and the shape as shown in FIG. 2B was not observed. .

Further, in the device of Comparative Example 2, the detailed shape was not known because the amount of the deposit was small.

Finally, deposits formed in the vicinity of the gap formed on the conductive thin film of the device of this example were subjected to electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XP).
S), and elemental analysis by Auger electron spectroscopy,
It was confirmed that the deposit mainly consisted of carbon.

From these observation results, in the device of this example, the deposited deposits 21 and 22 are films having carbon as a main component and are in the form of graphite.
Also has carbon, has a cavity in the center, and has a shape similar to the shape shown in FIG.
Good electron emission with large e and high emission efficiency η was obtained. When the devices of Example 1 and Comparative Examples 1 and 2 were driven for the same period of time, the device of Comparative Example showed faster deterioration of the electron emission characteristics than the device of this Example. Although rapid deterioration of device characteristics was observed due to electric discharge, the device of this example showed little deterioration and stable characteristics.

Example 2 In this example, the same steps as in Example 1 were performed up to Step-d. As the substrate 1, a Corning 7059 substrate was used.

Step-e Subsequently, in order to perform an activation step, benzonitrile was introduced into the vacuum apparatus through a slow leak bubble, and 1.3 was introduced.
× 10−4 Pa was maintained. Next, the formed element was boosted from 6 V to 15 V with the waveforms shown in FIGS. 7A and 7B, and the absolute value of the peak value was 1 as in the first embodiment.
When the voltage reached 5 V, the activation process was performed while maintaining the voltage value.
At this time, the activation process was performed while irradiating the laser light to the vicinity of the gap center, and the voltage applied to the device electrode 3 was positive, and 0 V was applied to the device electrode 2.
The element current If flows from the element electrodes 3 to 2 in a positive direction. After about 50 minutes, it was confirmed that the applied voltage was at a constant potential of 15 V, the device current was in the region II shown in FIG. 19, and then the energization was stopped, and the slow leak valve was closed.
Activation processing has been completed.

On the other hand, the devices of Comparative Examples 3 and 4 which were subjected to the same forming step as the device of this example were subjected to an activation process under the following conditions.

Element of Comparative Example 3 Same as the element of this example except that the partial pressure of benzonitrile was changed to 1.3 × 10 −2 Pa. Element of Comparative Example 4: The partial pressure of benzonitrile was 1. 3x
Step-f Subsequently, a stabilization step is performed. While the vacuum device and the electron-emitting device were heated by the heater and maintained at about 250 ° C., the evacuation of the vacuum device was continued. After 20 hours, the heating by the heater was stopped and the temperature was returned to room temperature.
It reached about -8 Pa of × 10.

Subsequently, the electron emission characteristics were measured.

The distance H between the anode electrode 34 and the electron-emitting device was set to 4 mm, and the anode electrode 3 was
4 was given a potential of 1 kV. In this state, a rectangular pulse voltage having a peak value of 15 V is applied between the device electrodes 2 and 3 using the power source 31 at 0 V for the device electrode 2 and 15 V for the device electrode 3. Device current If and emission current Ie of the device of the present example and the device of the comparative example
Was measured respectively.

The device of this example is different from the device of Comparative Example 1 in the device current I
Although f was almost the same, the emission current Ie showed a larger value than that of Comparative Example 1, and an element having high efficiency was obtained. Also,
In the device of Comparative Example 2, the device current If was extremely low, and a sufficient emission current Ie could not be obtained.

From the results, it was found that the device of this example had a larger emission current Ie and an excellent electron emission efficiency η as compared with the device of the comparative example. In the same manner as in Example 1, the device of this example manufactured in the above steps was observed with a scanning microscope (STM) and an atomic force microscope (A).
As a result of observation by FM) and transmission electron microscope (TEM), the conductivity of the film having carbon in the vicinity of the electron-emitting portion in the device of this example was directed toward the gap as shown in FIG. And the shape of the membrane is
The deposits 21 and 22 had the same shape as the shape shown in FIG. In the device of this example, the height of the portion corresponding to the deposits 21 and 22 in FIG. 2B was about 10 nm. Further, the depth of the altered portion of the substrate was 40 nm, and a cavity was observed at the center. Next, the probe is squeezed in a TEM, and energy dispersive X-ray spectroscopy (EDS: Energy Dis
persive X-Ray Spectroscop
In y), the elemental analysis of the deteriorated portion 23 of the substrate was performed. Under the conductive film 4 having the same depth as the deteriorated portion 23 of the substrate, when compared with the substrate portion (unchanged portion), the ratio of Ba and Al in the substrate is:
Although it did not change, S for each of Ba and Al
It was found that i decreased. In addition, carbon was detected on the surface of the concave portion, which is a cavity of the deteriorated substrate.

Finally, the deposit near the gap 8 of the device of this embodiment is subjected to elemental analysis by EDS, X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy. It was confirmed that the film had carbon.

From these observation results, also in the device of this embodiment, the deposits 21 and 22 are mainly composed of graphite-like carbon, and have the same shape as that shown in FIG. Have. In addition, it was found that the deteriorated substrate 23 had a hollow structure containing carbon and consuming Si.
From these, good electron emission with high emission efficiency η was obtained. In addition, when the device of this example and the devices of Comparative Examples 3 and 4 were driven under the same conditions for the same time, the device of the comparative example was found to have faster deterioration of characteristics and discharge than the device of this example. Although a phenomenon was observed, the device of this example had very stable characteristics.

In step e, laser light irradiation is not performed in the initial stage of formation of the deposits 21 and 22, and is started after the deposits 21 and 22 have grown to a certain size. By changing the irradiation intensity in accordance with, it is possible to set the change in the conductivity to a more appropriate one.

(Embodiment 3) This embodiment is an example of an image forming apparatus using an electron source in which a large number of surface conduction electron-emitting devices are arranged in a simple matrix.

FIG. 13 is a plan view of a part of the electron source. FIG. 14 is a sectional view taken along the line AA ′ in the figure. However, FIG.
3. In FIG. 14, the same symbols indicate the same components. Here, 101 is a substrate, 102 is an X-direction wiring (also referred to as a lower wiring) corresponding to DXm in FIG. 9, and 103 is a D in FIG.
Y direction wiring corresponding to Yn (also referred to as upper wiring), 4 is a conductive thin film, 2, 3 is an element electrode, 171 is an interlayer insulating layer,
Reference numeral 72 denotes a contact hole for electrical connection between the element electrode 2 and the lower wiring 102.

Next, the manufacturing method will be specifically described with reference to FIGS.

Step-a On a substrate 1 in which a 0.5 mm thick silicon oxide film was formed on a cleaned blue sheet glass by a sputtering method, 5 nm thick Cr and 0.6 mm thick Au were deposited by vacuum evaporation. After sequentially laminating, a photoresist (manufactured by Hoechst AZ1370) is spin-coated with a spinner and baked, then a photomask image is exposed and developed to form a resist pattern of the lower wiring 102, and the Au / Cr deposited film is wet-etched. To form the lower wiring 102 having a desired shape (FIG. 15).
(A)).

Step-b Next, an interlayer insulating layer 171 made of a silicon oxide film having a thickness of 1.0 μm is deposited by RF sputtering (FIG. 15B).

Step-c A photoresist pattern for forming a contact hole 172 is formed in the interlayer insulating layer 171 deposited in the step-b, and the interlayer insulating layer 171 is etched using the photoresist pattern as a mask to form a contact hole 172 (FIG. 15 (c)).

Step-d After that, a pattern to be a gap L between the device electrode 2 and the device electrode is formed by a photoresist (RD-2000N-41 manufactured by Hitachi Chemical Co., Ltd.), and a thickness of 5 nm is formed by a sputtering method.
Of Ti and Pt having a thickness of 0.1 mm were sequentially deposited. The photoresist pattern was dissolved in an organic solvent, and the Pt / Ti deposited film was lifted off to form device electrodes 2 and 3 having a device electrode interval L = 3 mm and a device electrode width W = 0.3 mm (FIG. 15 (d) )).

Step-e After forming a photoresist pattern of the upper wiring 103 on the device electrodes 2 and 3, Ti having a thickness of 5 nm and a thickness of 0.5 mm
Are sequentially deposited by vacuum evaporation, and unnecessary portions are removed by lift-off to form an upper wiring 103 having a desired shape (FIG. 16A).

Step-f A Cr film 191 having a thickness of 0.1 mm is deposited by vacuum evaporation.
Patterning was performed, and an organic palladium compound solution (ccp4230 manufactured by Okuno Pharmaceutical Co., Ltd.) was spin-coated thereon with a spinner and heated and baked at 300 ° C. for 10 minutes (FIG. 16B). The conductive thin film 4 made of fine particles of Pd as the main element thus formed had a thickness of 10 nm and a sheet resistance of 2 × 104Ω / □.

Step-g The Cr film 191 and the baked conductive thin film 4 were etched off with an acid etchant and lifted off to form a conductive thin film 4 having a desired pattern (FIG. 16C).

Step-h A pattern was formed such that a resist was applied to portions other than the contact hole 172, and 5 nm thick Ti and 0.5 mm thick Au were sequentially deposited by vacuum evaporation. Unnecessary portions were removed by lift-off to bury the contact holes 172 (FIG. 16D).

Through the above steps, the lower wiring 102, the interlayer insulating layer 171, the upper wiring 103, the device electrodes 2, 3, and the conductive thin film 4 were formed on the insulating substrate 1.

Next, an example in which an electron source and a display device are configured using the electron source substrate manufactured as described above will be described with reference to FIGS.

After fixing the substrate 1 on which the element was manufactured as described above on the rear plate 111, a face plate 116 (a fluorescent film 114 and a metal back 115 were formed on the inner surface of the glass substrate 113) 5 mm above the substrate 1. Is arranged via a support frame 112, frit glass is applied to the joint between the face plate 116, the support frame 112, and the rear plate 111, and 10 f at 400 ° C. in the air.
It was sealed by baking for a minute. The fixing of the substrate 1 to the rear plate 111 was also performed using frit glass.

In this embodiment, reference numeral 104 in FIG. 10 denotes an electron-emitting device (corresponding to, for example, FIG. 4B) before forming an electron-emitting portion, and reference numerals 102 and 103 denote device wirings in the X and Y directions, respectively. It is.

The fluorescent film 114 is made of only a phosphor in the case of monochrome, but in this embodiment, the phosphor has a stripe shape. First, a black stripe was formed, and a phosphor of each color was applied to the gap, thereby forming a phosphor film 114. As the material for the black stripe, a material mainly containing graphite, which is generally used, was used. Glass substrate 1
A slurry method was used to apply the phosphor to the substrate 13.

Further, a metal back 115 is usually provided on the inner surface side of the fluorescent film 114. The metal back was manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after the fluorescent film was manufactured, and then vacuum-depositing Al.

In the face plate 116, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 114 in order to further increase the conductivity of the fluorescent film 114, but in this embodiment, only the metal back is used. Omitted because sufficient conductivity was obtained.

When the above-mentioned sealing was performed, in the case of color, the phosphors of each color and the electron-emitting device had to correspond to each other, so that sufficient alignment was performed.

The atmosphere in the glass container completed as described above is evacuated by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, external terminals Doxl to Doxm and Doyl to Doyn. A voltage is applied between the electrodes 2 and 3 of the electron-emitting device 104 through the
Was formed. The voltage waveform of the forming process is the same as that shown in FIG. The maximum voltage applied during the forming was about 5V.

In this embodiment, T1 is 1 msec, and T2 is 1
The process was performed under a vacuum atmosphere of about 1.3.times.10@-3 Pa at 0 msec.

Next, after evacuation was continued until the pressure in the panel reached the level of 10 −6 Pa, tolunitrile was introduced into the panel from the exhaust pipe of the panel such that the total pressure was 1.3 × 10 −4 Pa. And maintained. Terminal Doxl or Do outside the container
xm and the electron emitting device 10 through Doyl or Doyn
7, a voltage was started to be applied from 6 V with the same waveform as in FIG. 7, the voltage was increased to 20 V, and then maintained at a constant voltage of 20 V. The activation process was performed by setting the element electrode 2 to 0 V and setting the maximum value of the voltage applied to the element electrode 3 to 20 V.

As described above, the electron-emitting device 104 was manufactured by performing the forming and the activation processes. The termination of the activation is the same as in the first and second embodiments when the applied voltage is constant (20 V).
This was performed after confirming that the element current corresponded to the region II in FIG.

Next, the entire panel was evacuated while being heated to 250 ° C., and the temperature was lowered to room temperature to set the inside to a pressure of about 10 −7 Pa. The enclosure was sealed.

Finally, in order to maintain the pressure after sealing, a getter treatment was performed by a high-frequency heating method.

In the image display device of the present invention completed as described above, each of the electron-emitting devices has a terminal Doxl outside the container.
Through Doxm and Doyl through Doyn, respectively, to apply a scanning signal and a modulation signal from a signal generating means (not shown), thereby causing electrons to be emitted.
7, a high voltage of 5 kV or more was applied to the metal back 115 or the transparent electrode (not shown) to accelerate the electron beam, collide with the fluorescent film 114, and excite and emit light to display an image.

The image display device of this example was able to display a stable and good image with high luminance for a long time.

Embodiment 4 In this embodiment, an example of a display device configured to display image information provided from various image information sources such as television broadcasting will be described. Display was performed on the image forming apparatus shown in FIG. 10 using the driving circuit shown in FIG. 12 according to an NTSC television signal.

In the present display device, the depth of the display device can be reduced because the thickness of the display panel using the surface conduction electron-emitting device as an electron beam source can be easily reduced. In addition, the display panel using the display conduction type electron-emitting device as the electron beam source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display with good visibility.

The display device in this example was able to display a television image according to the NTSC television signal in a good and stable manner.

[0222]

According to the present invention described above, the conductivity of the carbon-containing film increases toward the first gap, so that the change in the potential distribution near the electron-emitting portion is reduced. Therefore, at the time of driving the electron-emitting device with the first gap as a boundary, the electron-emitting device falls and is absorbed by a film or a conductive thin film or a device electrode having carbon on the side to which a higher voltage is applied, and a part of the device current is absorbed. While the amount of electrons decreases, the emission current increases and the electron emission efficiency improves.

Further, since the substrate in the first gap portion has a concave portion, the creepage distance between the films having carbon opposed to each other with the gap portion increased depending on the depth of the concave portion. At the same time, a high-efficiency element that is suppressed can be obtained, and even under a strong electric field applied between the above-described films having carbon, a stable element can be obtained in which the deterioration of characteristics that is considered to be caused by the discharge phenomenon between the gaps is suppressed. Was done.

Further, it is assumed that the surface of the substrate exposed between the first gaps is exposed to the irradiation of the emitted electrons. In the device of the present invention, at least the surface of the substrate exposed in the gaps is exposed. Since carbon is present on the surface of the concave portion, fluctuations and deterioration of device characteristics, which are considered to be due to a decrease in charge on the surface of the concave portion of the substrate due to irradiation of the electrons, are suppressed,
A device having stable electron emission characteristics for a long time was obtained.

Furthermore, in an electron source or an image forming apparatus using a device having high efficiency and stable characteristics over a long period of time, the present invention is very stable even if a large number of electron-emitting devices are arranged. Particularly in an image display device using a phosphor,
An image display device with high brightness, stable for a long time and low power consumption was obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an electron-emitting device of the present invention.

FIG. 2 is an enlarged schematic view of the vicinity of an electron emitting portion according to the present invention.

FIG. 3 is a schematic diagram illustrating an example of a vacuum processing apparatus having a measurement evaluation function.

FIG. 4 is a schematic view showing a part of the manufacturing process of the electron-emitting device of the present invention.

FIG. 5 is a schematic view showing an example of a voltage waveform that can be used in a forming step which is a part of the manufacturing process of the electron-emitting device of the present invention.

FIG. 6 is a schematic view showing an activation step which is a part of the manufacturing process of the electron-emitting device of the present invention.

FIG. 7 is a schematic diagram showing an example of a voltage waveform that can be used in an activation step which is a part of the manufacturing process of the electron-emitting device of the present invention.

FIG. 8 is a schematic diagram showing the relationship between the emission current Ie, the device current If, and the device voltage Vf of the electron-emitting device of the present invention.

FIG. 9 is a schematic diagram showing an example in which the electron-emitting device of the present invention is applied to an electron source in which a simple matrix is arranged.

FIG. 10 is a schematic diagram illustrating an example in which the electron-emitting device of the present invention is applied to an image forming apparatus.

FIG. 11 is a schematic diagram illustrating an example of a fluorescent film.

FIG. 12 is a block diagram of a driving circuit for performing display according to an NTSC television signal when the electron-emitting device of the present invention is applied to an image forming apparatus.

FIG. 13 is a schematic diagram showing an example in which the electron-emitting device of the present invention is applied to an electron source in which a simple matrix is arranged.

FIG. 14 is a schematic partial cross-sectional view taken along line AA ′ of FIG.

FIG. 15 is a schematic diagram for explaining a part of the manufacturing process of the electron source according to the embodiment of the present invention.

FIG. 16 is a schematic diagram for explaining a part of the manufacturing process of the electron source according to the embodiment of the present invention.

FIG. 17 is a schematic diagram showing a configuration of a conventional electron-emitting device.

FIG. 18 is a schematic diagram showing a configuration of another conventional electron-emitting device.

FIG. 19 is a schematic diagram showing a change in device current during an activation step of the present invention.

FIG. 20 is an enlarged schematic view of the vicinity of an electron emitting portion according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2, 3 device electrode 4 conductive thin film 5 electron emitting portion 6 carbon or carbon compound 7 gap portion (second gap portion) 8 gap portion (first gap portion) 21, 22 deposit (film containing carbon) ) 23 recess 30 ammeter 31 power supply 32 ammeter 33 voltage power supply 34 anode electrode 101 electron source substrate 102 X-direction wiring 103 Y-direction wiring 104 electron emission element 111 rear plate 112 support frame 113 glass substrate 114 fluorescent film 115 metal back 116 face Plate 117 High voltage terminal 118 Envelope 121 Black member 122 Phosphor 131 Display panel 132 Scan circuit 133 Control circuit 134 Shift register 135 Line memory 136 Synchronization signal separation circuit 137 Modulation signal generator Vx, Va DC power supply 171 Interlayer insulating layer 172 Contact hole

Claims (13)

[Claims] 1. A semiconductor device comprising: a pair of electrodes disposed on a surface of a base; and a film having a pair of carbons connected to the pair of electrodes and separated by a first gap, respectively. An electron-emitting device, wherein the conductivity of the film increases toward the first gap. 2. The electron emission device according to claim 1, wherein the film having a pair of carbons is electrically connected to the electrodes via a conductive thin film disposed between the pair of electrodes. element. 3. The conductive thin film has a second gap between the pair of electrodes, and a first gap of the pair of carbon-containing films is disposed in the second gap. 3. The electron-emitting device according to claim 2, wherein: 4. The first gap portion of the film having a pair of carbons has an end portion whose narrowest portion in a direction perpendicular to the surface of the substrate is away from the substrate surface of the film having a pair of carbons. The electron-emitting device according to claim 3, wherein 5. The substrate according to claim 4, wherein the base has a concave portion in the first gap portion, and carbon has on a surface of the concave portion.
3. The electron-emitting device according to item 1. 6. A thickness of the film having a pair of carbons present in an extension line connecting a narrowest portion of the first gap in a direction perpendicular to the surface of the base, is 100 nm.
The electron-emitting device according to claim 4, wherein: 7. The carbon in the film having a pair of carbons,
The electron-emitting device according to any one of claims 1 to 6, wherein the electron-emitting device is graphite-like carbon. 8. The electron-emitting device according to claim 2, wherein said conductive thin film is made of a Pd fine particle film. 9. An electron-emitting device according to claim 1, wherein a plurality of the electron-emitting devices are arranged on a substrate, and electrons are emitted from at least one of the electron-emitting devices in response to an input signal. Electron source. 10. An image forming apparatus, comprising: the electron source according to claim 9; and an image forming member that forms an image by irradiating electrons emitted from the electron source. 11. A voltage is applied between a pair of conductive thin films having a gap in an atmosphere containing an organic substance, and a film containing carbon is formed around the gap from the organic substance present in the atmosphere. A method of manufacturing an electron-emitting device for performing an activation process of the gap portion, wherein the activation process is performed while the gap portion is partially heated. 12. The method according to claim 11, wherein the extreme heating of the gap is not performed in the initial stage of forming the carbon-containing film, but is performed during and after the formation of the carbon-containing film. The manufacturing method of the electron-emitting device of the above. 13. The method according to claim 11, wherein the extreme heating of the gap is performed by irradiating a laser beam.