JP3639739B2 - Electron emitting element, electron source using electron emitting element, image forming apparatus using electron source, and display device using image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electron-emitting device, an electron source using the electron-emitting device, and an image forming apparatus using the electron source.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, two types of electron sources using electron-emitting devices are known: a thermal electron source and a cold cathode electron source. Electron emission elements constituting the cold cathode electron source include field emission type (FE type), metal / insulating layer / metal type (MIM type), and surface conduction type electron emission elements.
[0003]
Examples of FE type electron-emitting devices include W.W. P. Dyke & W. W. Dolan, “Field Emission”, Advance in ElectroPhysics, 8, 89 (1956) or C.I. A. Spindt, “Physical Properties of Thin-Film Field Emission Cath with MollybdeniumCones”, J. Am. Appl. Phys. 47, 5248 (1976).
[0004]
Examples of MIM type electron-emitting devices include C.I. A. Mead, “Operation of Tunnel-Emission Devices”, J. Am. Apply. Phys. 32,646 (1961) and the like are known.
[0005]
Examples of surface conduction electron-emitting devices include M.I. I. Elinson, Radio Eng. Electron Phys. , 10, 1290 (1965).
[0006]
A surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is applied in parallel to a film surface of a small-area thin film formed on a substrate. As this surface conduction electron-emitting device, a device using the SnO2 thin film by Erinson et al., A device using Au thin film [G. Ditmmer, Thin Solid Films, 9, 317 (1972)], by ln2 O3-SnO2 thin film [M. Hartwell and C.H. G. Fonsted, IEEE Trans. ED Conf. 519 (1975)], and carbon thin film [Hisa Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported.
[0007]
The present applicant has made a number of proposals regarding surface conduction electron-emitting devices and their applications. The configuration and the manufacturing method thereof are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 7-235255 and 8-171849.
[0008]
The gist of these publications will be briefly described. As schematically shown in FIGS. 19A and 19B, the surface conduction electron-emitting device includes a pair of device electrodes 2 and 3 opposed to the substrate 1 and a part of the device electrodes connected to the device electrodes. And the conductive thin film 4 having the electron emission portion 5. FIG. 19A is a plan view, and FIG. 19B is a cross-sectional view. The electron emission portion 5 is a portion where a part of the conductive thin film is broken, deformed or altered to form a gap, and the conductive thin film 4 in and near the gap is formed by a process called activation. A deposit mainly composed of carbon and / or carbon compound is formed. This greatly increases the amount of electrons emitted.
[0009]
The conductive thin film 4 is composed of conductive fine particles in order to form the gaps in a preferable state by a process (formation process) by energization described later.
An image forming apparatus can be configured by using an electron source substrate on which a plurality of electron-emitting devices as described above are formed and combining with an image forming member made of a phosphor or the like.
[0010]
[Problems to be solved by the invention]
However, in order to achieve higher performance as an image forming apparatus, that is, an image forming apparatus having a larger screen, power saving, higher definition, higher image quality, space saving, etc., an image to which an electron-emitting device is applied There is a demand for a technique that can maintain stable electron emission characteristics for a long time with a sufficient amount of electron emission so that the forming apparatus can stably provide a bright display image.
[0011]
According to the activation process described later, carbon or a carbon compound is deposited in and near the gap formed in the conductive thin film to form a new narrow gap. Thereby, the emission current Ie and the device current If increase, but the device characteristics such as the amount of emitted electrons and the lifetime depend on the structure and stability of the carbon or carbon compound deposited by the activation treatment.
[0012]
Therefore, in order to realize a high-quality image forming apparatus that can be applied to a flat TV using an electron-emitting device, the electron-emitting portion of the electron-emitting device is formed of carbon or a carbon compound having a suitable structure and stability. There is a need to.
[0013]
An object of the present invention is to provide an electron-emitting device that realizes good electron-emitting characteristics and high luminance over a long period of time, and an electron source and an image forming apparatus using the electron-emitting device.
[0014]
[Means for Solving the Problems]
  In order to solve the above problems, an electron-emitting device of the present invention is provided on the main surface of an insulating substrate.A pair of electrode members disposed on, A first carbon film and a second carbon film disposed between the pair of electrode members, and each end of the first carbon film and the second carbon film face each other with a gap therebetween, The first carbon film is electrically connected to one of the pair of electrode members, and the second carbon film is connected to the other of the pair of electrode members.Electrically connectedAn electron-emitting deviceFirst and secondCarbon filmIs the π plasmon loss energy of single crystal graphite.70% or more, 9The intensity of the π plasmon loss peak is in the range of 0% or less and the π plasmon loss peak intensity of the single crystal graphiteOf 7The configuration is 0% or more.
[0015]
  Also,One of the pair of electrode members and the first carbon film are connected via a first conductive thin film, and the other of the pair of electrode members and the second carbon film are second conductive. It is preferable to be connected through a conductive thin film.
[0016]
In this configuration, the π plasmon loss energy and the intensity of the π plasmon loss peak of the first and second carbon-containing film members are obtained by reflection type electron energy loss spectroscopy. More specifically, a primary electron beam having an energy in the range of about 200 eV to 3 keV is used for the intensity of the π plasmon loss energy and the π plasmon loss peak of the first and second carbon-containing film members, And it is measured by a reflection type electron energy loss spectroscopic analyzer under the condition that the half width of the elastic scattering peak is about 1 eV or less.
[0017]
[Action]
In the electron-emitting device of the present invention, the π plasmon loss energy of the carbon-containing film (carbon film) constituting the electron emission portion is in the range of about 70% or more and about 90% or less of the π plasmon loss energy of the single crystal graphite. And the intensity of the π plasmon loss peak is about 70% or more of the π plasmon loss peak intensity of the single crystal graphite, and the π plasmon loss energy is high despite the π plasmon loss peak intensity being higher than that of a general carbon material. A low material is used.
[0018]
This is considered to correspond to having a fine crystallite diameter while having a high π electron density.
In the electron-emitting device using the film having carbon having the above characteristics in the intensity of the π plasmon loss energy and the π plasmon loss peak, the emission current amount is large and stable electron emission can be performed.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
1A and 1B are a plan view and a cross-sectional view schematically showing an electron-emitting device of the present invention. A pair of element electrodes 2 and 3 are arranged opposite to each other on an insulating substrate 1 formed of a glass material, and a gap 6 formed in a part of the conductive thin film 4 by a forming process or the like to be described later is placed. The conductive thin film 4 faces the substrate 1 surface in the lateral direction. Then, the conductive thin film 4 covers the surface of the device electrodes 2 and 3, whereby the pair of electrodes 2 and 3 and the conductive thin film 4 are electrically connected.
[0020]
In addition, when using a technique such as FIB and forming the gap between the electrodes at a width of about the gap 6 formed by forming, the conductive thin film 4 and the electrodes 2 and 3 do not have to be formed separately.
[0021]
Further, a carbon-containing film (carbon film) 10 as a deposit is disposed on the substrate 1 in the gap 6 and the conductive thin film 4 in the vicinity thereof by an activation process described later. Further, as described above, when the conductive thin film 4 is not used, the electrodes 2 and 3 and the carbon-containing film 10 are directly connected. In the present invention, the deposit and the film containing carbon are the same. The carbon-containing film 10 is disposed so as to face the surface of the substrate 1 in the lateral direction with a gap 7 disposed in the gap 6.
[0022]
The carbon-containing film 10 is deposited up to the element electrodes 2 and 3 depending on the distance (L) between the element electrodes and the activation conditions described later, and in some cases, the element electrode is not interposed through the conductive thin film 4. Connect directly with. Alternatively, the carbon-containing film 10 can be provided so as to cover approximately half of the distance from the gap 7 to the device electrodes 2 and 3.
[0023]
Not only the configuration shown in FIG. 1 but also a configuration in which the conductive thin film 4 and the opposing element electrodes 2 and 3 are laminated in this order on the substrate 1 can be adopted. 1 (A) and 1 (B), the conductive thin film 4 is shown as being separated from the left and right and facing each other with the gap 6 as a boundary, but may be connected at a part of the gap 6. Similarly, the carbon-containing film 10 is shown to be separated from the left and right so as to face each other with the gap 7 as a boundary. However, the carbon-containing film 10 may be connected by a part of the gap 7. In either case, the device characteristics are not greatly affected.
[0024]
Here, the π bond and σ bond of carbon will be described.
The electron configuration of carbon is 1s2 <square> · 2s2 <square> · 2p2 <square> in the ground state. The outermost shell electrons are 2s and 2p in total. When these atoms combine to create a molecule or crystalline solid, one of the 2s electrons is excited to enter the 2p orbital, creating a so-called sp hybrid orbital.
[0025]
The sp3 <cube> hybrid orbital takes a three-dimensional arrangement with an electron cloud extending toward each vertex of the regular tetrahedron centered on the nucleus. Diamonds are aggregates of carbon atoms having sp3 <cube> hybrid orbitals, and these bonds are called σ bonds and all consist of σ electrons.
[0026]
On the other hand, sp2 <squared> hybrid orbits form an electron cloud in which four of the four electrons are 120 degrees apart from each other in the plane, and the remaining one is a dumbbell shape above and below the plane. Create an electronic cloud. The three bonds in the same plane form a carbon hexagonal network plane with σ bonds. The remaining one electron, called π-electron, is oriented perpendicular to the network plane, and its orbits overlap each other along the network plane, further strengthening the coupling of the network plane. π-electrons can move almost freely along the network plane and can be regarded as free electrons. It is well known that graphite is a stack of such layers.
[0027]
As is well known, there is an intermediate structure other than diamond and graphite as described above. In addition to the π bond and σ bond included in the in-layer bond of graphite, carbon has an intermediate structure. Since σ bonds typified by interatomic bonds of diamond are mixed at a certain ratio, the ratio of π bonds to σ bonds can be used to specify the state of the polycrystalline structure. .
[0028]
Regarding carbon, differences in its structure, such as graphite, diamond, glassy carbon, and amorphous carbon, can be obtained from the spectrum of carbon K-shell electrons with different spectral profiles of π electrons and σ electrons. . Specifically, it is known that the energy loss derived from π electrons appears at about 285 eV, and the energy loss derived from σ electrons appears at about 292 eV. Therefore, the state can be identified from the intensity ratio. Furthermore, regarding the spectrum of carbon K-shell electrons, the intensity of energy loss due to π electrons is almost 40% higher than that of σ electrons in the case of graphite, and the energy loss due to π electrons is almost peaked in the case of diamond. This state can be specified by the difference that only energy loss due to σ electrons is observed.
[0029]
Next, the process for forming the element electrode and the conductive thin film and the forming process will be described with reference to FIGS.
The substrate 1 is sufficiently washed with a detergent, pure water, an organic solvent, and the like, and an element electrode material is deposited by a vacuum deposition method, a sputtering method, etc. Is formed (FIG. 2A).
[0030]
An organometallic compound solution is applied to the substrate 1 provided with the device electrodes 2 and 3 to form an organometallic compound thin film. The organometallic compound thin film is heated and baked, and patterned by lift-off, etching, or the like to form the conductive thin film 4 (FIG. 2B).
[0031]
Here, the application method of the organic metal solution has been described, but the method of forming the conductive thin film 4 is not limited to this, and a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, A dipping method, a spinner method, or the like can also be used. In addition, a method of applying the solution of the organometallic compound as a droplet to a desired position by an ink jet apparatus can be used, and in this case, a patterning process by lift-off or etching is not necessary.
[0032]
Subsequently, a forming process is performed. As a forming method, a method by an energization process in an atmosphere containing a gas that promotes reduction of the conductive thin film 4 will be described. When the conductive thin film 4 is made of a metal oxide, particularly PdO, hydrogen can be used as this gas. The electron-emitting device on which the conductive thin film 4 is formed is placed in a vacuum apparatus, and the inside is evacuated to a pressure of about 1 × 10 −5 <−5> Torr, for example, N2: 98% − When H2: 2% mixed gas is introduced into the vacuum apparatus to the extent of 1 × 10 −3 <−3> Torr and energized between the device electrodes 2 and 3 using a power source (not shown), the conductivity becomes A gap 6 is formed in the thin film 4 (FIG. 2C).
[0033]
At this time, the substance constituting the conductive thin film is changed from a metal oxide to a metal by reduction with hydrogen gas, and at this time, formation of the gap 6 is promoted with aggregation. Further, preferably, the substrate temperature is set to a temperature of room temperature or higher: about 50 to 100 ° C.
[0034]
The voltage waveform is preferably a pulse waveform, and a method shown in FIG. 3 in which a pulse having a pulse peak value as a constant voltage is continuously applied. T1 and T2 in FIG. 3 are the pulse width and pulse interval of the voltage waveform. Usually, T1 is 1 μsec. -10 msec. , T2 is 10 μsec. To several hundred msec. It is set in the range. The peak value of the rectangular wave is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens of minutes.
[0035]
The end of the energization forming process is performed by inserting a pulse voltage that does not cause local destruction or deformation of the conductive thin film 4 between the forming pulse voltages, and measuring the current at that time to detect the resistance value. Can be determined. For example, the element current that flows when a voltage of about 0.1 V is applied is measured, the resistance value is obtained, and when a resistance of 1 MΩ or more is indicated, the energization forming is terminated.
[0036]
As the forming method, any method other than the above can be adopted as long as the gap 6 is appropriately formed.
Furthermore, it is preferable to remove impurities adsorbed on the surface by heating the element that has completed the forming process in a vacuum. At this time, when PdO is used as the conductive thin film 4 as described above, it is preferably reduced to metal Pd sufficiently by heating at about 200 ° C.
[0037]
Next, an activation process is performed. In the activation treatment step, a pulse voltage is repeatedly applied between the pair of device electrodes in an atmosphere containing an organic substance gas to deposit a film 10 containing carbon on and around the substrate 1 in the gap 6. It is a process to make. By this process, the device current If which is a current flowing through the device is remarkably changed, and the electron emission current Ie is also increased. The end of the activation process is appropriately determined while measuring the device current If. The pulse width, pulse interval, pulse peak value, etc. are set as appropriate.
[0038]
The atmosphere containing the organic substance gas used in the activation treatment is preferably an atmosphere containing an organic substance gas that has a low vapor pressure and is easily polymerized. Moreover, what contains a nitrogen atom is preferable and especially a nitrile compound is used preferably. Specific examples of satisfying this condition include an atmosphere containing vaporized tolunitrile, but there is a particular limitation if there is no inconvenience in the formation of the carbon-containing film 10 in and around the gap 6. Is not to be done.
[0039]
This atmosphere can be obtained by, for example, introducing an appropriate organic substance gas into a vacuum that has been sufficiently evacuated by an ion pump or the like. Further, the preferable gas pressure of the organic material at this time is appropriately set according to the case because it varies depending on the application form, the shape of the vacuum vessel, the kind of the organic material, and the like.
[0040]
Moreover, it is preferable that the film thickness of carbon constituting the carbon-containing film 10 as a deposit is in the range of 5 to 100 nm. Here, in the film 10 having carbon, the π plasmon loss energy is in the range of about 70% to about 90% of the π plasmon loss energy of the single crystal graphite, and the intensity of the π plasmon loss peak is that of the single crystal graphite. It is characterized by being 70% or more of the π plasmon loss peak intensity.
[0041]
Next, the measurement of the π plasmon loss energy and the π plasmon loss peak intensity of the electron-emitting device will be described in detail.
FIG. 4 shows a schematic view of an apparatus used for reflection type electron energy loss spectroscopy (REELS). In FIG. 4, 51 is a vacuum vessel, 52 is an electron gun, 53 is an electron energy analyzer, 54 is a sample stage, 55 is a sample to be analyzed, 56 is a primary electron beam, and 57 is a reflected electron.
[0042]
The electron gun 52 is an electron beam emitted from an electron gun or an electron gun provided with an electron beam deflector. For example, a field emission type electron gun is preferably used. This is because the sensitivity of the measurement can be increased when the energy half-value width ΔE of the primary electron beam 56 used for the measurement is small, that is, the monochromaticity is good. Although a thermionic emission electron gun can be used as the electron gun 52, in this case, in order to reduce the energy half-value width ΔE of the electron beam from the electron gun, it is preferable to combine a monochromatic mechanism.
[0043]
The primary electron beam 56 preferably has an energy range of 200 eV to 3 keV. This is because it is difficult to detect the reflected electrons 57 with an energy smaller than 200 eV, and the sample 55, that is, the carbon-containing film 10 of the electron-emitting device of the present invention may be damaged by an electron beam when the energy is larger than 3 keV. The electron beam diameter of the primary electron beam 56 greatly depends on the electron gun used and the acceleration voltage. For example, when the field emission electron gun is used and the acceleration voltage is set to a typical 1 keV as described above. It is about 200 nm.
[0044]
The reflected electron 57 is an electron beam reflected by the sample 55, an electron having an energy equal to that of the primary electron beam 56, that is, an electron that has been lost due to the interaction with the sample 55 in addition to the electron elastically scattered by the sample 55. Is included. Here, in order to have sufficient measurement resolution in the present invention, the measurement is preferably performed under the condition that the energy spread of the elastically scattered electrons, that is, the half width of the elastic scattering peak is 1 eV or less. For this reason, it is preferable to set the energy half-value width ΔE of the primary electron beam 56 to 0.4 eV or less, and to further improve the resolution of the electron energy analyzer 53.
[0045]
As the electron energy analyzer 53, it is preferable to use a deflection dispersion type energy analyzer capable of obtaining high energy resolution. The energy analyzer includes a magnetic field deflection method, an electrostatic deflection method, and a Wien-filter method that combines a magnetic field and an electric field. Among these, a small and economical electrostatic deflection method energy analyzer is preferable. Used. In addition, as long as it is an electrostatic deflection type energy analyzer, any analyzer such as a concentric hemisphere type, a cylindrical mirror type, and a coaxial cylindrical mirror type may be used. When a concentric hemispherical analyzer is used as the energy analyzer, an electrostatic lens for the purpose of converging, accelerating and decelerating reflected electrons may be added to the incident side of the analyzer.
[0046]
For detection of reflected electrons, a channeltron, a multichannel plate, an electron multiplier, or the like can be used, and an amplifier may be added if necessary. As a detection method, either a method of using an analog mode and amplifying with a lock-in amplifier, or a method of using a pulse count mode and making a pulse count after discriminating a pulse height may be used.
[0047]
When the reflection electron energy loss spectrum of graphite is measured using the reflection type electron energy loss spectroscopy (REELS) measuring apparatus as described above, a π plasmon loss peak and a π + σ plasmon peak are observed. The π plasmon loss peak is derived from sp2 <squared> carbon, and this peak does not appear in principle in sp3 <cube> carbon (for example, diamond). The energy (loss energy) of the π plasmon peak is considered to reflect the graphite crystallite diameter and / or π electron density, and the peak intensity is considered to be correlated with the π electron density.
[0048]
FIG. 5 shows a plot of π plasmon loss energy and π plasmon loss peak intensity measured for graphite (HOPG) and some glassy carbon samples having different crystallite diameters by the above-described apparatus. FIG. 5 also shows the π plasmon loss energy and the π plasmon loss peak intensity measured as an example of the carbon-containing film 10 used in the present invention.
[0049]
Further, FIG. 6 shows crystal data of graphite (HOPG) and glassy carbon samples. The π plasmon loss energy shown in FIG. 6 is an actually measured value of the π plasmon loss peak position, and the π plasmon loss peak intensity is a relative intensity with respect to the elastic scattering peak.
[0050]
These measured values may differ at a certain ratio depending on the specifications of the measuring apparatus. In order to eliminate such an error, it is preferable to use a single crystal graphite (HOPG) as a standard sample and use a relative value, that is, a ratio with respect to a value obtained from the single crystal graphite as a characteristic value.
[0051]
As shown in FIG. 5, in general carbon materials, that is, graphite (HOPG) and glassy carbon, as the crystallite diameter decreases, the π plasmon loss energy shifts to the lower energy side, and at the same time, the π plasmon loss peak. Strength decreases. This indicates that the π electron density in carbon decreases as the crystallite size decreases.
[0052]
On the other hand, the π plasmon loss energy and the π plasmon loss peak intensity obtained in the carbon-containing film 10 according to the present invention are out of the correlation in the carbon material and are in the upper left region. This is presumed to mean that the π electron density is high despite the small crystallite diameter.
[0053]
Such a feature has the following advantages with respect to the electron emission characteristics of the electron-emitting device of the present invention.
That is, carbon having a small crystallite diameter is characterized in that the gap width can be formed uniformly especially when the gap 7 is formed. When the crystallite diameter is large, the width of the gap 7 has a distribution about the crystallite diameter, and therefore, when a voltage is applied to the device, a point that causes excessive electric field concentration occurs and the electron emission characteristics become unstable. There is a case.
[0054]
On the other hand, carbon having a high π electron density generally has a low resistivity, and a voltage drop when a voltage is applied to the element through the element electrodes 2 and 3 is small. Therefore, a sufficient effective voltage can be applied to the gap 7. Furthermore, the amount of electrons emitted is considered to be limited by the free electron density of the electron-emitting member (which is considered to correspond to the π electron density in the carbon material), and a higher π electron density is preferable.
[0055]
In the present invention, carbon having π plasmon loss energy in the range of about 70% or more and about 90% or less of π plasmon loss energy of single crystal graphite and having a π plasmon loss peak intensity of 70% or more of single crystal graphite. When the film 10 having the above is used, the above advantages are reflected in the element characteristics.
[0056]
In order to form the carbon-containing film 10 having such characteristics, as described above, the surface of the conductive thin film 4 is cleaned by cleaning the surface of the conductive thin film 4 in a vacuum or the like. Although it is speculated that it is important to enhance the interaction with the carbon-containing film 10 or to activate in an organic compound atmosphere containing nitrogen, the present invention is not limited to these manufacturing methods. .
[0057]
The electron-emitting device obtained through the above steps is preferably subjected to stabilization treatment. This treatment is a step of removing excess organic material molecules adsorbed on the electron-emitting device. The electron-emitting device is installed in a vacuum container, and the inside of the container is evacuated. It is preferable to use an evacuation apparatus that does not use oil so that oil generated from the apparatus does not diffuse into the vacuum vessel. Specifically, a vacuum evacuation device or the like combining a sorption pump and an ion pump.
[0058]
The partial pressure of the organic component in the vacuum vessel is preferably a partial pressure at which carbon and carbon compounds are not newly deposited on the device, and is preferably 1 × 10 −8 <−8> Torr or less, and more preferably 1 × 10 −10 < Particularly preferred is −10th power> Torr or less. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel so that excess organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device can be easily evacuated. The heating conditions at this time are 80 to 300 ° C., preferably 250 ° C. or higher, and it is desirable to perform the treatment for as long as possible. However, the heating conditions are not particularly limited, and the size and shape of the vacuum vessel and the configuration of the electron-emitting device are not limited. The conditions are appropriately selected according to various conditions such as the above. The pressure in the vacuum vessel needs to be as low as possible, preferably 1 × 10 −7 <−7th power> Torr or less, more preferably 1 × 10 −8 <−8th power> Torr or less.
[0059]
The driving atmosphere after the stabilization process is preferably maintained at the end of the stabilization process. However, the present invention is not limited to this. If the organic substance is sufficiently removed, the degree of vacuum Even if it is somewhat lowered, it can maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, it is possible to suppress the deposition of new carbon or carbon compounds, and it is possible to remove H2 O, O2 and the like adsorbed on the vacuum vessel or the substrate. As a result, the device current If and the emission current Ie Is stable.
[0060]
The basic characteristics of an electron-emitting device to which the present invention can be applied obtained through the above-described steps will be described with reference to FIGS.
FIG. 7 is a block diagram showing an example of a vacuum processing apparatus. This vacuum processing apparatus also has a function as a measurement evaluation apparatus. In FIG. 7, electron-emitting devices are arranged in the vacuum device 35. That is, 1 is a substrate (substrate) constituting an electron-emitting device, 2 and 3 are device electrodes, 4 is a conductive thin film, 5 is an electron-emitting portion which is a gap 6 and 7 and a region in the vicinity thereof. 31 is a power source for applying the device voltage Vf to the electron-emitting device, 30 is an ammeter for measuring the device current If flowing through the conductive thin film 4 between the device electrodes 2 and 3, and 34 is emitted from the electron-emitting portion. This is an anode electrode for capturing the emission current Ie. Reference numeral 33 denotes a high voltage power source for applying a voltage to the anode electrode 34, and reference numeral 32 denotes an ammeter for measuring an emission current Ie due to electron emission of the element. As an example, the measurement can be performed with the voltage of the anode electrode in the range of 1 kV to 10 kV and the distance H between the anode electrode and the electron-emitting device in the range of 2 mm to 8 mm.
[0061]
Equipment necessary for measurement in a vacuum atmosphere, such as a vacuum gauge, is provided in the vacuum device 35 so that measurement evaluation in a desired vacuum atmosphere can be performed. Needless to say, if the power source 31 can supply sufficient power, this apparatus can be used for the forming process. Moreover, if the whole vacuum processing apparatus can be heated with a heater, it can also be used for said stabilization process.
[0062]
FIG. 8 is a diagram schematically showing the relationship among the emission current Ie, device current If, and device voltage Vf measured using the vacuum processing apparatus shown in FIG. In FIG. 8, since the emission current Ie is remarkably smaller than the device current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.
[0063]
As is apparent from FIG. 8, the surface conduction electron-emitting device to which the present invention can be applied has three characteristic properties with respect to the emission current Ie. That is,
(1) When an element voltage equal to or higher than a certain voltage (referred to as a threshold voltage, Vth in FIG. 8) is applied to this element, the emission current Ie increases abruptly, while the emission current Ie decreases below the threshold voltage Vth. Almost no detection. That is, it is a non-linear element having a clear threshold voltage Vth for the emission current Ie.
[0064]
(2) Since the emission current Ie is monotonically dependent on the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.
(3) The amount of emitted electrons captured by the anode electrode 34 depends on the application time of the device voltage Vf. That is, the amount of electrons trapped by the anode electrode 34 can be controlled by the time during which the element voltage Vf is applied.
[0065]
FIG. 8 shows an example in which the element current If monotonously increases with respect to the element voltage Vf (MI characteristic). Depending on the manufacturing process described above, the element current If may exhibit a voltage-controlled negative resistance characteristic (VCNR characteristic) with respect to the element voltage Vf. However, the MI characteristic is changed by performing the stabilization process.
[0066]
As can be understood from the above description, the surface conduction electron-emitting device to which the present invention can be applied can easily control the electron emission characteristics in accordance with the input signal. By utilizing this property, it is possible to apply to various fields such as an electron source and an image forming apparatus configured by arranging a plurality of electron-emitting devices.
[0067]
Using the above characteristics, it is possible to produce an electron source and an image forming apparatus in which a plurality of the electron-emitting devices are arranged on a substrate. Various arrangements of the electron-emitting devices can be employed. As an example, a plurality of electron-emitting devices arranged in parallel are connected at both ends, and a plurality of rows of electron-emitting devices are arranged (row direction), and the electron-emitting devices are arranged in a direction perpendicular to the wiring (column direction). There is a ladder-type arrangement in which electrons from the electron-emitting device are controlled and driven by a control electrode (grid) disposed above the substrate.
[0068]
Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of the electrodes of the plurality of electron-emitting devices arranged in the same row is connected in common to the wiring in the X direction. Examples include one in which the other of the electrodes of the plurality of electron-emitting devices arranged in the same column is commonly connected to the wiring in the Y direction. Such is a so-called simple matrix arrangement.
[0069]
This simple matrix arrangement will be further described. As described above, the surface conduction electron-emitting device has the characteristics (1) to (3). That is, the emitted electrons from the surface conduction electron-emitting device can be controlled by the peak value and width of the pulsed voltage applied between the device electrodes facing each other above the threshold voltage. On the other hand, it is hardly emitted below the threshold voltage. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulsed voltage is appropriately applied to each device, a surface conduction electron-emitting device is selected according to the input signal and electron emission is performed. You can control the amount.
[0070]
Hereinafter, an electron source substrate obtained by arranging a plurality of electron-emitting devices to which the present invention can be applied based on this principle will be described with reference to FIG. In FIG. 9, 81 is an electron source substrate, 82 is an X direction wiring, and 83 is a Y direction wiring. 84 is a surface conduction electron-emitting device, and 85 is a connection. The m X-directional wirings 82 are made of Dx1, Dx2,..., Dxm, and can be made of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The material, film thickness, and width of the wiring are appropriately designed. The Y-direction wiring 83 includes n wirings Dy1, Dy2,..., Dyn, and is formed in the same manner as the X-direction wiring 82. An interlayer insulating layer (not shown) is provided between the m X-direction wirings 82 and the n Y-direction wirings 83 to electrically isolate the two.
[0071]
An interlayer insulating layer (not shown) is made of SiO2 or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 1 formed with the X direction wiring 82, and in particular, the film thickness, so as to withstand the potential difference at the intersection of the X direction wiring 82 and the Y direction wiring 83. Materials and manufacturing methods are set as appropriate. The X-direction wiring 82 and the Y-direction wiring 83 are drawn out as external terminals, respectively.
[0072]
A pair of electrodes (not shown) constituting the surface conduction electron-emitting device 84 are electrically connected by m X-direction wirings 82, n Y-direction wirings 83, and a connection 85 made of a conductive metal or the like. Yes.
[0073]
The material constituting the wiring 82 and the wiring 83, the material constituting the connection 85, and the material constituting the pair of element electrodes may be the same or partially different from each other in the constituent elements. These materials are appropriately selected from, for example, the above-described element electrode materials. When the material constituting the element electrode and the wiring material are the same, the wiring connected to the element electrode can also be called an element electrode.
[0074]
The X direction wiring 82 is connected to a scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the surface conduction electron-emitting devices 84 arranged in the X direction. On the other hand, the Y-direction wiring 83 is connected to modulation signal generating means (not shown) for modulating each column of the surface conduction electron-emitting devices 84 arranged in the Y direction according to an input signal. The drive voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.
[0075]
In the above configuration, individual elements can be selected and driven independently using a simple matrix wiring.
An image forming apparatus configured using the electron source having the simple matrix arrangement described above will be described with reference to FIGS. FIG. 10 is a block diagram showing an example of a display panel of the image forming apparatus, and FIG. 11 is a block diagram of a fluorescent film used in the image forming apparatus of FIG.
[0076]
In FIG. 10, reference numeral 81 denotes an electron source substrate on which a plurality of surface conduction electron-emitting devices are arranged, 91 denotes a rear plate to which the substrate 81 is fixed, 96 denotes a fluorescent film 94 and a metal back 95 formed on the inner surface of a glass substrate 93. Face plate. Reference numeral 92 denotes a support frame. The rear frame 91 and the face plate 96 are baked at 400 to 500 ° C. for 10 minutes or more in the air or in nitrogen using a low melting point frit glass or the like. , Joined. 84 is an electron-emitting device. Reference numerals 82 and 83 denote X-direction wirings and Y-direction wirings connected to a pair of device electrodes of the surface conduction electron-emitting device.
[0077]
The envelope (vacuum container) 98 includes the face plate 96, the support frame 92, and the rear plate 91 as described above. Since the rear plate 91 is provided mainly for the purpose of reinforcing the strength of the substrate 110, if the substrate 110 itself has sufficient strength, the separate rear plate 91 can be omitted. That is, the support frame 92 may be sealed directly to the substrate 110, and the envelope 98 may be configured by the face plate 96, the support frame 92, and the substrate 110. On the other hand, by installing a support member (not shown) called a spacer between the face plate 96 and the rear plate 91, an envelope 98 having sufficient strength against atmospheric pressure can be configured.
[0078]
FIG. 11 is a schematic configuration diagram showing the fluorescent film 94. In the case of monochrome, the fluorescent film 94 can be composed of only a phosphor. In the case of a color fluorescent film, it can be composed of a black member 101 called a black stripe or a black matrix, and a phosphor 102 depending on the arrangement of the phosphors.
[0079]
The purpose of providing the black stripe and the black matrix is to make the mixed colors and the like inconspicuous by making the coating portion between the phosphors 102 of the required three primary color phosphors black in the case of color display, The purpose is to suppress a decrease in contrast due to light reflection. As a material for the black stripe, in addition to a commonly used material mainly composed of graphite, a material having electrical conductivity and little light transmission and reflection can be used.
[0080]
As a method of applying the phosphor on the glass substrate 93, a precipitation method, a printing method, or the like can be adopted regardless of monochrome or color. A metal back 95 is usually provided on the inner surface side of the fluorescent film 94. The purpose of providing the metal back is to improve the luminance by specularly reflecting the light emitted from the phosphor toward the inner surface to the face plate 96 side, to act as an electrode for applying an electron beam acceleration voltage, For example, the phosphor is protected from damage caused by the collision of negative ions generated in the envelope.
[0081]
After the metal back and the phosphor film are produced, the inner surface of the phosphor film can be smoothed (usually called “filming”), and then Al is deposited by vacuum evaporation or the like. The face plate 96 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 94 in order to further increase the conductivity of the fluorescent film 94.
[0082]
When performing the above-described sealing, in the case of color, it is necessary to associate each color phosphor with the electron-emitting device, and sufficient alignment is performed.
The envelope 98 is sealed after the degree of vacuum is about 1 × 10 −7 <−7> Torr through an exhaust pipe (not shown). In addition, a getter process may be performed in order to maintain the degree of vacuum after the envelope 98 is sealed. This is because the getter disposed at a predetermined position (not shown) in the envelope 98 is heated by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 98 is sealed. This is a process for forming a deposited film. The getter usually has Ba or the like as a main component, and maintains a vacuum degree of, for example, 1 × 10 −5 <−5> or 1 × 10 −7 <−7> Torr by the adsorption action of the deposited film. .
[0083]
In the image forming apparatus (image display apparatus) completed as described above, each electron-emitting device is caused to emit electrons by applying a voltage through the external terminals Dox1 to Doxm, Doy1 to Doyn, and through the high-voltage terminal 97 to the metal. A high voltage of several kV or more is applied to the back 95 or a transparent electrode (not shown), the electron beam is accelerated, collides with the fluorescent film 94, and is excited and emitted to display an image.
[0084]
The above-described configuration is a schematic configuration necessary for producing a suitable image forming apparatus used for display or the like. For example, detailed portions such as materials of each member are not limited to the above-described contents. It selects suitably so that it may suit the use of an image forming apparatus.
[0085]
Next, a configuration example of a driving circuit for performing television display based on an NTSC television signal on a display panel configured using an electron source having a simple matrix arrangement will be described with reference to FIG.
[0086]
FIG. 12 is a block diagram illustrating an example of a drive circuit for performing display in accordance with NTSC television signals. In FIG. 12, 111 is a display panel, 112 is a scanning signal generating circuit, 113 is a timing control circuit, and 114 is a shift register. Reference numeral 115 is a line memory, 116 is a synchronizing signal separation circuit, 117 is a modulation signal generating circuit, and Vx and Va are DC voltage sources.
[0087]
The display panel 111 is connected to an external electric circuit via terminals Dox1 to Doxm, terminals Doy1 to Doyn, and a high voltage terminal Hv. For the terminals Dox1 to Doxm, in order to sequentially drive one row (n elements) of an electron source 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. The scanning signal is applied. Modulation signals for controlling the output electron beams of the surface conduction electron-emitting devices in one row selected by the scanning signal are applied to the terminals Doy1 to Doyn. The high-voltage terminal Hv is supplied with a DC voltage of, for example, 10 kV from the DC voltage source Va, which gives sufficient energy to excite the phosphor to the electron beam emitted from the surface conduction electron-emitting device. It is an acceleration voltage to do.
[0088]
The scanning signal generation circuit 112 includes m switching elements therein (schematically indicated by S1 to Sm in the drawing). 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 111. Each of the switching elements S1 to Sm operates based on a control signal Tscan output from the control circuit 113, and can be configured by combining switching elements such as FETs.
[0089]
In the case of this example, the direct current voltage source Vx has a driving voltage applied to an element not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. Is set to output a constant voltage.
[0090]
The timing control circuit 113 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 113 generates Tscan, Tsft, and Tmry control signals for each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 116.
[0091]
The synchronization signal separation circuit 116 is a circuit for separating a synchronization signal component and a luminance signal component from an NTSC television signal input from the outside, and can be configured using a general frequency separation (filter) circuit or the like. The synchronization signal separated by the synchronization signal separation circuit 116 includes a vertical synchronization signal and a horizontal synchronization signal, but is illustrated here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. This DATA signal is input to the shift register 114.
[0092]
The shift register 114 is for serial / parallel conversion of the DATA signal input serially in time series for each line of the image, and operates based on the control signal Tsft sent from the timing control circuit 113. (In other words, it can be said that the control signal Tsft is a shift clock of the shift register 114). Data for one line (corresponding to drive data for N electron-emitting devices) subjected to serial / parallel conversion is output from the shift register 114 as N parallel signals ld1 to ldn.
[0093]
The line memory 115 is a storage device for storing data for one line of an image for a required time, and appropriately stores the contents of ld1 to ldn according to the control signal Tmry sent from the timing control circuit 113. The stored contents are output as l′ d1 to l′ dn and input to the modulation signal generator 117.
[0094]
The modulation signal generator 117 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data l′ d1 to l′ dn, and an output signal thereof is output from the terminals Doy1 to Doy1. The voltage is applied to the surface conduction electron-emitting device in the display panel 111 through Doyn.
[0095]
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, there is a clear threshold voltage Vth for electron emission, and electron emission occurs only when a voltage equal to or higher than Vth is applied. For voltages above the electron emission threshold, the emission current also changes with changes in the voltage applied to the device. For this reason, when a pulsed voltage is applied to the device, for example, electron emission does not occur even when a voltage lower than the electron emission threshold is applied, but when a voltage higher than the electron emission threshold is applied, the electron beam is not Is output. At that time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. Further, 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 for modulating the electron-emitting device in accordance with the input signal.
[0096]
When implementing the voltage modulation method, a voltage modulation method circuit that generates a voltage pulse of a predetermined length and modulates the peak value of the pulse as appropriate according to the input data is used as the modulation signal generator 117. be able to.
[0097]
When implementing the pulse width modulation method, the modulation signal generator 117 generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to the input data. A circuit can be used.
[0098]
The shift register 114 and the line memory 115 may be digital signal type or analog signal type. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.
[0099]
When the digital signal system is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 116 into a digital signal. For this purpose, an A / D converter may be provided at the output portion of the synchronization signal separation circuit 116. . In this connection, the circuit used for the modulation signal generator 117 is slightly different depending on whether the output signal of the line memory 115 is a digital signal or an analog signal.
[0100]
That is, in the case of a voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 117, and an amplifier circuit or the like is added as necessary. In the case of the pulse width modulation method, the modulation signal generator 117 includes, for example, a high-speed oscillator and a counter that counts the wave number output from the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. A circuit combining (comparators) is used. If necessary, an amplifier can be added to amplify the voltage of the pulse width modulated modulation signal output from the comparator to the driving voltage of the surface conduction electron-emitting device.
[0101]
In the case of a voltage modulation method using an analog signal, for example, an amplifier circuit using an operational amplifier or the like can be adopted as the modulation signal generator 117, and a bell shift circuit or the like can be added if necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillation circuit (VCO) can be adopted, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device can be added as necessary.
[0102]
In the image display apparatus to which the present invention that can take such a configuration can be applied, electron emission occurs by applying a voltage to each electron-emitting device via the external terminals Dox1 to Doxm and Doy1 to Doyn. A high voltage is applied to the metal back 95 (see FIG. 10) or the transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 94 (see FIG. 10), light emission is generated, and an image is formed.
[0103]
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. As for the input signal, the NTSC system is mentioned, but the input signal is not limited to this. Besides the PAL, SECAM system, and the like, a TV signal composed of a large number of scanning lines (for example, the MUSE system and the like) High-definition TV) system can also be adopted.
[0104]
The image forming apparatus of the present invention can be used as an image forming apparatus as an optical printer configured using a photosensitive drum or the like in addition to a display apparatus for a television broadcast, a video conference system, a computer, or the like. it can.
[0105]
【Example】
Next, based on an Example, this invention is explained in full detail.
[Example 1]
The electron-emitting device formed by the present invention has a configuration schematically shown in FIGS. 1 (A) and 1 (B). A manufacturing process of the electron-emitting device manufactured in this example will be described with reference to FIGS.
[0106]
Step-a:
Quartz is used as the substrate 1, and this is washed with a detergent, pure water and an organic solvent, and then a photoresist RD-2000N (manufactured by Hitachi Chemical Co., Ltd.) is applied with a spinner (2500 rpm, 40 seconds) at 80 ° C., 25 Pre-bake for minutes.
[0107]
Next, contact exposure was performed using a mask corresponding to the pattern of the device electrodes, development using a developer, and post-baking at 120 ° C. for 20 minutes to form a resist mask.
[0108]
Next, Ni was formed into a film by a vacuum evaporation method. The film formation rate is 0.3 mm / sec. The film pressure was 10 nm.
Next, the substrate was immersed in acetone to dissolve the resist mask, and Ni element electrodes 2 and 3 were formed by lift-off. The electrode gap H is 2 μm, and the electrode length W is 500 μm (FIG. 2A).
[0109]
Step-b:
The substrate on which the electrode is formed is washed with acetone, isopropanol, and butyl acetate and dried, and then Cr is deposited to a thickness of 50 nm by vacuum deposition. Subsequently, photoresist AZ1370 (manufactured by Hoechst) was applied (2500 rpm, 30 seconds) with a spinner, and prebaked at 90 ° C. for 30 minutes.
[0110]
Next, an opening corresponding to the shape of the conductive thin film was formed by exposure and development using a mask, and post-baking was performed at 120 ° C. for 30 minutes to form a resist mask.
[0111]
Next, it was immersed in an etchant ((NH4) Ce (NO3) 6 / HC1 / H2O = 17 g / 5cc / 100cc) for 30 seconds, Cr etching of the mask opening was performed, and then the resist was stripped with acetone to form a Cr mask. .
[0112]
Next, a solution of an organic Pd compound (ccp-4230: manufactured by Okuno Pharmaceutical Co., Ltd.) was applied with a spinner (800 rpm, 30 seconds) and baked at 300 ° C. for 10 minutes to form a conductive thin film made of PdO fine particles. Formed.
[0113]
Next, it was immersed again in the above etchant, the Cr mask was removed, and the conductive thin film 4 having a desired pattern was formed by lift-off (FIG. 2B).
Step-c:
Next, the above elements were installed in the apparatus schematically shown in FIG. 7, and the inside of the vacuum chamber 35 was evacuated by an unillustrated evacuation apparatus, so that the pressure was 1 × 10 −5 <−5 to the power of Torr or less. Next, a mixed gas of N2: 98% -H2: 2% was introduced into the vacuum chamber 35. The pressure in the vacuum chamber was set to 1.3 × 10 −3 <−3> Pa. Next, a constant rectangular wave pulse having a peak value of 10 V was applied between the device electrodes 2 and 3 as shown in FIG. The pulse width T1 is 0.1 msec. The pulse interval T2 is 16.6 msec. It was. When voltage was continuously applied for about 20 minutes under these conditions, forming was completed (FIG. 2C).
[0114]
A rectangular wave pulse having a peak value of 0.1 V was inserted between the pulses, and the resistance value of the element was measured. When this exceeded 1 MΩ, the application of the pulse voltage was stopped and the vacuum chamber 35 was evacuated. Further, after the pressure becomes 1 × 10 −7 <−7th power> Torr or less, the element is baked at 200 ° C. for 2 hours, and the conductive thin film 4 is sufficiently reduced to form the conductive thin film 4 made of the metal Pd film. did.
[0115]
Step-d:
After the element returned to room temperature and the pressure became 1 × 10 −8 <−8th power> Torr or less, tolunitrile was introduced to set the pressure to 1 × 10 −6 <−6th power> Torr. A rectangular wave pulse for reversing the polarity with a constant peak value as shown in FIG. 13 was repeatedly applied between the element electrodes. The peak value was 15V.
[0116]
Step-e:
Next, the device was heated to 300 ° C. and held while the inside of the vacuum chamber 35 was evacuated by an evacuation device, and reached a pressure of 1 × 10 −9 <−9th power> Torr.
[0117]
After returning the element to room temperature, a voltage of 8 kV was applied to the anode electrode 34, and a rectangular wave pulse voltage having a constant peak value was applied between the element electrodes, and the characteristics were measured. The distance H between the anode electrode 34 and the element was set to 4 mm.
[0118]
When the device was driven for a certain time, the emission current Ie was sufficiently large, and the fluctuations of the device current If and the emission current Ie were very small. A very stable device having a large emission current Ie was obtained.
[0119]
An energy loss spectrum was measured using a reflection type electron energy loss spectroscopy (REELS) measuring apparatus shown in FIG. 4 for an analysis element manufactured in exactly the same manner as the element whose characteristics were measured. The measurement in this example was performed using a commercially available Auger electron spectrometer equipped with a field emission electron gun and a concentric hemispherical energy analyzer.
[0120]
The main measurement conditions are primary electron acceleration energy: about 1 keV, primary electron current: about 2 nA, analyzer operation mode: constant resolution mode (pass energy is 5 to 20 eV), pressure in the apparatus: 5 × 8−8 <-8th power> Pa or less. The primary electron beam diameter under this condition was about 150 nm.
[0121]
FIG. 14 shows an energy loss spectrum of reflected electrons measured under such conditions. In the figure, energy loss spectra measured for graphite (HOPG) and glassy carbon (see FIG. 6) are shown for comparison. In FIG. 14, the peak observed in the range of loss energy of 4 to 8 eV is called π plasmon peak and is derived from double bond carbon. Further, the peak observed in the range of the loss energy of 20 to 30 eV is called π + σ plasmon peak.
[0122]
As shown in FIG. 14, the π plasmon energy and the π plasmon peak intensity of the carbon-containing film 10 on the electron-emitting device of the present invention peak as compared with single crystal graphite or glassy carbon while shifting to a lower energy side. It has the characteristic that strength is strong. Specifically, the π plasmon energy was 5.1 eV, which was about 77% of the π plasmon energy (6.64 eV) in HOPG. On the other hand, the π plasmon peak intensity is 2.8% of the elastic scattering peak, which is about 82% of the π plasmon peak intensity (3.42% of the elastic scattering peak) in HOPG.
[0123]
[Example 2]
The present embodiment is a method for manufacturing an electron source of a matrix wiring schematically shown in FIG. 15 and an image forming apparatus (FIG. 10) using the same. FIG. 15 is a partial plan view schematically showing the configuration of the electron source of the matrix wiring formed according to the present embodiment, and FIG. 16 shows a cross-sectional structure along the broken line A-A ′ in FIG.
[0124]
Hereinafter, the manufacturing process of the electron source will be described with reference to FIGS. 17 and 18, and the manufacturing process of the image forming apparatus will also be described.
Step-A:
A silicon oxide film of 0.5 μm is formed on the cleaned soda glass by sputtering, using this as a substrate, Cr 5 nm and Au 600 nm are sequentially formed by vacuum evaporation, and then a photoresist AZ1370 (manufactured by Hoechst) is formed. Then, the lower wiring 82 was formed by a photolithography technique (FIG. 17A).
[0125]
Step-B:
Next, an interlayer insulating layer 151 made of a silicon oxide film having a thickness of 1 μm is deposited by sputtering (FIG. 17B).
[0126]
Step-C:
A photoresist pattern for forming a contact hole 152 in the interlayer insulating layer was created, and the interlayer insulating layer 151 was etched by RIE (Reactive Ion Etching) using CF4 and H2 using this as a mask (FIG. 17C) .
[0127]
Step-D:
A mask pattern of photoresist (RD-2000N-41: manufactured by Hitachi Chemical Co., Ltd.) having an opening corresponding to the pattern of the device electrode is formed, and 5 nm of Ti and 100 nm of Ni are sequentially deposited from the vacuum evaporation method ratio, and then an effective solvent Then, the photoresist was removed and element electrodes 5 and 6 were formed by lift-off. The distance L between the device electrodes was 3 μm (FIG. 17D).
[0128]
Process-E:
An upper wiring 83 having a laminated structure of 5 nm Ti and 500 nm Au was formed by the photolithography method using the same photoresist as in Step-A (FIG. 18E).
[0129]
Process-F:
The conductive thin film 4 made of PdO fine particles was formed by lift-off using the same Cr mask 191 as in step-b of Example 1 (FIG. 18F).
[0130]
Process-G:
Form a resist pattern that covers areas other than the contact hole 152, sequentially deposit 5 nm of Ti and 500 nm of Au by vacuum deposition, remove the resist pattern, remove unnecessary stacked films, fill the contact holes, and form A previous electron source substrate was prepared (FIG. 17G).
[0131]
An image forming apparatus having the configuration shown in FIG. 10 was produced using the electron source substrate.
An electron source substrate 81 is fixed to the rear plate 91, a face plate 96 is disposed 5 mm above the substrate via a support frame 92, frit glass is applied to the joint, and the substrate is held at 400 ° C. for 10 minutes in a nitrogen atmosphere. Thus, the envelope 98 was formed. A fluorescent film 94 and a metal back 95 are formed on the inner surface of the face plate 96. The fluorescent film 94 has a stripe shape (FIG. 11A) and is formed by a printing method. The black conductive material used was a material mainly composed of graphite. The metal back 95 was formed by vacuum-depositing Al after smoothing (filming) the inner surface of the phosphor film 94.
[0132]
When the above assembly was performed, it was necessary to accurately correspond the phosphor and the electron-emitting device, and the alignment was performed sufficiently. A getter device (not shown) is also attached in the envelope.
[0133]
Process-H:
The inside of the envelope is evacuated by an unillustrated exhaust device, and after introducing a mixed gas of N2: 98% -H2: 2% into the envelope in the same manner as in step-c of Example 1, a rectangular wave pulse Was applied to form a gap, and a gap was formed in each conductive thin film. Further, the inside of the envelope was heated while evacuating, and the conductive thin film 4 was sufficiently reduced.
[0134]
Step-I:
Subsequently, in the same manner as in step d of Example 1, activation treatment was performed by introducing tolunitrile into the envelope.
[0135]
Process-J:
As in step 1-e of Example 1, the inside of the envelope was heated while being evacuated and stabilized, and as a result, the internal pressure reached 1 × 10−8 <−8th power> Torr in about 3 hours. did.
[0136]
When a drive circuit (not shown) is attached to the envelope created by the above steps, a high voltage of 10 kV is applied to the metal back, and a TV signal (NTSC signal) is input to display an image, uneven brightness is obtained. A high-definition image with no image was stably obtained over a long period of time.
[0137]
【The invention's effect】
As described above, in the electron-emitting device of the present invention, the π plasmon loss energy of the carbon-containing film member is in the range of about 70% or more and about 90% or less of the π plasmon loss energy of the single crystal graphite, and π Since the intensity of the plasmon loss peak is about 70% or more of the π plasmon loss peak intensity of single crystal graphite, the amount of emitted electrons is large, and stable device characteristics can be realized over a long period of time.
[0138]
This is because the carbon-containing film member is made of a carbon material having a small crystallite diameter and a high π electron density, so that the gap width of the opposing gap can be formed uniformly and a sufficient effective voltage is applied to the gap. In addition, it is considered that the effect is that the amount of electrons emitted is large.
[0139]
In addition, the electron source and the image forming apparatus using the electron-emitting device of the present invention have an effect that a high-brightness image can be stably obtained over a long period of time.
[Brief description of the drawings]
1A and 1B are a schematic plan view and a cross-sectional view showing a configuration of an electron-emitting device according to an embodiment of the present invention.
FIG. 2 shows a part of a manufacturing process of an electron-emitting device according to one embodiment.
FIG. 3 shows an example of a voltage waveform that can be used in a forming process that is a part of the manufacturing process of the electron-emitting device according to the embodiment.
FIG. 4 is a schematic configuration diagram of an apparatus for analyzing an electron-emitting device.
FIG. 5 is a view for explaining the relationship between the π plasmon loss energy and the π plasmon loss peak intensity of the carbon-containing film of the electron-emitting device according to one embodiment.
FIG. 6 is a diagram showing the results of X-ray diffraction, Raman spectroscopic analysis, and reflected electron energy loss spectroscopic analysis of a standard carbon sample element.
FIG. 7 is a configuration diagram showing an example of a vacuum processing apparatus having a measurement evaluation function.
FIG. 8 shows a relationship among an emission current Ie, a device current If, and a device voltage Vf of the electron-emitting device according to the embodiment.
FIG. 9 is a configuration diagram showing an example in which the electron-emitting device of one embodiment is applied to an electron source arranged in a simple matrix.
FIG. 10 is a configuration diagram showing an example in which the electron-emitting device of one embodiment is applied to an image forming apparatus.
FIG. 11 is a configuration diagram showing an example of a fluorescent film.
FIG. 12 is a configuration diagram of a driving circuit of an example in which the image forming apparatus according to the embodiment performs display according to an NTSC television signal.
FIG. 13 shows an example of a voltage waveform that can be used in an activation process that is a part of the manufacturing process of the electron-emitting device according to one embodiment.
FIG. 14 is a diagram showing an energy loss spectrum of the electron-emitting device according to one embodiment.
FIG. 15 is a configuration diagram showing an example in which the electron-emitting device of one embodiment is applied to an electron source arranged in a simple matrix.
16 is a partial cross-sectional view taken along a broken line A-A ′ in FIG. 15;
FIG. 17 is a view for explaining a part of the manufacturing process of the electron source according to the embodiment.
FIG. 18 is a view for explaining a part of the manufacturing process of the electron source according to the embodiment.
19A and 19B are a schematic plan view and a cross-sectional view showing a configuration of a conventional surface conduction electron-emitting device.
[Explanation of symbols]
1 Substrate
2, 3 electrodes
4 Conductive thin film
5 Electron emission part
6 Gap formed in part of conductive thin film
7 Gaps between carbon-containing films (sediment / carbon film) 10
10 Carbon-containing film (sediment / carbon film)
30 Ammeter for measuring element current If flowing through the conductive thin film 4 between the element electrodes 2 and 3
31 Power supply for applying device voltage Vf to the electron-emitting device
32 Ammeter for measuring the emission current Ie emitted from the electron-emitting device
33 High-voltage power supply for applying voltage to the anode electrode 34
34 Anode electrode for accelerating and capturing electrons emitted from the electron-emitting device
35 Vacuum equipment (vacuum chamber)
81 Electron source substrate
82 X direction wiring
83 Y-direction wiring
84 Electron emitter
85 connection
91 Rear plate
92 Support frame
93 Glass substrate
94 Fluorescent membrane
95 metal back
96 face plate
98 Envelope
101 Black member
102 phosphor
151 Interlayer insulation layer
152 contact hole

Claims (7)

A pair of electrode members disposed on the main surface of the insulating substrate ; A first carbon film and a second carbon film disposed between the pair of electrode members , each of the first and second carbon films facing each other across a gap, An electron-emitting device in which the first carbon film is electrically connected to one of a pair of electrode members, and the second carbon film is electrically connected to the other of the pair of electrode members ,
Before SL first and second carbon film, [pi plasmon loss energy monocrystalline graphite [pi plasmon loss energy of 70% or more, in the range of 90% or less, and the strength of the [pi plasmon loss peak is a single crystal An electron-emitting device characterized by being 70 % or more of the π plasmon loss peak intensity of graphite. One of the pair of electrode members and the first carbon film are connected via a first conductive thin film, and the other of the pair of electrode members and the second carbon film are second conductive. The electron-emitting device according to claim 1, wherein the electron-emitting device is connected via a conductive thin film . 3. The electron-emitting device according to claim 1, wherein the π plasmon loss energy and the intensity of the π plasmon loss peak are obtained by a reflection type electron energy loss spectroscopic analysis. Using the primary electron beam having the intensity of the π plasmon loss energy and the π plasmon loss peak of the first and second carbon films and an energy in the range of 200 eV to 3 keV, and the half width of the elastic scattering peak is 1 4. The electron-emitting device according to claim 3, wherein the electron-emitting device is measured by a reflection type electron energy loss spectrometer under a condition of eV or less. An electron source in which a plurality of electron-emitting devices are arranged on a substrate,
An electron source, wherein each of said plurality of electron-emitting devices is an electron-emitting device according to any one of claims 1 to 4. An electron source, an image forming apparatus and an image forming member for forming an image by irradiation with electrons emitted from said electron source, said electron source is an electron source according to claim 5 An image forming apparatus. A television broadcast display device comprising: an image forming device; and a circuit for displaying a television broadcast signal on the image forming device, wherein the image forming device is the image forming device according to claim 6. A display device for television broadcasting, characterized in that there is.

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