JP3638264B2 - Cold cathode device manufacturing method, cold cathode device, and display device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cold cathode device and a method for manufacturing the cold cathode device, and in particular, a carbon-based material containing graphite (graphite), which is a plate-like crystal belonging to a hexagonal system, as a main material is a cold cathode (field emission cold cathode). The present invention relates to a technique effective when applied to a cold cathode device.
[0002]
[Prior art]
A conventional cold cathode is called a Spindt type in which a voltage is applied between a cathode having a cone shape with a sharp tip and a gate electrode surrounding the cathode to emit electrons from the cathode tip by an electric field. The structure was common. The electron emission efficiency of the Spindt-type cold cathode device is greatly influenced by the electric field concentration formed on the cathode surface and various characteristics such as work function φ and surface physical properties of the cathode material.
[0003]
The electric field concentration of the Spindt-type cold cathode device is determined by the sharpness of the cathode and the distance between the cathode and the gate electrode, so that a significant improvement in efficiency is achieved by improving the precision of microfabrication technology centered on lithography and further miniaturization technology. Relying on progress.
[0004]
As cold cathodes that do not require such fine processing, there are surface emission types such as MIM type (Metal / Insulator / Metal) and MIS type (Metal / Insulator / Semiconductor). In the surface emission type cold cathode device, there are problems in combination of materials and improvement in electron emission efficiency.
[0005]
On the other hand, refractory metals such as molybdenum (Mo) and nickel (Ni) and semiconductors such as silicon have been mainly used as cold cathode materials, but these materials have a work function φ of about 4 to 5 eV. In addition, materials having a lower work function have been demanded. On the other hand, diamond, diamond-like carbon (DLC), aluminum nitride (AlN), and boron nitride (BN) are also said to have negative electron affinity (NEA) characteristics. In combination with its high hardness performance and chemical stability, it is considered promising as a cold cathode material.
[0006]
In contrast, in recent years, carbon nanotubes or carbon nanofibers are said to exhibit good electron emission characteristics. However, clear NEA characteristics or high-efficiency electron emission characteristics have not yet been found for cold cathodes using these materials, which impedes practical application.
[0007]
As a technique for improving electron emission characteristics, a method of adsorbing impurity atoms on the material surface is known. For example, Cs (cesium), Ba (barium), U (uranium), I ₂ (Iodine), Br ₂ (Bromine), Cl ₂ It is known that the work function φ can be greatly reduced by adsorbing (chlorine) or the like. This is due to the movement of electrons between the adsorbed species and the W single crystal substrate. However, with this method, impurities adsorbed on the surface are unstable, and it is considered difficult to use in vacuum devices such as displays and image sensors.
[0008]
[Problems to be solved by the invention]
As a result of examining the prior art, the present inventor has found the following problems.
The diamond crystal that is expected to have the most performance as a cold cathode material is usually CH. ₄ (Methane), C ₂ H ₂ It is produced by chemical vapor deposition (CVD) using hydrogen carbide such as (acetylene) or carbon monoxide CO as a raw material. However, in this method, since the substrate is kept at a high temperature of about 800 ° C. or more, the raw material is decomposed, and diamond crystal growth is performed on the substrate, it is difficult to process a large area. In particular, diamond has a problem that the diffusion coefficient of atoms is very small and the growth rate is generally small on the order of 0.1 μm / hour.
[0009]
On the other hand, diamond-like carbon is an amorphous carbon, but exhibits characteristics similar to diamond, which is advantageous for processing a large area. Although the deposited DLC film may be used as a thin-film cold cathode as it is, a cold-cathode cone comprising a cathode having a sharp tip made of Mo (molybdenum) or silicon in advance and a gate electrode surrounding the cathode via an insulator. An attempt is made to deposit a DLC film (or polycrystalline diamond film) on the tip of the cathode from above the cathode by the above-mentioned CVD method or the like from above the cathode. In addition, a method has also been attempted in which a pyramid-shaped depression is formed in advance on a substrate such as silicon, DLC or polycrystalline diamond is deposited thereon by CVD, and then the substrate is removed. However, even when such a coating method is used, as described above, the substrate cold cathode needs to be maintained at a high temperature of 800 ° C. or higher, and the surface layer contains a large amount of defects. There was a problem of being an amorphous layer. That is, since the characteristics of the cold cathode are greatly affected by the state of the surface layer, the structure of such a surface layer is unstable and undesirable.
[0010]
On the other hand, as a low-temperature manufacturing method for these materials, a laser ablation method in which a graphite target is irradiated with powerful laser light to evaporate carbon atoms, molecules, ions, clusters and the like and deposit them on a substrate has been tried. Excimer laser pulse light such as ArF (wavelength: 193 nm), KrF (wavelength: 256 nm), or the like is used as the laser light to be irradiated. However, there is a report that the size of the diamond crystal that can be produced by this method is very small and is DLC. Such a DLC film is sp. ² Bond and sp ³ Consists of a bond. The reason why DLC has not yet exhibited sufficient performance as a cold cathode is that the relationship between the bonding ratio and the structure and properties of other materials and the electron emission characteristics are not yet clearly understood. Recent research has shown that the electron emission characteristics of DLC are sp ² It became clear that union plays an important role. Therefore, this sp ² Although a control technique for the binder phase (region) is required, a method for realizing high-efficiency electron emission efficiency at low temperatures has not yet been found for both diamond and DLC. However, since these carbon-based materials are stable to an electron emission environment and have a merit that a high degree of vacuum is not required for stable operation, it is possible to form a cold cathode of a carbon-based material at a low temperature and There is a need for the development of technology that can achieve efficient electron emission efficiency.
[0011]
Also, Cs, Ba, U, I ₂ , Br ₂ , Cl ₂ In the method of improving the electron emission characteristics by depositing, etc. on the surface of the metal cold cathode, as described above, not only is it unstable and difficult to make a device, but also the optimum concentration that maximizes the work function φ reduction effect. Further, even if these elements are deposited on the surface layer of the metal cold cathode, the effect cannot be improved and the work function reducing effect is limited.
[0012]
An object of the present invention is to provide a cold cathode device capable of improving the electron emission efficiency while taking advantage of the chemical stability of carbon in electron emission.
The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.
[0013]
[Means for Solving the Problems]
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
[0014]
(1) In a method of manufacturing a cold cathode device having a cathode bus formed on a substrate and a field emission cold cathode made of a carbon-based material electrically connected to the cathode bus, the cathode bus is formed on the substrate. A step of forming a carbon-based material layer having graphite as a main component material and electrically connected to the cathode bus, and an impurity atom or molecule having a work function smaller than that of the graphite. layer Between plate crystals And a step of forming a field emission cold cathode.
[0015]
(2) In a cold cathode device having a cathode bus formed on a substrate and a field emission cold cathode made of a carbon-based material electrically connected to the cathode bus, the cathode bus is electrically connected to the cathode bus. Thus, a carbon-based material layer made of a carbon-based material is formed, and regions where impurity atoms or molecules are introduced are formed between the plate-like crystals of the carbon-based material layer. A cathode is formed.
[0016]
(3) A cold cathode device in which a plurality of field emission cold cathodes are formed and a phosphor anode are arranged opposite to each other, and an image signal is controlled by controlling a voltage applied between the field emission cold cathode and the phosphor anode. In the display device that performs image display according to the above, the cold cathode device includes a carbon-based material layer formed of a carbon-based material so as to be electrically connected to a cathode bus formed on a substrate, and A plurality of regions into which impurity atoms or molecules are introduced are formed between the plate-like crystals of the carbon-based material layer, and the impurity-introduced region forms a field emission cold cathode.
[0017]
According to the means (1) described above, a step of forming a cathode bus on the substrate, a step of forming a carbon-based material layer electrically connected to the cathode bus using graphite as a main component material, and Impurity atoms or molecules with a low work function can be used as a carbon-based material layer. Between plate crystals As shown in the following principle section, the work function (about 5 eV) of the graphite forming the carbon-based material layer is smaller than the work function of this graphite. Since the work function of impurity atoms or molecules can be approximated, the carbon-based material layer can be used as a field emission cold cathode.
[0018]
At this time, since it is configured to introduce impurity atoms or molecules into the graphite (intercalation), it is possible to obtain highly efficient and selective electron emission characteristics while taking advantage of the chemical stability of carbon in electron emission. it can.
[0019]
(principle)
The structure of the cold cathode device according to the present invention will be described with reference to FIG. In FIG. 1, 101 represents a carbon atom, 102 represents an intercalation atom, and 103 represents an emitted electron.
[0020]
As shown in FIG. 1, the cold cathode of the cold cathode device of the present invention forms a layered structure crystal (hereinafter referred to as a “graphite layered crystal”) formed by continuous carbon atoms 101 bonded in a ring in the same plane. In addition, impurities and atoms or molecules are introduced (intercalated) between the carbon atoms 101. That is, the cold cathode of the cold cathode device according to the present invention introduces (intercalates) impurity atoms or molecules having a small work function between the layers of the graphite layered crystal, while taking advantage of the chemical stability of carbon in electron emission. It has a structure that obtains selective electron emission characteristics with high efficiency.
[0021]
In general, the work function of graphite is about ˜5 eV, so it is not used as a cold cathode material. On the other hand, when carbon forms a compound with Cs, Ba, etc., the compound shows a work function that is rather close to the work function of Cs, Ba. Therefore, instead of adsorbing these alkali metals on the surface, in the present invention, impurity atoms or molecules are introduced as intercalation atoms 102 between the graphite layered crystals formed by a plurality of carbon atoms 101. Thus, a cold cathode having both the chemical stability of the carbon surface when the emitted electrons 103 are emitted from the graphite layered crystal and the reduction of the work function by intercalation is formed.
[0022]
That is, different atoms (molecules) are formed in the graphite layer structure in which the vertical stacking of the carbon atoms 101 having a very large interval (periodic interval) compared to the interval between the carbon atoms 101 adjacent in the left-right direction shown in FIG. Intercalation is applied to increase the efficiency of electron emission and to form an in-plane selective electron emission region by inserting Cs or Ba, which can reduce the resistance as a layer). In this case, a cold cathode having both the chemical stability of the carbon surface and the reduction of the work function by intercalation is formed. However, the order of the intercalation is the number ratio of the carbon atom layer to the intercalation layer, that is, how many carbon atom layers composed of the carbon atoms 101 each form one intercalation layer 102. It is known that characteristics such as resistance can be controlled by controlling the order.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) of the invention.
Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the invention, and the repetitive description thereof is omitted.
[0024]
(Embodiment 1)
FIG. 2 is a diagram for explaining the structure and manufacturing method of the cold cathode device according to the first embodiment of the present invention. Hereinafter, the structure and manufacturing method of the cold cathode device according to the first embodiment will be described with reference to FIG. Will be explained. 2A to 2C are cross-sectional views of the cold cathode device according to the first embodiment.
[0025]
First, as shown in FIG. 2A, after depositing, for example, a photosensitive paste serving as a cathode bus 202 on a glass substrate 201 serving as a substrate, lines in the column direction (vertical direction in FIG. 2) are formed by lithography or the like. To process. As shown in FIG. 2A, the cathode bus 202 is formed on the upper surface of the glass substrate 201, and the five cathode buses 202 are independent from each other.
[0026]
Next, PSG (phosphosilicate glass) or the like is deposited as a glass paste for photo embedding having a thickness of several microns or less by a known reflow technique, and a layer of this photo embedding glass paste is formed. Thereafter, as shown in FIG. 2A, the cell region 210 is formed from the upper surface side to the depth at which the cathode bus 202 and the glass substrate 201 are exposed by lithography or the like on the substrate manufactured by the above-described steps. Form. In this way, first, a cell structure separated by the barrier 203 is formed on the upper surface side of the glass substrate 201. The process of forming the cathode bus 202 and the cell structure on the upper surface side of the glass substrate 201 is the same as the conventional process.
[0027]
Thereafter, the glass substrate 201 on which the cathode bus 202 and the cell structure are formed is subjected to CH at low temperature. ₄ A diamond-like carbon 205 (DLC: Diamond-Like Carbon) is deposited by a chemical vapor deposition method (CVD: Chemical I Vapor Deposition) or the like using a hydrocarbon system such as CO or a raw material, and the DLC layer 204 is formed.
[0028]
Next, as shown in FIG. 2 (b), the DLC layer 204 is annealed by scanning and irradiating a laser beam 206 from the upper surface side of the deposited DLC layer 204, and DLC is graphitized. A graphite layer 207 which is a carbon-based material layer is formed. However, since the DLC phase 204 produced by the chemical vapor deposition method using the above raw materials is usually graphitized by heating at a temperature of about 600 ° C. for about 10 minutes, the laser irradiation seems to bring about such a heating effect. In addition, the graphite layer 207 is formed by selecting the wavelength, beam power, and irradiation time. The graphite layer (graphite film) 207 may be formed directly on the cell region 210 by using other methods such as known arc discharge or laser ablation.
[0029]
Next, as shown in FIG. 2C, impurities such as Cs and Ba that become intercalation atoms 208 are added to the graphite layer (graphite film) 207 by a known ion implantation or thermal diffusion method. Intercalation. By this intercalation, as shown in FIG. 1 described above, an intercalation layer in which Cs, Ba, etc., which are impurities are introduced (intercalated) between the layers of the graphite layered crystal composed of a plurality of carbon atoms 101. 209 is formed. That is, the cold cathode device of the first embodiment has a structure in which Cs, Ba or the like, which is an impurity having a work function smaller than that of graphite, is introduced (intercalated) between the layers of the graphite layered crystal. Thus, it is possible to obtain a highly efficient and selective electron emission characteristic while making use of the chemical stability.
[0030]
In the above-described method, 1) DLC can be deposited at a temperature of room temperature to about 300 ° C., 2) Laser annealing is heating of the surface only, 3) Intercalation of Cs, Ba, etc. can be performed at a low temperature, etc. It is possible to obtain the effect that the whole process can be performed at a low temperature. As a result, it is possible to use an inexpensive glass or plastic substrate without using an expensive crystal glass or the like excellent in heat resistance for the glass substrate 201 and, as will be described later, the cold cathode device of the first embodiment When used as a display device, the weight can be reduced.
[0031]
On the other hand, the cold cathode device according to the first embodiment is arranged in a vacuum hermetic container, and an electrode serving as an anode is arranged in a position facing the cold cathode device in the vacuum hermetic container. By disposing a known phosphor on the cathode device side, a fluorescent light emitting display device that displays characters, graphics, and the like can be formed. Therefore, by supplying a drive signal of a predetermined voltage between the cathode bus 202 and the anode, the phosphor emits light by electrons emitted from the intercalation layer 209 of the cold cathode device, and the formation pattern and drive signal of each electrode are used. A light-emitting display as a light-emitting element or a light-emitting display of characters or graphics can be performed. At this time, in the cold cathode device of the first embodiment, it is possible to obtain highly efficient and selective electron emission characteristics while taking advantage of the chemical stability of carbon in electron emission from the intercalation layer 209. Even with a display device with an area, a highly efficient and high-quality light-emitting display with greatly reduced display unevenness can be obtained.
[0032]
(Embodiment 2)
FIG. 3 is a diagram for explaining the structure and manufacturing method of the cold cathode device according to the second embodiment of the present invention. Hereinafter, the structure and manufacturing of the cold cathode device according to the second embodiment will be described with reference to FIG. The method will be described. However, the cold cathode device of the second embodiment shown in FIG. 3 is a manufacturing example on a glass substrate having no cell structure or cell barrier in order to obtain a high-density cold cathode array.
[0033]
First, as shown in FIG. 3A, a cathode bus 302 made of a refractory metal or the like is formed on a glass substrate 301. At this time, as will be described later, DLC is deposited on the upper surface of the cathode bus 302, and the DLC is further heated to be graphitized. Therefore, the material of the cathode bus 302 is stable against these heat treatments, for example, A refractory metal such as tantalum, molybdenum, or tungsten is desirable.
[0034]
Next, as shown in FIG. 3B, the DLC layer 303 is formed on the upper surface side of the glass substrate 301 on which the cathode bus 302 is formed, that is, on the side of the glass substrate 301 on which the cathode bus 302 is formed. However, the DLC layer 303 is formed at a low temperature with respect to the glass substrate 301 on which the cathode bus 302 is formed, for example, as in the first embodiment. ₄ It is formed by depositing diamond-like carbon 304 (DLC: Diamond-Like Carbon) by using a hydrocarbon system such as CO or a raw material by a chemical vapor deposition method or the like.
[0035]
Next, as shown in FIG. 3 (c), an energy beam such as a laser beam 305 is narrowed down, and only the region to be an electron emission region on the cathode bus 302 is irradiated with the laser beam 305. The inside of 308 is annealed. By this annealing treatment, only the DLC layer 303 in the irradiation region 308 of the laser beam 305 is locally graphitized to form a graphite region, that is, a graphite layer 306. At this time, the graphite layer 306 serving as an electron emission region is substantially determined by the beam diameter of the laser beam 305 to be irradiated. Therefore, by repeatedly moving and irradiating the irradiation region 308 of the laser beam 305, it is possible to easily form an array of the graphite layer 306 serving as an electron emission region.
[0036]
Next, as shown in FIG. 3D, the intercalation atoms 307 such as Cs and Ba are applied to the irradiation region (graphite layer 306) of the laser beam 305 as in the first embodiment. An intercalation layer 309 is formed by adding impurities by ion implantation or thermal diffusion and performing intercalation. However, since the intercalation atoms Ca and Ba penetrate between graphite layers to form an intercalation layer, the DLC layer 303 in an almost amorphous state does not form an intercalation layer. Only the graphitized region can selectively form an intercalation layer.
[0037]
That is, the cold cathode device of the second embodiment has a structure in which Cs, Ba, etc., which are impurities having a low work function, are introduced (intercalated) between the layers of the graphite layered crystal. A structure capable of obtaining highly efficient and selective electron emission characteristics while utilizing stability. At this time, since the intercalation layer 309 can be formed by controlling the irradiation with the laser beam 305 and controlling the addition of impurities such as Cs and Ba, a high-density cold cathode array structure can be formed. As a result, when the cold cathode device of Embodiment 2 is used as a display device, a display device with high display resolution and high definition can be manufactured.
[0038]
However, when the cold cathode device of the second embodiment is used as a display device, as in the first embodiment, electron emission is performed with a bipolar structure in which an anode is disposed opposite to the cold cathode device of the second embodiment. Do.
[0039]
(Embodiment 3)
FIG. 4 is a diagram for explaining the structure and manufacturing method of the cold cathode device according to the third embodiment of the present invention. Hereinafter, the structure and manufacturing of the cold cathode device according to the third embodiment will be described with reference to FIG. The method will be described. 4 (a) and 4 (c) are plan views of the cold cathode device of the third embodiment, and FIG. 4 (b) is an AA ′ line shown in FIG. 4 (a). 4D is a cross-sectional view taken along line CC ′ shown in FIG. 4C.
First, the DLC layer 402 is uniformly formed on the upper surface side of the glass substrate 401. However, the DLC layer 402 is formed at a low temperature with respect to the glass substrate 401, for example, as in the second embodiment. ₄ It is formed by depositing diamond-like carbon (DLC) by using a hydrocarbon system such as CO or a raw material by a chemical vapor deposition method or the like.
[0040]
Next, as shown in FIG. 4A, the DLC layer 402 is annealed with a predetermined width by narrowing an energy beam such as laser light and moving the laser light in the lateral direction of the glass substrate 401. At this time, the annealing process is performed on the graphite layer 403 formed by the annealing process as shown in FIG. 4A by moving the annealing process region downward (upward) sequentially and performing a plurality of times. The DLC layer 402 which is a non-existing region is alternately arranged in a streak shape (linear shape). However, as shown in FIG. 4B, the upper surface of the glass substrate 401 is heated by heating so that the annealing process reaches the lower surface side of the DLC layer 402, that is, the side where the DLC layer 402 and the glass substrate 401 are in contact with each other. A graphite layer 403 is formed on the side. In the cold cathode device of the third embodiment, the graphite layer 403 is a region corresponding to the cathode bus.
[0041]
Next, an impurity such as Cs or Ba is added to the graphite layer 403 by ion implantation or thermal diffusion, and an intercalation layer (not shown) is formed on a part or all of the graphite layer 403 by intercalation. Form. Since this intercalation layer originally has low resistance characteristics, it can be used as it is as a cathode bus.
[0042]
Next, as shown in FIGS. 4C and 4D, an insulating film 405 is formed on the upper surface side of the graphite layer 403 and the intercalation layer, for example, with a thickness of several microns or less by a known reflow technique. PSG (phosphosilicate glass) or the like is deposited as a glass paste for photo embedding, and this glass paste for photo embedding is used as an insulating layer (insulating film) 405.
[0043]
Next, as shown in FIG. 4C, a gate electrode bus 404 extending in a direction not parallel to the DLC layer 402 or the graphite layer 403 (for example, an orthogonal direction) is formed on the upper surface side of the insulating film. . However, the gate electrode bus 404 of the third embodiment corresponds to five lines in which the direction orthogonal to the DLC layer 402 and the graphite layer 403 is the extending direction. At this time, the intercalation layer and each gate electrode bus 404 are separated by a thickness of several microns or less, that is, a thick insulating film.
[0044]
Thereafter, as shown in FIGS. 4C and 4D, an electron emission hole 406 serving as an electron emission region is formed in the gate electrode bus 404 by a lithography method or the like on the substrate manufactured by the steps described above. It is formed from the side to the depth where the intercalation layer is exposed. For example, as shown in FIG. 4D, one electron emission hole 406 is formed in each of the regions where the intercalation layer and the gate electrode bus 404 intersect with each other through the insulating film 405. Needless to say, the number of electron emission holes 406 in the intersecting region may be two or more.
[0045]
In the cold cathode device of the third embodiment formed as described above, an electric field is applied between the gate electrode bus 404 and the intercalation layer to emit electrons.
[0046]
Even in this case, the cold cathode device of the third embodiment has a structure in which Cs, Ba or the like, which is an impurity having a small work function, is introduced (intercalated) between the layers of the graphite layered crystal. It is possible to obtain a highly efficient and selective electron emission characteristic while taking advantage of the chemical stability of carbon.
[0047]
On the other hand, the cold cathode device according to the third embodiment is disposed in a vacuum hermetic container, and an electrode serving as an anode is disposed in the vacuum hermetic container at a position facing the cold cathode device. By arranging a well-known phosphor, a fluorescent light-emitting display device that displays characters, graphics and the like can be formed. Accordingly, the phosphor emits light by electrons emitted from the intercalation layer (not shown) of the cold cathode device by supplying a drive signal of a predetermined voltage between the graphite layer 403 and the gate electrode bus 404 and the anode electrode which become the cathode bus. In addition, it is possible to perform light emission display such as characters and graphics or light emission display as a light emitting element according to the formation pattern of each electrode and the drive signal. At this time, in the cold cathode device of the third embodiment, a high-efficiency and selective electron emission characteristic can be obtained while utilizing the chemical stability of carbon in the electron emission from the intercalation layer. Even with this display device, it is possible to obtain a high-efficiency and high-quality light-emitting display with significantly reduced display unevenness.
[0048]
In the first to third embodiments, the case where Cs or Ba is used as the impurity has been described. However, the present invention is not limited to this, and graphite such as K (potassium), Rb (rubidium), and Sr (strontium) is used. Needless to say, an alkali metal having a small work function may be used. Furthermore, U, I ₂ , Br ₂ , Cl ₂ It goes without saying that metals such as these may be used.
[0049]
In the first to third embodiments, the case where the field emission cold cathodes of the cold cathode devices are arranged in an array to configure the display device has been described. However, the cold cathode devices and the photoelectric conversion films are disposed to face each other. Needless to say, the imaging apparatus can be configured as described above. In particular, in Embodiment 2, since a high-density cold cathode array structure can be formed, a high-definition imaging device can be manufactured.
[0050]
In the first to third embodiments, the stage (order) for introducing the impurity is not particularly limited. However, the structure in which electrons emitted from the field emission cold cathode are controlled by combining the impurity introduction stage. Needless to say.
[0051]
The invention made by the present inventor has been specifically described based on the embodiment of the invention, but the invention is not limited to the embodiment of the invention and does not depart from the gist of the invention. Of course, various changes can be made.
[0052]
【The invention's effect】
The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
[0053]
(1) A stable and highly efficient cold cathode or an array thereof can be produced at a low temperature.
[0054]
(2) By narrowing the energy beam such as a laser, it is possible to form an electron emission region and an array corresponding to the beam size. High-definition imaging device can be achieved.
[0055]
(3) Since the cathode bus can be formed of the same base material, there is an effect that the structure and process of the cold cathode array can be simplified.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the principle of the structure of a cold cathode device according to the present invention.
FIG. 2 is a diagram for explaining the structure and manufacturing method of the cold cathode device according to the first embodiment of the present invention;
FIG. 3 is a diagram for explaining the structure and manufacturing method of a cold cathode device according to a second embodiment of the present invention.
FIG. 4 is a diagram for explaining the structure and manufacturing method of a cold cathode device according to a third embodiment of the present invention.
[Explanation of symbols]
101 ... carbon atom 102 ... intercalation atom
103 ... emitted electrons
201 ... Glass substrate 202 ... Cathode bus
203 ... Barrier 204 ... DLC layer
205 ... Diamond-like carbon 206 ... Laser beam
207 ... Graphite layer 208 ... Intercalation atom
209 ... Intercalation layer 210 ... Cell area
301 ... Glass substrate 302 ... Cathode bus
303 ... DLC layer 304 ... Diamond-like carbon
305 ... Laser light 306 ... Graphite layer
307 ... Intercalation atom 308 ... Irradiation area of laser beam
309 ... Intercalation layer
401 ... Glass substrate 402 ... DLC layer
403 ... Graphite layer 404 ... Gate electrode bus
405 ... Insulating film 406 ... Electron emission hole

Claims (7)

In a method for manufacturing a cold cathode device having a cathode bus formed on a substrate and a field emission cold cathode made of a carbon-based material electrically connected to the cathode bus, the cathode bus is formed on the substrate. A step of forming a carbon-based material layer having graphite as a main component material and electrically connected to the cathode bus, and an impurity atom or molecule having a work function smaller than that of the graphite is formed into a plate shape of the carbon-based material layer And a step of forming a field emission cold cathode by introducing between the crystals . 2. The method for manufacturing a cold cathode device according to claim 1 , wherein an alkali metal having a work function smaller than that of the graphite is introduced as the impurity atom or molecule. 3. The method of manufacturing a cold cathode device according to claim 2 , wherein any one of K, Rb, Cs, Ba, and Sr is introduced as the alkali metal. 2. The method of manufacturing a cold cathode device according to claim 1 , wherein any one of U, I ₂ , Br ₂ , and Cl ₂ is introduced as the impurity atom or molecule. Manufacturing method.   In a cold cathode device having a cathode bus formed on a substrate and a field emission cold cathode made of a carbon-based material electrically connected to the cathode bus, carbon is connected to the cathode bus so as to be electrically connected A carbon-based material layer made of a carbon-based material is formed, and a region where impurity atoms or molecules are introduced is formed between the plate-like crystals of the carbon-based material layer, and the impurity-doped region forms a field emission cold cathode A cold cathode device. 6. The cold cathode device according to claim 5 , wherein a plurality of the field emission regions are formed in a surface of the carbon-based material layer.   A cold cathode device in which a plurality of field emission cold cathodes are formed and a phosphor anode are arranged opposite to each other, and a voltage applied between the field emission cold cathode and the phosphor anode is controlled in accordance with an image signal. In the display device for displaying an image, the cold cathode device includes a carbonaceous material layer formed of a carbonaceous material so as to be electrically connected to a cathode bus formed on a substrate, and the carbonaceous material A display device, wherein a plurality of regions into which impurity atoms or molecules are introduced are formed between the plate-like crystals of the layer, and the region into which the impurities are introduced forms a field emission cold cathode.

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