JP2006080021A - Electron emitting element, and manufacturing method of electron emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively and stably provide an electron emitting element having a high durability, a high reliability, and a low gate voltage without passing through a complicated manufacturing process. <P>SOLUTION: This is the electron emitting element which has a plated layer, an insulation membrane layer, and a metal membrane layer on a metallic supporting substrate having a site of a quadrangular pyramid structure, and in which a carbon nanotube where a part is embedded in the plated layer is installed at the site of the quadrangular pyramidal structure, and in which surroundings of the site of the quadrangular pyramidal structure becomes an opening part where the insulation membrane layer or the metal membrane layer does not exist. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a small X-ray generator, an electron-emitting device used for other devices that use electron emission, and a manufacturing method thereof.

  X-ray tubes are used in various fields such as therapy, X-ray imaging, and industrial analyzers. Conventional electron-emitting devices for X-ray tubes have been the mainstream using hot cathode tubes. However, since a filament is used as the electron-emitting source, the size of the electron-emitting source is increased, resulting in the generation of electrons. The electron beam diameter (focal diameter) could not be reduced when X-rays were generated on the target. In recent years, the necessity of introducing an X-ray mammography examination has been frequently discussed in order to detect breast cancer at an early stage, but as an X-ray generator used for X-ray mammography, it is preferable to obtain an image of 0. A focal spot size of 1 mm or less is required. X-rays have been used in many medical fields such as diagnostics and treatments, but as long as a hot cathode tube is used, its use in X-ray mammography is limited.

  In view of the above circumstances, recently, development of an X-ray tube using a cold cathode having no thermionic emission source has been advanced. These include those using carbon nanotubes with excellent electron-emitting properties, and those that form protrusions and concentrate an electric field at the tip to emit electrons (Spindt type).

  As a conventional technique, for example, as shown in FIG. 6, an electroless process is first performed using a plating bath in which carbon nanotubes or fullerenes are dispersed in a mold of a single crystal silicon substrate 41 partially formed with a recess by anisotropic etching. In some cases, plating is performed, and then electroplating is performed to form a protruding portion made of a plating material, and the carbon nanotube or fullerene 44 is fixed to the tip of the protruding portion. In this technique, the glass substrate 45 is bonded to the surface opposite to the plating projection to form a support substrate for the plating portion, and then the silicon layer is peeled off to obtain the electron emission electrode 43 fixed on the support substrate. (For example, see Patent Document 1).

Further, as shown in FIG. 7, a pair of parallel plate electrodes are placed in an alcoholic suspension 107 in which carbon nanotubes 106 are dispersed, and one Al electrode 104 is applied by electrophoresis by applying a voltage to the parallel plates. There is a technique of aligning and standing carbon nanotubes on an electrode, for example, that the carbon nanotubes are moved and oriented in a state where they are aligned (see, for example, Patent Document 2).
JP 2001-283716 A Japanese Patent Laid-Open No. 2001-20093

  However, in the method of Patent Document 1 described above, since electroless plating is first performed using a single crystal silicon mold, the arrangement of carbon nanotubes is disordered, and most of the carbon nanotubes or fullerenes are plated metal materials. It will be buried inside. Therefore, the carbon nanotube or fullerene portion protruding from the surface of the electron emission electrode after peeling the electron emission electrode from the mold of the single crystal silicon substrate is extremely small. Therefore, an etching process of the plating material is required until a part of the carbon nanotube protrudes sufficiently from the surface of the plating with respect to the electron emission electrode peeled from the mold of the single crystal silicon substrate.

  In the above-described method, it is essential to perform electroless plating first in order to form an undercoat layer (also referred to as a seed layer) to be an electrode before electroplating. It is inevitable that the carbon nanotubes are randomly deposited on the portion in contact with the surface.

  Also, when the glass plate is electrostatically bonded to the opposite side of the projection of the plated portion, generally the surface of the plated portion is not flat due to the action of the stress inside the plating, resulting in poor adhesion at the time of bonding. There is a problem in that the oxide film layer and the gate electrode layer are peeled off due to heat when the oxide film layer and the gate electrode layer are subjected to the sputtering process. In addition, since the plating layer is thin, there is a problem that it is not suitable for an application with a large emission current such as an X-ray generator.

  In addition, in the method of propelling carbon nanotubes on an Al electrode by electrophoresis of Patent Document 2, the carbon nanotubes can be thrust sufficiently firmly on the surface of the Al electrode, no matter how high voltage is applied. Instead, some of the carbon nanotubes are detached in the subsequent manufacturing process, and there is a problem in reliability and life such that the carbon nanotubes are detached due to an electric field when used as an electron-emitting device after completion of the electrode.

  The present invention has been made in view of the above problems, and an electron-emitting device having high durability, high reliability, and low gate voltage is obtained by orienting a carbon tube on an electrode in a direction of an electric field and firmly protruding the electrode. The object is to enable stable and inexpensive provision without going through a complicated manufacturing process.

  In order to solve the above problems, the present inventor has found an electron-emitting device having any one of the following configurations.

1. An electron-emitting device having a plating layer, an insulating film layer, and a metal film layer on a support substrate having a quadrangular pyramid structure,
In the tip portion of the quadrangular pyramid structure, a part of the carbon nanotube is embedded in a plating layer and oriented in the normal direction of the surface of the tip portion,
An electron-emitting device characterized in that the periphery of the quadrangular pyramid structure is an opening in which the insulating film layer and the metal film layer do not exist.

  2.1. An electron-emitting device, wherein a plurality of the electron-emitting devices are arranged in a planar shape.

  The electron-emitting device according to 3.1 or 2, wherein the support substrate has a thickness of 0.3 mm or more.

4. A method for manufacturing an electron-emitting device according to 1, 2, or 3,
Forming a metal support substrate on the mold having a quadrangular pyramid recess using an electroforming method;
Separating the support substrate from the mold;
And a step of electroplating the separated support substrate in a plating bath in which carbon nanotubes are dispersed.

  5.4. The method of manufacturing an electron-emitting device according to 5.4, wherein the mold having the concave portion of the quadrangular pyramid structure is manufactured using anisotropic etching on a silicon substrate having a (100) crystal plane.

  In 6.4 or 5, the metal support substrate is peeled from the mold having the quadrangular pyramid-shaped recesses, and then an insulating film layer and a metal film layer are laminated on the metal support substrate, and photolithography and etching are performed. And forming an opening in the insulating film layer and the metal film layer.

  According to the first aspect of the present invention, by arranging the carbon nanotubes that are concentrated in the electric field direction in a concentrated manner at the tips of the protrusions of the support substrate, and using the carbon nanotube group as an electron emission source, A low electron-emitting device can be realized, and electrons can be stably emitted even with a high emission current. In addition, by using a chemically stable carbon nanotube as an electron emission source, a highly reliable electron emission element with little deterioration against residual gas can be obtained.

  According to the second aspect of the present invention, the configuration in which a large number of the electron-emitting devices are arranged in a planar manner allows thermionic emission using a filament due to the chemical stability of the carbon nanotubes and the electron emission stability of the multiple-electron emission source. It is possible to stably obtain an emission current sufficient as an electron-emitting device for X-rays while being much smaller than the method.

  According to the invention of claim 3, since the support substrate is formed to a sufficient thickness, sufficient mechanical strength is obtained, and another member needs to be attached to the support substrate for reinforcement. In addition, after the support substrate is formed by electroforming, mechanical peeling is possible in the step of peeling from the die, and it is not necessary to dissolve the die by etching as in the prior art. As a result, an electron-emitting device can be manufactured at low cost by a simple device structure and a simple manufacturing process. In addition, since the support substrate is sufficiently thick, a sufficient current can be supplied even for applications that require a large emission current such as an X-ray generator.

  According to the invention of claim 4, by performing electroplating while applying an electric field to the carbon nanotubes dispersed in the plating bath, the carbon nanotubes are concentrated at the protrusion tips of the support substrate while being oriented in the direction of the electric field, A part of the plating material is securely fixed. For this reason, carbon nanotubes are not detached even in subsequent manufacturing processes such as gate electrode formation. Even when the device is used as an electron-emitting device after completion of the device, the carbon nanotube is not detached by the applied electric field.

  Further, in order to form the carbon nanotubes by orientation, it is not necessary to use an expensive apparatus such as a CVD apparatus for growing the carbon nanotubes as in the conventional case, and a low-cost manufacturing apparatus such as a plating bath can be used.

  According to the invention which concerns on Claim 5, since the hollow with the sharp bottom shape can be formed with sufficient reproducibility, it is a manufacturing method suitable for mass production. In addition, since microfabrication is possible, when a plurality of the portions of the quadrangular pyramid structure are arranged in a planar shape, it is possible to arrange with high accuracy and high density, and a small and high emission current can be stably obtained. An electron-emitting device can be easily manufactured at low cost.

  According to the sixth aspect of the present invention, the openings are formed in the insulating film layer and the metal film layer using photolithography and etching, so that it is possible to form the openings with high accuracy and good reproducibility. .

  Embodiments according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of an embodiment of an electron-emitting device according to the present invention. Reference numeral 24 in FIG. 1 denotes a support substrate, which is made of a metal such as Ni. Reference numeral 34 denotes a metal plating layer on the surface, and the material is, for example, Ni. An insulating layer 29 having an opening 33 insulates the metal film layer 30 and the metal plating layer 34 thereon. The insulating film layer 29 has a thickness of about 5 μm, for example, and the opening 33 has a diameter of about 10 to 20 μm, for example. The insulating film layer 29 only needs to have a resistivity of about 10 × 10 ¹² Ω · cm or more, and a SiO ₂ film, a Si ₃ N ₄ film, a polyimide film, or the like can be used. Reference numeral 25 denotes a protrusion having a height of, for example, about 5 μm. Reference numeral 28 denotes a group of carbon nanotubes formed on the protrusion 25. The carbon nanotube group 28 has an angle in the range of 70 degrees to 110 degrees with respect to the normal direction of the surface of the protrusion 25, and about 50% or more of the entire carbon nanotube group 28 is oriented.

  The thickness of the metal plating layer 34 is, for example, about 1 μm or less. A part of the lower end of the carbon nanotube group 28 is embedded and mechanically fixed, and the carbon nanotube group 28 and the support substrate 24 are electrically connected. ing. The metal film layer 30 and the support substrate 24 become a gate electrode and a cathode electrode, respectively, when this electron-emitting device is operated.

  Next, an embodiment of the method for manufacturing an electron-emitting device according to the present invention will be described with reference to FIGS.

  FIG. 4 is a diagram illustrating a method for manufacturing an electron-emitting device according to the method of the present invention. Hereinafter, a method for manufacturing the electron-emitting device will be described with reference to FIG.

FIG. 4 (A) to form an SiO ₂ film 21 on both sides of the Si substrate 20 of (100) crystal plane, photolithography in the SiO ₂ film 21, RIE square side a with (reactive ion etching) or the like It is sectional drawing of what formed the opening part. The SiO ₂ film 21 is formed by a method such as sputtering or thermal oxidation and has a thickness of about 0.5 μm.

When anisotropic etching is performed on the Si substrate 20 in an etching solution (here, KOH solution), the etching proceeds from the opening 25 in accordance with the crystal orientation of the Si substrate, and finally an inverted pyramid shape having a as a base. The recess 22 is formed. Thereafter, when the SiO ₂ film 21 is removed by etching, the Si substrate 20 shown in FIG. 4B is obtained.

  FIG. 4C shows a case where an undercoat layer 23 for electroforming with a Ni film having a thickness of 0.5 μm is formed by sputtering Ni on the Si substrate 20. The material for forming the undercoat layer 23 is preferably the same as the metal used for the next electroforming. Here, electroforming is also called electroforming or electroforming, and plating is performed on the surface of the mother die to form a metal layer (also referred to as an electrodeposition layer) of a predetermined thickness, and the formed metal layer is removed from the mother die. This is a method for producing a metal layer by peeling.

  Electroforming is performed on the Si substrate on which the undercoat layer 23 is formed. That is, a direct current is applied for a long time while rotating the Si substrate on which the undercoat layer 23 is formed, and a Ni layer is deposited on the undercoat layer 23 by electroplating. By controlling the direct current, the stress generated during electroforming is controlled, and the graininess and flatness of the Ni layer can be maintained. By electroforming, a Ni layer can be deposited on the undercoat layer 23 to a thickness of about 1 mm, for example. Thereafter, the Si substrate 20 is removed by mechanical peeling or Si etching, and a support substrate 24 having protrusions 25 on the surface as shown in FIG. 4D is obtained.

  In the present invention, since a thick Ni layer of about 1 mm can be formed by electroforming, the Ni layer itself has strength, and the Ni layer is reinforced by bonding a support substrate such as a glass plate as in the prior art. There is no need to do. Further, since it has mechanical strength, when the Ni layer is peeled off from the mold, it can be peeled off mechanically without dissolving the mold by etching as in the prior art. Therefore, the number of parts and processes for reinforcing the Ni layer are reduced, and the efficiency of the manufacturing process can be increased.

  Thus, in this embodiment, the thickness of the support substrate is 1 mm. However, in order to obtain a support substrate that does not require reinforcement, the thickness of the support substrate is generally set to at least 0.3 mm or more. Is desirable.

  Next, a method for fixing the carbon nanotubes to the support substrate 24 will be described.

  FIG. 4E is a diagram illustrating a process for fixing carbon nanotubes by electroplating, which will be described in detail below with reference to FIG.

  In FIG. 5, 39 indicates an electroplating system. A plating tank 38 is filled with an electroplating bath 36 in which carbon nanotubes 40 are dispersed. The support substrate 24 is arranged in parallel to face the flat plate electrode 35, and the support substrate 24 and the flat plate electrode 35 are connected to a direct current power source 37 for electroplating to perform electroplating.

  The carbon nanotubes are usually oriented in different directions in the electroplating bath 36, but are polarized when an electric field is applied by the power source 37 and move toward the cathode side while being oriented along the direction of the electric lines of force. One end is embedded in the metal plating layer 34 and fixed while being oriented.

  In addition, by arranging the support substrate 24 and the planar electrode 35 in parallel and applying a constant voltage by the DC power source 37 therebetween, the electric lines of force 4 are concentrated on the tip of the protrusion 25 on the support substrate 24. The carbon nanotubes 40 are attracted to the tips of the protrusions 25 and are gathered while being oriented in the direction of the lines of electric force (that is, the normal direction of the surface of the protrusions). In this way, the carbon nanotubes are gathered in an oriented state at the tip of the protrusion 25, and one end of the carbon nanotube is embedded in the metal plating layer 34 to form the carbon nanotube group 28 fixed to the tip portion of the protrusion 25. .

  As described above, in the present invention, by dispersing the carbon nanotubes in the electroplating bath, one end of the carbon nanotubes can be reliably fixed by the plating layer after moving to the electrode. It was possible to achieve a strong fixation without detachment. Such carbon nanotube fixing technology with high durability could not be found from the idea of the prior art in which carbon nanotubes dispersed in an alcohol-based solvent were moved by electrophoresis and fixed on an electrode. It is.

  Since the length of the carbon nanotube is about several microns, the carbon nanotube is buried in the plating layer and is wasted even if the plating thickness is increased too much. Therefore, it is desirable that the thickness of the plating layer be about 1 μm or less.

  Returning to FIG. 4, FIG. 4F is a diagram of the support substrate 24 manufactured as described above. Reference numeral 34 denotes a metal plating layer, and 28 denotes a group of carbon nanotubes having one end embedded in the metal plating layer 34, which are formed concentrated on the tip portion of the protrusion 25.

An insulating film layer 29 made of SiO ₂ or the like and a metal film layer 30 to be a gate electrode (also referred to as an extraction electrode) for applying an electric field to the carbon nanotube group 28 are formed on the support substrate 24 by using, for example, a sputtering method. A support substrate 24 shown in FIG. The insulating film layer 29 is formed by CVD (Chemical Vapor Deposition) or the like and has a thickness of about 5 μm. The metal film layer 30 is made of a metal material such as Al, Ti, Mo, and W, and has a thickness of about 0.3 to 1 μm. The insulating film layer 29 is used to electrically insulate the support substrate 24 that is a cathode electrode and the metal film layer 30 that is a gate electrode.

  FIG. 4H shows a state in which the opening 32 is formed. A negative dry film is attached on the metal film layer 30 of the support substrate 24 in FIG. 4G, or spin coating or electrodeposition is performed. After coating the resist 31, the opening 32 is formed by photolithography etching or the like. The opening 32 is a portion that determines the opening diameter of the gate electrode, and is patterned into a circular shape having a diameter b about the protrusion 25 of about 10 to 20 μm, for example.

  FIG. 4I is a completed drawing of the electron emission electrode. The metal film layer 30 and the insulating layer 29 of the support substrate 24 of FIG. 4H are etched by RIE (reactive ion etching) using the resist 31 as a mask. The opening 33 is formed, and then the resist 31 is removed. A carbon nanotube group 28 is formed as an electron emission source at the tip portion of the protrusion 25, and includes an insulating film layer 29 having a protrusion 25 made of the same material as the support substrate 24, a circular opening 33 centered on the protrusion 25, and a gate. A metal film layer 30 serving as an electrode surrounds the electrode.

  In this embodiment, the carbon nanotube fixing process is performed on the support substrate 24 of FIG. 4D, but this process can be performed at the end of the electron-emitting device manufacturing process. That is, the carbon nanotube fixing process is not performed on the support substrate 24 of FIG. 4D, and the subsequent steps are performed to manufacture an electron-emitting device in which the carbon nanotubes are not fixed. Then, the carbon nanotubes are fixed to the element by using an electroplating system 39. At this time, it may be the same as the planar electrode 35 of the metal film layer 30.

  Next, an example of a compact X-ray generator using the electron-emitting device according to the embodiment of the present invention will be described with reference to the configuration diagram of FIG.

  Reference numeral 24 denotes a conductive support substrate formed of an electroformed material such as Ni, and a metal plating layer 34 on the surface thereof, a protrusion 25 formed by electroforming using a Si mold, and a carbon nanotube group at the tip thereof 28.

Reference numeral 29 denotes an insulating layer made of a material such as SiO _{2 so} as to surround the protrusion 25 of the support substrate 24. A gate electrode 30 is formed on the insulating film layer 29 and draws electrons from the tip of the carbon nanotube group 28. 24, 34, 29, 30, 25, and 28 together constitute an electron-emitting device. Reference numeral 5 denotes a target electrode for generating X-rays when electrons extracted from the carbon nanotube group 28 collide, and W (tungsten), Mo (molybdenum) or the like is generally used for diagnostic X-rays. ing. 7 is a pulse voltage generator for applying a positive pulse voltage to the gate electrode 30 with reference to the support substrate 24 which is a cathode electrode, and 8 is a positive high-voltage DC voltage applied to the target electrode 5 with reference to the support substrate 1. DC bias power supply for applying. 6 is a container including an X-ray shielding structure made of glass or metal material for sealing the X-ray generator in a vacuum state and holding each electrode, and 10 is an X-ray generated inside having a certain angle range. An X-ray window that passes outside, and an X-ray passing material such as Be is generally used for the passing portion.

The operation in the above configuration will be described. First, when a pulse voltage generator 7 applies a pulse of, for example, about 100 V to the gate electrode 30 with the cathode electrode (support substrate 24) as a reference, the gate electrode 30 is arranged on a circumference centered on the protrusion 25. An electric field concentrates on the tip of the carbon nanotube group 28, and generally an electron emission phenomenon in which electrons jump out from the tip of the carbon nanotube group 28 occurs by applying an electric field of about 10 ⁸ V / cm or more in a vacuum.

  The electrons thus emitted are accelerated in the direction indicated by the arrow 9 by the electric field generated by the target electrode 5 biased to about 30 kV by the DC bias power supply 8 and finally collide with the surface of the target electrode 5, and the metal X-rays having a wavelength corresponding to the material and acceleration voltage are generated.

  Here, as described above, W, Mo, or the like is used as the target electrode material. In addition, among the X-rays generated from the surface of the target electrode, the X-ray 11 that is controlled by the X-ray window 10 in a range corresponding to the focal spot size required for imaging is irradiated through the X-ray window 10 to an irradiated object (not shown). The

  The smaller the focal spot size at this time, the better the resolution of the captured X-ray image. In particular, in an X-ray generator for mammography that requires high resolution, a focal spot size of about 0.1 mm is required. ing.

  FIG. 3 is a plan view of the electron-emitting device for an X-ray generator according to the present invention.

  In FIG. 2, the protrusion 25 is described as an example of one electron-emitting device as an electron-emitting source for the purpose of explaining the principle. However, the electron-emitting device in an actual X-ray generation apparatus is shown in FIG. 3 in order to obtain an emission current. In this manner, a large number of insulating layers 29 (not shown), gate electrodes 30, and protrusions 25 are arranged in a plane in parallel electrical connection on a metal plating layer 34 provided on a support substrate 24 (not shown). It has a configuration.

  The operation as the electron-emitting device is similar to the operation in FIG. 2, by applying a pulse voltage to the gate electrode 30 with respect to the carbon nanotube group 28 (not shown) at the tip of the protrusion 25, the tip of each carbon nanotube group 28. More electrons are emitted and an emission current is generated. Most of the electrons emitted from the tip of each carbon nanotube group 28 are accelerated toward the target electrode 5 (not shown), and finally collide with the target electrode 5 to generate X-rays.

  The feature of the present invention is that a carbon nanotube group 28 oriented in the electron emission direction is formed at the tip of the protrusion 25 of FIGS. 2 and 3, and electrons are emitted from the tip by field emission. It is.

  A carbon nanotube is a highly conductive electronic material having a diameter of several nanometers to several tens of nanometers, a length direction of several microns, and an extremely large aspect ratio. By using the carbon nanotube as an electron emission source, the electric field concentration becomes extremely high, and as a result, it is possible to realize an electron emission element having a very low gate applied voltage.

  Furthermore, the chemical stability of the carbon nanotube is better when a plurality of aligned carbon nanotubes are used as the electron emission source than when the single protrusion 25 is used as the electron emission source for each gate electrode. As a result, the electron emission stability by a large number of electron emission sources is expressed, and there is an advantage that a high emission current can be obtained in a very stable state compared to a single protrusion.

  In the method of manufacturing an electron-emitting device using carbon nanotubes as an electron emission source according to the present invention described above, the concave shape of the inverted pyramid structure is easily formed with good reproducibility by using anisotropic etching depending on the crystal plane of Si. Therefore, by electroforming the mold, it is possible to simultaneously form a large number of quadrangular pyramidal structures with good reproducibility, and there is little manufacturing variation of the quadrangular pyramidal structure. There is an advantage of using a casting process.

  In addition, by applying electroplating to the surface of the support substrate while applying an electric field to the carbon nanotubes dispersed in the plating bath, the carbon nanotubes can be concentrated on the tip of the protrusion in an oriented state to ensure more reliable plating material. Fixed. As a result, it is possible to form an electron-emitting device that can stably obtain a high emission current without detaching the carbon nanotubes in subsequent processes such as gate electrode formation. In addition, since carbon nanotubes are oriented and fixed using an electroplating process, it is not necessary to use an expensive apparatus such as a CVD apparatus for growing carbon nanotubes as in the prior art, and a plating bath is low. It has an excellent point that a costly manufacturing apparatus can be used.

  Further, the electron-emitting device according to the present invention uses a group of carbon nanotubes oriented in the electron emission direction (the direction of the electric field, that is, the normal direction of the surface) fixed on the protrusion of the support substrate by electroforming, It is possible to realize an electron-emitting device with a very low gate applied voltage, and by arranging a large number of carbon nanotube electron emission sources on a flat surface, the chemical stability of the carbon nanotubes and the large number of electron emission sources There is an advantage that a stable electron emission property is expressed, and an emission current sufficient as an electron-emitting device for X-rays can be obtained while being much smaller than a thermal electron emission method using a filament.

  In the embodiment, the application example to the small X-ray generator has been described. However, the present invention can be applied to a display having the same electron-emitting device and other devices having the electron-emitting device.

1 is a configuration diagram of an electron-emitting device according to the present invention. It is a block diagram of the small X-ray generator which concerns on this invention. It is a block diagram of the electron-emitting element for X-ray generators which concerns on this invention. It is a figure which shows the manufacturing method of the electron emission element which concerns on this invention. It is a figure which shows the manufacturing method of the electron emission element which concerns on this invention. It is a figure which shows the manufacturing method of the electron emission electrode by a prior art. It is a figure which shows the manufacturing method of the electron emission electrode by a prior art.

Explanation of symbols

4 Electric field line 5 Target electrode 6 Container 7 Pulse voltage generator 8 DC bias power supply 9 Electron acceleration direction 10 X-ray window 11 X-ray 20 Si substrate 21 SiO ₂ film 22 Recess 23 Undercoat layer 24 Support substrate 25 Projection 28 Carbon Nanotube group 29 Insulating film layer 30 Metal film layer 31 Resist 32 Opening 33 Opening 34 Plating layer 35 Planar electrode 36 Electroplating bath 37 DC power supply 38 Plating tank 39 Electroplating system 41 Si single crystal substrate 42 Silicon oxide film 43 Metal plating Layer 44 Fullerene 45 Glass substrate 101 Electrophoresis vessel 103 Flat plate electrode 104 Al electrode 105 Glass substrate 106 Carbon nanotube 107 Suspension 108 DC power supply

Claims (6)

An electron-emitting device having a plating layer, an insulating film layer, and a metal film layer on a support substrate having a quadrangular pyramid structure,
In the tip portion of the quadrangular pyramid structure, a part of the carbon nanotube is embedded in a plating layer and oriented in the normal direction of the surface of the tip portion,
An electron-emitting device characterized in that the periphery of the quadrangular pyramid structure is an opening in which the insulating film layer and the metal film layer do not exist. The electron-emitting device according to claim 1, wherein a plurality of the electron-emitting devices are arranged in a planar shape. The electron-emitting device according to claim 1, wherein the support substrate has a thickness of 0.3 mm or more. A method for manufacturing an electron-emitting device according to claim 1, 2 or 3,
Forming a metal support substrate on the mold having a quadrangular pyramid recess using an electroforming method;
Separating the support substrate from the mold;
And a step of electroplating the separated support substrate in a plating bath in which carbon nanotubes are dispersed. 5. The method of manufacturing an electron-emitting device according to claim 4, wherein the mold having the concave portion of the quadrangular pyramid structure is manufactured by using anisotropic etching on a silicon substrate having a (100) crystal plane. After peeling the metal support substrate from the mold having the concave portion of the quadrangular pyramid structure,
Laminating an insulating film layer and a metal film layer on the metal support substrate,
6. The method for manufacturing an electron-emitting device according to claim 4, wherein openings are formed in the insulating film layer and the metal film layer by using photolithography and etching.

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