Electron emission device and electronic device

Abstract

The invention provides an electron emission device and an electronic device, the electron emission device comprises a fire-resistant container, a heating power supply, an electron extraction electrode plate and a lead-out power supply, an electron emission material is arranged in a cavity part, the electron extraction electrode plate is arranged below the fire-resistant container, and a plurality of through holes are formed in the bottom of the fire-resistant container to form an electron emission array. According to the invention, the electron beams emitted in an array form can be obtained, the electron beams in the array are consistent, and the brightness of the electron beams is improved through field emission; the liquid in the cavity and the through holes below the cavity are reused to form the liquid needle tip, so that the selection range of an electron emission material can be expanded, and furthermore, the surface of a liquid drop with a micron curvature formed by the micron-sized through holes is further stretched to form a liquid needle tip structure with a nano-sized curvature radius under the action of an electron extraction electric field; and the field emission effect of electrons is realized.

Description

Technical Field

[0001] The present application relates to the field of electron emission sources, and particularly to an electron emission device and an electronic device. Background Art

[0002] The electron emission device is an important invention in modern times. Its applications in people's daily lives include cathode ray tube displays and ray tubes that accelerate the electron beams generated by them to high voltages and then bombard heavy metals to generate X-rays. Although cathode ray tube displays have now faded out of our daily lives, the X-ray sources excited by electron emission devices are still widely used in medical devices such as chest fluoroscopy and CT for examinations. The vacuum electron tubes prepared by electron emission devices still play a very important role in high-frequency and high-power microwave technologies, such as radar. In scientific research, scanning electron microscopes, transmission electron microscopes, mass spectrometers, etc. all rely on electron emission devices, and the electron beam exposure machine for manufacturing lithography masks in modern chip production technology also relies on electron emission devices.

[0003] The main physical mechanisms of existing electron emission devices are photoexcitation, thermal excitation, electric field excitation, and secondary electron generation, or their combined use. Among them, photoexcitation electron emission technology is mainly used in photomultiplier tubes; scanning electron microscopes and electron beam exposure technologies mainly use thermal excitation and electric field excitation technologies, especially thermal field emission and cold field emission technologies. Thermal field emission technology is widely used in electron beam exposure machines, high-end scanning electron microscopes, and transmission electron microscopes because it can output a very stable and high electron beam current for a long time. The current thermal field emission electron beam device is a thermal field electron emission filament (also known as an "electron gun"). When electrons are emitted, the filament material is solid, and the strong electric field required for field emission depends on the processing accuracy of the filament tip. Usually, chemically etched tungsten single crystals are used to form tips with a very large aspect ratio, and the tip curvature radius is within 100 nm to ensure the strong electric field required for field emission. Its disadvantages are as follows:

[0004] 1) The geometry and size repeatability of the tips processed from chemically etched tungsten single crystals are poor, the electron emission consistency of the processed filaments is not high, and the installation and debugging are troublesome.

[0005] 2) The filament has a large geometric size. Usually, the diameter of the filament assembled for an electron microscope is 1 - 2 cm. Such a filament is very difficult to be made into an array and installed in an electron microscope or an electron beam exposure machine.

[0006] 3) The filament has a relatively short lifespan, generally about 10,000 hours.

[0007] 4) Due to defects, adsorption, etc. in the tungsten tips after chemical etching, the electron beam current emitted by the filament is unstable or fails, etc.

[0008] 5) The current tip preparation process is currently limited to a few materials such as W and LaB6, which limits the selection range of materials for electron beam emission devices. Summary of the Invention

[0009] The object of the present application is to provide an electron emission device and an electronic device, which can improve the disadvantages of poor product consistency of solid thermal emission or thermionic emission filaments, difficulty in preparing the filaments into a compact array, and short service life.

[0010] To achieve the above object, the present application provides the following solutions:

[0011] In a first aspect, the present application provides an electron emission device, characterized in that the electron emission device includes: a refractory container, a heating power supply, an electron extraction electrode plate, and an extraction power supply; the refractory container has a cavity portion with a certain vacuum degree; the cavity portion is a circular cavity; an electron emission material is arranged in the cavity portion, and a plurality of through holes are arranged at the bottom of the refractory container. After the electron emission material is heated and melted, it passes through the through holes to form an outwardly convex liquid surface with an arc shape and realizes electron emission outward; under the action of a high electric field, the outwardly convex liquid surface is further stretched into a droplet structure with a smaller radius to form a liquid tip structure, so as to further enhance the local electric field and generate a field emission effect of electrons; a plurality of the through holes are arranged at the bottom of the refractory container to form an electron emission array; the through holes are micron-sized through holes formed by micro-nano processing technology, and the diameter of the through holes is between 0.1 um and 100 um; no chemical reaction or alloy formation occurs between the electron emission material and the material of the refractory container; the electron emission material is at least one of a semiconductor material, an electrical insulating material, and a metal material; the semiconductor material is GaAs or InP; or the electrical insulating material is at least one of CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, Ir2O3; or the metal material is at least one of W, Re, Ru, Pt, Zr; the heating power supply is connected to the outer wall of the refractory container, and the heating power supply heats the electron emission material in the refractory container to its melting temperature or above by adjusting the power; the refractory container is made of a conductive material; the heating power supply is a constant voltage DC power supply, and its output current is between 0 A and 10 A; the electron extraction electrode plate is arranged below the refractory container, and a cavity for electrons to pass through is opened on the electron extraction electrode plate; the through holes correspond to the cavities one by one, and an extraction electric field for extracting electrons is formed between the refractory container and the electron extraction electrode plate; the axis of the cavity is collinear with the axis of the corresponding through hole; the distance between the refractory container and the electron extraction electrode plate ranges from 50 um to 5000 um; the extraction power supply is arranged outside the refractory container, the negative electrode of the extraction power supply is connected to the outwardly convex liquid surface of the electron emission material through the inner wall of the refractory container, and the positive electrode of the extraction power supply is connected to the electron extraction electrode plate.

[0012] Furthermore, the melting temperature of the refractory container is higher than the melting temperature of the electron emission material and the operating temperature of the electron emission device, and the melting temperature of the electron emission material is lower than the operating temperature of the electron emission device.

[0013] Furthermore, the cross-section of the refractory container is at least one of circular, rectangular, oblong, and elliptical, and the cavity part is a circular cavity.

[0014] Furthermore, the electron emission device further includes a heating device, which is arranged on the side wall of the refractory container and is used to heat the refractory container and the electron emission material therein.

[0015] In a second aspect, an electronic device uses the electron emission device described above, and the electronic device includes at least one of a vacuum electron tube, an X-ray generator, an electronic display, and a thermoelectric transducer.

[0016] According to the specific embodiments provided in the present application, the following technical effects are disclosed in the present application:

[0017] In the present application, micron-level through holes are formed under the refractory container by micro-nano processing technology, and the diameter of the through holes is between 0.1 μm and 100 μm. When the electron emission material is heated and melted and passes through these small through holes to form an outwardly convex liquid surface with an arc shape and realizes electron emission outwardly, the field emission effect of electrons is improved. By arranging a plurality of through holes at the bottom of the refractory container and cooperating with the corresponding electron extraction electrode plates, an electron beam current emitted in a stable equidistant array form can be obtained, improving the product structure consistency and debugging efficiency. The service life of the electron emission structure is proportional to the mass of the accommodated electron emission material, so that the electron generation life can be significantly extended compared with the service lives of traditional thermal field emission and cold field emission filaments. By connecting the heating power supply to the outer wall of the refractory container, the heating process is simplified, and the applications of electron beam exposure machines, scanning electron microscopes, transmission electron microscopes, and other X-ray sources can be satisfied. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of the electron emission device provided in the embodiment of the present application.

[0020] Figure 2 It is a schematic principle diagram of the electron emission device provided in the embodiment of the present application.

[0021] Figure 3 Schematic diagram of electron emission of the electron emission device provided in the embodiment of the present application. Detailed implementation manners

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0023] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0024] Embodiment 1, as Figures 1 - 3 shown, this embodiment provides an electron emission device 100, and the electron emission device 100 includes: a refractory container 1, a heating power supply 6, an electron extraction electrode plate 2, and an extraction power supply 7.

[0025] The refractory container 1 has a cavity portion 11, and the cavity portion 11 has a certain degree of vacuum; the cavity portion 11 is a circular cavity; an electron emission material is arranged in the cavity portion 11, and a plurality of through holes 3 are arranged at the bottom of the refractory container 1. After the electron emission material is heated and melted, it passes through the through holes 3 to form an outwardly convex liquid surface 8 with an arc shape and realizes electron emission outward; the outwardly convex liquid surface 8 is further stretched into a droplet structure with a smaller radius under the action of a high electric field to form a structure of a liquid tip 9, so as to further enhance the local electric field and generate a field emission effect of electrons; a plurality of through holes 3 are arranged at the bottom of the refractory container 1 to form an electron emission array; the through holes 3 are micron-level through holes 3 formed by micro-nano processing technology, and the diameter of the through holes 3 is between 0.1 um and 100 um; no chemical reaction or alloy formation occurs between the electron emission material and the material of the refractory container 1; the electron emission material is at least one of a semiconductor material, an electrical insulating material, and a metal material; the semiconductor material is GaAs or InP; or at least one of the electrical insulating materials CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, Ir2O3; or the metal material is at least one of W, Re, Ru, Pt, Zr.

[0026] Among them, regarding the micro-nano processing technology, high-temperature metals such as W and Ta, which are materials for the refractory container 1, are very hard. It is impossible to machine through-holes with a micron scale, especially those with a diameter below 50 um, on a 200-300 um thick W plate that can maintain a certain strength at high temperatures using traditional mechanical processing. Therefore, this application takes advantage of the special features of the micro-nano processing technology to develop a processing technology for achieving micron-scale through-holes with a high aspect ratio under the container using the micro-nano technology. In the range of 0.1 um to 100 um in diameter, using a silicon wafer as the substrate and adopting micro-nano processing technologies such as photolithography and deep silicon etching, a template for the through-hole can be fabricated. After depositing an electroplating seed layer, electroplating the container metal, and etching the silicon substrate, the bottom structure of the container with through-holes having a high aspect ratio can be manufactured.

[0027] Compared with mechanical processing, the advantages of micro-nano processing are as follows:

[0028] 1) It is possible to fabricate a through-hole structure with a high aspect ratio and a diameter ranging from 0.1 um to 100 um.

[0029] 2) The micro-nano manufacturing accuracy is higher than that of mechanical processing, which can ensure the consistency of product performance.

[0030] 3) It is possible to fabricate shapes such as circles, squares, rectangles, and ellipses.

[0031] 4) It is easy to fabricate a through-hole array, and the array period can be between 10 um and 200 um.

[0032] 5) Realize wafer-level production of multiple liquid electron emission filament containers, improving production efficiency.

[0033] Optionally, the electron emission material here refers to a material that absorbs a certain amount of energy, enabling electrons to break free from the bondage of atomic nuclei and be emitted from the atom.

[0034] Optionally, the electron emission material has a fixed melting temperature.

[0035] Optionally, the material used for the refractory container 1 is a metallic material.

[0036] Optionally, between room temperature and the melting temperature of the refractory container 1, no chemical reaction occurs and no alloy is formed between the electron emission material and the material of the refractory container 1.

[0037] Optionally, by providing multiple through-holes 3 to facilitate the formation of an electron emission array, the micro-nano processing technology can ensure a high degree of consistency in the fabricated structure.

[0038] In the actual application process, the melting temperature of the material of the refractory container 1 is higher than the melting temperature of the electron emission material and also higher than the operating temperature of the electron emission device 100, and the melting temperature of the electron emission material is lower than the operating temperature of the electron emission device 100. Thus, when the electron emission device 100 is operating, the electron emission material will melt into a liquid state, while the refractory container 1 will not be melted.

[0039] Among them, the electron emission material can be a semiconductor material. As a preference, a semiconductor material with a low work function can be used, such as GaAs, InP, etc. The energy band gap of this material at room temperature is between 0.2 eV and 5 eV; in addition, the electron emission material can also be an electrically insulating material. As a preference, an oxide material with a low work function can be used, such as CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, Ir2O3, etc.; of course, the electron emission material can also be a metal material. As a preference, a metal material with a low work function can be used, such as W, Re, Ru, Pt, Zr, etc.

[0040] Optionally, if the refractory container 1 is made of a conductive material, such as a metal material, the heating device 4 may not be provided either, and the heating power supply 6 can be directly connected to the outer wall of the refractory container 1, so as to heat the electron emission material in the refractory container 1 to its melting temperature and above by adjusting the power.

[0041] The heating power supply 6 is connected to the outer wall of the refractory container 1. The heating power supply 6 heats the electron emission material in the refractory container 1 to its melting temperature and above by adjusting the power; the refractory container 1 is made of a conductive material; the heating power supply 6 is a constant-voltage DC power supply, and its output current is between 0 A and 10 A.

[0042] As another alternative embodiment, the heating device 4 is provided on the side wall of the refractory container 1, and it is used to heat the refractory container 1 and the electron emission material therein. It can be a device such as a resistance wire, etc.; the heating power supply 6 is connected to the heating device 4 to provide electrical energy to heat the electron emission material in the refractory container 1 to its melting temperature and above through the heating device 4. It is provided outside the refractory container 1, and it adjusts the electrical energy provided to the heating device 4 by adjusting the power.

[0043] The electron extraction electrode plate 2 is arranged below the refractory container 1, and a cavity 21 for electrons to pass through is formed on the electron extraction electrode plate 2; the through holes 3 correspond to the cavities 21 one by one, and an extraction electric field 22 for extracting electrons is formed between the refractory container 1 and the electron extraction electrode plate 2; the axis of the cavity 21 is collinear with the axis of the corresponding through hole 3; the distance between the refractory container 1 and the electron extraction electrode plate 2 ranges from 50um to 5000um. For the Gaussian electron beam current used in a single-filament electron beam exposure machine, the circular symmetry of the tungsten tip after chemical etching and the circular symmetry of the electron extraction ring are beneficial to generating a Gaussian electron beam, but this limits the further optimization of the total emission beam current and the emission angle. In order to meet the specific application requirements of electronic devices, the electron beam current, the spatial distribution shape of the electron beam, and the emission solid angle of the electron beam emitted by the electron emission device need to be further optimized. For example, the electron beam emitted from the square LaB6 end face is beneficial to the application of electron beam exposure. The present application discovers that the electron extraction electrode adopts a non-circular structure electron extraction electrode plate other than the traditional annular structure electron extraction electrode ring, such as square, elliptical and other shapes. The symmetry of the electric field generated by it in the direction perpendicular to the electron emission axis corresponds to the shape of the electrode plate. The shape of the electrode plate can be the same as the shape of the through hole below the container or can be set to be inconsistent with the through hole shape according to the actual requirements of electron emission. Through their combination, the selection and use of the shape of the electron extraction electrode plate can greatly improve the design dimension of the electron emission device, generating electron beam spots such as square and elliptical and the Gaussian electron beam spots emitted by traditional solid filaments.

[0044] Optionally, the cross-section of the cavity 21 is circular, and the diameter range of the cavity 21 is from 1um to 120um.

[0045] Optionally, the axis of the cavity 21 coincides with the symmetry axis of the corresponding arc-shaped convex liquid surface. After the liquid needle is formed, the tip of the liquid needle can reliably point to the middle of the cavity 21, thus ensuring reliable electron emission.

[0046] The extraction power supply 77 is arranged outside the refractory container 11. The negative electrode of the extraction power supply 7 is connected to the convex liquid surface 8 of the electron emission material through the inner wall of the refractory container 1, and the positive electrode of the extraction power supply 7 is connected to the electron extraction electrode plate 2.

[0047] Optionally, the extraction power supply 7 is an adjustable DC voltage source, and its output voltage is between 0V and 6kV. The extraction power supply 7 is used to establish the electron extraction electric field 22 between the refractory container 1 and the electron extraction electrode plate 2.

[0048] Furthermore, the melting temperature of the refractory container 1 is higher than the melting temperature of the electron emission material and the operating temperature of the electron emission device 100, and the melting temperature of the electron emission material is lower than the operating temperature of the electron emission device 100.

[0049] Furthermore, the cross-section of the refractory container 1 is at least one of circular, rectangular, oblong, and oval, and the cavity portion 11 is a circular cavity.

[0050] Furthermore, the electron emission device 100 further includes a heating device 4 disposed on the side wall of the refractory container 1 for heating the refractory container 1 and the electron emission material therein.

[0051] Optionally, the electron emission device is mainly applied in electron microscopes and electron beam exposure technologies, and can also be used in devices such as vacuum electron tubes, X-ray generators, electron displays, and thermoelectric transducers. For example, it can be disposed at the top of the electron lens barrel of devices such as scanning electron microscopes, transmission electron microscopes, and electron beam exposure machines.

[0052] The following is the actual use process of the electron emission device and the electronic device in this embodiment:

[0053] In order to construct an electric field to facilitate the emission of electron beams from the convex liquid surface 8, an electron extraction electrode plate 2 is disposed below the refractory container 1. The electron extraction electrode plate 2 is provided with a cavity 21 for electrons to pass through. The through holes 3 correspond to the cavities 21 one by one, and an extraction electric field 22 for extracting electrons is formed between the refractory container 1 and the electron extraction electrode plate 2. After the electron emission material melts, under the action of gravity and capillary action, it flows through the through hole array below the refractory container 1 to the outside of the through hole 3, and then is affected by the wetting action of the side wall of the through hole 3, forming an arc-shaped convex liquid surface at the outside of each through hole 3. Under the action of the electron extraction electric field 22, each convex surface further stretches out a liquid needle structure with a smaller radius, further enhancing the local electric field and realizing the field emission effect of electrons. Each liquid needle serves as an electron emission source to form an electron emission array, and this array can emit a very large beam current. When the electron sources emitted by each liquid needle are focused, scanning and switching can be achieved, which can be used in multi-beam scanning electron microscopes and multi-beam electron beam exposure devices, greatly improving the efficiency of electron microscopes and electron beam exposure.

[0054] As described above, when the electron emission material is heated to its melting temperature and above, the electron emission material will be in a liquid state after melting. The liquid electron emission material passes through the through hole 3 under the action of gravity and the like to form an arc-shaped convex liquid surface 8. Specifically, since the working temperature range of the electron emission device 100 is higher than the melting temperature of the electron emission material, there will be a wetting action between the liquid and the solid between the melting temperature of the electron emission material and the working temperature of the electron emission device 100. That is, the liquid electron emission material will form an arc-shaped convex liquid surface 8 at the opening of the through hole 3 after passing through the through hole 3 under the action of gravity and the like.

[0055] In this way, when the electron-emitting material reaches the melting temperature and melts upon heating, under the wetting effect between the solid and liquid on the sidewall of the through-hole 3, the liquid electron-emitting material, under the action of gravity or capillary force, forms an arcuate convex liquid surface 8 at the opening of the through-hole 3 after passing through the through-hole 3 of the refractory container 1 based on the wetting effect of the sidewall of the through-hole 3. The convex liquid surface 8 can emit an electron beam under the action of a strong electric field. Further, as Figure 3 shown, the convex liquid surface 8 can further stretch out a droplet structure with a smaller radius under the action of a high electric field, that is, form a structure of a liquid tip 9, thereby being able to further enhance the local electric field and enhance the field emission effect of electrons. Each liquid needle in the electron emission array emits high-brightness electrons, and the liquid needle array emits a high-brightness electron source array, realizing a high-brightness electron emission source array.

[0056] In this embodiment, by using the cooperation between the liquid after melting of the electron-emitting material and the through-hole 3, the convex liquid surface 8 can be formed. The convex liquid surface 8 forms a liquid tip 9 under the action of a strong electrostatic field, thereby being able to expand the selection range of the electron-emitting material. The structural life of this electron emission device 100 is proportional to the mass of the accommodated electron-emitting material. Therefore, the electron emission life of the electron emission device 100 can be increased much more than the life of the filaments of traditional thermal field emission and cold field emission.

[0057] In the process of using the electron emission device 100 of this embodiment, in combination with Figures 1 - 3 shown, it can be carried out in the following manner: If it is in a scanning electron microscope, a transmission electron microscope, and an electron beam lithography machine, the refractory container 1 in the electron emission device 100 is arranged at the top of the electron lens barrel therein. Further, the electron-emitting material in the above embodiment is arranged in the cavity portion 11 of the refractory container 1. The heating power supply 6 is connected to the heating device 4 and the heating device 4 is connected to the refractory container 1. If the refractory container 1 is made of a metal material, the heating power supply 6 can be directly connected to the refractory container 1.

[0058] Furthermore, the cavity portion 11 of the refractory container 1 located at the top of, for example, an electron lens barrel is evacuated to a high vacuum state. For example, after adjusting the vacuum degree in the cavity portion 11 to 1 micropascal, the power V1 of the heating power supply 6 is adjusted until the temperature of the electron emission material reaches the melting temperature. Then, the electron emission material starts to melt. Subsequently, the power V1 of the heating power supply 6 is slowly increased until the molten electron emission material in the refractory container 1 passes through the through-hole 3 at the lower end of the refractory container 1 and continuously drops under the action of gravity or capillary force. In this way, at the lower end opening of the through-hole 3, due to the combined action of the wetting effect between the liquid electron emission material and the solid through-hole 3 and the liquid surface energy, a stable convex liquid surface 8 with an arc shape is formed. Then, the voltage of the extraction power supply 7 is continuously and slowly increased, so that a strong electric field is formed under the action of the extraction power supply 7. The convex liquid surface 8 emits an electron beam under the action of the strong electric field, thereby achieving the purpose of electron emission. Of course, the convex liquid surface 8 can also form a stable liquid tip 9 under the action of the strong electric field and the liquid surface energy. The liquid tip 9 can further enhance the local electric field strength, thereby increasing the field emission effect of the emitted electron beam and achieving the purpose of forming a high-brightness electron emission device. At this time, an array of liquid tips 9 is formed on the outer side of the array of through-holes 3. Each liquid tip 9 in the array emits high-brightness electrons, and the array of liquid tips 9 emits a high-brightness electron source array, realizing a high-brightness electron source array.

[0059] During the process of emitting an electron beam through the electron emission device herein, the capillary action of the liquid, the structure of the micro-scale capillary pipeline, the wetting effect of the material, the electric field effect, etc. are adopted, which has a relatively high field emission effect of electrons, a relatively high degree of structural consistency, improves the debugging efficiency, and the lifetime of the electron emission structure is proportional to the mass of the accommodated electron emission material, so that the electron emission lifetime can be significantly extended compared with the lifetimes of traditional thermal field emission and cold field emission filaments.

[0060] The technical effects of this application are as follows:

[0061] In this application, micron-sized through-holes are formed under the refractory container through micro-nano processing technology, and the diameter of the through-holes is between 0.1 um and 100 um. When the electron-emitting material melts and passes through these small through-holes to form an outwardly convex liquid surface with an arc shape and realizes electron emission outward, the field emission effect of electrons is improved. By arranging a plurality of through-holes at the bottom of the refractory container and cooperating with the corresponding electron extraction electrode plates, an electron beam current emitted in a stable equidistant array form can be obtained, improving the product structure consistency and debugging efficiency. The electron extraction electrode plates can have annular and non-annular shapes, such as square, oval, etc. The symmetry of the electric field generated by them in the direction perpendicular to the electron emission axis corresponds to the shape of the electrode plate. The shape of the electrode plate can be the same as the shape of the through-holes under the container or can be set to be inconsistent with the shape of the through-holes according to the actual requirements of electron emission. Through their combination, the selection and use of the shape of the electron extraction electrode plates can greatly increase the design dimension of the electron emission device, generating electron beam spots such as square and oval and the Gaussian-type electron beam spots emitted by traditional solid filaments. By using the electron extraction electrode plates, an electron beam current emitted in a stable equidistant array form can be obtained. The lifespan of the electron emission structure is proportional to the quality of the electron-emitting material accommodated, so that the electron emission lifespan can be significantly extended compared with the lifespans of traditional thermal field emission and cold field emission filaments. By connecting the heating power supply to the outer wall of the refractory container, the heating process is simplified, which can meet the applications of electron beam exposure machines, scanning electron microscopes, transmission electron microscopes, and other X-ray sources.

[0062] Embodiment 2, an electronic device, adopts the electron emission device 100 as described above in the claims. The electronic device includes at least one of a vacuum electron tube, an X-ray generator, an electronic display, and a thermoelectric transducer.

[0063] All actions of obtaining signals, information, or data in this application are carried out on the premise of complying with the corresponding data protection regulations and policies of the country where it is located and with the authorization given by the owner of the corresponding device.

[0064] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0065] Specific examples are used in this article to elaborate on the principles and implementation manners of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. An electron emission device, characterized in that, the electron emission device includes: a refractory container, a heating power supply, an electron extraction electrode plate, and an extraction power supply; the refractory container has a cavity portion with a certain vacuum degree; the cavity portion is a circular cavity; an electron emission material is arranged in the cavity portion, and a plurality of through holes are arranged at the bottom of the refractory container. After the electron emission material is heated and melted, it passes through the through holes to form an outwardly convex liquid surface with an arc shape and realizes electron emission outward; the outwardly convex liquid surface is further stretched into a droplet structure with a smaller radius under the action of a high electric field to form a structure of a liquid tip, so as to further enhance the local electric field and generate a field emission effect of electrons; a plurality of the through holes are arranged at the bottom of the refractory container to form an electron emission array; the through holes are micron-level through holes formed by micro-nano processing technology, and the diameter of the through holes is between 0.1 μm and 100 μm; no chemical reaction occurs between the electron emission material and the material of the refractory container, nor does an alloy form; the electron emission material is at least one of a semiconductor material, an electrical insulating material, and a metal material; the semiconductor material is GaAs or InP; or at least one of the electrical insulating materials CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, Ir2O3; or the metal material is at least one of W, Re, Ru, Pt, Zr; the heating power supply is connected to the outer wall of the refractory container, and the heating power supply heats the electron emission material in the refractory container to its melting temperature and above by adjusting the power; the refractory container is made of a conductive material; the heating power supply is a constant voltage DC power supply, and its output current is between 0 A and 10 A; the electron extraction electrode plate is arranged below the refractory container, and a cavity for electrons to pass through is opened on the electron extraction electrode plate; the through holes correspond to the cavities one by one, and an extraction electric field for extracting electrons is formed between the refractory container and the electron extraction electrode plate; the axis of the cavity is collinear with the axis of the corresponding through hole; the distance between the refractory container and the electron extraction electrode plate ranges from 50 μm to 5000 μm; the extraction power supply is arranged outside the refractory container, the negative electrode of the extraction power supply is connected to the outwardly convex liquid surface of the electron emission material through the inner wall of the refractory container, and the positive electrode of the extraction power supply is connected to the electron extraction electrode plate.

2. The electron emission device according to claim 1, characterized in that, the melting temperature of the refractory container is higher than the melting temperature of the electron emission material and the operating temperature of the electron emission device, and the melting temperature of the electron emission material is lower than the operating temperature of the electron emission device.

3. The electron emission device according to claim 1, characterized in that, the cross-section of the refractory container is at least one of a circle, a rectangle, a rectangle, and an ellipse, and the cavity portion is a circular cavity.

4. The electron emission device according to claim 1, characterized in that, The electron emission device further includes a heating device, which is disposed on the side wall of the refractory container and is used to heat the refractory container and the electron emission material therein.

5. An electronic device, characterized in that it employs the electron emission device described in any one of claims 1-4, and the electronic device includes at least one of a vacuum electron tube, an X-ray generator, an electronic display, and a thermoelectric transducer.

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