Electron emission device and electronic device

Abstract

The embodiment of the present disclosure provides an electron emission device and an electronic device, the electron emission device comprising a fireproof container having a cavity with a certain vacuum degree and a heating power source, the cavity is provided with an electron emission material, the bottom of the fireproof container is provided with at least one through hole, the electron emission material is melted by heat and passes through the through hole to form an arc-shaped outer convex liquid surface, and electrons are emitted to the outside. The embodiment of the present disclosure has a relatively high electron field emission effect, a relatively high degree of consistency of the product structure, is easy to debug, the life of the electron emission device is proportional to the quality of the electron emission material accommodated, and the life of the disclosed electronic device is significantly extended compared to the life of the conventional thermal field emission filament and cold field emission filament, and can meet the application of electron beam exposure machines, scanning electron microscopes, transmission electron microscopes and other X-ray sources.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to electron emission sources, and more particularly to electron emission devices. [Background technology]

[0002] Electron emitters are an important invention in modern times, and their applications in people's daily life include cathode ray tube displays and electron beam tubes, which accelerate the electron beam generated by them to high voltage and then collide with heavy metals to generate X-rays. CRT displays have basically disappeared from people's daily lives at present, but X-ray sources excited by electron emitters are still widely used in medical equipment such as chest X-ray examinations and CT scans. Vacuum electron tubes made from electron emitters have a very important position in high-frequency, high-power microwave technology such as radar. In scientific research, scanning electron microscopes, transmission electron microscopes, mass spectrometry instruments, etc. cannot do without electron emitters, and electron beam exposure machines, which are manufacturing devices for photolithography masks in modern chip production technology, cannot do without electron generators.

[0003] In conventional electron generating devices, the main physical mechanisms are photoexcitation, thermal excitation, field excitation, secondary electron generation, or a combination of these. Among them, photoexcitation electron generating technology is mainly used in photomultiplier tubes, while scanning electron microscopes and electron beam exposure technology mainly use thermal excitation and field excitation technologies, especially thermionic emission and cold field electron emission technologies. Thermal field emission technology can output a very stable and high electron beam for a long time, so it is widely applied in electron beam exposure machines, high-end scanning electron microscopes, and transmission electron microscopes. The current thermal field emission electron beam device is a thermal field electron emission filament. During electron emission, the filament material is solid, and the strong electric field required for field emission depends on the processing accuracy of the filament tip, and usually chemically etched tungsten single crystal is used to form a needle tip with a very large aspect ratio, and its tip radius is within 100 nm to ensure the strong electric field required for field emission. Its disadvantages include: 1) the repeatability of the geometric dimensions of the needle tip processed from the chemically etched tungsten single crystal is poor, and the consistency of the electron emission of the processed filament is not high, making installation and debugging cumbersome; 2) the geometric dimensions of the filament are large, and typically, the diameter of an assembled filament for an electron microscope is 1-2 cm, and it is difficult to array and install such a filament in an electron microscope or an electron beam exposure machine; 3) the life of the filament is relatively short, typically about 10,000 hours; 4) defects and adsorption in the tungsten needle tip after chemical etching can cause the electron beam emitted by the filament to become unstable or fail; and 4) due to the conventional needle tip manufacturing process, the materials are currently limited to a few materials such as W and LaB6, limiting the range of materials that can be selected for the electron beam emission device. Summary of the Invention

[0004] In view of the above, the embodiments of the present disclosure have been made, and an electron emission device and an electronic device are proposed to solve the shortcomings of conventional solid thermal emission or thermal field emission filament products, such as lack of consistency, difficulty in manufacturing compact arrays of filaments, and short lifespan.

[0005] The present disclosure provides an electron emission device including a fireproof container having a cavity with a certain degree of vacuum, and a heating power source, wherein an electron emission material is provided in the cavity, and at least one through hole is provided in the bottom of the fireproof container, and after the electron emission material is heated and melts, it passes through the through hole to form an arc-shaped outer convex liquid surface, thereby realizing electron emission to the outside.

[0006] In an embodiment, the fireproof container has a melting temperature higher than the melting temperature of the electron emitting material and the operating temperature of the electron emitting device, and the electron emitting material has a melting temperature lower than the operating temperature of the electron emitting device.

[0007] In some embodiments, the refractory vessel has a cross-section that is at least one of circular, rectangular, oblong, and elliptical, and the cavity portion is a circular cavity.

[0008] In some embodiments, the electron emitting material is at least one of a semiconductor material, an electrically insulating material, and a metallic material.

[0009] In some embodiments, the semiconductor material is GaAs or InP, or the electrically insulating material is at least one of CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, Ir2O3, or the metallic material is at least one of W, Re, Ru, Pt, Zr.

[0010] In some embodiments, the bottom of the refractory container is provided with a plurality of the through holes, and providing a plurality of the through holes can facilitate the formation of an electron emission array.

[0011] In some embodiments, the apparatus further includes a heating device disposed in a sidewall of the refractory container for heating the refractory container and the electron emitting material therein.

[0012] In some embodiments, a ring-shaped extraction electrode is provided below each of the through holes, and the extraction electrode is disposed opposite the outer convex liquid surface.

[0013] In some embodiments, the device further includes an extraction power supply having a negative electrode connected to the outer convex liquid surface of the electron emitting material through an inner wall of the refractory container and a positive electrode connected to the annular extraction electrode.

[0014] The present disclosure further provides an electronic device employing an electron emission device according to any one of the above claims, the electronic device including at least one of a vacuum electron tube, an X-ray generator, an electronic display, and a thermoelectric converter.

[0015] The embodiments of the present disclosure have a relatively high electron field emission effect, a relatively high degree of consistency of the product structure, and are easy to debug; the life of the electron emission structure is proportional to the quality of the electron emission material accommodated therein, thereby significantly extending the electron generation life beyond that of conventional thermal field emission filaments and cold field emission filaments, and meeting the application of electron beam exposure machines, scanning electron microscopes, transmission electron microscopes, and other X-ray sources. [Brief description of the drawings]

[0016] In order to more clearly describe the technical solutions in the embodiments of the present disclosure or the prior art, the following briefly describes the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some of the embodiments described in the present disclosure, and it is obvious to those skilled in the art to obtain other drawings based on these drawings without paying creative labor. [Figure 1] 1 is a schematic diagram illustrating the configuration of an electron emission device according to an embodiment of the present disclosure. [Diagram 2] 1 is a schematic diagram illustrating the configuration of an electron emission device according to an embodiment of the present disclosure. [Diagram 3] 1 is a functional schematic diagram of an electron emission device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present disclosure in combination with the drawings of the embodiments of the present disclosure. Of course, the embodiments described herein are not all the embodiments, but are only some of the embodiments of the present disclosure. Based on the embodiments of the present disclosure described herein, all other embodiments that can be obtained by those skilled in the art without requiring creative labor belong to the protection scope of the present disclosure.

[0018] Unless otherwise specified, technical or scientific terms used in this disclosure should have the ordinary meaning understood by a person of ordinary skill in the field to which this disclosure belongs. The terms "first", "second" and similar terms used in this disclosure do not denote any order, number, or importance, but are only used to distinguish different components. Similar terms such as "include" or "included" mean that the element or thing appearing before this term covers the elements or things listed after this term and their equivalents, without excluding other elements or things. Similar terms such as "connected" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect connections. "Top", "bottom", "left", "right", etc. are only used to express relative positional relationships, and if the absolute position of the described object changes, the relative positional relationships may change accordingly.

[0019] For clarity and conciseness of the following description of the embodiments of the present disclosure, the present disclosure omits detailed descriptions of known features and components.

[0020] The embodiment of the present disclosure relates to an electron emission device, where the electron emission device is mainly applied to electron microscopes and electron beam exposure techniques, and may of course be used in devices such as vacuum electron tubes, X-ray generators, electronic displays, and thermoelectric converters. As shown in FIG. 1, the embodiment of the present disclosure relates to an electron emission device 100 that can be installed at the tip of an electron lens barrel of a device such as a scanning electron microscope, a transmission electron microscope, or an electron beam exposure machine, and specifically, the electron emission device 100 includes a fireproof container 1, where the cross section of the fireproof container 1 may be circular or may have other shapes such as a rectangular, oblong, or elliptical shape. The fireproof container 1 has one cavity 11, where the cavity 11 is a vacuum chamber having a certain degree of vacuum, where the cavity 11 may be a circular cavity, and the inner diameter of the cavity 11 is within a range of 1 um to 100 um. The cavity 11 of the fireproof container 1 is provided with an electron emission material 2 having a certain melting temperature.

[0021] Further, the fireproof container 1 here is made of a material with a high melting temperature, for example a metal material, and the melting temperature of the material of the fireproof container 1 is higher than that of the electron emitting material 2 and higher than the operating temperature of the electron emitting device 100, and the melting temperature of the electron emitting material 2 is lower than the operating temperature of the electron emitting device 100. In this way, when the electron emitting device 100 is operating, the electron emitting material 2 melts and becomes liquid, and the fireproof container 1 does not melt. Note that, between the room temperature and the melting temperature of the fireproof container 1, no chemical reaction occurs between the electron emitting material 2 and the material of the fireproof container 1, and no alloy is formed.

[0022] Furthermore, the electron emission material 2 here refers to a material that absorbs a certain amount of energy so that electrons are released from the nucleus and atoms are released. The electron emission material 2 here may be a semiconductor material, preferably a semiconductor material with a low work function such as GaAs or InP, and such a material has a band gap between 0.2 eV and 5 eV at room temperature. The electron emission material 2 may also be an electrically insulating material, preferably an oxide material with a low work function such as CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, or Ir2O3. Of course, the electron emission material 2 may be a metal material, preferably a metal material with a low work function such as W, Re, Ru, Pt, or Zr.

[0023] Furthermore, at least one through hole 3 is provided at the bottom of the fireproof container 1, and the electron emission material 2 realizes electron emission to the outside through the through hole 3, where the through hole 3 is a micron-level through hole formed by micro-nano processing technology, and the diameter of the through hole 3 is between 0.1 um and 100 um, and the micro-nano processing technology can improve the consistency of the processed structure. In another embodiment, a plurality of through holes 3 may be provided at the bottom of the fireproof container 11, and the provision of a plurality of through holes 3 can facilitate the formation of an electron emission array.

[0024] The electron emission device 100 also includes a heating device 4, which is provided on a side wall of the fire-resistant container 1 and can be a device such as a resistance wire for heating the fire-resistant container 1 and the electron emission material 2 therein, and a heating power source 6, which is connected to the heating device 4 and supplies electrical energy so that the heating device 4 heats the electron emission material 2 in the fire-resistant container 1 to above its melting temperature, and is provided separately from the fire-resistant container 1 and adjusts the electrical energy supplied to the heating device 4 by adjusting the power, where the heating power source 6 is a constant-voltage DC power source with an output current between 0 A and 10 A.

[0025] In some embodiments, when the fire-resistant container 1 is made of a conductive material, for example a metal material, the heating device 4 may be omitted, and the heating power source 6 may be directly connected to the outer wall of the fire-resistant container 1, so that the electron emission material 2 in the fire-resistant container 1 can be heated to above its melting temperature by adjusting the power.

[0026] As described above, after the electron emission material 2 is heated to or above its melting temperature, the electron emission material 2 melts and becomes liquid, and the liquid electron emission material 2 passes through the through-hole 3 due to the action of gravity and the like to form the arc-shaped outer convex liquid surface 8. Specifically, since the operating temperature range of the electron emission device 100 is higher than the melting temperature of the electron emission material 2, the liquid has an infiltration effect with a solid between the melting temperature of the electron emission material 2 and the operating temperature of the electron emission device 100, that is, the liquid electron emission material 2 passes through the through-hole 3 due to the action of gravity and the like to form the arc-shaped outer convex liquid surface 8 at the opening of the through-hole 3.

[0027] In this way, after the electron emission material 2 reaches the melting temperature, i.e., melts under heat, the liquid electron emission material 2 passes through the through hole 3 of the fireproof container 1 by the infiltration action of the side wall of the through hole 3 due to the action of gravity or capillary force, and forms the arc-shaped outer convex liquid surface 8 at the opening of the through hole 3, and the outer convex liquid surface 8 can emit electron beams under the action of a strong electric field. Furthermore, as shown in Fig. 2, the outer convex liquid surface 8 can further pull the droplet structure with a smaller radius under the action of a strong electric field, that is, form the structure of a liquid needle tip 9, which can further increase the local electric field and improve the field emission effect of electrons.

[0028] In order to create an electric field that makes the outer convex liquid surface 8 easy to emit an electron beam, a corresponding annular extraction electrode 5 is provided below each of the through holes 3, and the extraction electrode 5 is installed facing the outer convex liquid surface 8, that is, the central axis of the extraction electrode 5 overlaps with the symmetric axis of the outer convex liquid surface 8. Here, the pitch between the through holes 3 and the extraction electrode 5 is 50 um to 5000 um, and the extraction electrode 5 has an annular structure with an inner diameter of 1 um to 100 um.

[0029] Furthermore, the electron emission device 100 further includes an extraction power supply 7 which can be installed separately from the fireproof container 1, has a negative electrode connected to the outer convex liquid surface 8 of the electron emission material 2 through the inner wall of the fireproof container 1, and has a positive electrode connected to the annular extraction electrode 5. The extraction power supply 7 is an adjustable DC voltage source with an output voltage between 0V and 6kV.

[0030] In the embodiment of the present disclosure, the combination of the liquid in which the electron emission material is melted and the through-holes can form a convex liquid surface, and the convex liquid surface forms a liquid needle tip under the action of a strong DC electric field, so that the selection range of the electron emission material can be expanded. The structural life of such an electron emission device is proportional to the quality of the electron emission material contained therein, and therefore the electron emission life of the electron emission device can be significantly longer than the life of conventional thermal field emission filaments and cold field emission filaments.

[0031] In the process of adopting the electron emission device 100 of the embodiment of the present disclosure, the following can be implemented with reference to the contents shown in FIG. 3, that is, in the case of a scanning electron microscope, a transmission electron microscope, or an electron beam exposure machine, the fireproof container 1 in the electron emission device 100 is installed at the tip of the electron tube therein, and further, the electron emission material 2 in the above embodiment is provided in the cavity portion 11 of the fireproof container 1, the heating power source 6 is connected to the heating device 5, and the heating device 5 is connected to the fireproof container 1, but if the fireproof container 1 is made of a metal material, the heating power source 6 can be directly connected to the fireproof container 1.

[0032] Furthermore, for example, the cavity 11 of the fireproof container 1 located at the tip of the electron lens column is evacuated to a high vacuum state, and the degree of vacuum in the cavity 11 is adjusted to 1 micropascal, and then the power V1 of the heating power source 6 is adjusted until the temperature of the electron-emitting material 2 reaches the melting temperature, and then the power V1 of the heating power source 6 is gradually increased until the electron-emitting material 2 starts to melt, and the electron-emitting material 2 that is in a liquid state and melted in the fireproof container 1 continues to fall by gravity or capillary force through the through-hole 3 at the lower end of the fireproof container 1. In this way, a stable arc-shaped outer convex liquid surface 8 is formed at the lower end opening of the through-hole 3 by the infiltration action between the electron-emitting material 2 in a liquid state and the through-hole 3 in a solid state and the cooperation of the liquid surface energy. Then, a strong electric field is formed under the action of the extraction electrode 7, and the voltage of the extraction power supply 7 is gradually increased so that the outer convex liquid surface 8 emits electron beams under the action of the strong electric field, thereby achieving the purpose of electron emission. Of course, the outer convex liquid surface 8 can also form a stable liquid needle tip 9 under the action of the strong electric field and the liquid surface energy, and the liquid needle tip 9 can further increase the local electric field intensity, improve the field emission effect of the electron beam emission, and achieve the purpose of forming a high-brightness electron emission device.

[0033] Here, in the process of emitting electron beams by the electron emission device, by utilizing the capillary action of liquid, the structure of micron-level capillary channels, the infiltration action of materials, the electric field effect, etc., it has a relatively high electron field emission effect, a relatively high degree of structural consistency, is easy to debug, and the life of the electron emission structure is proportional to the quality of the electron emission material accommodated therein, so that the electron generation life can be significantly extended compared to the life of conventional thermal field emission filaments and cold field emission filaments.

[0034] An embodiment of the present disclosure further provides an electronic device employing an electron emission device in any one of the technical solutions described above, wherein the electronic device includes at least one of a vacuum electron tube, an X-ray generator, an electronic display, and a thermoelectric converter.

[0035] The above description is merely a description of the preferred embodiments of the present disclosure and the technical principles applied thereto. It is understood by those skilled in the art that the scope of the disclosure of the present disclosure is not limited to the technical solutions based on the specific combinations of the above technical features, and should also cover other technical solutions that combine the above technical features or their equivalent features in any way without departing from the spirit of the above disclosure. For example, the above features are substituted with technical features having similar functions (but not limited to) disclosed in the present disclosure.

[0036] Additionally, although operations are depicted in a particular order, they should not be understood as requiring execution in the particular order or sequentially depicted. In certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although the above discussion includes some specific implementation details, these should not be construed as limitations on the scope of the disclosure. Some features that are described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments alone or in any suitable subcombination.

[0037] Although the present subject matter has been described using specific language for structural features and / or methodological logical operations, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or operations described above. On the contrary, the specific features and operations described above are merely example forms of implementing the claims.

[0038] Although several embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to these specific embodiments, and a person skilled in the art can make various changes and modifications to the embodiments based on the concept of the present disclosure, and these variations and modifications should be included in the scope of the present disclosure.

Claims

1. An electron emission device including a refractory container having a cavity with a certain degree of vacuum and a heating power source, The cavity portion is provided with an electron emitting material, At least one through hole is provided at the bottom of the fireproof container, and the electron emitting material melts under heat and passes through the through hole to form an arc-shaped outer convex liquid surface, thereby emitting electrons to the outside.

2. An electron emission device comprising:

2. the melting temperature of the fireproof container is higher than the melting temperature of the electron emitting material and the operating temperature of the electron emitting device, and the melting temperature of the electron emitting material is lower than the operating temperature of the electron emitting device; 2. The electron emission device according to claim 1.

3. The cross section of the fireproof container is at least one of a circle, a rectangle, a rectangle, and an ellipse, The cavity portion is a circular cavity.

2. The electron emission device according to claim 1.

4. The electron emission material is at least one of a semiconductor material, an electrically insulating material, and a metal material.

2. The electron emission device according to claim 1.

5. the semiconductor material is GaAs or InP; Alternatively, the electrically insulating material is at least one of CsO2, Zr2O3, Y2O3, BeO, WO3, Rb2O, and Ir2O3; Alternatively, the metal material is at least one of W, Re, Ru, Pt, and Zr; 5. The electron emission device according to claim 4.

6. a plurality of the through holes are provided in the bottom of the fireproof container, and providing a plurality of the through holes can facilitate the formation of an electron emission array; 2. The electron emission device according to claim 1.

7. a heating device disposed on a side wall of the refractory container for heating the refractory container and the electron emitting material therein; 2. The electron emission device according to claim 1.

8. A ring-shaped extraction electrode is provided below each of the through holes, and the extraction electrode is disposed opposite the outer convex liquid surface.

2. The electron emission device according to claim 1.

9. a negative electrode connected to the outer convex liquid surface of the electron emitting material through an inner wall of the refractory container, and a positive electrode connected to the annular extraction electrode; 9. The electron emission device according to claim 8.

10. An electronic device employing an electron emission device according to any one of the preceding claims, comprising at least one of a vacuum electron tube, an X-ray generator, an electronic display, and a thermoelectric converter.

1. An electronic device comprising:

Images