Search

CN-119170466-B - Double-layer field emission cold cathode electron source and manufacturing method thereof

CN119170466BCN 119170466 BCN119170466 BCN 119170466BCN-119170466-B

Abstract

The invention provides a double-layer field emission cold cathode electron source and a manufacturing method thereof, and relates to the technical field of nano electrons, wherein the double-layer field emission cold cathode electron source comprises a first cathode, an insulating layer, a second cathode and a grid electrode which are sequentially connected from bottom to top; the first cathode comprises a conductive substrate and a first layer of field emitters, the first layer of field emitters are arranged on the upper surface of the conductive substrate, the second cathode comprises a conductive grid and a second layer of field emitters, the second layer of field emitters are arranged on the upper surface of the conductive grid, and the effective emission area of the cold cathode emitters is increased to improve the field emission current and current density.

Inventors

  • ZHANG YU
  • JIANG JUN
  • DENG SHAOZHI
  • XU NINGSHENG

Assignees

  • 中山大学

Dates

Publication Date
20260512
Application Date
20240918

Claims (9)

  1. 1. A preparation method of a double-layer field emission cold cathode electron source is characterized in that the double-layer field emission cold cathode electron source comprises a first cathode (1), an insulating layer (2), a second cathode (3) and a grid electrode (4) which are sequentially connected from bottom to top, wherein the first cathode (1) comprises a conductive substrate (11) and a first layer field emitter (12), the first layer field emitter (12) is arranged on the upper surface of the conductive substrate (11), the second cathode (3) comprises a conductive grid (31) and a second layer field emitter (32), and the second layer field emitter (32) is arranged on the upper surface of the conductive grid (31); the preparation method of the double-layer field emission cold cathode electron source specifically comprises the following steps: s1, preparing a first cathode (1), namely preparing a first layer of field emitters (12) on a conductive substrate (11); S2, preparing a second cathode (3), namely preparing a second layer of field emitters (32) on the conductive grid (31); s3, placing a conductive grid (31) of the second cathode (3) above the conductive substrate (11) containing the first cathode (1), aligning the first layer field emitter (12) and the second layer field emitter (32) in a staggered manner, and separating and fixing the first cathode (1) and the second cathode (3) through the insulating layer (2); S4, placing the grid electrode (4) above the second layer of field emitter (32) to finish the preparation of the double-layer field emission cold cathode electron source.
  2. 2. The method for preparing a double-layer field emission cold cathode electron source according to claim 1, wherein the grid electrode (4) has a flat plate structure or an open pore structure.
  3. 3. The method of manufacturing a dual layer field emission cold cathode electron source according to claim 1, wherein the first layer field emitters (12) are arrayed field emitters spatially staggered with respect to the holes of the conductive grid (31).
  4. 4. A method of manufacturing a dual-layer field emission cold cathode electron source according to claim 3, wherein the first layer field emitter (12) has a circular, linear or polygonal shape.
  5. 5. A method of manufacturing a dual layer field emission cold cathode electron source according to claim 3, wherein the conductive mesh (31) has the same shape as the first layer field emitter (12).
  6. 6. A method of manufacturing a dual-layer field emission cold cathode electron source according to claim 3, wherein the first layer field emitters (12) have the same array period as the holes of the conductive mesh (31), and the array unit size is equal to or smaller than the holes of the conductive mesh (31).
  7. 7. The method for preparing a dual-layer field emission cold cathode electron source according to claim 1, wherein the second layer field emitters (32) are arranged on grid strips in a conductive grid (31) to form grid emitters, and the second layer field emitters (32) are spatially staggered with respect to the first layer field emitters (12).
  8. 8. The method of manufacturing a dual-layer field emission cold cathode electron source according to claim 1, wherein the second layer field emitter (32) applies a higher potential than the first layer field emitter (12).
  9. 9. A method of manufacturing a dual layer field emission cold cathode electron source according to claim 1, wherein the grid (4) is applied with a potential higher than the potential applied by the second layer field emitter (32).

Description

Double-layer field emission cold cathode electron source and manufacturing method thereof Technical Field The present invention relates to the field of nanoelectronics, and more particularly, to a double-layer field emission cold cathode electron source and a method of manufacturing the same. Background The field emission cold cathode electron source has important application potential in vacuum electronic devices, and common applications include microwave tubes, X-ray sources and the like. Compared with a hot cathode, the cold cathode has the advantages of normal-temperature operation, low power consumption and high current density. However, the emission current of the cold cathode is smaller at the present stage, and further current improvement is a key problem for meeting the application requirements of the device. Although the current can be increased by increasing the area of the cathode film, the field emitters which are densely arranged are shielded from each other due to the existence of an electric field shielding effect, and the electric field intensity of the cathode edge is far greater than that in the middle. This causes poor emission uniformity and severe edge emission phenomenon, so that an increase in area does not achieve an equal proportion of current rise. In order to solve this problem, a conventional processing method is to manufacture a cold cathode thin film in an array form, such as a dot array, a line array, etc., and to circumvent a shielding effect by dispersing emitters, thereby obtaining a uniform electric field distribution. For example, the prior art discloses a field emission electron source structure including a support substrate, a photo-cathode layer formed on the substrate, a source electrode formed on a portion of the photo-cathode layer, an insulating layer covering the source electrode and the photo-cathode layer, a gate electrode formed on the insulating layer, and a vacuum channel penetrating the gate electrode and the insulating layer and exposing the photo-cathode layer. The scheme avoids the shielding effect by dispersing the emitters, so that uniform electric field distribution is obtained, the working voltage required by an electron source structure is reduced, the emission current density and the ion bombardment resistance are improved, but no emitter exists in a blank area between the lattices, and the total emission area is extremely reduced. According to calculation, the proportion of the effective emission area of the array to the whole area is less than one half, so that the current lifting effect is limited by adopting a method of dispersing the emitters. Disclosure of Invention In order to solve the problem that the current field emission shielding effect method is limited in emission area and current lifting effect, the invention provides a double-layer field emission cold cathode electron source and a manufacturing method thereof, which can solve the field emission shielding effect problem, improve the effective emission area of a cold cathode emitter, and improve the field emission current and current density. In order to achieve the technical effects, the technical scheme of the invention is as follows: A double-layer field emission cold cathode electron source comprises a first cathode, an insulating layer, a second cathode and a grid electrode which are sequentially connected from bottom to top, wherein the first cathode comprises a conductive substrate and a first layer of field emitters, the first layer of field emitters are arranged on the upper surface of the conductive substrate, the second cathode comprises a conductive grid and a second layer of field emitters, and the second layer of field emitters are arranged on the upper surface of the conductive grid. According to the technical scheme, the effective emission area of the cold cathode is increased by designing the double-layer field emission cold cathode electron source with an integrated structure, so that the field emission performance of the cold cathode is improved, the conductive substrate, the conductive grid and the grid comprise conductive materials such as silicon, stainless steel, tungsten, molybdenum and copper, the conductive materials can be the same material or different materials, the first layer field emitter and the second layer field emitter comprise field emission films, field emission one-dimensional nano materials, field emission two-dimensional nano materials and the like, the two layers of field emitters can be the same material or different materials, and the insulating layer can comprise materials such as alumina and silicon dioxide. Preferably, the grid is of a flat plate structure or an open pore structure. Preferably, the first layer of field emitters are arrayed field emitters and are aligned with the conductive grid holes in a space staggered manner, so that the effective field emission area is increased, and further, the field emission performance is improve