CN114655952B - Electron multiplying material for microchannel plate, preparation thereof, microchannel plate prepared from electron multiplying material and preparation method of microchannel plate - Google Patents
Electron multiplying material for microchannel plate, preparation thereof, microchannel plate prepared from electron multiplying material and preparation method of microchannel plate Download PDFInfo
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- CN114655952B CN114655952B CN202111515815.XA CN202111515815A CN114655952B CN 114655952 B CN114655952 B CN 114655952B CN 202111515815 A CN202111515815 A CN 202111515815A CN 114655952 B CN114655952 B CN 114655952B
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/25—Diamond
- C01B32/26—Preparation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B1/00—Devices without movable or flexible elements, e.g. microcapillary devices
- B81B1/002—Holes characterised by their shape, in either longitudinal or sectional plane
- B81B1/004—Through-holes, i.e. extending from one face to the other face of the wafer
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
- B81C1/00023—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems without movable or flexible elements
- B81C1/00119—Arrangement of basic structures like cavities or channels, e.g. suitable for microfluidic systems
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00436—Shaping materials, i.e. techniques for structuring the substrate or the layers on the substrate
- B81C1/00523—Etching material
- B81C1/00531—Dry etching
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J43/00—Secondary-emission tubes; Electron-multiplier tubes
- H01J43/04—Electron multipliers
- H01J43/06—Electrode arrangements
- H01J43/18—Electrode arrangements using essentially more than one dynode
- H01J43/24—Dynodes having potential gradient along their surfaces
- H01J43/246—Microchannel plates [MCP]
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C2201/00—Manufacture or treatment of microstructural devices or systems
- B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
- B81C2201/0101—Shaping material; Structuring the bulk substrate or layers on the substrate; Film patterning
- B81C2201/0111—Bulk micromachining
Abstract
The invention discloses an electron multiplication material for a microchannel plate, a preparation method thereof, the microchannel plate prepared from the electron multiplication material and a preparation method of the microchannel plate. The method solves the problems that in the prior microchannel plate technology, the secondary electron emission coefficient of oxide materials for an electron multiplication layer is generally not high, and how to better combine the materials of the electron multiplication layer (especially diamond materials) in the micropores with large aspect ratio holes of the microchannel plate.
Description
Technical Field
The invention relates to the technical field of vacuum electronics. And more particularly, to an electron multiplying material for a microchannel plate, preparation thereof, a microchannel plate prepared therefrom, and a method of preparing a microchannel plate.
Background
The electron multiplier tube is a vacuum tube capable of amplifying charges, primary electrons at the inlet of the vacuum tube impact the inner wall of the tube to strike the electrode under the acceleration of an electric field to generate amplified secondary emission electrons, and the amplified electrons continuously collide with the subsequent strike electrode and are circularly repeated for a plurality of times, so that a large number of electrons can be generated at the outlet of the vacuum tube to form an electron multiplier effect. Electron multiplier tubes as photoelectric detection devices have been studied successfully in 1934 and are increasingly used in the fields of machinery, geology, metallurgy, astronomy, chemical industry, electronics, medical imaging detection, and cosmic space research.
Conventionally processed dynode type electron multiplier tubes, as shown in fig. 1, electrodes are often separated from each other, and the voltage of the electrode of the latter stage is 100-200V higher than that of the former stage to achieve electron acceleration. The dynode type electron multiplier is simple to manufacture and easy to realize high current, but has long transit time and larger transit time dispersion (TTS). With technological progress and rapid development of high and new technologies, performance requirements of scientific research and detection technology are continuously improved, and a micro-channel plate (MCP) electron multiplier tube is generated.
The microchannel plate type electron multiplier tube has the advantages of high gain, quick response, low power consumption, light weight and high resolution of two-dimensional space images, and the basic structure is shown in figures 2a-2 b. The microchannel plate body is formed by connecting a plurality of mutually parallel micron-sized channels in parallel, wherein each channel is a continuous electron multiplication unit. The beating electrode in the micro-channel is not separated any more, but is connected into an integral electron multiplication layer. The incident electrons continuously collide with the electron multiplication layer for multiple times, and the electron flow enhancement is continuously realized.
The initial microchannel plate preparation main body is based on a lead silicate glass tube stretching technology, closely-spaced glass tubes are longitudinally stretched and cut into blanks to form tube bundle matrixes, and an electron multiplication layer is formed on the inner wall of the tubes by reducing lead in the glass matrixes. With the advancement of micromachining technology, miniaturized, high performance microchannel plates can be fabricated using advanced microelectromechanical systems technology. U.S. Pat. nos. 5086248 and 5997713 respectively propose a process for preparing microchannel plates based on silicon materials, wherein a Deep Reactive Ion Etching (DRIE) technique, or electrochemical and photoelectrochemical etching techniques are adopted to directly prepare a densely-arranged high-aspect-ratio micropore array on a silicon wafer, and then an electron multiplying layer is manufactured on the inner wall of the micropore array by a Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) method. The micro-machined silicon-based micro-channel plate has the advantages that the preparation flow is compatible with micro-machining technology, different shapes and sizes are easy to realize, the process repeatability and the batch manufacturing capability are good, the micro-machined silicon-based micro-channel plate is suitable for the development trend of multifunction, miniaturization, modularization, high reliability and integration of high-precision detection instruments, and the micro-machined silicon-based micro-channel plate becomes an important development direction of electron multiplier tubes.
The key technology of the electron multiplier is to achieve an electron multiplication effect through secondary electron emission, and the electron multiplier layer material is required to have a high secondary electron emission coefficient. The high secondary electron emission coefficient material mainly comprises an oxide material, a photocathode material, a negative electron affinity material, an alloy, glass and the like. Wherein the oxide material is widely applied due to simple process, easy preparation and strong physical and chemical stability. However, the secondary electron emission coefficient of the existing oxide material is generally not high, and the maximum secondary electron emission coefficient delta m Generally only between 3 and 8.
Ordinary diamond is an insulating material, but its conductivity can be improved by doping, and diamond subjected to specific surface treatment is the only negative electron affinity material stable in air. Due to the low atomic number and large secondary electron escape depth, the diamond has high secondary electron emission capability. In addition, the diamond material has high heat conductivity and good chemical stability, has great advantages when being used as an electron multiplication layer material, and is expected to greatly improve the performance of the existing electron multiplier.
The diamond material is used as a beating electrode of a traditional electron multiplier tube, and is relatively simple to prepare due to macroscopic volume, but is difficult to use as an electron multiplier layer of a microchannel plate. The microchannel plate electron multiplying layer is formed by growing/coating a thin film in the tube after the electron channel is formed. The electron transmission channel is a thin pipe with a large depth-to-width ratio, the diameter of which is several micrometers to tens micrometers and the length of which is several hundred micrometers, no matter the glass tube type or the silicon-based microchannel plate, even if a Chemical Vapor Deposition (CVD) method with the best film forming quality is adopted to manufacture the diamond film, the uniform film coverage with smooth surface is difficult to realize on the inner wall of the electron transmission channel and the consistency among the micro pipes is realized due to a series of technological processes such as nucleation, film forming, treatment and the like.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide an electron multiplying material for a microchannel plate, a preparation method thereof, a microchannel plate prepared therefrom, and a preparation method of the microchannel plate. The method solves the problems that in the prior microchannel plate technology, the secondary electron emission coefficient of oxide materials for an electron multiplication layer is generally not high, and how to better combine the materials of the electron multiplication layer (especially diamond materials) in the micropores with large aspect ratio holes of the microchannel plate.
In one aspect, the invention provides an electron multiplying material for a microchannel plate, the electron multiplying material being a group III element P-doped diamond film.
Further, the group iii element is selected from boron.
In yet another aspect, the present invention provides a method for preparing an electron multiplying material for a microchannel plate, comprising the steps of:
uniformly coating diamond superfine nano grain powder on a substrate, and forming cores to obtain a core forming seed layer;
and depositing a III-group element doped diamond film on the surface of the nucleation seed layer by adopting a vapor deposition method.
Further, the grain size of the diamond ultra-fine nanocrystalline grain powder is <10nm.
Further, nucleation density of the nucleation seed layer>10 10 /cm 2 。
In yet another aspect, the present invention provides a microchannel plate comprising an electron multiplying layer, the electron multiplying layer being prepared from the electron multiplying material described above or from the method of preparing the electron multiplying material described above.
Further, the electron multiplication layer has a thickness of 50-1000nm.
In yet another aspect, the present invention provides a method for preparing a microchannel plate, comprising the steps of:
providing a substrate;
forming a columnar array at a preselected location on one surface of the substrate;
uniformly coating diamond superfine nano grain powder on the surfaces of the substrate and the columnar array, and forming cores to obtain a nucleation seed layer; depositing a III-group element doped diamond film on the surface of the nucleation seed layer by adopting a vapor deposition method to form an electron multiplication layer;
applying an insulating material on the electron multiplying layer until the electron multiplying layer completely covers the columnar arrays to form an insulating layer;
grinding and polishing the surface of the insulating layer in the obtained structure until the top end of the columnar array is exposed;
removing the substrate, and grinding and polishing the surface combined with the substrate in the structure until the bottom end of the columnar array is exposed;
removing the columnar array to obtain an insulating layer structure with a through hole and an electron multiplication layer coated on the through hole;
depositing conductive materials on the upper and lower surfaces of the insulating layer structure except for the through holes respectively to form an input electrode and an output electrode;
carrying out surface treatment on the electron multiplication layer;
and obtaining the microchannel plate.
Further, the insulating material is an insulating material resistant to high electric field breakdown.
Further, the mode of applying the insulating material is selected from one of filling solidification, filling sintering, chemical vapor deposition and vacuum coating.
Further, the method of removing the substrate is selected from etching or grinding and polishing.
Further, the method of removing the columnar arrays is etching.
Further, the electron multiplication layer is subjected to surface treatment by hydrogenation treatment or cesium treatment.
The beneficial effects of the invention are as follows:
in the preparation of the microchannel plate, the high secondary electron emission characteristic of the doped diamond film and the advantages of the micro structure prepared by the micro processing technology are combined into a whole, so that the performance of the existing electron multiplier can be preferentially improved. The method is simple and easy to implement, is beneficial to obtaining the high-quality processing microchannel plate, and meets urgent requirements of scientific research and practicality.
The method for manufacturing the microchannel plate by using the prefabricated die and then processing the microchannel plate is simple in process, can obtain the doped diamond film with high quality, high uniformity and smooth surface on the inner wall of the electron transmission channel by using the optimized process to the greatest extent, overcomes the limitation that the traditional microchannel plate only depends on glass and silicon material matrixes, and realizes more excellent structure and device performance by selecting the matrixes and processing process diversity.
Drawings
The following describes the embodiments of the present invention in further detail with reference to the drawings.
Fig. 1 shows a schematic diagram of a conventional dynode type electron multiplier.
Wherein, 101-electron multiplier tube wall, 102-beating electrode, 103-incident electron flow, 104-emergent electron flow.
Fig. 2a shows the overall structure of a prior art microchannel plate type electron multiplier and fig. 2b shows a schematic diagram of a single microchannel of a prior art microchannel plate type electron multiplier.
Wherein 201-micro channel tube wall, 202-electron multiplication layer, 203-input electrode, 204-output electrode, 205-incident electron flow, 206-emergent electron flow.
Fig. 3 shows photographs of diamond coated with different thicknesses on the surface of a silicon tip cone.
Fig. 4a-4h show a process flow diagram of the fabrication of a doped diamond electron multiplying layer microchannel plate of the present invention.
Fig. 4i shows a doped diamond electron multiplying layer microchannel plate of the invention.
Wherein, 301-silicon substrate, 302-columnar array, 303-nucleation seed layer, 401-doped diamond electron multiplying layer, 402-microchannel plate matrix, 403-electron transfer channel, 404-input electrode, 405-output electrode, 406-negative electron affinity surface.
Fig. 5 shows the secondary electron emission coefficient of diamond films with different boron doping concentrations obtained by the method of two embodiments of the invention as a function of incident energy.
Detailed Description
In order to more clearly illustrate the present invention, the present invention will be further described with reference to preferred embodiments and the accompanying drawings. Like parts in the drawings are denoted by the same reference numerals. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and that this invention is not limited to the details given herein.
In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "head," "tail," and the like are used as an orientation or positional relationship based on that shown in the drawings, merely to facilitate description of the invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention.
One embodiment of the invention provides an electron multiplying material for a microchannel plate, wherein the electron multiplying material is a III-element P-type doped diamond film.
The electron multiplying material, when used in a microchannel plate, has a higher secondary electron emission coefficient relative to existing oxide materials.
Illustratively, the group III element is selected from boron. At this time, the mass ratio of boron to diamond is preferably 3 to 16ppm.
Yet another embodiment of the present invention provides a method of preparing an electron multiplying material for a microchannel plate. The method comprises the following steps:
uniformly coating diamond superfine nano grain powder on a substrate, and forming cores to obtain a core forming seed layer;
and depositing a III-group element doped diamond film on the surface of the nucleation seed layer by adopting a vapor deposition method.
Illustratively, the diamond ultra-fine nanocrystalline grain powder has a grain size <10nm.
Illustratively, the nucleation density of the nucleation seed layer>10 10 /cm 2 。
In the embodiment, no other requirements are required for the substrate, and the diamond film can stably grow on the substrate.
Illustratively, the electron multiplying material preferably has a thickness of 50-1000nm.
Another embodiment of the present invention provides a method for manufacturing a microchannel plate, as shown in fig. 4a-4h, comprising the steps of:
1) A substrate 301 is provided.
The substrate 301 suitable for use in this embodiment may be a smooth, flat silicon wafer, preferably a surface polished silicon wafer, having a flatness and roughness that meets the requirements of micromachining, particularly photolithography processes.
The dimensions of the substrate 301 are preferably micromachined standard dimensions, such as 2 inches, 3 inches, 4 inches, 6 inches, or greater than 6 inches standard substrates and non-standard substrates that can be achieved by micromachining.
A suitable thickness of the substrate 301 is preferably 400-2000 microns, considering the columnar height and maintaining substrate resistance to deformation during subsequent fabrication steps.
2) Columnar arrays 302 are formed at preselected locations on one surface of substrate 301, as shown in fig. 4 a.
The size and shape of columnar arrays 302 correspond to the size and shape of the vias in the resulting microchannel plate (i.e., the effective practical area in the microchannel plate) to be fabricated. In the columnar array 302, the column shape corresponds to the inner hole of the microchannel plate, the column gap corresponds to the channel wall thickness of the microchannel plate, and the column height corresponds to the thickness of the microchannel plate.
The shape of the columnar array 302 includes, but is not limited to, a cylinder, square column, hexagonal prism, or the like. The shape of the correspondingly formed electronic channels is respectively round, square, honeycomb and the like.
In columnar array 302, the column gap is preferably about 4 microns, the diameter or edge-to-edge length of individual columns is preferably 6-40 microns, the column height is preferably 160-400 microns, and the aspect ratio of the columns is preferably 10-40.
The material forming columnar arrays 302 is preferably silicon, or other material suitable for micromachining to form high aspect ratio columnar structures and which is resistant to the diamond CVD growth temperature.
The method of forming columnar array 302 may be a micromachining process. Specifically, deep reactive ion etching (DRIE, processing directly on a silicon substrate), or other suitable micromachining techniques such as femtosecond lasers, and the like.
The pattern of columnar arrays 302 may be sized as desired, or the pattern of columnar arrays 302 may be densely packed across the substrate and cut to size as desired after preparation.
3) Uniformly coating diamond superfine nano grain powder on the surfaces of the substrate 301 and the columnar arrays 302, and nucleation to obtain a nucleation seed layer 303, as shown in fig. 4 b;
a group iii element doped diamond film is deposited on the surface of the nucleation seed layer 303 by a vapor deposition method to form an electron multiplying layer 401, as shown in fig. 4 c.
Illustratively, in diamond ultra-fine nanocrystalline grain powder, the grain size is preferably <10nm, more preferably 3-5nm.
Exemplary methods of coating diamond ultra-fine nanocrystalline powders include, but are not limited to, dielectrophoresis, ultrasonic coating, bias deposition, and the like.
Illustratively, the nucleation density of the nucleation seed layer>10 10 /cm 2 。
The electron multiplying layer 401 has a thickness of, for example, 50-1000nm.
In the present embodiment, the reaction gas for vapor deposition is preferably B 2 H 6 And CH (CH) 4 Conversely, the volume ratio of the two is preferably 2/10 6 -10/10 6 。
4) An insulating material is applied over the electron multiplying layer 401 to completely cover the columnar arrays 302, forming an insulating layer 402 (i.e., microchannel plate substrate), as shown in fig. 4 d.
Insulating materials that are easily densely formed, strong, and resistant to high electric field breakdown include, but are not limited to, resins, glass, quartz, ceramics, and the like.
The insulating material is preferably applied by one of filling sintering, chemical vapor deposition and vacuum coating.
The applied insulating material completely masks the patterned structure of columnar array 302 such that the thickness of insulating layer 402 is greater than the height of columnar array 302. Thereby facilitating the subsequent obtaining of a flat and smooth upper plane of the microchannel plate.
5) The resulting structure is planarized and polished with the surface of insulating layer 402 until the top ends of columnar arrays 302 are exposed, as shown in fig. 4 e.
It will be appreciated that by grinding and polishing, portions of the insulating layer 402 and all of the electron multiplying layer 401 at the top ends of the columnar arrays 302 are removed in sequence, so that the top ends of the columnar arrays 302 are just exposed on the surface obtained by grinding and polishing.
The method of planarizing, polishing is preferably Chemical Mechanical Polishing (CMP), in which the insulating layer is first rapidly polished to thin near the upper end of the array of pillars, and then slowly polished to remove material exposing the array of pillars while simultaneously polishing the entire upper surface.
By this method, separation of the insulating layer 402 (microchannel plate substrate) and the electron multiplying material is achieved.
6) Removing the substrate 301 and grinding and polishing the surface of the structure combined with the substrate 301 until the bottom ends of the columnar arrays 302 are exposed; and removing the columnar array 302 to obtain an insulating layer structure with a through hole 403 (i.e., an electron transport channel) and an electron multiplying layer 401 covering the through hole 403, as shown in fig. 4 f.
Methods of removing the substrate 301 include, but are not limited to, etching or grinding and polishing.
The surface of the structure to which the substrate 301 is bonded is ground, polished, i.e., the portion of the electron-multiplying layer 401 to which the substrate 301 is bonded is removed.
Among them, the above-mentioned grinding and polishing method is preferably Chemical Mechanical Polishing (CMP).
The method of further removing columnar array 302 may be etching, which is wet chemical etching, and the same/different chemical etching solution is selected according to the same/different materials of substrate 301 and columnar array 302, and the etching solution has good etching selectivity to other materials, i.e. the etching removal process cannot damage the insulating substrate of the microchannel plate and electron multiplying layer 401.
The invention surprisingly discovers that compared with the existing silicon-based microchannel plate preparation method, the deep reactive ion etching silicon through hole is changed into etching silicon column, thereby reducing the process difficulty and improving the quality of the electron transmission channel; compared with the existing microtube stretching method which only uses glass as a matrix and the micro-processing method which only uses silicon as a matrix, the microchannel plate matrix material has more selectivity.
According to the microchannel preparation process, the doped diamond electron multiplication layer is coated on the inner wall of the existing large-aspect-ratio pipeline and is coated on the outer surface of the cylinder structure, so that the process difficulty is greatly reduced, and better uniformity, consistency and surface smoothness are realized. Research has shown that even for micro-nano structures, uniform, smooth conformal deposition can be achieved. FIG. 3 shows the results of coating diamond film on the surface of silicon cone with a height of 8 μm and a tip radius of curvature of 10nm, and the film thickness is 0.1-2.4 μm to achieve uniform conformality. The electron multiplication layer is obtained by the preparation method, the actual secondary electron emission surface is attached to the inner surface of the silicon column die, and the surface is easier to realize high smoothness relative to the outer surface of the chemical vapor deposition die, so that the electron multiplication capacity is improved.
7) Conductive material is deposited on the upper and lower surfaces of the insulating layer structure except for the via 403, respectively, to form an input electrode 404 and an output electrode 405, as shown in fig. 4 g.
The method of depositing the conductive material is preferably a thin film deposition method. An exemplary thin film deposition method is a well-oriented vacuum evaporation coating method. In order to ensure that the deposition layer is only positioned on the upper end face and the lower end face of the micro-channel plate and does not enter the electronic channel, the evaporation source is far away from the micro-channel plate and keeps a small glancing angle with the end face of the micro-channel plate for oblique evaporation. Meanwhile, in order to ensure uniformity, the micro-channel plate rotates around the normal line of the end surface in the evaporation process.
The conductive material comprises but is not limited to one selected from chromium nickel, titanium nickel, chromium gold and titanium gold for combining firmness and good conductivity.
The thickness of the input electrode 404 and the output electrode 405 are each independently selected from 100-300nm.
8) The electron multiplying layer 401 is subjected to surface treatment as shown in fig. 4 h.
A negative electron affinity surface 406 is formed on the surface of the electron multiplying layer 401 by surface treatment.
The method of surface-treating the electron-multiplying layer is exemplified by hydrogenation treatment or cesium treatment.
Yet another embodiment of the present invention provides a microchannel plate, as shown in fig. 4i, comprising an electron multiplying layer 401, the electron multiplying layer being prepared from the electron multiplying material described above or from the method of preparing the electron multiplying material described above.
Further, the thickness of the electron multiplying layer 401 is 50-1000nm.
Example 1
A microchannel plate, as shown in fig. 4i, comprises a doped diamond electron multiplication layer 401, a microchannel plate substrate 402, an electron transport channel 403, an input electrode 404 and an output electrode 405, wherein the surface of the doped diamond electron multiplication layer 401 has a negative electron affinity surface 406.
The preparation method comprises the following steps:
1) A <100> crystal orientation polished silicon wafer is selected as a substrate 301, wherein the diameter of the silicon wafer is 4 inches, the thickness is 500 microns, and the surface flatness and the warping degree are better than 10 microns; thermally oxidizing 0.5-micrometer silicon dioxide on the surface of the silicon wafer and sputtering 1-micrometer metal aluminum by magnetron sputtering, and taking the silicon dioxide and the metal aluminum as masking layers by standard photoetching and etching; etching the silicon substrate to form columnar arrays 302 using STS corporation Bosch patent deep silicon etching techniques; the etching power is 600W/15W, the etching rate is 1.5 mu m/min, the etching time is 200min, and the etching depth is 300 microns; according to the design pattern, a densely-distributed hexagonal cylindrical array 302 is obtained on a silicon wafer, wherein the distance between the opposite sides of the cylinders is 15 micrometers, the space between the cylinders is 4 micrometers, the height of the cylinders is 300 micrometers, and the height-width ratio of the cylinders is 20.
2) Placing a substrate 301 and a columnar array 302 into ethanol suspension of 3-5nm diamond superfine nanocrystalline powder, performing ultrasonic vibration for 30min at 100W, immersing into acetone, cleaning for 5 min, and forming a nucleation seed layer 303 of diamond on the surfaces of the substrate 301 and the columnar array 302, wherein the nucleation density is the same as the nucleation seed layer>10 10 /cm 2 。
3) The substrate 301, the columnar arrays 302 and the nucleation seed layer 303 are formed into a structure, the whole is placed in a chemical vapor deposition device, and a boron doped diamond film is deposited on the surface of the substrate by means of the nucleation seed layer 303 to serve as an electron multiplying layer 401. The diamond carbon source adopts CH during deposition 4 B is adopted as the doping boron source 2 H 6 ，B 2 H 6 And CH (CH) 4 Feed volume ratio of 10/10 6 The total gas flow is 300sccm, the discharge reaction pressure is 80Torr, the microwave power is 1400W, and the substrate heating temperature is 800 ℃. The deposition time was 60 minutes, resulting in a film thickness of about 1 micron.
4) The microchannel plate substrate 402 is formed by vapor deposition of 95% alumina ceramic to the substrate and columnar array gap using an electron beam evaporation process. The evaporation power is 2kW, the evaporation rate is 2 mu m/min, the evaporation time is 160min, and the thickness of the aluminum oxide ceramic microchannel plate substrate 402 is about 320 mu m, so that the columnar array 302 with the height of 300 mu m and the surface nucleation seed layer 303 are completely covered.
5) The alumina ceramic microchannel plate substrate 402 is polished flat using a chemical mechanical polishing process with diamond powder as an abrasive. Firstly, rapidly grinding by adopting an abrasive with the granularity of 10 microns and a rotating speed of 200RPM, and reducing the thickness of the alumina ceramic matrix to 300 microns; and then slowly polishing with a 1-micrometer abrasive at a speed of 60RPM until the silicon material is exposed by polishing through the alumina ceramic matrix 402 and the doped diamond electron multiplying layer 401 on top of the silicon-based columnar array 302.
6) And (3) flattening and polishing the substrate 301 by adopting a chemical mechanical polishing method, such as a step 5), until the substrate 301 and the diamond electron multiplication layer 401 at the bottom of the alumina ceramic matrix 402 are completely removed, and the alumina ceramic material is exposed. Then corroding the silicon material with potassium hydroxide solution to completely remove the columnar arrays 302; the concentration of the potassium hydroxide solution is 30%, the corrosion temperature is 80 ℃, and the corrosion rate of the silicon material is about 1 mu m/min; for the 300 micron columnar array 302, 200 minutes of overetching (double sided etching) was performed to ensure removal of all silicon material (the columnar array had difficulty in narrow channel cladding removal), and electron transport channels 403 were formed at the original columnar array 302 locations due to material removal. A microchannel plate structure consisting of the doped diamond electron multiplying layer 401, the microchannel plate substrate 402 and the electron transport channels 403 is thus obtained. The honeycomb electron transport channels 403 correspond in shape to a cylindrical array with hexagonal through holes at a distance of 15 microns on opposite sides, a wall thickness of 4 microns, and a depth of 300 microns.
7) The input electrode 404 is fabricated by depositing a conductive material on the upper surface of the microchannel plate by electron beam vapor deposition. The target source is far away from the micro-channel plate during evaporation and forms an incidence glancing angle of 15 degrees with the end face, and meanwhile, the micro-channel plate rotates along the normal direction of the end face, so that the evaporated matter is ensured to be uniformly deposited on the surface and not enter the electron transmission channel 403. The input electrode 404 is a composite film of 20nm titanium and 100nm nickel. The same method prepares the output electrode 405 on the lower end face of the microchannel plate.
8) The diamond film is surface treated to obtain negative electron affinity performance by using hydrogenAnd (3) plasma. Placing the microchannel plate with the integral structure in chemical vapor deposition equipment again, and introducing H 2 The gas flow rate is 300sccm, the discharge reaction pressure is 80Torr, the microwave power is 1000W, the substrate heating temperature is 800 ℃, and the treatment is carried out for 10min, so that a negative electron affinity surface 406 is formed on the surface of the doped diamond electron multiplication layer 401 on the inner wall of the electron transmission channel 403.
Example 2
A microchannel plate, as shown in fig. 4i, comprises a doped diamond electron multiplication layer 401, a microchannel plate substrate 402, an electron transport channel 403, an input electrode 404 and an output electrode 405, wherein the surface of the doped diamond electron multiplication layer 401 has a negative electron affinity surface 406.
The preparation method is the same as in example 1, except that:
b in step 3) 2 H 6 And CH (CH) 4 The feed volume ratio of the reaction gas is 10/10 6 Adjusted to 2/10 6 To reduce the boron doping concentration of the diamond electron multiplying layer 401, the remaining conditions remain unchanged.
According to the boron doped diamond film obtained by the chemical vapor deposition method in the embodiment, the surface morphology is similar to that of an undoped diamond film, but diamond grains are finer, and the film shows a lower resistance value by measurement of a universal meter, so that the conversion from a non-conductor to a conductor is shown. Measurement of the boron doped diamond film showed that the secondary electron emission coefficient increased substantially with increasing electron incident energy, reached a maximum at 1keV and subsequently decreased; the secondary electron emission coefficient increases with the boron doping concentration in the film within a certain range.
Boron doped diamond films were prepared by chemical vapor deposition in two examples, highly doped case B in example 1 2 H 6 /CH 4 ＝10/10 6 Low doping case B in example 2 2 H 6 /CH 4 ＝2/10 6 The secondary electron emission coefficient test results are shown in fig. 5. The results show that even in the case of the lower boron doping in example 2, the secondary electron emission coefficient δ is 10.9 at an electron incident energy of 1keV, and the δ value is as high as 18 at the higher doping in example 1.3, both of which are much higher than existing oxide electron multiplying layer materials. Therefore, when the boron doped diamond film is used as the electron multiplication layer material in the microchannel plate, and by the preparation method of the microchannel plate in the embodiment of the invention, the uniform boron doped diamond film with smooth surface is realized on the inner wall of the electron transmission channel, so that the microchannel plate also has the effects brought by the uniform boron doped diamond film, and the details are not repeated here.
Conclusion: the invention surprisingly discovers that the micro-channel plate is prepared by using a prefabricated die post-processing method, the process is simple, material limitation is theoretically avoided, the mutual influence between preparation processes caused by material characteristic difference is avoided, the smooth and uniform diamond material electron multiplication layer can be conveniently realized on the inner wall of the electron transmission channel, and a high-quality result is obtained. The method provided by the invention is simple and easy to implement, low in cost and wide in range of selectable materials, and meets urgent requirements of scientific research and practicality.
It should be understood that the foregoing examples of the present invention are provided merely for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention, and that various other changes and modifications may be made therein by one skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.
Claims (6)
1. The preparation method of the microchannel plate is characterized by comprising the following steps of:
providing a substrate;
forming a columnar array at a preselected position on one surface of the substrate, wherein the columnar array is made of silicon;
uniformly coating diamond superfine nano grain powder on the surfaces of the substrate and the columnar arrays, and forming cores to obtain a nucleation seed layer; depositing a III-element doped diamond film on the surface of the nucleation seed layer by adopting a vapor deposition method to form an electron multiplication layer, wherein the III-element is selected from boron, and the grain size of the diamond superfine nano-grain powder is less than 10nm;
applying an insulating material on the electron multiplying layer until the electron multiplying layer completely covers the columnar arrays to form an insulating layer;
grinding and polishing the surface of the insulating layer in the obtained structure until the top end of the columnar array is exposed;
removing the substrate, and grinding and polishing the surface combined with the substrate in the structure until the bottom end of the columnar array is exposed;
removing the columnar array to obtain an insulating layer structure with a through hole and an electron multiplication layer coated on the through hole;
depositing conductive materials on the upper and lower surfaces of the insulating layer structure except for the through holes respectively to form an input electrode and an output electrode;
carrying out surface treatment on the electron multiplication layer;
obtaining the microchannel plate;
nucleation density of the nucleation seed layer>10 10 /cm 2 ；
The thickness of the electron multiplication layer is 50-1000nm.
2. The method of claim 1, wherein the insulating material is a high electric field breakdown resistant insulating material.
3. The method of claim 1, wherein the insulating material is applied by one of a filler curing, a filler sintering, a chemical vapor deposition, and a vacuum coating.
4. The method of claim 1, wherein the method of removing the substrate is selected from etching or grinding, polishing.
5. The method of claim 1, wherein the method of removing the columnar array is etching.
6. The method according to claim 1, wherein the electron multiplication layer is subjected to surface treatment by hydrogenation treatment or cesium treatment.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5569355A (en) * | 1995-01-11 | 1996-10-29 | Center For Advanced Fiberoptic Applications | Method for fabrication of microchannel electron multipliers |
| US6521149B1 (en) * | 2000-06-06 | 2003-02-18 | Gerald T. Mearini | Solid chemical vapor deposition diamond microchannel plate |
| US20130146778A1 (en) * | 2010-06-18 | 2013-06-13 | Photonis France | Electron multiplier detector formed from a highly doped nanodiamond layer |
| CN103168339A (en) * | 2010-09-13 | 2013-06-19 | 法国甫托尼公司 | Electron multiplier device having a nanodiamond layer |
| CN106206213A (en) * | 2016-07-18 | 2016-12-07 | 中国科学院西安光学精密机械研究所 | A kind of method using MEMS technology to prepare organic microchannel plate |
| CN110557936A (en) * | 2019-10-11 | 2019-12-10 | 陕西科技大学 | diamond microchannel Cu-based CVD diamond heat-sink sheet and preparation method thereof |
| CN113337806A (en) * | 2020-03-03 | 2021-09-03 | 核工业理化工程研究院 | Diamond micro-channel heat sink, preparation method and application thereof, and semiconductor laser |
-
2021
- 2021-12-13 CN CN202111515815.XA patent/CN114655952B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5569355A (en) * | 1995-01-11 | 1996-10-29 | Center For Advanced Fiberoptic Applications | Method for fabrication of microchannel electron multipliers |
| US6521149B1 (en) * | 2000-06-06 | 2003-02-18 | Gerald T. Mearini | Solid chemical vapor deposition diamond microchannel plate |
| US20130146778A1 (en) * | 2010-06-18 | 2013-06-13 | Photonis France | Electron multiplier detector formed from a highly doped nanodiamond layer |
| CN103168339A (en) * | 2010-09-13 | 2013-06-19 | 法国甫托尼公司 | Electron multiplier device having a nanodiamond layer |
| CN106206213A (en) * | 2016-07-18 | 2016-12-07 | 中国科学院西安光学精密机械研究所 | A kind of method using MEMS technology to prepare organic microchannel plate |
| CN110557936A (en) * | 2019-10-11 | 2019-12-10 | 陕西科技大学 | diamond microchannel Cu-based CVD diamond heat-sink sheet and preparation method thereof |
| CN113337806A (en) * | 2020-03-03 | 2021-09-03 | 核工业理化工程研究院 | Diamond micro-channel heat sink, preparation method and application thereof, and semiconductor laser |
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