CN108374151B - Metal and zinc oxide doped magnesium oxide secondary electron emission film and preparation method thereof - Google Patents
Metal and zinc oxide doped magnesium oxide secondary electron emission film and preparation method thereof Download PDFInfo
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- CN108374151B CN108374151B CN201810183512.4A CN201810183512A CN108374151B CN 108374151 B CN108374151 B CN 108374151B CN 201810183512 A CN201810183512 A CN 201810183512A CN 108374151 B CN108374151 B CN 108374151B
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Abstract
A metal and zinc oxide doped magnesium oxide secondary electron emission film and a preparation method thereof comprise a substrate, and a zinc oxide doped magnesium oxide film layer and a metal doped magnesium oxide film layer which are sequentially arranged on the substrate from top to bottom, wherein a metal material is only doped in the metal doped magnesium oxide film layer or the metal material and zinc oxide are co-doped, the atomic number percentage content of metal in the metal doped magnesium oxide film layer which is only doped with the metal material is 6-30%, the atomic number percentage content of metal in the metal doped magnesium oxide film layer which is co-doped with the metal material and zinc oxide is 5-25%, and the atomic number percentage content of zinc is not higher than 5%; the size of Mg-Zn-O compound crystal grains formed in the zinc oxide doped magnesium oxide film layer is 8nm-30nm, the atomic number percentage content of zinc is 0.2% -8%, and the preparation method is adopted, so that the secondary electron emission coefficient can be effectively improved, and the electron emission stability is enhanced.
Description
Technical Field
The invention belongs to the technical field of photoelectron materials and devices, and particularly relates to a metal and zinc oxide doped magnesium oxide secondary electron emission film and a preparation method thereof, which can be applied to devices such as an electron multiplier, a photomultiplier and the like.
Background
The magnesium oxide film has the advantages of high secondary electron emission coefficient, good charged particle bombardment resistance, simple preparation process and the like, and is widely applied to electronic devices such as an image intensifier, an electron multiplier, a photomultiplier, an orthogonal field amplifier and the like as a secondary electron emission material at present. In order to obtain a longer service life of the electronic device, the secondary electron emission material used therein must be able to withstand the long-term bombardment of the electron beam with a larger beam current density, and thus the thickness of the prepared magnesium oxide film needs to reach tens of nanometers or even more than one hundred nanometers. However, since magnesium oxide is an insulating material, a thicker magnesium oxide film generates a surface charging phenomenon under electron beam bombardment, which causes the secondary electron emission to be rapidly attenuated, thereby affecting the stability of the secondary electron emission of the film. This problem limits the use of magnesium oxide films in high gain, long life electronic devices.
In order to avoid the surface charging phenomenon of the thicker magnesium oxide film under the continuous bombardment of electron beams, a certain proportion of metal materials with good conductivity and stable chemical properties can be doped in the magnesium oxide film to form the magnesium oxide composite film doped with the metal materials. Due to the doping of the metal material, dispersed metal particles exist in the composite film, the conductivity of the film is improved, so that the surface charging can be effectively avoided when the film layer is thicker, and the performance of the film for enduring long-time bombardment of electron beams with larger beam density can be improved by increasing the thickness of the film. However, experimental studies show that the metal-doped magnesium oxide composite film still has a certain degree of secondary electron emission attenuation under the bombardment of electron beams with larger beam current, and the reason is that the surface charging phenomenon cannot be completely eliminated, and magnesium oxide decomposition etching caused by the electron beam bombardment also exists. The magnesium oxide film is doped with the metal material, so that the conductivity of the film can be improved, but because the secondary electron emission coefficient of the metal material is very low, and metal particles are easy to agglomerate in the process of depositing the film at high temperature, the surface roughness of the film is increased, the secondary electron emission coefficient of the film can be obviously reduced by excessively high metal doping amount, and the metal doping amount in the magnesium oxide film is limited. The conductivity of the magnesium oxide film is improved to a certain extent by a small amount of metal doping, when the metal-doped magnesium oxide film is bombarded by the electron beam with lower beam current density to generate secondary electron emission, the surface charging phenomenon can be avoided, but when the metal-doped magnesium oxide film is continuously bombarded by the electron beam with higher beam current density to perform secondary electron emission, the conductivity of the film is still insufficient, and the positive charge rapidly accumulated on the surface of the film is difficult to eliminate in time. In addition, the magnesium oxide can generate decomposition etching under the bombardment of electron beams with higher beam current density, the crystal structure of the magnesium oxide is damaged, the surface appearance of the film is changed, and secondary electron emission attenuation occurs. Therefore, the secondary electron emission performance (especially under the bombardment of electron beams with higher beam current density) of the metal-doped magnesium oxide composite film needs to be further improved.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a metal and zinc oxide doped magnesium oxide secondary electron emission film and a preparation method thereof, which can effectively improve the secondary electron emission coefficient and enhance the electron emission stability.
In order to realize the purpose, the metal and zinc oxide doped magnesium oxide secondary electron emission film adopts the technical scheme that: the metal-doped magnesium oxide film comprises a substrate, and a zinc oxide-doped magnesium oxide film layer and a metal-doped magnesium oxide film layer which are sequentially arranged on the substrate from top to bottom, wherein the metal-doped magnesium oxide film layer is doped with a metal material or is co-doped with the metal material and zinc oxide, the atomic number percentage content of metal in the metal-doped magnesium oxide film layer doped with the metal material is 6% -30%, the atomic number percentage content of metal in the metal-doped magnesium oxide film layer doped with the metal material and the zinc oxide is 5% -25%, and the atomic number percentage content of zinc is not higher than 5%; the size of Mg-Zn-O compound crystal grains formed in the zinc oxide doped magnesium oxide film layer is 8nm-30nm, and the atomic number percentage content of zinc is 0.2% -8%.
The metal material doped in the metal-doped magnesium oxide film layer is gold, silver or platinum.
The thickness of the metal-doped magnesium oxide film layer is 40nm-300nm, and the thickness of the zinc oxide-doped magnesium oxide film layer is 10nm-40 nm.
And a metal buffer layer made of gold or silver is arranged between the substrate and the metal-doped magnesium oxide film layer.
The thickness of the metal buffer layer is 5nm-30 nm.
The invention relates to a preparation method of a metal and zinc oxide doped magnesium oxide secondary electron emission film, which comprises the following steps:
1) sputtering a metal target and a magnesium target or a magnesium oxide target to deposit a metal-doped magnesium oxide film layer of a pure metal-doped material on the substrate; or sputtering a metal target, a magnesium target or a magnesium oxide target and a zinc target or a zinc oxide target, and depositing a metal-doped magnesium oxide film layer co-doped with the metal material and the zinc oxide on the substrate;
2) sputtering a magnesium target or a magnesium oxide target and a zinc target or a zinc oxide target on a metal-doped magnesium oxide film layer which is only doped with a metal material or is co-doped with a metal material and zinc oxide, and depositing a zinc oxide-doped magnesium oxide film layer.
In the steps 1) and 2), when the metal-doped magnesium oxide film layer purely doped with the metal material, the metal-doped magnesium oxide film layer codoped with the metal material and zinc oxide and the zinc oxide-doped magnesium oxide film layer are deposited, the temperature of the substrate is kept between 300 and 550 ℃.
The preparation method of the film comprises the steps of firstly sputtering a gold target or a silver target, depositing a metal buffer layer on a substrate, and then sequentially depositing a metal-doped magnesium oxide film layer and a zinc oxide-doped magnesium oxide film layer on the metal buffer layer.
When the metal buffer layer is deposited, the temperature of the substrate is kept between 10 and 200 ℃.
Step 1) and step 2) when magnesium oxide and zinc oxide are deposited by adopting a magnesium target and zinc target sputtering mode, introducing argon and oxygen into a coating cavity, wherein the flow ratio of the argon to the oxygen is (8:1) - (2: 1); when the magnesium oxide and the zinc oxide are deposited by adopting a mode of sputtering a magnesium oxide target and a zinc oxide target, argon and oxygen are introduced into a film coating cavity, and the flow ratio of the argon to the oxygen is (15:1) - (9: 1).
The air pressure in the coating cavity is kept between 0.1Pa and 0.8Pa when the film is deposited.
Compared with the prior art, the invention has the following beneficial effects: the existing metal-doped magnesium oxide secondary electron emission film mainly comprises a metal-doped magnesium oxide film layer and a pure magnesium oxide film layer with a thin surface layer, wherein a metal material is only doped in the metal-doped magnesium oxide film layer or the metal material and zinc oxide are co-doped in the metal-doped magnesium oxide film layer, a zinc oxide-doped magnesium oxide film layer is arranged on the top layer, the electronic structures of the magnesium oxide and the zinc oxide-doped magnesium oxide are calculated and analyzed by utilizing a first principle pseudopotential method, and the result shows that the surface work function and the forbidden bandwidth of the zinc oxide-doped magnesium oxide are reduced compared with the magnesium oxide, and for example, the average surface work function and the forbidden bandwidth of the zinc oxide-doped magnesium oxide with 1% of atomic number of zinc are respectively reduced by about 0.5eV and 0.39 eV. In addition, experimental measurement results show that the conductivity of the film can be further improved by doping a proper amount of zinc oxide into the metal-doped magnesium oxide film. The surface layer of the film is a zinc oxide doped magnesium oxide film layer, and the Mg-Zn-O compound can be formed in the zinc oxide doped magnesium oxide film layer due to the doping of the zinc oxide, and compared with magnesium oxide, the compound has lower surface work function, so that more internal secondary electrons in the film can escape from the surface of the film to form secondary electron emission, and the secondary electron emission coefficient of the film is improved. Compared with magnesium oxide, the Mg-Zn-O compound formed in the surface layer of the film has lower forbidden bandwidth, and the size of the crystal grains of the Mg-Zn-O compound is controlled, so that the electron transport property of the surface film layer can be improved, electrons from a substrate can move to the surface of the film in the continuous secondary electron emission process of the film to neutralize the accumulated positive charges, the charging effect on the surface of the film is better inhibited, and the stability of the secondary electron emission of the film is kept. For the metal and zinc oxide co-doped magnesium oxide film consisting of the metal and zinc oxide co-doped magnesium oxide film layer and the zinc oxide doped magnesium oxide film layer, the doping of the zinc oxide can improve the conductivity of the film, so that the metal particle agglomeration phenomenon in the film preparation process can be avoided by properly reducing the doping amount of the metal on the premise of ensuring that the film has certain conductivity, the film has lower surface roughness, and the film obtains high secondary electron emission coefficient. The metal and zinc oxide co-doped magnesium oxide film has a very high secondary electron emission coefficient, so when the film is applied to an electronic device, under the condition that the secondary electron emission coefficient meets the requirement, the decomposition and etching of electron beams on magnesium oxide can be reduced by properly reducing the energy of incident electrons, the secondary electron emission attenuation of the film is slowed, and the service life of the electronic device is prolonged. In view of the above, the metal and zinc oxide co-doped magnesium oxide secondary electron emission thin film of the present invention has high secondary electron emission performance.
Drawings
FIG. 1 is a schematic view of a film structure without a metal buffer layer according to the present invention;
FIG. 2 is a schematic diagram of a film structure with a metal buffer layer according to the present invention;
FIG. 3 is a graph comparing the secondary electron emission coefficient δ of the thin film with the incident electron energy Ep;
FIG. 4 is a graph comparing the decay of the film secondary electron emission coefficient δ with the electron beam bombardment time t.
Detailed Description
The invention is described in further detail below with reference to the figures and the embodiments.
In order to further improve the electron-induced secondary electron emission performance of the existing metal-doped magnesium oxide film (generally consisting of a metal-doped magnesium oxide film layer and a pure magnesium oxide film layer with a thin surface layer), the method is adopted to dope a proper amount of zinc oxide into the film to form the metal and zinc oxide co-doped magnesium oxide film, the film mainly consists of the metal-doped magnesium oxide film layer (or the metal and zinc oxide co-doped magnesium oxide film layer) and the zinc oxide doped magnesium oxide film layer with the thin surface layer, and the film layers are sequentially deposited on a substrate by adopting a sputtering method. Because the doping of zinc oxide in the magnesium oxide on the surface layer of the film can form Mg-Zn-O compound with lower surface work function, more internal secondary electrons in the film can escape from the surface of the film to form secondary electron emission, thereby improving the secondary electron emission coefficient of the film. The Mg-Zn-O compound formed in the surface layer of the film also has lower forbidden bandwidth, and the size of the crystal grains of the Mg-Zn-O compound can be controlled to improve the electron transport property of the surface film layer, so that electrons from a substrate can move to the surface of the film to neutralize accumulated positive charges in the continuous secondary electron emission process of the film, the charging effect of the surface of the film is better inhibited, and the stability of the secondary electron emission of the film is kept. For the metal and zinc oxide co-doped magnesium oxide film consisting of the metal and zinc oxide co-doped magnesium oxide film layer and the zinc oxide doped magnesium oxide film layer, the doping of the zinc oxide can improve the conductivity of the film, so that the doping amount of the metal can be properly reduced on the premise of ensuring that the film has certain conductivity, the phenomenon of metal particle agglomeration in the preparation process of the film is avoided, the film has lower surface roughness, and the film obtains higher secondary electron emission coefficient. Because the metal and zinc oxide co-doped magnesium oxide film has a very high secondary electron emission coefficient, when the film is applied to an electronic device, the incident electron energy can be properly reduced under the condition that the secondary electron emission coefficient meets the requirement, so that the decomposition and etching of electron beams on magnesium oxide are reduced, the secondary electron emission attenuation of the film is slowed down, and the service life of the electronic device is prolonged. In summary, the present invention can improve the emission performance of secondary electrons in principle.
Example 1
Referring to fig. 1, when the metal buffer layer 4 is not provided, the metal buffer layer is composed of a gold-doped magnesium oxide film layer on the surface of the substrate 1 and a zinc oxide-doped magnesium oxide film layer 3 on the top layer, each film layer is prepared by a sputtering method, and the method specifically comprises the following steps:
1) depositing a gold-doped magnesium oxide film layer on a substrate 1 by adopting a radio-frequency sputtering magnesium target and direct-current sputtering gold target mode, keeping the temperature of the substrate 1 at 300 ℃ in the deposition process, simultaneously introducing argon and oxygen into a film coating cavity, wherein the flow ratio of the argon to the oxygen is 5:1, the total air pressure in the film coating cavity is 0.2Pa, the thickness of the deposited gold-doped magnesium oxide film layer is 100nm, and the atomic number percentage content of gold in the gold-doped magnesium oxide film layer is 30%.
2) Depositing a zinc oxide doped magnesium oxide film layer 3 on the gold doped magnesium oxide film layer by adopting a radio frequency sputtering magnesium target and zinc target mode, wherein in the deposition process, the substrate temperature is kept at 500 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 4:1, the total air pressure in the film coating cavity is 0.4Pa, the thickness of the deposited zinc oxide doped magnesium oxide film layer 3 is 40nm, the percentage content of zinc atoms is 8%, and the average size of Mg-Zn-O compound crystal grains is about 25 nm.
Example 2
Referring to fig. 1, when the metal buffer layer 4 is not arranged, the metal buffer layer is composed of a gold and zinc oxide co-doped magnesium oxide film layer positioned on the surface of a substrate 1 and a zinc oxide doped magnesium oxide film layer 3 positioned on the top layer, and each film layer is prepared by adopting a sputtering method;
the method specifically comprises the following steps:
1) depositing a gold and zinc oxide co-doped magnesium oxide film layer on a substrate 1 by adopting a radio frequency sputtering magnesium oxide target, a zinc oxide target and a direct current sputtering gold target, wherein in the deposition process, the substrate temperature is kept at 400 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 10:1, the total air pressure in a film coating cavity is 0.25Pa, the thickness of the deposited gold and zinc oxide co-doped magnesium oxide film layer is 50nm, the atomic number percentage content of gold is 15%, and the atomic number percentage content of zinc is 6%.
2) Depositing a zinc oxide doped magnesium oxide film layer 3 on the gold and zinc oxide co-doped magnesium oxide film layer by adopting a radio frequency sputtering magnesium oxide target and zinc oxide target mode, wherein in the deposition process, the substrate temperature is kept at 520 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 12:1, the total air pressure in a film coating cavity is 0.3Pa, the thickness of the deposited zinc oxide doped magnesium oxide film layer 3 is 20nm, the atomic percentage content of zinc is 4%, and the average size of Mg-Zn-O compound crystal grains is about 15 nm.
Example 3
Referring to fig. 2, the thin film structure with the metal buffer layer 4 added in the invention is composed of a gold buffer layer on the surface of a substrate 1, a gold-doped magnesium oxide film layer and a zinc oxide-doped magnesium oxide film layer 3 on the top layer, and each film layer is prepared by a sputtering method.
The preparation method specifically comprises the following steps:
1) depositing a gold buffer layer on the substrate 1 by adopting a direct current sputtering gold target mode, wherein in the deposition process, the substrate temperature is kept at 100 ℃, argon is introduced into a coating cavity, the total air pressure in the coating cavity is 0.5Pa, and the thickness of the deposited gold buffer layer is 10 nm.
2) Depositing a gold-doped magnesium oxide film layer on the gold buffer layer by adopting a radio-frequency sputtering magnesium target and a direct-current sputtering gold target, wherein in the deposition process, the substrate temperature is kept at 450 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 4:1, the total air pressure in the film coating cavity is 0.15Pa, the thickness of the deposited gold-doped magnesium oxide film layer is 200nm, and the percentage content of gold atoms in the gold-doped magnesium oxide film layer is 20%.
3) Depositing a zinc oxide doped magnesium oxide film layer 3 on the gold doped magnesium oxide film layer by adopting a radio frequency sputtering magnesium target and zinc target mode, wherein in the deposition process, the substrate temperature is kept at 450 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 6:1, the total air pressure in the film coating cavity is 0.6Pa, the thickness of the deposited zinc oxide doped magnesium oxide film layer 3 is 16nm, the percentage content of zinc atoms is 2%, and the average size of Mg-Zn-O compound crystal grains is about 8 nm.
Example 4
Referring to fig. 2, the thin film structure with the metal buffer layer 4 added in the invention is composed of a silver buffer layer on the surface of a substrate 1, a silver and zinc oxide co-doped magnesium oxide film layer and a zinc oxide doped magnesium oxide film layer 3 on the top layer, wherein each film layer is prepared by a sputtering method, and the preparation method specifically comprises the following steps:
1) depositing a silver buffer layer on the substrate 1 by adopting a direct current sputtering silver target mode, keeping the substrate temperature at 20 ℃ in the deposition process, introducing argon into a coating cavity, wherein the total air pressure in the coating cavity is 0.7Pa, and the thickness of the deposited silver buffer layer is 8 nm.
2) Depositing a silver and zinc oxide co-doped magnesium oxide film layer on a silver buffer layer by adopting a radio frequency sputtering magnesium target and a direct current sputtering silver target, wherein in the deposition process, the substrate temperature is kept at 400 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 7:1, the total air pressure in the film coating cavity is 0.5Pa, the thickness of the deposited silver and zinc oxide co-doped magnesium oxide film layer is 150nm, the atomic number percentage of the silver is 16%, and the atomic number percentage of the zinc is 3%.
3) Depositing a zinc oxide doped magnesium oxide film layer 3 on the silver and zinc oxide co-doped magnesium oxide film layer by adopting a radio frequency sputtering magnesium target and zinc target mode, wherein in the deposition process, the substrate temperature is kept at 550 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 5:1, the total air pressure in a film coating cavity is 0.4Pa, the thickness of the deposited zinc oxide doped magnesium oxide film layer 3 is 18nm, the atomic number percentage content of zinc is 3%, and the average size of Mg-Zn-O compound crystal grains is about 10 nm.
Example 5
Referring to fig. 2, the thin film structure with the metal buffer layer 4 added in the invention is composed of a gold buffer layer on the surface of a substrate 1, a platinum and zinc oxide co-doped magnesium oxide film layer and a zinc oxide doped magnesium oxide film layer 3 on the top layer, each film layer is prepared by a sputtering method, and the preparation method specifically comprises the following steps:
1) depositing a gold buffer layer on the substrate 1 by adopting a direct current sputtering gold target mode, wherein in the deposition process, the substrate temperature is kept at 30 ℃, argon is introduced into a coating cavity, the total air pressure in the coating cavity is 0.7Pa, and the thickness of the deposited gold buffer layer is 8 nm.
2) Depositing a platinum and zinc oxide co-doped magnesium oxide film layer on a gold buffer layer by adopting a radio frequency sputtering magnesium target, a zinc target and a direct current sputtering platinum target, wherein in the deposition process, the substrate temperature is kept at 420 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 7:1, the total air pressure in a film coating cavity is 0.5Pa, the thickness of the deposited platinum and zinc oxide co-doped magnesium oxide film layer is 150nm, the atomic number percentage content of platinum is 10%, and the atomic number percentage content of zinc is 7%.
3) Depositing a zinc oxide doped magnesium oxide film layer 3 on a platinum and zinc oxide co-doped magnesium oxide film layer by adopting a radio frequency sputtering magnesium target and zinc target mode, wherein in the deposition process, the substrate temperature is kept at 510 ℃, argon and oxygen are simultaneously introduced into a film coating cavity, the flow ratio of the argon to the oxygen is 5:1, the total air pressure in a film coating cavity is 0.35Pa, the thickness of the deposited zinc oxide doped magnesium oxide film layer 3 is 25nm, the atomic number percentage content of zinc is 4%, and the average size of Mg-Zn-O compound crystal grains is about 15 nm.
Referring to fig. 3, comparing the curves of the secondary electron emission coefficient δ of the gold-doped magnesium oxide thin film (the percentage of atomic number of zinc in the surface layer of the thin film is 1%) and the secondary electron emission coefficient δ of the gold-doped magnesium oxide thin film changing with the incident electron energy Ep prepared by the secondary electron emission thin film preparation method disclosed by the invention and reported in the literature, it can be seen that the gold-doped magnesium oxide thin film and the zinc oxide co-doped magnesium oxide thin film have higher secondary electron emission coefficients, especially under the bombardment of incident electrons with higher energy.
Referring to fig. 4, comparing the curves of the gold and zinc oxide co-doped magnesium oxide thin film (the percentage of atomic number of zinc in the surface layer of the thin film is 1%) prepared by the secondary electron emission thin film preparation method disclosed by the present invention and reported in the literature and the secondary electron emission coefficient delta of the gold-doped magnesium oxide thin film decaying with the electron beam bombardment time t under the bombardment of the electron beam with the same energy, it can be seen that the gold and zinc oxide co-doped magnesium oxide thin film always has a higher secondary electron emission coefficient with the increase of the incident electron bombardment time. Compared with the gold-doped magnesium oxide film, the gold and zinc oxide co-doped magnesium oxide film works with a higher secondary electron emission coefficient, so that positive charges can be generated on the surface of the gold-doped magnesium oxide film at a higher speed, but the secondary electron emission attenuation of the gold-doped magnesium oxide film is not accelerated. The result shows that the gold and zinc oxide co-doped magnesium oxide film has better secondary electron emission attenuation performance.
It can be seen from the above specific examples and the related descriptions that, compared with the existing secondary electron emission material, the metal and zinc oxide co-doped magnesium oxide film of the present invention has a higher secondary electron emission coefficient and a better secondary electron emission attenuation performance under the bombardment of electron beams with a larger beam density due to the lower surface work function, better electron transport property, and the like.
Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited thereto. The invention is not limited to the scheme, and belongs to the protection scope of the invention as long as the metal and zinc oxide co-doped magnesium oxide composite film structure and the corresponding film preparation method are adopted according to the basic concept of the invention to improve the electron-induced secondary electron emission performance of the magnesium oxide film and achieve the purpose of enabling the film to obtain higher secondary electron emission coefficient and emission stability.
Claims (4)
1. A metal and zinc oxide doped magnesium oxide secondary electron emission film is characterized in that: comprises a substrate (1), and a zinc oxide doped magnesium oxide film layer (3) and a metal doped magnesium oxide film layer (2) which are sequentially arranged on the substrate (1) from top to bottom;
the metal-doped magnesium oxide film layer (2) is co-doped with a metal material and zinc oxide, wherein the metal atom percentage content of the metal-doped magnesium oxide film layer (2) which is co-doped with the metal material and the zinc oxide is 5-25%, and the atom percentage content of the zinc is not higher than 5%; the size of Mg-Zn-O compound crystal grains formed in the zinc oxide doped magnesium oxide film layer (3) is 8-30 nm, and the atomic number percentage of zinc is 0.2-8%; the thickness of the metal-doped magnesium oxide film layer (2) is 40nm-300nm, and the thickness of the zinc oxide-doped magnesium oxide film layer (3) is 10nm-40 nm; a metal buffer layer (4) made of gold or silver is arranged between the substrate (1) and the metal-doped magnesium oxide film layer (2); the thickness of the metal buffer layer (4) is 5nm-30 nm.
2. The metal and zinc oxide doped magnesium oxide secondary electron emission film of claim 1, wherein: the metal material doped in the metal-doped magnesium oxide film layer (2) is gold, silver or platinum.
3. A method for preparing a metal-and-zinc oxide-doped magnesium oxide secondary electron emission thin film as claimed in any one of claims 1 to 2, comprising the steps of:
1) sputtering a metal target and a magnesium target or a magnesium oxide target and a zinc target or a zinc oxide target, and depositing a metal-doped magnesium oxide film layer (2) which codope a metal material and zinc oxide on the substrate (1);
2) sputtering a magnesium target or a magnesium oxide target and a zinc target or a zinc oxide target on the metal-doped magnesium oxide film layer (2) co-doped with the metal material and the zinc oxide to deposit a zinc oxide-doped magnesium oxide film layer (3);
step 1) and step 2) are carried out, when a metal-doped magnesium oxide film layer (2) codoped with metal materials and zinc oxide and a zinc oxide-doped magnesium oxide film layer (3) are deposited, the temperature of the substrate (1) is kept between 300 ℃ and 550 ℃;
firstly sputtering a gold target or a silver target, depositing a metal buffer layer (4) on a substrate (1), and then sequentially depositing a metal-doped magnesium oxide film layer (2) and a zinc oxide-doped magnesium oxide film layer (3) on the metal buffer layer (4), wherein the temperature of the substrate (1) is kept at 10-200 ℃ during the deposition of the metal buffer layer (4).
4. The production method according to claim 3, characterized in that: when the magnesium oxide and the zinc oxide are deposited by adopting a magnesium target and zinc target sputtering mode, introducing argon and oxygen into a coating cavity, wherein the flow ratio of the argon to the oxygen is (8:1) - (2: 1); when the magnesium oxide and the zinc oxide are deposited by adopting a mode of sputtering a magnesium oxide target and a zinc oxide target, introducing argon and oxygen into a coating cavity, wherein the flow ratio of the argon to the oxygen is (15:1) - (9: 1); the air pressure in the coating cavity is kept between 0.1Pa and 0.8Pa when the film is deposited.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103789730A (en) * | 2014-01-16 | 2014-05-14 | 西安交通大学 | Preparation method of secondary-electron emission thin film |
| CN104599923A (en) * | 2015-01-12 | 2015-05-06 | 西安交通大学 | MgO/ ZnO composite medium protecting film and preparation method thereof |
| CN106637079A (en) * | 2016-12-02 | 2017-05-10 | 西安交通大学 | Buffer layer of secondary electron emission film and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103789730A (en) * | 2014-01-16 | 2014-05-14 | 西安交通大学 | Preparation method of secondary-electron emission thin film |
| CN104599923A (en) * | 2015-01-12 | 2015-05-06 | 西安交通大学 | MgO/ ZnO composite medium protecting film and preparation method thereof |
| CN106637079A (en) * | 2016-12-02 | 2017-05-10 | 西安交通大学 | Buffer layer of secondary electron emission film and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| Influence of the deposition temperature on electronic transport and structural properties of radio frequency magnetron-sputtered Zn1-xMgxO:Al and ZnO:Al films;André Bikowski等;《Journal of Materials Research》;20120914;第27卷(第17期);第2249-2256页 * |
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