阅读说明：本技术 一种电子束发散角测量装置及其制备方法和测量方法 (Electron beam divergence angle measuring device and preparation method and measuring method thereof ) 是由 马玉田 刘俊标 韩立 赵伟霞 王鹏飞 于 2020-04-15 设计创作，主要内容包括：本发明公开一种电子束发散角测量装置及其制备方法和测量方法,包括荧光屏和钨微纳米图形,六羰基钨通过氦离子显微镜沉积在所述荧光屏上形成所述钨微纳米图形,所述钨微纳米图形为多个同心圆,同心圆的圆心位于所述荧光屏的中心处。利用氦离子显微镜离子辅助沉积,在荧光屏上构建钨微纳米图形,移动荧光屏时,电子束打在荧光屏的斑点形状及其大小将会发生变化,依据钨微纳米图形的尺寸和大小直接测量电子束束斑和电子束发散角。该装置具有多功能、测量精度高、操作简单等优点；制备方法具有精度高、易控制、工艺简单等优点。(The invention discloses an electron beam divergence angle measuring device and a preparation method and a measuring method thereof. The method comprises the steps of utilizing helium ion microscope ions to assist deposition, constructing a tungsten micro-nano pattern on a fluorescent screen, changing the shape and the size of spots of an electron beam on the fluorescent screen when the fluorescent screen is moved, and directly measuring the beam spot and the divergence angle of the electron beam according to the size and the size of the tungsten micro-nano pattern. The device has the advantages of multiple functions, high measurement precision, simple operation and the like; the preparation method has the advantages of high precision, easy control, simple process and the like.)

1. An electron beam divergence angle measuring apparatus characterized in that: the tungsten hexacarbonyl micro-nano pattern is deposited on the fluorescent screen through a helium ion microscope to form the tungsten micro-nano pattern, the tungsten micro-nano pattern is a plurality of concentric circles, and the center of each concentric circle is located at the center of the fluorescent screen.

2. The electron beam divergence angle measuring apparatus according to claim 1, characterized in that: the shape of the fluorescent screen is square, the side length of the fluorescent screen is 20-30mm, and the thickness of the fluorescent screen is 1-3 mm.

3. The electron beam divergence angle measuring apparatus according to claim 2, characterized in that: the side length of the fluorescent screen is 25mm, and the thickness is 2 mm.

4. The electron beam divergence angle measuring apparatus according to claim 1, characterized in that: the tungsten wire obtained by tungsten hexacarbonyl deposition is cylindrical and has the diameter of 50-150 nm; the concentric circles are formed by the tungsten wires.

5. The electron beam divergence angle measuring apparatus according to claim 4, characterized in that: the diameter of the tungsten wire is 100 nm.

6. The electron beam divergence angle measuring apparatus according to claim 4, characterized in that: the minimum radius of a circle in a plurality of concentric circles of the tungsten micro-nano graph is 10 micrometers, and the maximum radius is 150 micrometers; the radius interval between two adjacent concentric circles is 10-20 μm.

7. The electron beam divergence angle measuring apparatus according to claim 1, characterized in that: the ion auxiliary deposition function of the helium ion microscope adopts a helium ion source, the accelerating voltage is 25-30kV, and the beam current is 5-10 pA.

8. A method of manufacturing an electron beam divergence angle measuring apparatus for manufacturing the electron beam divergence angle measuring apparatus according to any one of claims 1 to 7, comprising the steps of:

1) cleaning the surface of the fluorescent screen: placing the fluorescent screen in a helium ion microscope, and cleaning with ions for 3-5 minutes when the vacuum is pumped to below 10-3Pa to remove oxides and pollutants on the surface of the fluorescent screen;

2) preparing a tungsten micro-nano pattern: after the fluorescent screen is cleaned, the helium ion microscope is operated under the conditions that the acceleration voltage is 25-30kV, the beam current is 5-10pA, the center position of the fluorescent screen is taken as the center of a circle, and a helium ion source is adopted to deposit tungsten hexacarbonyl with the diameter of 50-150nm according to concentric circles with the minimum radius of 10 mu m, the maximum radius of 150 mu m and the radius interval of 10-20 mu m, so that the electron beam divergence angle measuring device is obtained.

9. A method of measuring an electron beam divergence angle, applied to the electron beam divergence angle measuring apparatus according to any one of claims 1 to 7, characterized by comprising the steps of:

adjusting the spot position of an electron beam on a fluorescent screen to be in the center position of the fluorescent screen, measuring and reading the spot size by a tungsten micro-nano graphic scale of the fluorescent screen, adopting a nano workpiece stage to move the fluorescent screen back and forth along the incident direction of the electron beam, reading the moving distance by the step pitch of the workpiece stage, measuring the spot size of the electron beam on the fluorescent screen by the tungsten micro-nano graphic scale of the fluorescent screen, calculating the ratio of the change value of the spot size to the moving distance of the fluorescent screen, wherein the ratio is the tangent value of the divergence angle of the electron beam, and calculating the divergence angle of the electron beam by the tangent value of a trigonometric function.

Technical Field

The invention relates to the technical field of electron beam divergence angle measurement, in particular to an electron beam divergence angle measuring device and a preparation method and a measuring method thereof.

Background

The reflection-type high-energy electron diffractometer (RHEED) mainly consists of an electron gun and a fluorescent screen, and is a powerful in-situ analysis and monitoring means in the surface science and atomic-level artificial synthetic material engineering at present. In order to improve the resolution of electron diffraction, the divergence angle of the electron beam is required to be relatively high, and is generally less than 0.1 mrad. Conventional methods for measuring the divergence angle of an electron beam include a fluorescent screen method, a multi-slit method, a single slit scanning method, a pepper-hole method, and the like, but these methods have poor measurement accuracy. At present, the more advanced method is a cerenkov radiation method, for example, the cerenkov radiation method is introduced in the document "research on the advanced measurement method of high-brightness electron beam divergence, beam length and beam spot (doctor thesis, 2008) of the university of qing" and the patent "a measurement device and measurement method for electron beam divergence angle distribution (CN 106970411A)" for measuring the electron beam divergence angle, but the measurement method has extremely high requirements for the collimation of an experimental device, has the problems of complex system adjustment, difficult development on the measurement site and the like, and is not suitable for the measurement of the electron beam divergence angle of a reflection-type high-energy electron diffractometer.

Disclosure of Invention

The invention aims to provide an electron beam divergence angle measuring device, a preparation method and a measuring method thereof, which are used for solving the problems in the prior art, and micro-nano patterns are constructed on a fluorescent screen by adopting a micro-nano processing technology, so that the electron beam divergence angle can be measured, parameters such as electron beam spot and the like can also be measured, and the electron beam divergence angle measuring device has the advantages of multiple functions, high measuring precision, simplicity in operation and the like; the preparation method has the advantages of high precision, easy control, simple process and the like.

In order to achieve the purpose, the invention provides the following scheme: the invention provides an electron beam divergence angle measuring device which comprises a fluorescent screen and a tungsten micro-nano graph, wherein tungsten hexacarbonyl is deposited on the fluorescent screen through a helium ion microscope to form the tungsten micro-nano graph, the tungsten micro-nano graph is a plurality of concentric circles, and the center of each concentric circle is located at the center of the fluorescent screen.

Preferably, the phosphor screen is square in shape, with a side length of 20-30mm and a thickness of 1-3 mm.

Preferably, the side length of the phosphor screen is 25mm and the thickness is 2 mm.

Preferably, the tungsten wire obtained by tungsten hexacarbonyl deposition is cylindrical in shape and has the diameter of 50-150 nm; the concentric circles are formed by the tungsten wires.

Preferably, the tungsten wire has a diameter of 100 nm.

Preferably, the minimum radius of a circle in a plurality of concentric circles of the tungsten micro-nano graph is 10 micrometers, and the maximum radius is 150 micrometers; the radius interval between two adjacent concentric circles is 10-20 μm.

Preferably, the ion-assisted deposition function of the helium ion microscope adopts a helium ion source, the acceleration voltage is 25-30kV, and the beam current is 5-10 pA.

The invention also discloses a preparation method of the electron beam divergence angle measuring device, which comprises the following steps:

1) cleaning the surface of the fluorescent screen: placing the fluorescent screen in a helium ion microscope, and cleaning with ions for 3-5 minutes when the vacuum is pumped to below 10-3Pa to remove oxides and pollutants on the surface of the fluorescent screen;

2) preparing a tungsten micro-nano pattern: after the fluorescent screen is cleaned, the helium ion microscope is operated under the conditions that the acceleration voltage is 25-30kV, the beam current is 5-10pA, the center position of the fluorescent screen is taken as the center of a circle, and a helium ion source is adopted to deposit tungsten hexacarbonyl with the diameter of 50-150nm according to concentric circles with the minimum radius of 10 mu m, the maximum radius of 150 mu m and the radius interval of 10-20 mu m, so that the electron beam divergence angle measuring device is obtained.

The invention also provides a method for measuring the divergence angle of the electron beam, which is applied to the device for measuring the divergence angle of the electron beam and comprises the following steps:

adjusting the spot position of an electron beam on a fluorescent screen to be in the center position of the fluorescent screen, measuring and reading the spot size by a tungsten micro-nano graphic scale of the fluorescent screen, adopting a nano workpiece stage to move the fluorescent screen back and forth along the incident direction of the electron beam, reading the moving distance by the step pitch of the workpiece stage, measuring the spot size of the electron beam on the fluorescent screen by the tungsten micro-nano graphic scale of the fluorescent screen, calculating the ratio of the change value of the spot size to the moving distance of the fluorescent screen, wherein the ratio is the tangent value of the divergence angle of the electron beam, and calculating the divergence angle of the electron beam by the tangent value of a trigonometric function.

Compared with the prior art, the invention has the following technical effects:

the electron beam divergence angle measuring device of the reflection-type high-energy electron diffractometer utilizes helium ion microscope ions to assist deposition, a tungsten micro-nano graph is constructed on a fluorescent screen, the shape and the size of spots of an electron beam on the fluorescent screen are changed when the fluorescent screen is moved, and the beam spot and the electron beam divergence angle of the electron beam are directly measured according to the size and the size of the micro-nano graph. The device has the advantages of multiple functions, high measurement precision, simple operation and the like; the preparation method has the advantages of high precision, easy control, simple process and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic view of an overall structure of an electron beam divergence angle measuring apparatus;

FIG. 2 is a cross-sectional view of a tungsten wire forming a tungsten micro-nano pattern;

wherein, 1a fluorescent screen; 201 tungsten micro-nano graph; 202 tungsten wire; 203 the center position of the screen.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide an electron beam divergence angle measuring device, a preparation method and a measuring method thereof, which are used for solving the problems in the prior art, and micro-nano patterns are constructed on a fluorescent screen by adopting a micro-nano processing technology, so that the electron beam divergence angle can be measured, parameters such as electron beam spot and the like can also be measured, and the electron beam divergence angle measuring device has the advantages of multiple functions, high measuring precision, simplicity in operation and the like; the preparation method has the advantages of high precision, easy control, simple process and the like.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.