Electron detection device, method and electron microscope

Abstract

The application discloses an electron detecting device, method and electron microscope, wherein the electron detecting device comprises: a first opening angle adjusting component, a second opening angle adjusting component and a detector arranged in sequence along an electron beam movement path; the first opening angle adjusting component is used for adjusting the divergence degree of backscattered electrons and secondary electrons passing through the first opening angle adjusting component; the second opening angle adjusting component is used for adjusting the divergence degree of secondary electrons passing through the second opening angle adjusting component; the detector is used for detecting electrons; and a controller is electrically connected with the first opening angle adjusting component and the second opening angle adjusting component respectively and used for adjusting the voltage of the first opening angle adjusting component and the second opening angle adjusting component, so as to adjust the divergence angle of the backscattered electrons and the secondary electrons, so that the detector detects the backscattered electrons or the secondary electrons alone. The application can adjust the divergence degree of the backscattered electrons and the secondary electrons, so that the detector only detects the backscattered electrons or the secondary electrons.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of scanning electron microscopy, and particularly relates to an electron detection device and method and electron microscope. BACKGROUND

[0002] Modern low-voltage scanning electron microscopes (LV-SEM) use a focused electron beam to scan the surface of a sample for imaging and characterization analysis, and can be used for sample surface or cross-section observation in many fields. The interaction of the electron beam with the sample will produce signal electrons such as SE (Secondary Electron) and BSE (Backscattered Electron). The energy of the secondary electrons is about 0-50 eV, and the energy of the backscattered electrons is about 50 eV or more.

[0003] Secondary electrons can reflect information about the surface topography of the sample, and backscattered electrons can reflect information about the composition and crystal structure of the sample. At the same time, different energies of backscattered electrons carry different types of information. For example, backscattered electrons produced by complete elastic scattering on the sample surface have almost no energy loss, and contain not only composition information but also surface topography structure information. Therefore, the goal of the signal detector of the electron microscope is to fully distinguish different types / energies of signal electrons, improve the separation degree of different types / energies of signal electrons, and at the same time improve the collection efficiency (collect as many signal electrons as possible) to improve the signal analysis capability and efficiency.

[0004] If a conventional electron microscope needs to detect different types of electrons such as secondary electrons or backscattered electrons, it needs to design a plurality of complex detectors, and use a plurality of detectors and an energy filter to separate and receive backscattered and secondary electrons. However, the calibration between the plurality of detectors is complex, which reduces the reliability of the device and also leads to an increase in the cost of the overall detection system. SUMMARY

[0005] Therefore, the present application provides an electron detection device and method and electron microscope to solve the problems of poor stability and high cost of the existing electron microscope.

[0006] To solve the above technical problems, one technical solution of the present application is to provide an electronic detection device, which comprises: a first opening angle adjusting component, a second opening angle adjusting component and a detector arranged in sequence along the path of an electron beam; the first opening angle adjusting component is used to adjust the divergence degree of backscattered electrons and secondary electrons passing through the first opening angle adjusting component; the second opening angle adjusting component is used to adjust the divergence degree of secondary electrons passing through the second opening angle adjusting component; the detector is used to detect electrons; and a controller is electrically connected with the first opening angle adjusting component and the second opening angle adjusting component respectively, and is used to adjust the voltage of the first opening angle adjusting component and the second opening angle adjusting component, so as to adjust the divergence angle of backscattered electrons and secondary electrons, so that the detector can detect backscattered electrons or secondary electrons alone.

[0007] As a further improvement of the present application, when the first opening angle adjusting component adjusts backscattered electrons and secondary electrons to be in a concentrated state, the second opening angle adjusting component diverges the secondary electrons in the concentrated state; and when the first opening angle adjusting component adjusts backscattered electrons and secondary electrons to be in a divergent state, the second opening angle adjusting component converges the secondary electrons in the divergent state.

[0008] As a further improvement of the present application, the detector is arranged in a ring shape and is provided with a central hole in the center for the concentrated electrons to pass through, so that the detector can detect secondary electrons when backscattered electrons are concentrated and secondary electrons are diverged, or detect backscattered electrons when backscattered electrons are diverged and secondary electrons are concentrated.

[0009] As a further improvement of the present application, the second opening angle adjusting component comprises a layer of grid electrodes.

[0010] As a further improvement of the present application, the second opening angle adjusting component comprises three layers of grid electrodes, and the grid electrodes of the upper and lower layers are arranged with the same voltage, and the grid electrodes of the middle layer are adjustable in voltage.

[0011] As a further improvement of the present application, the first opening angle adjusting component comprises a ring electrode.

[0012] To solve the above technical problems, another technical solution of the present application is to provide an electron detection method, which is applied to one of the above-mentioned electron detection devices, and the electron detection device includes a first opening angle adjusting component, a second opening angle adjusting component, a detector and a controller; the method includes: the controller receives an externally input control instruction; when the control instruction is to detect backscattered electrons, the controller adjusts the voltage of the first opening angle adjusting component so that the backscattered electrons and the secondary electrons are in a divergent state, and then adjusts the voltage of the second opening angle adjusting component to concentrate the secondary electrons in the divergent state, so that the secondary electrons pass through the central hole of the detector, and the backscattered electrons are detected by the detector; when the control instruction is to detect secondary electrons, the controller adjusts the voltage of the first opening angle adjusting component so that the backscattered electrons and the secondary electrons are in a concentrated state, and then adjusts the voltage of the second opening angle adjusting component to diverge the secondary electrons in the concentrated state, so that the backscattered electrons pass through the central hole of the detector, and the secondary electrons are detected by the detector.

[0013] To solve the above technical problems, another technical solution of the present application is to provide an electron detection method, which is applied to one of the above-mentioned electron detection devices, and the electron detection device includes a first opening angle adjusting component, a second opening angle adjusting component, a detector and a controller; the method includes: the controller receives an externally input control instruction; when the control instruction is to detect backscattered electrons, the controller adjusts the voltage of the first opening angle adjusting component so that the backscattered electrons and the secondary electrons are in a divergent state, and then adjusts the voltage of the second opening angle adjusting component to concentrate the secondary electrons in the divergent state, so that the secondary electrons pass through the central hole of the detector, and the backscattered electrons are detected by the detector; when the control instruction is to detect secondary electrons, the controller adjusts the voltage of the first opening angle adjusting component so that the backscattered electrons and the secondary electrons are in a concentrated state, and then adjusts the voltage of the second opening angle adjusting component to diverge the secondary electrons in the concentrated state, so that the backscattered electrons pass through the central hole of the detector, and the secondary electrons are detected by the detector.

[0014] As a further improvement of the present application, the second opening angle adjusting component includes three layers of grid electrodes, and the voltages of the upper and lower grid electrodes are the same as the voltage of the lens barrel, and the voltage of the middle layer of grid electrodes is adjustable.

[0015] As a further improvement of the present application, the controller of the electron detection device is also used to control the electron detection device to work at a preset objective lens current, and the preset objective lens current is calculated by the controller based on the current and voltage parameters of all components in the lens barrel, and under the preset objective lens current, the beam spot of the electron beam on the sample surface is the smallest.

[0016] The beneficial effects of the present application are:

[0017] The electronic detection device of the present application separates backscattered electrons and secondary electrons by setting a first opening angle adjusting component and a second opening angle adjusting component, adjusting the divergence degree of backscattered electrons and secondary electrons passing through the first opening angle adjusting component by the first opening angle adjusting component, so that the backscattered electrons and secondary electrons are in a divergent state or a concentrated state, adjusting the divergence degree of secondary electrons by the second opening angle adjusting component, adjusting the secondary electrons in the divergent state to the concentrated state or adjusting the secondary electrons in the concentrated state to the divergent state, so that the divergence degrees of the backscattered electrons and secondary electrons are different, thereby separating the backscattered electrons and secondary electrons, and finally detecting the backscattered electrons or secondary electrons by a detector, which can detect the backscattered electrons and secondary electrons by a single detector, without the need for calibration between multiple detectors, and the structure is more simplified, reducing the production cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of an embodiment of the electronic detection device of the present application;

[0019] Figure 2 is a schematic diagram of detecting secondary electrons of an embodiment of the electronic detection device of the present application;

[0020] Figure 3 is a schematic diagram of detecting backscattered electrons of an embodiment of the electronic detection device of the present application;

[0021] Figure 4 is a structural schematic diagram of the second opening angle adjusting component of an embodiment of the electronic detection device of the present application;

[0022] Figure 5 is a flowchart of an embodiment of the electronic detection method of the present application;

[0023] Figure 6 is a structural schematic diagram of an embodiment of the electron microscope of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] The terms "first", "second", "third", etc. in the present application are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative spatial position, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0026] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to one of skill in the art, embodiments described herein can be combined with other embodiments.

[0027] Figure 1 is a structural schematic diagram of an electronic detection device according to an embodiment of the present application. As shown in Figure 1 , the electronic detection device includes a first opening angle adjusting component 1, a second opening angle adjusting component 2, a detector 3, and a controller (not shown in the figure). The first opening angle adjusting component 1, the second opening angle adjusting component 2, and the detector 3 are sequentially arranged along an electron beam movement path, and the electron beam movement path is shown by the arrow 1 in the figure.

[0028] It should be noted that the exit energy of secondary electrons is about 0-50 eV, and the movement speed is relatively low, the exit energy of backscattered electrons is about 50 eV or more, and the movement speed is relatively high, and there is a relatively obvious energy difference and speed difference between the two. According to the action law of electrostatic field on charged particles, the deflection degree of the movement trajectory of electrons depends on the electric field strength and the electron speed. Therefore, the first opening angle adjusting component 1 and the second opening angle adjusting component 2 are used to adjust the deflection degree of the movement trajectory of backscattered electrons and secondary electrons in the present embodiment, so as to adjust the divergence degree of backscattered electrons and secondary electrons.

[0029] The first opening angle adjusting component 1 is used to adjust the divergence degree of the backscattered electrons and the secondary electrons passing through the first opening angle adjusting component 1.

[0030] Specifically, in order to better control the divergence degree of the backscattered electrons and the secondary electrons, the first opening angle adjusting component 1 is used to generate a radial divergence electric field perpendicular to the electron motion path. Under the influence of the radial divergence electric field, the backscattered electrons and the secondary electrons are subjected to electrostatic force in the radial direction, so that the motion trajectory of the backscattered electrons and the secondary electrons can be deflected in the radial direction, and the divergence degree of the backscattered electrons and the secondary electrons in the radial direction is adjusted.

[0031] Further, in order to form the radial divergence electric field, the first opening angle adjusting component 1 comprises a ring electrode.

[0032] The second opening angle adjusting component 2 is used to adjust the divergence degree of the secondary electrons passing through the second opening angle adjusting component 2.

[0033] Specifically, the second opening angle adjusting component 2 is used to generate an axisymmetric electric field to form a weak electrostatic lens. For the secondary electrons with low energy, the focal length is short, and strong focusing is formed, so that the divergence angle of the secondary electrons can be significantly changed. For the backscattered electrons with high energy, the focal length is long, and weak focusing is formed, and the motion trajectory almost does not change. Therefore, the second opening angle adjusting component 2 only affects the divergence degree of the secondary electrons.

[0034] Specifically, in order to separate the secondary electrons and the backscattered electrons, as shown in Figure 2 and Figure 3 When the first opening angle adjusting component 1 adjusts the backscattered electrons and the secondary electrons to be in a concentrated state, the second opening angle adjusting component 2 diverges the secondary electrons in the concentrated state. When the first opening angle adjusting component 1 adjusts the backscattered electrons and the secondary electrons to be in a divergent state, the second opening angle adjusting component 2 concentrates the secondary electrons in the divergent state.

[0035] The detector 3 is used to detect the electrons.

[0036] Specifically, the detector 3 is used to detect the secondary electrons in the divergent state, and does not detect the backscattered electrons in the concentrated state, or is used to detect the backscattered electrons in the divergent state, and does not detect the secondary electrons in the concentrated state.

[0037] The controller is electrically connected with the first opening angle adjusting component 1 and the second opening angle adjusting component 2 respectively, and is used to adjust the voltage of the first opening angle adjusting component 1 and the second opening angle adjusting component 2, so as to adjust the divergence angle of the backscattered electrons and the secondary electrons, so that the detector 3 detects the backscattered electrons or the secondary electrons alone.

[0038] Specifically, the controller is configured to adjust the voltage when the first and second angular adjustment components are powered on, so as to change the electric field intensity of the first and second angular adjustment components, and change the divergence degree of the backscattered electrons and secondary electrons by using the changed electric field intensity.

[0039] The electronic detection device of the embodiment separates the backscattered electrons and secondary electrons by adjusting the divergence degree of the backscattered electrons and secondary electrons by using the first angular adjustment component, and changing the divergence degree of the secondary electrons by using the second angular adjustment component, so that the backscattered electrons and secondary electrons are in different emission states, and then detects the backscattered electrons or secondary electrons by using the detector 3. The single detector 3 can be used to detect the backscattered electrons and secondary electrons respectively, without the need for calibration between multiple detectors 3, and the structure is more compact, reducing the production cost.

[0040] Further, in order to improve the detection efficiency, on the basis of the above embodiment, in other embodiments, the detector 3 is arranged in a ring shape and is provided with a central hole at the center for the concentrated state of the electrons to pass through, so that when the first angular adjustment component adjusts the backscattered electrons and secondary electrons to be in the concentrated state, the second angular adjustment component diverges the secondary electrons in the concentrated state, and the detector 3 detects the secondary electrons, or when the first angular adjustment component adjusts the backscattered electrons and secondary electrons to be in the divergent state, the second angular adjustment component converges the secondary electrons in the divergent state, and the detector 3 detects the backscattered electrons.

[0041] In the embodiment, by using the ring-shaped detector 3 and the central hole at the center, when the first angular adjustment component adjusts the backscattered electrons and secondary electrons to be in the concentrated state, the second angular adjustment component diverges the secondary electrons in the concentrated state, and the diverged secondary electrons are detected by the ring-shaped detector 3, while the backscattered electrons in the concentrated state pass through the central hole, so that a pure secondary electron imaging diagram is obtained; or when the first angular adjustment component adjusts the backscattered electrons and secondary electrons to be in the divergent state, the second angular adjustment component converges the secondary electrons in the divergent state, and the diverged backscattered electrons are detected by the ring-shaped detector 3, while the secondary electrons in the concentrated state pass through the central hole, so that a pure backscattered electron imaging diagram is obtained.

[0042] It should be noted that due to the limitations of materials, processes, and assembly, the central aperture of the annular detector 3 is usually in the order of millimeters, and the hole is relatively large compared to the electron. If the divergence angle of the secondary electron is not adjusted, a large number of secondary electrons will pass through the hole and be missed, especially the secondary electrons reflecting the high aspect ratio information. In the embodiment, by setting the second angular adjustment component 2, the divergence angle of the secondary electron can be effectively adjusted, thereby reducing the loss rate of the secondary electron in the central hole when detecting the secondary electron, thereby improving the detection efficiency.

[0043] Further, in some embodiments, as shown in Figure 4 The second angular adjustment component 2 includes three layers of grid electrodes, and the grid electrodes of the upper and lower layers have the same voltage setting, and the grid electrode of the middle layer has adjustable voltage.

[0044] Specifically, in order to avoid the influence of the electric field formed by the grid electrode on other components, as shown in Figure 4 The second angular adjustment component 2 is designed as three layers of grid electrodes, wherein the upper and lower layers of grid electrodes have the same voltage setting and the same as the reference voltage of the working environment of the electron detection device, and the voltage of the middle layer of grid electrode is adjustable, so that a shielding space is formed by the upper and lower layers of grid electrodes, and the voltage change of the middle layer of grid electrode does not affect the work of other components.

[0045] It should be noted that compared with the traditional energy filter, the grid electrode of the embodiment cancels the metal shielding tube penetrating the hole on the grid electrode, thereby allowing the electric field to penetrate and forming a weak electrostatic lens.

[0046] Further, in some other embodiments, the second angular adjustment component 2 includes a layer of grid electrode.

[0047] Figure 5 The flowchart of the electron detection method of the embodiment of the application is shown. The electron detection method is applied to the electron detection device of one of the above embodiments, wherein the electron detection device includes a first angular adjustment component, a second angular adjustment component, a detector, and a controller. The electron detection method includes:

[0048] Step S1: The controller receives an externally input control instruction. When the control instruction is to detect backscattered electrons, step S2 is performed; when the control instruction is to detect secondary electrons, step S3 is performed.

[0049] Step S2: The controller adjusts the voltage of the first angular adjustment component so that the backscattered electrons and the secondary electrons are in a divergent state, and then adjusts the voltage of the second angular adjustment component to concentrate the secondary electrons in the divergent state, so that the secondary electrons pass through the central hole of the detector, and the backscattered electrons are detected by the detector.

[0050] Step S3: the controller adjusts the voltage of the first angular adjustment component so that the backscattered electrons and the secondary electrons are in a concentrated state, and then adjusts the voltage of the second angular adjustment component to diverge the secondary electrons in the concentrated state, so that the backscattered electrons pass through the central hole of the detector and the secondary electrons are detected by the detector.

[0051] Specifically, the embodiment executes the backscattered electron detection mode or the secondary electron detection mode through the control instruction input by the user, detects the backscattered electrons by using the electron detection device in the backscattered electron detection mode, generates a pure backscattered electron image by using the backscattered electrons, detects the secondary electrons by using the electron detection device in the secondary electron detection mode, and generates a pure secondary electron image by using the secondary electrons, so that different modes can be used for work according to the needs of the user.

[0052] Figure 6 The structural schematic diagram of the electron microscope of the embodiment of the application is shown. Figure 6 As shown in the figure, the electron microscope includes an electron source 10, a lens barrel 20, a sample stage 30, and the electron detection device 40 of one of the above embodiments, which includes the first angular adjustment component 1, the second angular adjustment component 2, the detector 3, and the controller (not shown in the figure).

[0053] The electron source 10 is used to generate an electron beam. The emission mode of the electron source 10 can be one of thermal emission, hot field emission, or cold field emission.

[0054] The objective lens 50 is arranged at the bottom end of the lens barrel 20. The objective lens 50 is used to focus the electron beam onto the sample, and can be one of a magnetic lens, an electric lens, or an electromagnetic composite lens.

[0055] The sample stage 30 is arranged in the space outside the bottom end of the lens barrel 20 and is used to carry the sample.

[0056] The first angular adjustment component 1 of the electron detection device 40 is arranged between the objective lens 50 and the sample stage 30, and the second angular adjustment component 2 and the detector 3 of the electron detection device 40 are arranged in the lens barrel 20.

[0057] Specifically, due to the existence of the retarding voltage, in the embodiment, the second angular adjustment component 2 and the detector 3 of the electron detection device 40 are arranged in the lens barrel 20. After the secondary electrons and the backscattered electrons are sucked back into the lens barrel 20 by the retarding voltage, they are again converged and diverged by the objective lens 50, so that the electron beam flows upward (the flight direction is shown by the arrow in the figure). Figure 6

[0058] ​In the embodiment, the backscattered electrons and secondary electrons generated after the electron beam acts on the sample first pass through the first angular adjustment component 1, are diverged or concentrated under the action of the first angular adjustment component 1, pass through the objective lens 50 into the lens barrel 20, and then are diverged or concentrated under the action of the second angular adjustment component 2, so that the separated backscattered electrons and secondary electrons are obtained, and finally the separated backscattered electrons or secondary electrons are detected by the detector 3.

[0059] Further, the second angular adjustment component 2 includes three layers of grid electrodes, and the grid electrodes of the upper and lower layers have the same voltage as the voltage of the lens barrel, and the voltage of the grid electrode of the middle layer is adjustable.

[0060] Specifically, by setting the voltage of the grid electrodes of the upper and lower layers to be the same as the voltage of the lens barrel, the influence of the grid electrode of the middle layer on other components in the lens barrel 20 is shielded. The voltage of the grid electrode of the middle layer is between the voltage of the sample stage 30 and the voltage of the lens barrel.

[0061] Further, the controller of the electron detection device 40 is further configured to control the electron detection device 40 to work at a preset objective lens current, and the preset objective lens current is calculated by the controller based on the current and voltage parameters of all components in the lens barrel 20. At the preset objective lens current, the beam spot of the electron beam on the sample surface is the smallest.

[0062] Specifically, in order to compensate for the influence of the weak electrostatic lens formed by the second angular adjustment component 2 on the main electron beam, the excitation current of the objective lens 50 needs to be adjusted accordingly. In the embodiment, the electromagnetic field generated by all components in the lens barrel 20 is calculated, and then the Runge-Kutta method is used to solve the dynamic differential equation of the electron to calculate the trajectory of the electron. The current and voltage parameters of each component in the lens barrel 20 are scanned, and the objective lens current is adjusted until the beam spot of the electron beam landing on the sample surface is the smallest, so that the optimal current of the objective lens is obtained. The optimal current of the objective lens is used as the preset objective lens current. The electron microscope is controlled to perform backscattered electron detection or secondary electron detection at the preset objective lens current, and the objective lens current is fine-tuned during the detection process to achieve the best resolution.

[0063] The electron microscope of the embodiment realizes the separation of backscattered electrons and secondary electrons through the electron detection device, so that pure backscattered electrons or secondary electrons can be detected, and pure backscattered electron images or secondary electron images can be generated. This does not need to set multiple detectors to detect backscattered electrons and secondary electrons respectively, improves the reliability of the detection result, and reduces the production cost of the electron microscope.

[0064] The above merely describes the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made by using the content of the present application specification and drawings, is also included in the patent protection scope of the present application.

Claims

1. An electronic detection device, characterized in that It comprises: a first opening angle adjusting component, a second opening angle adjusting component and a detector arranged in sequence along the electron beam movement path; the first opening angle adjusting component is used for adjusting the divergence degree of backscattered electrons and secondary electrons passing through the first opening angle adjusting component; the second opening angle adjusting component is used for adjusting the divergence degree of the secondary electrons passing through the second opening angle adjusting component; the detector is used for detecting electrons; a controller, electrically connected with the first opening angle adjusting component and the second opening angle adjusting component respectively, is used for adjusting the voltage of the first opening angle adjusting component and the second opening angle adjusting component, so as to adjust the divergence angle of the backscattered electrons and the secondary electrons, so that the detector detects the backscattered electrons or the secondary electrons alone; the first opening angle adjusting component is used for generating a radial divergence electric field perpendicular to the electron movement path, and the second opening angle adjusting component is used for generating an axisymmetric electric field to form a weak electrostatic lens; the first opening angle adjusting component adjusts the backscattered electrons and the secondary electrons to be in a concentrated state, and the second opening angle adjusting component diverges the secondary electrons in the concentrated state; the first opening angle adjusting component adjusts the backscattered electrons and the secondary electrons to be in a divergent state, and the second opening angle adjusting component converges the secondary electrons in the divergent state; the detector is arranged in a ring shape and is provided with a central hole for the electrons in the concentrated state to pass through, so that the backscattered electrons are detected when the backscattered electrons are concentrated and the secondary electrons are diverged, or the backscattered electrons are detected when the backscattered electrons are diverged and the secondary electrons are concentrated.

2. The electronic detection device of claim 1, wherein, The second opening angle adjusting component comprises a layer of grid electrodes.

3. The electronic detection device of claim 1, wherein, The second opening angle adjusting component comprises three layers of grid electrodes, and the grid electrodes of the upper and lower layers are provided with the same voltage, and the grid electrodes of the middle layer are adjustable.

4. The electronic detection device of claim 1, wherein, The first opening angle adjusting component comprises a ring electrode.

5. An electronic detection method, characterized in that, It is applied to the electron detection device in any one of claims 1-4, and the electron detection device comprises a first opening angle adjusting component, a second opening angle adjusting component, a detector and a controller; the method comprises: the controller receives an externally input control instruction; when the control instruction is to detect backscattered electrons, the controller adjusts the voltage of the first opening angle adjusting component so that the backscattered electrons and the secondary electrons are in a divergent state, and then adjusts the voltage of the second opening angle adjusting component so that the secondary electrons in the divergent state are concentrated, so that the secondary electrons pass through the central hole of the detector, and the backscattered electrons are detected by the detector; when the control instruction is to detect secondary electrons, the controller adjusts the voltage of the first opening angle adjusting component so that the backscattered electrons and the secondary electrons are in a concentrated state, and then adjusts the voltage of the second opening angle adjusting component so that the secondary electrons in the concentrated state are diverged, so that the backscattered electrons pass through the central hole of the detector, and the secondary electrons are detected by the detector.

6. An electron microscope characterized by It comprises: an electron source for generating an electron beam; a lens barrel, the bottom end of the lens barrel is provided with an objective lens; a sample stage arranged in the outer space of the bottom end of the lens barrel and used for carrying a sample; The electron detection device according to any one of claims 1-4, wherein the first opening angle adjusting component is arranged between the objective lens and the sample stage, and the second opening angle adjusting component and the detector are arranged in the lens barrel.

7. The electron microscope of claim 6, wherein, The second opening angle adjusting component comprises three layers of grid electrodes, and the grid electrodes of the upper and lower layers have the same voltage as the voltage of the lens barrel, and the voltage of the grid electrodes of the middle layer is adjustable.

8. The electron microscope of claim 6, wherein, The controller of the electron detection device is further configured to control the electron detection device to work at a preset objective lens current, the preset objective lens current being calculated by the controller based on the current-voltage parameters of all components in the lens barrel, and at the preset objective lens current, the beam spot of the electron beam on the sample surface is the smallest.

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